阅读说明：本技术 富氧侧吹有柱熔炼的锑冶炼工艺中的制酸方法 (Acid making method in antimony smelting process of oxygen-enriched side-blown column smelting ) 是由 庞洲 杨世干 吴宝育 莫兴德 郭鼎 于 2021-07-19 设计创作，主要内容包括：本发明公开了富氧侧吹有柱熔炼的锑冶炼工艺中的制酸方法,废气主要来自干吸工段第二吸收塔吸收SO-(3)后的尾气,排放最大量为29905.948Nm～(3)/h,采用两次转化工艺和先进的催化剂,可使SO-(2)转化率达99.8％以上,经本发明所述的方法处理后,整个工艺的硫利用率高,大大降低了对周围环境的影响,废气中SO-(3)浓度≤50mg/Nm～(3),酸雾浓度≤20mg/Nm～(3),经过60米烟囱排放,低于《铜、钴、镍工业污染物排放标准》(GB25467-2010)要求。(The invention discloses an acid making method in an antimony smelting process of oxygen-enriched side-blown column smelting, wherein waste gas mainly comes from a second absorption tower in a dry absorption section to absorb SO 3 The maximum amount of discharged tail gas is 29905.948Nm 3 The SO can be converted by twice conversion process and advanced catalyst 2 The conversion rate reaches more than 99.8 percent, and after the treatment by the method of the invention, the sulfur utilization rate of the whole process is high, thereby greatly reducing the influence on the surrounding environment and the SO in the waste gas 3 The concentration is less than or equal to 50mg/Nm 3 The concentration of the acid mist is less than or equal to 20mg/Nm 3 And the emission of the waste gas is lower than the emission standard of industrial pollutants of copper, cobalt and nickel (GB25467-2010) through a chimney with the length of 60 meters.)

1. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting is characterized by comprising the following steps:

1) flue gas purification: the flue gas volatilized and smelted by the oxygen-enriched side-blown volatilizing furnace permeates a cloth bag to collect dust, enters a first-stage efficient scrubber to be contacted with dilute sulfuric acid with the mass concentration of 10%, the temperature of the flue gas is reduced to 48 ℃, then enters a filler washing tower to be contacted with the dilute sulfuric acid with the mass concentration of 2%, the temperature of the flue gas is reduced to below 38 ℃, then enters a second-stage efficient scrubber to be contacted with the dilute sulfuric acid with the mass concentration of 0.5%, and the temperature of the flue gas is reduced to below 38 ℃;

performing solid-liquid separation on a part of dilute sulfuric acid with the mass concentration of 10% from the first-stage efficient washer, periodically discharging the separated waste acid sludge to a waste acid pond to recover valuable filter residues, and feeding the supernatant into a circulating tank; removing SO from the other part of dilute sulfuric acid with the mass concentration of 10 percent by a desorption tower₂Then sending the sewage into a sewage treatment station for comprehensive treatment; SO removed by desorption tower₂Returning the gas to the inlet of the packed tower or the secondary efficient scrubber;

pumping dilute sulfuric acid with the mass concentration of 2% flowing out from the bottom of the filler washing tower into a dilute sulfuric acid plate type heat exchanger by using a circulating pump, and after the dilute sulfuric acid is indirectly cooled by circulating water, controlling the temperature to be 36 ℃, and feeding the dilute sulfuric acid into the top of the filler washing tower for circularly washing and cooling flue gas;

2) a conversion process: SO removed by the desorption tower in the previous step₂The gas returns to the inlet of the packed tower or the second-stage efficient scrubber, passes through the shell pass of the third heat exchanger and the shell pass of the first heat exchanger in turn, exchanges heat with high-temperature converted gas at the three-section outlet and the first-section outlet of the oxygen-enriched side-blown volatilization furnace, enters the first-section, the second-section and the third-section of the converter in turn for conversion, and three-section SO-containing gas is discharged₃The flue gas enters a first absorption tower after being subjected to heat exchange and temperature reduction by a third heat exchanger tube pass and a low-pressure boiler to 160 ℃, and SO is absorbed₃Then the heat is exchanged with high-temperature reformed gas at the four-section and two-section outlets of the oxygen-enriched side-blown volatilization furnace through the shell pass of the heat exchangers IV and IIThe gas after being converted enters a fourth section of the converter for second conversion after being heated, and the converted gas enters a second absorption tower after being subjected to heat exchange and temperature reduction of 120 ℃ through a tube pass of an IV heat exchanger;

3) a dry suction process: SO obtained in the above step₂Flue gas conditioning SO₂The flue gas enters a drying tower when the concentration is 5.0 percent, and the water content in the flue gas is reduced to 0.1g/Nm by spraying sulfuric acid with the mass concentration of 93 to 94 percent for drying³Then, after removing acid foam, entering a conversion process;

spraying and absorbing SO by sulfuric acid with the mass concentration of 93-94% in the drying tower₂The water in the flue gas flows into a circulating tank, sulfuric acid with the acid concentration adjusted to 93-94% by mass is sent into an anode protection acid cooler from the circulating tank, the sulfuric acid enters an acid separator at the top of a drying tower for spraying after being cooled, a part of the increased sulfuric acid with the mass concentration of 93-94% is connected in series with the circulating tank of a first absorption tower, and first converted gas from a conversion process enters the first absorption tower to absorb SO₃After acid mist is removed, the mixture enters a conversion system for second conversion; the first absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃The back concentration rises and flows into a circulating tank;

after sulfuric acid with the mass concentration of 93-94% from the drying tower is adjusted and maintained to maintain the acid concentration, the sulfuric acid is pumped into a first absorption tower anode protection acid cooler by a circulating acid pump to be cooled and then enters a first absorption tower to be sprayed, one part of the increased sulfuric acid with the mass concentration of 98% is connected into a drying tower circulating tank in series, and the other part of the increased sulfuric acid with the mass concentration of 98% is cooled and then is sent into a finished product acid tank;

the secondary converted gas from the conversion section in the step 2) enters a second absorption tower for absorption, then primarily removes acid mist and enters tail absorption, and the second absorption tower is sprayed by sulfuric acid with the mass concentration of 98 percent to absorb SO₃Then the concentrated acid with the raised concentration flows into a circulating tank, water is added for adjusting and maintaining the acid concentration, the concentrated acid is sent into a second absorption tower acid cooler by a circulating acid pump for cooling and then enters a second absorption tower for spraying, and the increased sulfuric acid with the mass concentration of 98 percent is connected into the circulating tank of the first absorption tower in series;

4) tail suction: tail gas from a gas outlet of the second absorption tower in the previous step sequentially passes through the first-stage tail absorption tower and the second-stage tail absorption tower from bottom to top, and is in reverse contact with sodium sulfite solution with the mass concentration of 45-50% sent from a circulating pump of the first-stage tail absorption tower and a circulating pump of the second-stage tail absorption tower in the two towers respectively, and the gas out of the second-stage tail absorption tower enters a tail absorption electric demister arranged at the top to remove sulfuric acid mist and particulate matters, and is exhausted through a tail gas chimney;

5) and (3) finished product working procedure: and (3) putting the finished product sulfuric acid with the mass concentration of 93 percent or 98 percent obtained in the dry absorption section in the step 3) into a sulfuric acid storage tank for storage.

2. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting according to claim 1, characterized by comprising the following steps: the smoke gas volatilized and smelted by the oxygen-enriched side-blown volatilizing furnace in the step 1) contains 0.15g/Nm of dust³Or contains more than or equal to 15 percent of sulfur and has the temperature of 85-95 ℃.

3. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting according to claim 1, characterized by comprising the following steps: the flue gas purification in the step 1) is implemented by that the flue gas volatilized and smelted by an oxygen-enriched side-blown volatilizing furnace permeates a cloth bag to collect dust, the flue gas enters a first-stage efficient scrubber to contact with dilute sulfuric acid with the mass concentration of 10%, the water in the dilute sulfuric acid is adiabatically evaporated, the sensible heat of the flue gas is converted into latent heat, the temperature of the flue gas is reduced to 48 ℃, and most of dust and SO in the flue gas are removed₃After impurities, the flue gas enters a filler washing tower to contact with dilute sulfuric acid with the mass concentration of 2%, the impurities in the flue gas are further removed and cooled, most of water vapor is condensed, the temperature is reduced to be below 38 ℃, the flue gas enters a secondary efficient scrubber to contact with dilute sulfuric acid with the mass concentration of 0.5%, the temperature of the flue gas is reduced to be below 38 ℃, and dust and SO are reduced₃And after the impurities are further reduced, the discharged flue gas passes through a two-stage electric demister to remove residual dust and acid mist impurities.

4. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting according to claim 1, characterized by comprising the following steps: in the step 1), a part of dilute sulfuric acid with the mass concentration of 10 percent pumped out by the circulating acid of the first-stage efficient scrubber is subjected to solid-liquid separation, and the separated waste acid sludge is discharged from a underflow valve at the lower part of a dilute sulfuric acid filterPeriodically discharging to a waste acid tank, performing filter pressing by a waste acid pumping full-automatic box type filter press to recover valuable filter residues, allowing most of liquid-solid separated supernatant to enter corresponding circulation tanks, and removing SO from a small part of supernatant by a desorption tower₂Then, the filtrate enters a dilute sulfuric acid storage tank together with the filtrate of the filter press, and is conveyed to a sewage treatment station for comprehensive treatment by a dilute sulfuric acid conveying pump; SO removed from desorption tower₂The gas returns to the inlet of the packed tower or the secondary efficient scrubber.

5. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting according to claim 1, characterized by comprising the following steps: in the step 1), redundant dilute sulfuric acid in a circulating tank of a packed tower washing tower is connected to a circulating tank at the lower part of a first-stage efficient washer in series, redundant dilute sulfuric acid in a circulating tank at the lower part of a second-stage efficient washer is connected to a circulating tank of a packed tower washing tower in series, dilute sulfuric acid discharged by an electric demister is discharged to a circulating tank at the lower part of the second-stage efficient washer, meanwhile, process water is supplemented to the circulating tank at the lower part of the second-stage efficient washer and the circulating tank of the packed tower, the concentration and the liquid level of the circulating dilute sulfuric acid in each tank are ensured to be stable, and each circulating tank is provided with a water feeding port, an overflow port and a liquid level meter; the irregular washing water of the electric demister adopts a secondary high-efficiency washer circulating pump to finish the washing of electric fog, and the electric fog washing water returns to a secondary high-efficiency washer circulating tank.

6. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting according to claim 1, characterized by comprising the following steps: the dry absorption procedure in the step 3) is to obtain SO in the previous step₂Flue gas is air-conditioned, SO₂The concentration is adjusted to 5.0 percent and then the flue gas enters a drying tower, and the water content in the flue gas is reduced to 0.1g/Nm by spraying sulfuric acid with the mass concentration of 93 to 94 percent for drying³Removing acid foam through a wire mesh demister at the top of the tower, and then entering a conversion process; spraying and absorbing SO by sulfuric acid with the mass concentration of 93-94% in the drying tower₂The method comprises the steps of feeding water in flue gas into a circulating tank, feeding sulfuric acid with the mass concentration of 98% from a circulating system of a first absorption tower into a circulating tank of a drying tower to adjust the acid concentration, feeding the sulfuric acid with the mass concentration of 93-94% into an anode protection acid cooler through a circulating pump, cooling, and feeding into a drying towerSpraying by an acid separator at the top, wherein a part of the increased sulfuric acid with the mass concentration of 93-94% is connected in series with a circulation tank of a first absorption tower, and a first converted gas from conversion enters the first absorption tower to absorb SO₃Removing acid mist by the fiber demister, and then entering a conversion system for second conversion; the first absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃The back concentration rises and flows into a circulating tank; sulfuric acid with the mass concentration of 93-94% from a drying tower or water is added for supplementing and adjusting to maintain the acid concentration, the sulfuric acid is pumped into a first absorption tower anode protection acid cooler by a circulating acid pump to be cooled and then enters the first absorption tower for spraying, one part of the increased sulfuric acid with the mass concentration of 98% is connected into a drying tower circulating tank in series, and the other part of the increased sulfuric acid is cooled by the anode protection acid cooler and then is sent into a finished product acid tank; the secondary converted gas from the conversion section in the step 2) enters a second absorption tower for absorption, then primarily removes acid mist through a fiber demister at the top of the second absorption tower and enters a tail absorber, and the second absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃And the concentrated acid with the raised concentration flows into a circulating tank, water is added for regulating and maintaining the acid concentration, the concentrated acid is sent into an acid cooler of a second absorption tower by a circulating acid pump for cooling and then enters the second absorption tower for spraying, and the increased sulfuric acid with the mass concentration of 98% is connected into the circulating tank of the first absorption tower in series.

7. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting according to claim 1, characterized by comprising the following steps: the tail absorption process in the step 4) is that the tail gas from the gas outlet of the second absorption tower in the previous step, which contains sulfur dioxide and harmful impurities of sulfuric acid mist, sequentially passes through the first-stage tail absorption tower and the second-stage tail absorption tower from bottom to top, and is in reverse contact with a sodium sulfite solution with the mass concentration of 45-50% sent by a first-stage tail absorption tower circulating pump and a second-stage tail absorption tower circulating pump respectively in the two towers, so that sulfur dioxide components in the tail gas are removed, and the gas out of the second-stage tail absorption tower enters a tail electric demister arranged at the top to remove sulfuric acid mist and particles under the action of electric field force and then is emptied through a tail gas chimney; during the absorption process, alkali liquor is supplemented into the tail absorption tower from an alkali liquor delivery pump in real time and in a proper amount in the self-dissolving alkali tank, when the content of total sodium sulfite in the solution is too high, process water is supplemented in time, the generated sodium sulfite solution is led out from an outlet of a circulating pump of the first-stage tail absorption tower and is sent into a dilute sulfuric acid collecting tank of a purification section, the sodium sulfite solution and the dilute sulfuric acid undergo a displacement reaction to release sulfur dioxide gas, the consumption of alkali liquor for neutralization is reduced, the accumulated liquid generated by the tail electric demister is collected and enters the second-stage tail absorption tower, and purchased liquid alkali or solid alkali is prepared and reserved through the alkali dissolving tank.

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of non-ferrous metal smelting, in particular to an acid making method in an antimony smelting process of oxygen-enriched side-blown column smelting.

[ background of the invention ]

Antimony is a specific mineral species for protective exploitation in China and is also a dominant mineral resource in China. Antimony is listed as a strategic material in developed countries. As the biggest antimony product production and export country in China, the yield of antimony products accounts for more than 80 percent of the world. Antimony metallurgy is divided into a pyrometallurgical process and a wet process, and the pyrometallurgical process in antimony metallurgy production has absolute advantages which are more than 95%;at present, the antimony smelting in China mainly adopts a blast furnace volatilization smelting process, and the process flow of 'antimony concentrate blast furnace volatilization smelting-crude antimony trioxide reverberatory furnace reduction smelting' is the basic process of most antimony smelting plants in China at present, wherein antimony concentrate, iron ore, limestone and coke are distributed in the blast furnace in layers for oxygen blowing smelting, and antimony oxide powder, antimony matte and calcium-iron-silicon slag are produced by smelting, although the process has the advantages of strong raw material adaptability, large bed capacity and the like, the process has the advantages of low unit productivity, low heat utilization rate, high energy consumption, more expensive metallurgical coke as fuel and reducing agent, and the coke consumption per ton of refined antimony is 800kg, so that the production cost is high; SO in flue gas generated by the same₂The concentration is extremely low, only 1-2%, the acid can not be recovered, and smoke dust and smoke gas can leak polluted air when the furnace condition is not good due to poor sealing of the furnace, so that the production environment is poor. The process is inconsistent with the national industrial policy of energy conservation and consumption reduction, and the blast furnace smelting process is eliminated in a technology lagging state along with the more and more strict requirements of the national environmental protection standard.

Chinese patent application CN200810031214 discloses a method for smelting antimony by using oxygen-enriched air in a blast furnace, in which 25-48% of oxygen-enriched air is used for smelting antimony ore or antimony-containing material, but the tail gas SO₂The concentration is less than 1.1 percent, the desulfurization treatment is still needed, the high-efficiency and low-cost utilization of sulfur resources is difficult to realize, and the environmental risk still exists. Compared with an oxygen-poor blast furnace, the antimony blast furnace oxygen-rich volatilization smelting process has the advantages that the bed capacity is greatly improved, the coke consumption is greatly reduced, but the coke consumption is still high and reaches 25%; the recovery rate of gold and silver in the antimony blast furnace oxygen-enriched volatilization smelting process is 90 percent. The Chinese patent application CN201310070398 discloses an antimony sulfide concentrate oxygen-enriched molten pool smelting method and a side-blown furnace, wherein the method only aims at antimony sulfide concentrate, the raw material is single in treatment, and the raw material needs to be granulated; the product is metallic antimony, but the direct yield is low, only 10-25%, the impurity content of the metallic antimony is high, and the treatment is difficult; the slag is high-iron slag, so that the flux consumption is high, the slag rate is high, and the recovery rate is low; the required oxygen-enriched pressure is as high as 1.6MPa, and industrialization is difficult to realize. Chinese patent application CN20131007039 discloses a method for smelting antimony sulfide concentrate in an oxygen-enriched molten pool, and the method comprises the following stepsThe method only aims at antimony sulfide concentrate, the treated raw material is single, and the raw material needs to be granulated; the product is dispersed, and the treatment process is long; the yield of the antimony in the slag is as high as 30-40%, the percentage content of the antimony is as high as 30%, and secondary treatment is needed to recover antimony metal; the slag is high-iron slag, so that the flux consumption is high, the slag rate is high, and the recovery rate is low; the gold in the raw materials basically enters the furnace slag, the gold recovery process is long, the efficiency is low, and the industrialization is difficult to realize. The antimony blast furnace volatilization smelting process has the advantages of strong raw material adaptability, large processing capacity and easy mechanical operation, but the special operating conditions of low stock column, thin stock layer, high coke rate and high temperature furnace top also determine that the process has high energy consumption, the coke rate is 30-45 percent, and especially the tail gas SO₂The concentration is less than 0.5 percent, the ecological environment is seriously polluted, the recovery rate of metals, particularly noble metals, is low, the return product rate is high, and the direct yield is low. The new antimony smelting technology developed at present adopts more advanced molten pool smelting devices such as an oxygen top-blown furnace, a bottom-blown furnace and the like, but the smelting principle still follows the technical characteristics of blast furnace volatilization smelting, and iron ore, limestone and quartz stone are adopted as slagging agents based on FeO-CaO-SiO₂And smelting the slag mould.

Studies show that antimony minerals mostly exist in the form of sulfides, such as jamesonite, lead-antimony mixed ore and the like, and a large amount of SO is generated in the smelting process of nonferrous metals containing copper, nickel, lead, zinc, molybdenum, tin, antimony, cobalt and the like₂The flue gas of (1). Because of the differences of smelting raw materials, smelting process and equipment, antimony smelting flue gas has various types, different characteristics, large flue gas amount and fluctuation, and flue gas SO₂Wide concentration distribution range and low concentration phi (SO)₂) Below 1.0%, high phi (SO)₂) Can reach 20.0 to 30.0 percent, and the antimony smelting flue gas contains various harmful impurities such as heavy metal, arsenic, fluorine, chlorine and the like, which brings certain difficulty to the environmental protection and treatment of the flue gas.

In recent years, the antimony smelting process of oxygen-enriched side-blown column smelting becomes an important antimony smelting process, the corresponding smelting flue gas acid-making environmental protection treatment technology is in a diversified development pattern, and the low SO content₂The concentrated flue gas is desulfurized by various advanced and applicable processes with medium and high SO content₂The concentration flue gas returnsAnd (5) acid is collected.

Therefore, it is necessary to research an acid making method of an antimony smelting process in which oxygen-enriched side-blown column smelting is performed.

[ summary of the invention ]

SO-containing for antimony smelting process in prior art₂The invention provides an acid making method in an antimony smelting process of oxygen-enriched side-blown column smelting, wherein the waste gas mainly comes from a second absorption tower of a dry absorption section to absorb SO₃The maximum amount of discharged tail gas is 29905.948Nm³The SO can be converted by twice conversion process and advanced catalyst₂The conversion rate reaches more than 99.8 percent, and after the treatment by the method of the invention, the sulfur utilization rate of the whole process is high, thereby greatly reducing the influence on the surrounding environment and the SO in the waste gas₃The concentration is less than or equal to 50mg/Nm³The concentration of the acid mist is less than or equal to 20mg/Nm³And the emission of the waste gas is lower than the emission standard of industrial pollutants of copper, cobalt and nickel (GB25467-2010) through a chimney with the length of 60 meters.

The purpose of the invention is realized by the following technical scheme:

the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting comprises the following steps:

1) flue gas purification: the flue gas volatilized and smelted by the oxygen-enriched side-blown volatilizing furnace permeates a cloth bag to collect dust, enters a first-stage efficient scrubber to be contacted with dilute sulfuric acid with the mass concentration of 10%, the temperature of the flue gas is reduced to 48 ℃, then enters a filler washing tower to be contacted with the dilute sulfuric acid with the mass concentration of 2%, the temperature of the flue gas is reduced to below 38 ℃, then enters a second-stage efficient scrubber to be contacted with the dilute sulfuric acid with the mass concentration of 0.5%, and the temperature of the flue gas is reduced to below 38 ℃;

performing solid-liquid separation on a part of dilute sulfuric acid with the mass concentration of 10% from the first-stage efficient washer, periodically discharging the separated waste acid sludge to a waste acid pond to recover valuable filter residues, and feeding the supernatant into a circulating tank; removing SO from the other part of dilute sulfuric acid with the mass concentration of 10 percent by a desorption tower₂Then sending the sewage into a sewage treatment station for comprehensive treatment; SO removed by desorption tower₂Returning the gas to the inlet of the packed tower or the secondary efficient scrubber;

pumping dilute sulfuric acid with the mass concentration of 2% flowing out from the bottom of the filler washing tower into a dilute sulfuric acid plate type heat exchanger by using a circulating pump, and after the dilute sulfuric acid is indirectly cooled by circulating water, controlling the temperature to be 36 ℃, and feeding the dilute sulfuric acid into the top of the filler washing tower for circularly washing and cooling flue gas;

2) a conversion process: SO removed by the desorption tower in the previous step₂The gas returns to the inlet of the packed tower or the second-stage efficient scrubber, passes through the shell pass of the third heat exchanger and the shell pass of the first heat exchanger in turn, exchanges heat with high-temperature converted gas at the three-section outlet and the first-section outlet of the oxygen-enriched side-blown volatilization furnace, enters the first-section, the second-section and the third-section of the converter in turn for conversion, and three-section SO-containing gas is discharged₃The flue gas enters a first absorption tower after being subjected to heat exchange and temperature reduction by a third heat exchanger tube pass and a low-pressure boiler to 160 ℃, and SO is absorbed₃Then the high-temperature reformed gas at the four-section and two-section outlets of the oxygen-enriched side-blown volatilization furnace exchanges heat through the shell side of the IV and II heat exchangers, the temperature is raised, the high-temperature reformed gas enters the four sections of the converter for secondary conversion, and the converted gas exchanges heat through the tube side of the IV heat exchanger, is cooled to 120 ℃ and enters a second absorption tower;

3) a dry suction process: SO obtained in the above step₂Flue gas conditioning SO₂The flue gas enters a drying tower when the concentration is 5.0 percent, and the water content in the flue gas is reduced to 0.1g/Nm by spraying sulfuric acid with the mass concentration of 93 to 94 percent for drying³Then, after removing acid foam, entering a conversion process;

spraying and absorbing SO by sulfuric acid with the mass concentration of 93-94% in the drying tower₂The water in the flue gas flows into a circulating tank, sulfuric acid with the acid concentration adjusted to 93-94% by mass is sent into an anode protection acid cooler from the circulating tank, the sulfuric acid enters an acid separator at the top of a drying tower for spraying after being cooled, a part of the increased sulfuric acid with the mass concentration of 93-94% is connected in series with the circulating tank of a first absorption tower, and first converted gas from a conversion process enters the first absorption tower to absorb SO₃After acid mist is removed, the mixture enters a conversion system for second conversion; the first absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃The back concentration rises and flows into a circulating tank;

after sulfuric acid with the mass concentration of 93-94% from the drying tower is adjusted and maintained to maintain the acid concentration, the sulfuric acid is pumped into a first absorption tower anode protection acid cooler by a circulating acid pump to be cooled and then enters a first absorption tower to be sprayed, one part of the increased sulfuric acid with the mass concentration of 98% is connected into a drying tower circulating tank in series, and the other part of the increased sulfuric acid with the mass concentration of 98% is cooled and then is sent into a finished product acid tank;

the secondary converted gas from the conversion section in the step 2) enters a second absorption tower for absorption, then primarily removes acid mist and enters tail absorption, and the second absorption tower is sprayed by sulfuric acid with the mass concentration of 98 percent to absorb SO₃Then the concentrated acid with the raised concentration flows into a circulating tank, water is added for adjusting and maintaining the acid concentration, the concentrated acid is sent into a second absorption tower acid cooler by a circulating acid pump for cooling and then enters a second absorption tower for spraying, and the increased sulfuric acid with the mass concentration of 98 percent is connected into the circulating tank of the first absorption tower in series;

4) tail suction: tail gas from a gas outlet of the second absorption tower in the previous step sequentially passes through the first-stage tail absorption tower and the second-stage tail absorption tower from bottom to top, and is in reverse contact with sodium sulfite solution with the mass concentration of 45-50% sent from a circulating pump of the first-stage tail absorption tower and a circulating pump of the second-stage tail absorption tower in the two towers respectively, and the gas out of the second-stage tail absorption tower enters a tail absorption electric demister arranged at the top to remove sulfuric acid mist and particulate matters, and is exhausted through a tail gas chimney;

5) and (3) finished product working procedure: and (3) putting the finished product sulfuric acid with the mass concentration of 93 percent or 98 percent obtained in the dry absorption section in the step 3) into a sulfuric acid storage tank for storage.

In the invention:

the flue gas volatilized and smelted by the oxygen-enriched side-blown volatilization furnace in the step 1) has too large dust content, the flue gas is subjected to dry dust removal before entering an acid making system, and the dust content of the flue gas before entering the system is 0.15g/Nm³Or contains more than or equal to 15 percent of sulfur and has the temperature of 85-95 ℃.

The flue gas purification in the step 1) is implemented by that the flue gas volatilized and smelted by an oxygen-enriched side-blown volatilizing furnace permeates a cloth bag to collect dust, the flue gas enters a first-stage efficient scrubber to contact with dilute sulfuric acid with the mass concentration of 10%, the water in the dilute sulfuric acid is adiabatically evaporated, the sensible heat of the flue gas is converted into latent heat, the temperature of the flue gas is reduced to 48 ℃, and most of dust and SO in the flue gas are removed₃After impurities are removed, the flue gas enters a filler washing tower to contact with dilute sulfuric acid with the mass concentration of 2%, impurities in the flue gas are further removed, the flue gas is cooled, most of water vapor is condensed, and the temperature is reduced to below 38 DEG CThen the waste gas enters a secondary efficient scrubber to contact with dilute sulfuric acid with the mass concentration of 0.5 percent, the temperature of the flue gas is reduced to be below 38 ℃, and dust and SO are enabled to be generated₃And the impurities are further reduced, and the discharged flue gas passes through a two-stage electric demister to remove the residual impurities such as dust, acid mist and the like.

In the step 1), a part of dilute sulfuric acid with the mass concentration of 10% pumped out by the circulating acid of the primary efficient scrubber is subjected to solid-liquid separation, the separated dirty acid sludge is periodically discharged to a dirty acid pool through a bottom flow valve at the lower part of a dilute sulfuric acid filter, the separated dirty acid sludge is sent to a full-automatic box type filter press through a dirty acid pump (a filter press pump) to be filter-pressed and recycled to obtain valuable filter residues, most of supernatant after the liquid-solid separation enters a corresponding circulating tank, and a small part of supernatant (the dilute sulfuric acid discharged according to the concentration requirement of the dilute sulfuric acid) is subjected to SO removal through a desorption tower₂Then, the filtrate enters a dilute sulfuric acid storage tank together with the filtrate of the filter press, and is conveyed to a sewage treatment station for comprehensive treatment by a dilute sulfuric acid conveying pump; SO removed from desorption tower₂The gas returns to the inlet of the packed tower or the secondary efficient scrubber.

In the step 1), in order to control the concentration of dilute sulfuric acid in a circulation tank of a first-stage efficient washer and ensure that the concentration of harmful impurities such As As and F in flue gas reaches the standard, redundant dilute sulfuric acid in a circulation tank of a washing tower of a packed tower is connected to a circulation tank at the lower part of the first-stage efficient washer in series, redundant dilute sulfuric acid in a circulation tank at the lower part of a second-stage efficient washer is connected to a circulation tank of a washing tower of the packed tower in series, dilute sulfuric acid discharged by an electric demister is discharged to a circulation tank at the lower part of the second-stage efficient washer, process water is supplemented to a circulation tank at the lower part of the second-stage efficient washer and a circulation tank of the packed tower at the same time, the concentration and the liquid level of the circulating dilute sulfuric acid in each tank are ensured to be stable, and each circulation tank is provided with a water feeding port, an overflow port and a liquid level meter; in order to save water resources and be beneficial to ensuring the concentration and the liquid level stability of dilute sulfuric acid in each circulation tank, the irregular flushing water of the electric demister does not adopt clear water, and an electric fog flushing tank and a flushing pump are not independently arranged, but the flushing of electric fog is completed by a circulation pump of a second-level efficient scrubber, and the electric fog flushing water returns to the circulation tank of the second-level efficient scrubber.

The dry absorption procedure in the step 3) is to obtain SO in the previous step₂Flue gas is air-conditioned, SO₂The concentration is adjusted to 5.0 percent and the mixture enters a drying tower and is sprayed with a mass concentration of 93 percentDrying with 94% sulphuric acid to reduce the water content of the flue gas to 0.1g/Nm³Removing acid foam through a wire mesh demister at the top of the tower, and then entering a conversion process; spraying and absorbing SO by sulfuric acid with the mass concentration of 93-94% in the drying tower₂The method comprises the steps of enabling the flue gas to flow into a circulating tank, enabling sulfuric acid with the mass concentration of 98% from a circulating system of a first absorption tower to enter a circulating tank of a drying tower to adjust the acid concentration, enabling the sulfuric acid with the mass concentration of 93-94% to be sent into an anode protection acid cooler through the circulating tank by an acid circulating pump, enabling the sulfuric acid to enter an acid distributor at the top of the drying tower to be sprayed after the sulfuric acid is cooled, enabling a part of the increased sulfuric acid with the mass concentration of 93-94% to flow into the circulating tank of the first absorption tower in series, enabling a first converted gas to enter the first absorption tower to absorb SO₃Removing acid mist by the fiber demister, and then entering a conversion system for second conversion; the first absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃The back concentration rises and flows into a circulating tank; sulfuric acid with the mass concentration of 93-94% from a drying tower or water is added for supplementing and adjusting to maintain the acid concentration, the sulfuric acid is pumped into a first absorption tower anode protection acid cooler by a circulating acid pump to be cooled and then enters the first absorption tower for spraying, one part of the increased sulfuric acid with the mass concentration of 98% is connected into a drying tower circulating tank in series, and the other part of the increased sulfuric acid is cooled by the anode protection acid cooler and then is sent into a finished product acid tank; the secondary converted gas from the conversion section in the step 2) enters a second absorption tower for absorption, then primarily removes acid mist through a fiber demister at the top of the second absorption tower and enters a tail absorber, and the second absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃And the concentrated acid with the raised concentration flows into a circulating tank, water is added for regulating and maintaining the acid concentration, the concentrated acid is sent into an acid cooler of a second absorption tower by a circulating acid pump for cooling and then enters the second absorption tower for spraying, and the increased sulfuric acid with the mass concentration of 98% is connected into the circulating tank of the first absorption tower in series.

The tail absorption process in the step 4) is that the tail gas from the gas outlet of the second absorption tower in the previous step, which contains harmful impurities such as sulfur dioxide and sulfuric acid mist, sequentially passes through the first-stage tail absorption tower and the second-stage tail absorption tower from bottom to top, and is in reverse contact with sodium sulfite solution with the mass concentration of 45-50% sent from a circulating pump of the first-stage tail absorption tower and a circulating pump of the second-stage tail absorption tower respectively in the two towers, so that the sulfur dioxide component in the tail gas is removed, and the gas out of the second-stage tail absorption tower enters a tail electric demister arranged at the top to remove the sulfuric acid mist and particulate matters under the action of electric field force and is evacuated through a tail gas chimney; in the absorption process, sodium sulfite components in solution components need to be reduced, sodium bisulfite components need to be raised, in order to ensure the constancy of absorption rate, alkali liquor needs to be supplemented into a tail absorption tower by an alkali liquor delivery pump in a self-alkali dissolution tank in real time, when the total sodium sulfite content in the solution is overhigh, process water is supplemented in time, the generated sodium sulfite solution is led out from an outlet of a circulating pump of a primary tail absorption tower and is sent into a dilute sulfuric acid collecting tank of a purification section, the sodium sulfite solution and the dilute sulfuric acid undergo a displacement reaction to release sulfur dioxide gas, the consumption of alkali liquor for neutralization can be reduced, the aggregation liquid generated by a tail electric absorption demister is collected and enters a secondary tail absorption tower, and outsourced liquid alkali or solid alkali is prepared and reserved through an alkali dissolution tank.

And 5) in the finished product process, when acid is sold, the stored sulfuric acid automatically flows into a finished product acid underground tank, and is conveyed into a high-position loading metering tank by a finished product acid conveying pump for loading and outward transportation.

Compared with the prior art, the invention has the following advantages:

1. the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting integrates the impurity removal of dynamic waves, the temperature reduction of a filler washing tower (gas cooling tower) and the deep purification of an electric demister, wherein the electric demister is movably arranged behind the filler washing tower, so that the equipment is smaller in size, and the overall process effect is better.

2. The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting has the following advantages that the heat exchange process adopted in the conversion process is as follows: firstly, the temperature is quickly raised; secondly, the adaptability to the concentration fluctuation of the sulfur dioxide gas is good; the sensitivity to the air leakage of the conversion heat exchanger is low; fourthly, the temperature of the gas at the inlet of the second absorption tower is lower, and the absorption and heat utilization of sulfur trioxide are more facilitated in the process.

3. According to the acid making method in the antimony smelting process with oxygen-enriched side-blown column smelting, acid mixing after a pump and cooling after the pump are adopted in the dry absorption process, automation is realized, the heat transfer coefficient of heat exchange equipment is improved, the sodium-alkali desulphurization process is adopted in the tail absorption process, and the tail absorption electric demister is additionally arranged to realize ultralow emission of tail gas.

[ detailed description ] embodiments

The present invention will be described in detail with reference to the following embodiments in order to make the aforementioned objects, features and advantages of the invention more comprehensible. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Example (b):

the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting comprises the following steps:

1) flue gas purification: the flue gas volatilized and smelted by the oxygen-enriched side-blown volatilizing furnace permeates a cloth bag to collect dust, enters a first-stage efficient scrubber to be contacted with dilute sulfuric acid with the mass concentration of 10%, the temperature of the flue gas is reduced to 48 ℃, then enters a filler washing tower to be contacted with the dilute sulfuric acid with the mass concentration of 2%, the temperature of the flue gas is reduced to below 38 ℃, then enters a second-stage efficient scrubber to be contacted with the dilute sulfuric acid with the mass concentration of 0.5%, and the temperature of the flue gas is reduced to below 38 ℃;

the flue gas volatilized and smelted by the oxygen-enriched side-blown volatilizing furnace permeates a cloth bag to collect dust, and the dust content of the flue gas is 0.15g/Nm³Then the flue gas enters a first-stage efficient scrubber to contact with dilute sulfuric acid with the mass concentration of 10%, moisture in the dilute sulfuric acid is adiabatically evaporated, sensible heat of the flue gas is converted into latent heat, the temperature of the flue gas is reduced to 48 ℃, and most of dust and SO in the flue gas are removed₃After impurities are waited, the flue gas enters a filler washing tower to contact with dilute sulfuric acid with the mass concentration of 2%, impurities in the flue gas are further removed and cooled, most of water vapor is condensed, the temperature is reduced to be below 38 ℃, the flue gas enters a secondary efficient scrubber to contact with dilute sulfuric acid with the mass concentration of 0.5%, the temperature of the flue gas is reduced to be below 38 ℃, and dust and SO are reduced₃When the impurities are further reduced, the discharged flue gas passes through a two-stage electric demister to remove the residualDust and acid mist and the like;

a part of dilute sulfuric acid with the mass concentration of 10 percent pumped out by a circulating acid pump of a first-stage efficient scrubber is subjected to solid-liquid separation, the separated dirty acid sludge is periodically discharged to a dirty acid pool through a bottom flow valve at the lower part of a dilute sulfuric acid filter, the dirty acid sludge is sent to a full-automatic box-type filter press by a dirty acid pump (a filter press pump) to be filter-pressed and recycled to obtain valuable filter residues, most of supernatant after the liquid-solid separation enters a corresponding circulating tank, and the small part of the supernatant (the dilute sulfuric acid which is discharged according to the concentration of the dilute sulfuric acid) is subjected to SO removal by a desorption tower₂Then, the filtrate enters a dilute sulfuric acid storage tank together with the filtrate of the filter press, and is conveyed to a sewage treatment station for comprehensive treatment by a dilute sulfuric acid conveying pump; SO removed from desorption tower₂Returning the gas to the inlet of the packed tower or the secondary efficient scrubber;

pumping dilute sulfuric acid with the mass concentration of 2% flowing out from the bottom of the filler washing tower into a dilute sulfuric acid plate type heat exchanger by using a circulating pump, and after the dilute sulfuric acid is indirectly cooled by circulating water, controlling the temperature to be 36 ℃, and feeding the dilute sulfuric acid into the top of the filler washing tower for circularly washing and cooling flue gas;

in order to control the concentration of dilute sulfuric acid in a circulating tank of a first-stage efficient washer and ensure that the concentration of harmful impurities such As As and F in flue gas reaches the standard, redundant dilute sulfuric acid in a circulating tank of a washing tower of a packed tower is connected to a circulating tank at the lower part of the first-stage efficient washer in series, redundant dilute sulfuric acid in a circulating tank at the lower part of a second-stage efficient washer is connected to a circulating tank of a washing tower of the packed tower in series, dilute sulfuric acid discharged by an electric demister is discharged to a circulating tank at the lower part of the second-stage efficient washer, process water is supplemented to the circulating tank at the lower part of the second-stage efficient washer and the circulating tank of the packed tower simultaneously, the concentration and the liquid level of the circulating dilute sulfuric acid in each tank are ensured to be stable, and each circulating tank is provided with a water feeding port, an overflow port and a liquid level meter; in order to save water resources and be beneficial to ensuring the concentration and the liquid level stability of dilute sulfuric acid in each circulation tank, the irregular flushing water of the electric demister does not adopt clear water, and an electric fog flushing tank and a flushing pump are not independently arranged, but the flushing of electric fog is completed by a circulation pump of a second-stage efficient washer, and the electric fog flushing water returns to the circulation tank of the second-stage efficient washer;

2) a conversion process: SO removed by the desorption tower in the previous step₂The gas returns to the inlet of the packed tower or the second-stage efficient scrubber and passes through the shell pass of the third heat exchanger and the shell pass of the first heat exchanger in turn,after exchanging heat with high-temperature reformed gas at the three-section and one-section outlets of the oxygen-enriched side-blown volatilization furnace, the gas enters a converter for conversion at the first section, the second section and the third section in sequence, and three-section SO-containing gas is discharged₃The flue gas enters a first absorption tower after being subjected to heat exchange and temperature reduction by a third heat exchanger tube pass and a low-pressure boiler to 160 ℃, and SO is absorbed₃Then the high-temperature reformed gas at the four-section and two-section outlets of the oxygen-enriched side-blown volatilization furnace exchanges heat through the shell side of the IV and II heat exchangers, the temperature is raised, the high-temperature reformed gas enters the four sections of the converter for secondary conversion, and the converted gas exchanges heat through the tube side of the IV heat exchanger, is cooled to 120 ℃ and enters a second absorption tower;

3) a dry suction process: SO obtained in the above step₂Flue gas is air-conditioned, SO₂The concentration is adjusted to 5.0 percent and then the flue gas enters a drying tower, and the water content in the flue gas is reduced to 0.1g/Nm by spraying sulfuric acid with the mass concentration of 93 to 94 percent for drying³Removing acid foam through a wire mesh demister at the top of the tower, and then entering a conversion process;

spraying and absorbing SO by sulfuric acid with the mass concentration of 93-94% in the drying tower₂The method comprises the steps of enabling the flue gas to flow into a circulating tank, enabling sulfuric acid with the mass concentration of 98% from a circulating system of a first absorption tower to enter a circulating tank of a drying tower to adjust the acid concentration, enabling the sulfuric acid with the mass concentration of 93-94% to be sent into an anode protection acid cooler through the circulating tank by an acid circulating pump, enabling the sulfuric acid to enter an acid distributor at the top of the drying tower to be sprayed after the sulfuric acid is cooled, enabling a part of the increased sulfuric acid with the mass concentration of 93-94% to flow into the circulating tank of the first absorption tower in series, enabling a first converted gas to enter the first absorption tower to absorb SO₃Removing acid mist by the fiber demister, and then entering a conversion system for second conversion; the first absorption tower is sprayed with sulfuric acid with the mass concentration of 98 percent to absorb SO₃The back concentration rises and flows into a circulating tank; sulfuric acid with the mass concentration of 93-94% from a drying tower or water is added for supplementing and adjusting to maintain the acid concentration, the sulfuric acid is pumped into a first absorption tower anode protection acid cooler by a circulating acid pump to be cooled and then enters the first absorption tower for spraying, one part of the increased sulfuric acid with the mass concentration of 98% is connected into a drying tower circulating tank in series, and the other part of the increased sulfuric acid is cooled by the anode protection acid cooler and then is sent into a finished product acid tank;

the secondary converted gas from the conversion section in the step 2) enters a second absorption tower for absorption and then passes through the top of the second absorption towerThe fiber demister preliminarily removes acid mist and enters tail absorption, the second absorption tower sprays sulfuric acid with the mass concentration of 98 percent to absorb SO₃Then the concentrated acid with the raised concentration flows into a circulating tank, water is added for adjusting and maintaining the acid concentration, the concentrated acid is sent into a second absorption tower acid cooler by a circulating acid pump for cooling and then enters a second absorption tower for spraying, and the increased sulfuric acid with the mass concentration of 98 percent is connected into the circulating tank of the first absorption tower in series;

4) tail suction: tail gas from a gas outlet of the second absorption tower in the previous step sequentially passes through the first-stage tail absorption tower and the second-stage tail absorption tower from bottom to top, and is in reverse contact with sodium sulfite solution with the mass concentration of 45-50% sent from a circulating pump of the first-stage tail absorption tower and a circulating pump of the second-stage tail absorption tower in the two towers respectively, and the gas out of the second-stage tail absorption tower enters a tail absorption electric demister arranged at the top to remove sulfuric acid mist and particulate matters, and is exhausted through a tail gas chimney;

the tail gas from the gas outlet of the second absorption tower in the previous step, which contains harmful impurities such as sulfur dioxide, sulfuric acid mist and the like, sequentially passes through a first-stage tail absorption tower and a second-stage tail absorption tower from bottom to top, is in reverse contact with a sodium sulfite solution with the mass concentration of 45-50% sent from a first-stage tail absorption tower circulating pump and a second-stage tail absorption tower circulating pump respectively in the two towers, so that the sulfur dioxide component in the tail gas is removed, and the gas out of the second-stage tail absorption tower enters a tail electric demister arranged at the top to remove sulfuric acid mist and particulate matters under the action of an electric field force and is emptied through a tail gas chimney; in the absorption process, sodium sulfite components in solution components need to be reduced, sodium bisulfite components need to be increased, in order to ensure constant absorption rate, alkali liquor needs to be supplemented into a tail absorption tower by an alkali liquor delivery pump in an automatic alkali tank in real time, when the total sodium sulfite content in the solution is overhigh, process water is supplemented in time, the generated sodium sulfite solution is led out from an outlet of a circulating pump of a primary tail absorption tower and is sent into a dilute sulfuric acid collecting tank of a purification section to perform a displacement reaction with the dilute sulfuric acid to release sulfur dioxide gas and reduce the consumption of alkali liquor for neutralization, an aggregation solution generated by a tail electric absorption demister is collected and enters a secondary tail absorption tower, and purchased liquid alkali or solid alkali is prepared and reserved through the alkali dissolving tank;

5) and (3) finished product working procedure: and (3) putting the finished sulfuric acid with the mass concentration of 93 percent or 98 percent obtained in the dry absorption working section in the step 3) into a sulfuric acid storage tank for storage, automatically flowing the stored sulfuric acid into a finished acid underground tank when selling the acid, and conveying the sulfuric acid into a high-level loading metering tank by a finished acid conveying pump for loading and transporting.

Experimental example:

the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting comprises the following steps: guangxi Fuchi, Guangxi Yuanjin industrialisation park, Guangxi river basin, Guangxi Yuanwa Metal chemical Co., Ltd.

1. Conditions for preparing acid by using flue gas

Flue gas parameters entering the acid making system are as follows: the inlet air temperature: 90 ℃; dust in the flue gas: 8g/Nm³。

1.1 conditions of public works

1.1.1 compressed air

Air supply pressure: not less than 0.6MPa (gauge pressure), the quality of the compressed air meets the following requirement of part 1: the requirement of the pollutant purification grade GB/T13277.1-2008.

1.1.2 Nitrogen gas

Purity of nitrogen (N) volume fraction/10^-2: not less than 99.20, oxygen (N) purity volume fraction/10^-2: less than or equal to 0.80, free water: no, the quality meets the requirements of GB/T3864-2008 for industrial nitrogen.

1.1.3 Instrument wind

The instrument gas supply meets the quality requirement of 4.1 on gas sources in petrochemical instrument gas supply design specification SH 3020-2013.

Air supply pressure: not less than 0.6MPa (gauge pressure).

1.1.4 Process Water

Water temperature: less than or equal to 30 ℃; water pressure: 0.4 Mpa; the water quality meets the requirement of GB/T19923-2005 standard of the quality of industrial water for recycling municipal sewage.

1.1.5 circulating water

The temperature of the outlet water: 32 ℃, return water temperature: 40 ℃; the water quality meets the standard requirements of industrial circulating cooling water treatment design specification GB/T50050-2017.

1.1.6 fire-fighting water (same pipe network with process water)

Pressure: 0.45MPa/0.25MPa

Temperature: at normal temperature

1.1.7 electric power specification

10kV/380V/220VAC，50Hz

2. Construction scale, product scheme and product standard

2.1 construction Scale: acid production in hours: 7066kg/H (calculated as 100% H2SO 4), or 56.5 kt/a; the annual production time is 8000 hours.

2.2 product scheme: 98% or 92.5% industrial sulfuric acid.

2.3 product Standard

The product quality meets the national standard of GB/T534-2014 and is a qualified product.

3. Technical index

3.1 Main technical index

3.2. Device pollutant discharge condition table

3.3 level of automation:

3.3.1 the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting adopts a set of Distributed Control System (DCS) to realize the display, recording, printing, accumulation, alarming and adjustment of all important parameters. In-situ instrumentation is employed throughout the plant for process parameters that are not important or require frequent monitoring.

3.3.2 control of the electric Motor: the stopping of the main electrical equipment of the whole production process can be completed on site or in a DCS. The operating state of the electric machine and the interlocking function of the electric motor are also performed in the DCS.

3.3.3SO₂The air blower adopts frequency conversion control to conveniently and timely adjust air volume.

3.4 major sources of contaminants

Waste gas: from the dry suction section, the amount of offgas was 29905.948Nm³/h。

Waste acid and wastewater: normal production produces-10% waste acid-8 m in the purification section³H is used as the reference value. Waste residues: no waste residue.

Noise: mainly the noise of the blower in the conversion section.

3.5 treatment and comprehensive utilization of three wastes

The acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting fully considers the factor of environmental protection, the raw material route and the process technology select a process production line which has less pollution, easy control of pollutants and stable and reliable operation, the utilization rate of resources and energy sources is improved to the maximum extent, the pollution is eliminated or reduced as much as possible in the process through scientific and strict management, the emission of the pollutants is fundamentally reduced, and the influence on the environment is reduced.

The pollution inevitably produced in the process is firstly recycled or comprehensively utilized, and advanced, reliable and economic treatment measures are adopted for the externally discharged pollutants so as to meet the discharge requirements regulated by the state.

3.5.1 waste gas: SO in exhaust gas₂Concentration dependent on SO₂Conversion to SO₃To the extent that the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting adopts a '3 + 1' twice conversion process and an advanced catalyst, SO that SO can be generated₂The conversion rate reaches more than 99.8 percent, and the sulfur content of the whole system is reduced after tail gas treatmentThe rate of utilization is high, greatly reduced device to the influence of surrounding environment. The waste gas mainly comes from a second absorption tower of a dry absorption section to absorb SO₃The maximum amount of discharged tail gas is 29905.948Nm³H is used as the reference value. SO in exhaust gas₃The concentration is less than or equal to 50mg/Nm³The concentration of the acid mist is less than or equal to 20mg/Nm³The emission through a chimney of 60 meters is lower than the emission standard of industrial pollutants of copper, cobalt and nickel (GB 25467-.

SO in tail gas₂The treatment reduces SO by applying novel and efficient catalyst, strictly controlling technological indexes, improving the operating skills of operators and other technical methods and management methods₂The amount of discharge of (c).

The tail gas acid mist treatment improves the mist removal efficiency by improving a mist remover of the second absorption tower; the acid separator of the absorption tower is improved, and the absorption rate is improved; the method of strictly controlling the temperature of the absorbed acid, the concentration of the acid, the liquid loading amount and the like reduces the concentration of the acid mist in the tail gas. Under the condition that the efficient candle fiber demister is arranged at the top of the second absorption tower, secondary acid mist cannot be generated as long as the temperature of absorbed acid is well controlled; the high absorption rate (99.96 percent) can be ensured by controlling the concentration of the absorbed acid; in addition, the acid separating device in the absorption tower is reasonable in design and ensures the installation quality, so that the sulfuric acid mist in the acid making tail gas for making acid is kept at a lower level, and the tail electric absorption demister is additionally arranged, so that the sulfuric acid mist is completely discharged in a qualified manner.

3.5.2 waste water: the purification section adopts a closed circulation technology and basically does not discharge outside. And a small amount of discharged dilute sulfuric acid is sent to a sewage treatment station of a main plant, and is discharged or the wastewater is recycled after the treatment reaches the standard.

3.5.3 noise: the mechanical noise generated by the fan is mainly treated by adopting sound insulation and absorption materials in a factory building and arranging a sound insulation operation room to reduce noise harm. The sealing of a factory building is strengthened in consideration of necessity, and the fan room is provided with an isolation measure independently. The aerodynamic noise generated by the airflow in the pipeline is preferably selected by on-site observation and test to accurately select the area section position when the device runs at full load after the vehicle is driven, and the noise intensity can be obviously reduced by wrapping the sound insulation layer outside the pipeline.

The treatment process of the acid making method pollutants in the antimony smelting process of oxygen-enriched side-blown column smelting is tested by actual production, the treatment principle is fully considered, and the treated pollutant discharge reaches the discharge standard specified by the state.

4. To summarize:

the acid making method in the antimony smelting process of oxygen-enriched side-blown columnar smelting fully considers the environmental protection and labor protection, so that the built device is a green factory. Mainly comprises the following steps:

4.1 flue gas purification process: adopts an adiabatic evaporation closed pickling process, and only discharges-10% of H for every 1 ton of sulfuric acid produced₂SO₄The diluted sulfuric acid is about 200-400kg, and the water is discharged by-14.5 t when compared with the common water washing process and each 1 ton of sulfuric acid is produced, thereby greatly saving the water consumption and reducing the sewage discharge. And (4) delivering the discharged dilute sulfuric acid and sewage to a sewage treatment station, and recycling the wastewater after the treatment reaches the standard. The system adopts a two-stage high-efficiency electric demister, so that the flue gas is highly purified, and the acid mist is completely removed, thereby ensuring that the emptied tail gas reaches the refreshing and transparent degree.

4.2 conversion procedure: adopts domestic high-quality catalyst, 3+1 type twice conversion process, SO₂The conversion rate is more than or equal to 99.8 percent, the tail gas is desulfurized by a sodium-alkali method and demisted by an electric demister, and SO in the discharged tail gas₂The content and the sulfuric acid mist are far superior to the national environmental protection standard. The conversion equipment and the pipeline adopt the measures of completely eliminating the thermal stress, and the air leakage is strictly prevented.

4.3 dry-suction process: the groove-tube acid distributor is adopted, so that the acid distribution point in unit area is more, the absorption is carried out twice with high efficiency, the flow is tower-groove-pump-device-tower, and the absorption efficiency is more than 99.96 percent.

4.4 System devices: the method selects high-efficiency and durable equipment, and is implemented by adopting a high-quality construction technology to eliminate bubbles, overflow, dripping and leakage. If the concentrated acid pump is the LSB alloy pump, the concentrated acid cooler is the high-efficiency anode protection shell-and-tube alloy cooler, and the like.

4.5 completion of the acid making method in the antimony smelting process of oxygen-enriched side-blown column smelting of the invention, the flue gas SO₂(v%) from less than 2 to more than or equal to 3, and realizes the preparation of industrial sulfuric acid, and achieves the aim of green manufacture in China, safe discharge and product sale.

The above examples are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the invention.