Acid recovery device and process method for reverse ion exchange
阅读说明：本技术 反向离子交换的酸回收装置及工艺方法 (Acid recovery device and process method for reverse ion exchange ) 是由 黄玉春 丁凡 于 2019-09-04 设计创作，主要内容包括：本发明公开了一种反向离子交换的酸回收装置,包括酸洗槽、热交换器、过滤器、离子交换柱、清水罐和废水站,离子交换柱为中空的圆柱体结构,离子交换柱的高度尺寸和内径尺寸之比为3:1,离子交换柱内填充有交换树脂颗粒,离子交换柱的底部位置设有废酸液进口、顶部位置设有清水出口,过滤器的底部位置设有废酸进口、顶部位置设有清水出口,酸洗槽与废酸液进口管路连接；离子交换柱右下阀门用作回收酸返回生产线；离子交换柱右上阀门用作将含金属废液回收并挂放到废水站。本发明简化了废酸液的回收利用流程,从而提高生产线的效能；而且可以减少污染,能够提供资源回收回用,从而减少酸资源浪费,节省设备和营运成本。(The invention discloses an acid recovery device for reverse ion exchange, which comprises a pickling tank, a heat exchanger, a filter, an ion exchange column, a clean water tank and a wastewater station, wherein the ion exchange column is of a hollow cylindrical structure, the ratio of the height size to the inner diameter size of the ion exchange column is 3:1, exchange resin particles are filled in the ion exchange column, a waste acid liquid inlet is formed in the bottom of the ion exchange column, a clean water outlet is formed in the top of the ion exchange column, a waste acid inlet is formed in the bottom of the filter, a clean water outlet is formed in the top of the filter, and the pickling tank is connected with the waste acid liquid inlet through a pipeline; the lower right valve of the ion exchange column is used for recycling acid and returning to the production line; the upper right valve of the ion exchange column is used for recovering and hanging the metal-containing waste liquid to a waste water station. The invention simplifies the recycling process of the waste acid liquor, thereby improving the efficiency of the production line; and the pollution can be reduced, and the resource can be recycled, so that the waste of acid resources is reduced, and the equipment and the operating cost are saved.)
1. Reverse ion exchange's acid recovery unit, including heat exchanger (2), ion exchange column (4), clear water jar (5) and waste water station (6), its characterized in that:
the heat exchanger (2) is respectively provided with a heat energy release inlet, a heat energy release outlet, a heat energy absorption inlet and a heat energy absorption outlet, the heat energy release inlet and the heat energy release outlet are respectively connected with the bottoms of the pickling tank (1) and the ion exchange column (4) in the production line through pipelines, the heat energy absorption inlet and the heat energy absorption outlet are respectively connected with the bottom of the ion exchange column (4) and the pickling tank (1) in the production line through pipelines, the heat energy of the waste acid liquor is released after the waste acid liquor enters the heat exchanger (2) from the pickling tank (1) in the production line, and then the heat exchanger (2) converts the heat into recovered acid liquor;
the ion exchange column (4) is of a hollow cylindrical structure, and ion exchange resin particles are filled in the ion exchange column (4);
the clean water tank (5) is connected with the top of the ion exchange column (4) through a pipeline, clean water in the clean water tank (5) enters the ion exchange column (4) from the top to desorb acid ions from ion exchange resin, is discharged from the bottom of the ion exchange column (4), enters the heat exchanger (2) through a heat energy absorption inlet of the heat exchanger (2) to absorb heat, and is discharged through a heat energy absorption outlet of the heat exchanger (2) to return to the pickling tank (1) in the production line;
the waste water station (6) is connected with the top of the ion exchange column (4) through a pipeline, and after the waste acid liquor enters the heat exchanger (2) from the pickling tank (1) in the production line through a heat energy release inlet of the heat exchanger (2) to release heat energy, the waste water is discharged through a heat energy release outlet of the heat exchanger (2) and enters the ion exchange column (4) to adsorb metal ions in the acid liquor to be washed out, and the waste water is discharged to the waste water station (6).
2. The acid recovery device of claim 1, wherein: the acid recovery device also comprises a filter (3), and the filter (3) is arranged in a pipeline between the pickling tank (1) and the heat exchanger (2) or between the heat exchanger (2) and the ion exchange column (4).
3. The acid recovery device of claim 1, wherein: the acid recovery device further comprises a collection tank which is installed in the pipeline after the heat exchanger (2).
4. The acid recovery device of claim 1, wherein: the acid recovery device further comprises a booster pump (8), a heat energy release outlet of the heat exchanger (2) and the clean water tank (5) are respectively connected with an inlet of the booster pump (8) through a valve I (71), a valve II (72) and a pipeline, an outlet pipeline of the booster pump (8) is divided into two pipelines, one pipeline is connected with the top of the ion exchange column (4) through a valve V (75), and the other pipeline is connected with the bottom of the ion exchange column (4) through a valve VI (76).
5. The acid recovery device of claim 1, wherein: the acid recovery device further comprises an air compressor (9), wherein the air compressor (9) and the waste water station (6) are respectively connected with the top of the ion exchange column (4) through a valve III (73), a valve IV (74) and a pipeline.
6. The acid recovery device of claim 1, wherein: the acid recovery device also comprises an acid liquor recovery tank (10) and an acid liquor recovery pump (11), wherein the inlet of the acid liquor recovery tank (10) is connected with the bottom of the ion exchange column (4) through a valve VIII (78) and a pipeline; the outlet of the acid liquor recovery tank (10) is connected with the heat energy absorption inlet of the heat exchanger (2) after being connected with the acid liquor recovery pump (11) through a pipeline.
7. The acid recovery device of claim 4, wherein: install filter (3) in the pipeline that booster pump (8) and ion exchange column (4) bottom are connected, install valve VI (76) and valve VII (77) respectively on the pipeline between booster pump (8) and filter (3) and the bottom of ion exchange column (4).
8. The acid recovery device of claim 1, wherein: the ratio of the height dimension to the inner diameter dimension of the ion exchange column (4) is 3: 1.
9. The acid recovery method of reverse ion exchange is divided into two steps, and the specific process is as follows:
the first step is that the waste acid liquor enters an ion exchange column (4) and metal ions in the washed acid liquor are discharged to a waste water station (6)
Firstly, connecting a waste acid solution from a pickling tank (1), flowing through a heat exchanger (2), entering an ion exchange column (4), and discharging the waste acid solution into a pipeline of a waste water station (6), closing other pipelines, enabling the waste acid solution from the pickling tank (1), entering the heat exchanger (2), releasing heat energy, cooling, entering the bottom of the ion exchange column (4), enabling the waste acid solution to flow from the bottom to the top of the ion exchange column (4), adsorbing acid ions by exchange resin, and finally discharging the waste acid solution from the top of the heat exchanger (2) to the waste water station (6) for metal ion recovery;
the second step is to wash out the acid solution in the ion exchange column (4) with clean water and to the heat exchanger (2)
Clear water in a clear water tank (5) enters a pipeline at the top of an ion exchange column (4), a pipeline from the bottom of the ion exchange column (4) to a heat exchanger (2) and a pipeline from the heat exchanger (2) to a pickling tank (1) are communicated, after other pipelines are closed, acid ions adsorbed on exchange resin in the ion exchange column (4) are desorbed and backwashed by utilizing the clear water to obtain purified acid liquid, the purified acid liquid is discharged from the bottom of the ion exchange column (4) to the heat exchanger (2), and the acid liquid returns to the pickling tank (1) in a production line for recycling after absorbing heat energy in the heat exchanger (2);
and when the second step is completed, returning to the first step to operate again.
10. The acid recovery process of claim 9, wherein: the acid recovery process is divided into three steps,
the first step is that the waste acid liquor enters an ion exchange column (4) and metal ions in the washed acid liquor are discharged to a waste water station (6)
Firstly, opening a valve I (71), a valve IV (74), a valve VI (76) and a valve VII (77), closing other valves, enabling the waste acid liquor to enter a heat exchanger (2) from a pickling tank (1) to release heat energy for cooling, then pressurizing the waste acid liquor discharged from the heat exchanger (2) by using a booster pump (8) to enter a filter (3) for filtering, enabling the waste acid liquor filtered by the filter (3) to enter the bottom of an ion exchange column (4), enabling the waste acid liquor to be adsorbed by exchange resin in the process of flowing from the bottom to the top of the ion exchange column (4), and finally discharging the waste acid liquor from the top of the heat exchanger (2) to a waste water station (6) for metal ion recovery;
the second step is to wash out the acid solution in the ion exchange column (4) with clean water and to the heat exchanger (2)
The valve I (71), the valve IV (74), the valve VI (76) and the valve VII (77) are closed, opening a valve II (72), a valve V (75), a valve VIII (78), a booster pump (8) and an acid liquor recovery pump (11), adding clear water in a clear water tank (5) into the top of the ion exchange column (4) by using the booster pump (8), desorbing and backwashing acid ions adsorbed on the exchange resin by the clear water in the process of flowing from the top to the bottom of the ion exchange column (4) to obtain purified acid liquor, discharging the purified acid liquor to an acid liquor recovery tank (10) from the bottom of the ion exchange column (4), and the acid liquor in the acid liquor recovery tank (10) is conveyed into the heat exchanger (2) through an acid liquor recovery pump (11), the acid liquor is returned to the pickling tank (1) in the production line for recycling after absorbing heat energy in the heat exchanger (2);
the third step is to press out the residual acid liquor in the ion exchange column (4) to an acid liquor recovery tank (10) by using compressed air
Closing a valve II (72) and a valve V (75), opening a valve III (73) and an air compressor (9), allowing compressed air generated by the air compressor (9) to enter from the top of the ion exchange column (4), completely discharging acid liquor in the ion exchange column (4) to an acid liquor recovery tank (10) by the compressed air, conveying the acid liquor in the acid liquor recovery tank (10) to a heat exchanger (2) through an acid liquor recovery pump (11), and returning the acid liquor to an acid washing tank (1) in the production line for recycling after absorbing heat energy in the heat exchanger (2);
and returning to the first step to operate again after the third step is completed.
11. The acid recovery process according to claim 9 or 10, characterized in that: the waste acid liquid in the first step flows from the bottom to the top of the ion exchange column (4) at a flow rate of 2-20 m/h; the clean water in the second step flows from the top to the bottom of the ion exchange column (4) at a flow rate of 2-20 m/h; the compressed air pressure in the third step is maintained at 0.5-3 bar.
Technical Field
The invention relates to an acid recovery device, in particular to an acid recovery device for reverse ion exchange and a process method.
Background
The pickling process for metal surface treatment in steel processing plants such as screw and nut plants, wire and steel plants and steel tube plants employs an acid solution to corrode iron oxide scale on the surface of iron material, thereby producing a pickling waste solution containing a large amount of iron ions and a small amount of heavy metals. Steel component blanks are typically pickled prior to surface plating and spraying to remove surface oxides, thereby producing spent pickling solution and waste pickling water. Wherein the acid-washing waste liquid has higher acid concentration and can recycle the regenerated acid. And a large amount of washing water, namely pickling wastewater, has low acid content, so that the washing water is uneconomical to recycle and is discharged as wastewater. Different components or different processing requirements are met, the types and the concentrations of the used acids are different, for example, sulfuric acid with the concentration of 250g/L is generally used for cleaning steel workpieces or blanks, the steel workpieces or blanks are heated to 70 ℃ for cleaning, the waste liquid contains 100-150 g/L of sulfuric acid, 200-250 g/L of ferrous sulfate, iron scales, oil stains and the like. The hydrochloric acid cleaning waste liquid generally contains 280-150 g/L FeCl and 10-50 g/L hydrochloric acid. The main harm of the acid-containing wastewater is to corrode sewer pipes, reinforced concrete and other hydraulic structures; hindering biological reproduction in the biological treatment of wastewater; the waste water with high acidity can poison fishes, so that crops are withered and dead, and the growth of aquatic crops is influenced. The acid-containing wastewater permeates into soil, and the soil calcification can be caused after a long time, so that the loose state of the soil layer is damaged, and the growth of crops is influenced. People and animals can cause gastrointestinal inflammation and even burn when drinking water with high acidity. A large amount of acid mist is generated in the acid pickling process, so that the health of workers is damaged, a factory building and equipment are corroded, and meanwhile, the acid liquor loss is caused due to volatilization of the large amount of acid mist, and the acid pickling cost is increased. The pickling wastewater also contains a large amount of heavy metal ions, and the pollution to water, the biological toxicity and the final damage to human health caused by the excessive heavy metal ions are self-evident. The waste acid is generally recycled.
In the treatment and comprehensive utilization of pickling waste water, the traditional waste acid recovery method comprises the following steps: neutralization, ferric sulfate, evaporation concentration-cooling crystallization, acid regulation-freezing crystallization, alkali liquor-ferrous sulfate coprecipitation, diffusion dialysis-diaphragm electrolysis and the like.
(1) Neutralization process
In the early days, the acid industrial wastewater with acid content below 1% is generally treated by a chemical neutralization method. The concrete method comprises the steps of neutralizing acid and alkali waste water, adding medicine for neutralization, filtering for neutralization and the like. The filtering neutralization is generally applicable to acidic wastewater containing less oil and salt and having low acid concentration (sulfuric acid is less than 2g/L, and hydrochloric acid and nitric acid are less than 20-30 g/L), and the method is generally not applicable to the treatment of steel pickling wastewater. The most common method for treating the steel pickling wastewater is a lime neutralization method, and slaked lime is added into the wastewater to neutralize the wastewater, so that the pH value reaches 5.6-6.5, and the wastewater is discharged after reaching the national discharge standard.
The neutralization method for treating the acidic wastewater is simple and easy, but has the following problems: the management is complicated, the control is not easy, and the wastewater treatment capacity is limited; sulfuric acid, water, FeO, Fe in wastewater3O4And FeSO4Can not be utilized; the gas generated in the treatment process diffuses to cause secondary pollution; the amount of sludge is large and the treatment of the remaining salt residues is difficult. New ways to effectively solve these problems have been sought.
(2) Ferric sulfate process
The method is characterized in that iron in the waste liquid can be recycled, so that the method is emphasized by researchers, and a mature practical technology is gradually formed. The following methods are put into production practice.
The concentration-filtration-natural crystallization method, also known as iron filings method, is characterized by that firstly, the waste liquor of sulfuric acid and iron filings are placed in a reaction tank, fully reacted, then the solution is heated to 100 deg.C, reacted for 2 hr, then heated and concentrated, naturally cooled to make ferrous sulfate crystallize and separate out, finally dewatered and dried by means of drying machine.
The process flow of the concentration filtration natural crystallization method comprises the following steps: the method can recover low, medium and high grade ferrous sulfate from acid washing wastewater for industrial, agricultural, pharmaceutical and chemical reagents. The method has the advantages of simplicity, easy operation, low investment, low cost and the like, but only can recover ferrous sulfate, but not sulfuric acid, and has small treatment capacity; the product quality is poor, the production cycle is long, and the method is suitable for small-scale production of township enterprises. The steel rolling pickling waste liquid is treated by a first steel special steel company by the method, and after centrifugal drying, the acid concentration of the residual liquid is 0.5%, and the ferrous sulfate is 150-170 g/L.
The main principle of the immersion combustion high-temperature crystallization method is that coal gas and air are combusted to generate high-temperature flue gas, and the high-temperature flue gas is directly sprayed into waste acid water to evaporate water, concentrate sulfuric acid and simultaneously separate out ferrous sulfate.
The technological process of the submerged combustion high-temperature crystallization method comprises the following steps: in the sixty-seven decades of the twentieth century, the Shanghai, Tianjin, Jilin and the like adopt an immersion combustion high-temperature crystallization methodThe waste acid with the concentration of 12-15 percent is improved to 45-57 percent, and simultaneously, ferrous sulfate (FeSO) containing crystal water is produced4.H2O). The method has the advantages of high thermal efficiency, high concentration of the regenerated acid and easy solution of equipment; the defects are that the acid mist is large, combustible gas is needed, and the method is more suitable for treating waste acid with large treatment capacity.
The steam jet vacuum crystallization method sprays the waste acid liquor onto burning flame by using a spray head with high atomization efficiency to evaporate water, so that about 35% of sulfuric acid and part of FeSO can be obtained4.H2And O. The working principle is that the evaporator and the crystallizer are kept in a certain vacuum degree through a steam ejector and a condenser. When the waste liquid passes through the heat-insulating device, the water in the waste liquid is evaporated under the heat-insulating condition, so that the waste liquid is concentrated, the temperature of the waste liquid is reduced, the solubility of ferrous sulfate is correspondingly reduced, and the supersaturation degree of the ferrous sulfate is increased. Meanwhile, the supersaturation degree of the ferrous sulfate is further improved in the evaporator due to the addition of the sulfuric acid. In this case, ferrous sulfate is crystallized. The method requires the used material to have higher corrosion resistance, and is easy to generate secondary pollution or unstable in operation so as not to be normally produced.
(3) Evaporative concentration-cooling crystallization method
The basic principle is that the waste liquid is evaporated and concentrated by negative pressure, and then ferrous sulfate crystals are separated out from the waste liquid at low temperature to obtain regenerated sulfuric acid. Is suitable for recovering ferrous sulfate and sulfuric acid in the pickling waste liquid of large-scale steel plants.
The technological process of evaporation, concentration, cooling and crystallization method comprises the following steps: in the early 70 s of the twentieth century, a process of evaporative concentration, cooling crystallization and hydrochloric acid separation was developed. The whole process does not produce secondary pollution, meets the requirement of harmless treatment and has good economic benefit and environmental benefit.
(4) Acid regulating-freezing crystallization method
The process for treating the waste sulfuric acid pickling liquid by freezing crystallization is to separate the ferrous sulfate crystal by controlling the condition of ferrous sulfate crystallization from the waste liquid. The effects of purifying the pickling waste liquid and recovering ferrous sulfate are achieved. The main process is to add concentrated sulfuric acid into the waste acid washing liquor to adjust the weight percentage concentration of sulfuric acid to 22-25%, then to reduce the temperature of the waste liquid from 20-40 ℃ to 0-3 ℃ by using a refrigeration method to reduce the solubility of ferrous sulfate and crystallize and separate out, and then to filter and carry out solid-liquid separation. Recovering ferrous sulfate and reusing the regenerated acid without ferrous sulfate.
(5) Coprecipitation method of alkali liquor and ferrous sulfate
The method combines a neutralization method and a ferrous sulfate method to treat the acidic wastewater. The basic principle is that alkali liquor or lime is added into the waste water to neutralize the acid waste water and generate sodium sulfate. The generated sodium sulfate still has certain solubility, and a polyacrylamide flocculant needs to be added to aggregate and settle the metal ions. Two-stage treatment is adopted, the sediment obtained from the first-stage treatment is stirred by a stirrer to destroy the balance between the sediment and ions in a liquid phase, then the sediment is fully reacted by a neutralization tower, and then the second-stage sedimentation treatment is carried out to obtain better effect. The method is suitable for treating the acid wastewater with higher sulfur concentration. Ningbo and Sen steel pipe Limited built in 1995 simultaneously builds an acid wastewater treatment device, the wastewater treatment capacity reaches 10t/h, the floor area is about 300m2, and the total investment is 17 ten thousand yuan.
(6) Diffusion dialysis-diaphragm electrolysis
In the seventies of the twentieth century, the acid washing wastewater is comprehensively treated by using a diffusion dialysis-diaphragm electrolysis method. Waste acid enters a diffusion dialyzer, wherein 204 anion exchange membranes S-203 are arranged in the dialyzer, the two sides of the membranes are respectively a water phase and a waste acid phase, and free acid in the waste acid continuously enters the water phase to become sulfuric acid to be recovered due to the concentration difference of acid existing in the two phases and the selective permeability and the molecular sieve action of the ion exchange membranes. The residual liquid enters a diaphragm electrolytic cell, a cathode and an anode are inserted, an anion exchange membrane F-201 is arranged between the cathode and the anode to form an cathode chamber and an anode chamber, iron ions and sulfate ions in the residual liquid are reduced into pure iron under the action of a direct current electric field by utilizing the selective permeability of the cathode membrane, and the sulfate ions and hydrogen ions are combined into sulfuric acid in the anode chamber. The method has the advantages of simple equipment and high recovery efficiency, and can recover waste acid and extract iron. The disadvantage is the higher power consumption.
An environment-friendly and energy-saving waste acid recovery method (namely acid retardation technology) is newly researched in recent years, but the effect is not good.
The regeneration and utilization of the waste hydrochloric acid are realized by utilizing the function that certain ion exchange resins can absorb acid from waste acid solution and remove metal salt. The waste hydrochloric acid from the waste acid tank enters a clean ferrous salt-containing tank after being filtered by a filtering device, the clean ferrous salt-containing acid flows through a resin bed from the bottom through a pipeline, HCl is absorbed by the resin, and liquid containing other ions is discharged and enters a metal salt recovery system. Thereby achieving acid salt separation. The method has the advantages of short process flow and easy operation; the energy consumption is low; normal temperature treatment can prolong the service life of equipment and pipelines and reduce the escape of chloride. However, the concentration of the hydrochloric acid recovered during the treatment under normal pressure is low, and the hydrochloric acid needs to be added for use.
According to patent No. CN205999182U, the short bed ion exchange resin method needs to separate acid and metal ions under high pressure environment, and the resin is easy to damage and lose efficacy under high pressure for a long time; the operation cost is high, and the separation effect is poor due to the short resin bed.
The existing methods for treating inorganic waste acid have the following disadvantages: although the short bed ion exchange resin method has short process flow, easy operation and low energy consumption, the concentration of the recovered inorganic acid is low during normal temperature treatment, and the inorganic acid can be used only by adding high-concentration acid; the roasting method does not produce new pollutants, and the recovered product can be recycled, but has great pollution to the environment, and the gas containing pollution is a big problem; although the equipment used in the concentration method is easy to scale and difficult to clean, the acid treated by the method can reach high concentration and can be directly utilized; the neutralization method ensures the pH value of the treated substance; the extraction method can separate organic matters from waste acid under certain conditions, but the treated waste acid still contains a large amount of organic matters, so that the treatment is difficult. Therefore, when waste acid is treated, different treatment methods are selected according to specific situations.
Disclosure of Invention
The invention aims to solve the technical problem of providing an acid recovery device for reverse ion exchange so as to solve the problem of recycling waste acid liquor.
In order to solve the existing technical problems, the technical scheme adopted by the invention is as follows: the acid recovery device comprises a heat exchanger, an ion exchange column, a clear water tank and a wastewater station, wherein the heat exchanger is respectively provided with a heat energy release inlet, a heat energy release outlet, a heat energy absorption inlet and a heat energy absorption outlet, the heat energy release inlet and the heat energy release outlet are respectively connected with the bottom of a pickling tank and the bottom of the ion exchange column in a production line through pipelines, the heat energy absorption inlet and the heat energy absorption outlet are respectively connected with the bottom of the ion exchange column and the pickling tank in the production line through pipelines, the heat energy of the waste acid liquor is released after the waste acid liquor enters the heat exchanger from the pickling tank in the production line, and then the heat exchanger converts the heat into recovered acid liquor; the ion exchange column is of a hollow cylindrical structure and is filled with ion exchange resin particles; the clean water tank is connected with the top of the ion exchange column through a pipeline, clean water in the clean water tank enters the ion exchange column from the top to desorb acid ions from ion exchange resin, and the acid ions are discharged from the bottom of the ion exchange column, enter the heat exchanger through a heat energy absorption inlet of the heat exchanger to absorb heat, and then are discharged through a heat energy absorption outlet of the heat exchanger to return to a pickling tank in a production line; the waste water station is connected with the top of the ion exchange column through a pipeline, and the waste acid liquid enters the heat exchanger from an acid washing tank in the production line through a heat energy release inlet of the heat exchanger to release heat energy, and is discharged through a heat energy release outlet of the heat exchanger to enter the ion exchange column to adsorb acid ions so as to wash out metal ions in the acid liquid, and the waste water is discharged to the waste water station.
In order to filter solid suspended matter, insoluble solid particles and the like in the spent acid solution, particularly, the acid recovery apparatus of the present invention preferably further comprises a filter installed in a pipe between the pickling tank and the heat exchanger or between the heat exchanger and the ion exchange column.
In order to facilitate collection of the spent acid solution in the pickling tank to improve the use efficiency of the acid recovery device, in particular, the acid recovery device of the present invention preferably further includes a collection tank installed in a pipeline after the heat exchanger.
In order to increase the fluidity of the waste acid liquid and facilitate the control of the acid recovery device, particularly, the acid recovery device preferably further comprises a booster pump, a heat energy release outlet and a clean water tank of the heat exchanger are respectively connected with an inlet of the booster pump through a valve I, a valve II and a pipeline, an outlet pipeline of the booster pump is divided into two pipelines, one pipeline is connected with the top of the ion exchange column through a valve V, and the other pipeline is connected with the bottom of the ion exchange column through a valve VI.
In order to reduce the use amount of clear water, improve the concentration of the recovered acid liquid and facilitate the control of the acid recovery device, particularly, the acid recovery device preferably further comprises an air compressor, and the air compressor and the waste water station are respectively connected with the top of the ion exchange column through a valve III, a valve IV and a pipeline.
In order to facilitate the collection of the purified acid solution in the ion exchange column, so as to improve the use efficiency of the acid recovery device and facilitate the control of the acid recovery device, particularly, the acid recovery device preferably further comprises an acid solution recovery tank and an acid solution recovery pump, wherein the inlet of the acid solution recovery tank is connected with the bottom of the ion exchange column through a valve VIII and a pipeline; the outlet of the acid liquor recovery tank is connected with the heat energy absorption inlet of the heat exchanger after being connected with the acid liquor recovery pump through a pipeline.
In order to facilitate filtering of solid suspended matters, insoluble solid particles and the like in the waste acid liquid and control of the acid recovery device, particularly, a filter is preferably arranged in a pipeline connecting the booster pump and the bottom of the ion exchange column, and a valve VI and a valve VII are respectively arranged on pipelines between the booster pump and the filter and between the filter and the bottom of the ion exchange column.
The
The invention also discloses a method for recovering acid by reverse ion exchange, which comprises two steps:
the first step is that the waste acid liquid enters an ion exchange column to discharge the metal ions in the washed acid liquid to a waste water station
Firstly, connecting a waste acid solution from a pickling tank, flowing through a heat exchanger, entering an ion exchange column, and discharging the waste acid solution into a pipeline of a waste water station, closing other pipelines, enabling the waste acid solution to enter the heat exchanger from the pickling tank, releasing heat energy, cooling the heat energy, entering the bottom of the ion exchange column, adsorbing acid ions by an exchange resin in the process that the waste acid solution flows from the bottom to the top of the ion exchange column, and finally discharging the waste acid solution from the top of the
the second step is to wash out the acid liquor in the ion exchange column with clean water and arrange the acid liquor to a heat exchanger
The method comprises the following steps of putting clean water in a clean water tank into a pipeline at the top of an ion exchange column, a pipeline from the bottom of the ion exchange column to a heat exchanger and a pipeline from the heat exchanger to a pickling tank, connecting the pipelines, closing other pipelines, desorbing and backwashing acid ions adsorbed on exchange resin in the ion exchange column by using the clean water to obtain purified acid liquor, discharging the purified acid liquor into the heat exchanger from the bottom of the ion exchange column, and returning the acid liquor to the pickling tank in a production line for recycling after absorbing heat energy in the heat exchanger;
and when the second step is completed, returning to the first step to operate again.
In particular, the invention also discloses a specific reverse ion exchange acid recovery method which is divided into three steps,
the first step is that the waste acid liquid enters an ion exchange column to discharge the metal ions in the washed acid liquid to a waste water station
Firstly, opening a valve I, a valve IV, a valve VI and a valve VII, closing other valves, enabling the waste acid liquid to enter a heat exchanger from a pickling tank to release heat energy for cooling, then pressurizing the waste acid liquid discharged from the heat exchanger by using a booster pump, enabling the waste acid liquid to enter a filter for filtering, enabling the waste acid liquid filtered by the filter to enter the bottom of an ion exchange column, enabling the waste acid liquid to be adsorbed by exchange resin in the process of flowing from the bottom to the top of the ion exchange column, and finally, discharging the waste acid liquid from the top of the heat exchanger to a waste water station for metal ion recovery;
the second step is to wash out the acid liquor in the ion exchange column with clean water and arrange the acid liquor to a heat exchanger
Closing the valve I, the valve IV, the valve VI and the valve VII, opening the valve II, the valve V, the valve VIII, the booster pump and the acid liquor recovery pump, adding clear water in the clear water tank into the top of the ion exchange column by using the booster pump, desorbing and backwashing acid ions adsorbed on the exchange resin by the clear water in the process of flowing from the top to the bottom of the ion exchange column to obtain purified acid liquor, discharging the purified acid liquor to the acid liquor recovery tank from the bottom of the ion exchange column, conveying the acid liquor in the acid liquor recovery tank into the heat exchanger by using the acid liquor recovery pump, and returning the acid liquor to a pickling tank in a production line for recycling after absorbing heat energy in the heat exchanger; the third step is to press out the residual acid liquor in the ion exchange column to an acid liquor recovery tank by using compressed air
Closing the valve II and the valve V, opening the valve III and the air compressor, enabling compressed air produced by the air compressor to enter from the top of the ion exchange column, completely discharging acid liquor in the ion exchange column to the acid liquor recovery tank by the compressed air, conveying the acid liquor in the acid liquor recovery tank into the heat exchanger by the acid liquor recovery pump, and returning the acid liquor to a pickling tank in the production line for recycling after absorbing heat energy in the heat exchanger;
and returning to the first step to operate again after the third step is completed.
In general, the flow rates of the spent acid solution and the clear water and the pressure of the compressed air can be selected as required, and particularly, the spent acid solution in the first step of the acid recovery method of the present invention flows from the bottom to the top of the ion exchange column at a flow rate of 2 to 20 m/h; the clean water in the second step flows from the top to the bottom of the ion exchange column at the flow speed of 2-20 m/h; the compressed air pressure in the third step is maintained at 0.5-3 bar.
The ion exchange column of the present invention should provide sufficient height, and the longer the stacking distance of the ion exchange resin, the better the separation of the acid from the metal is performed. The separation by ion exchange is an important technology of chromatographic separation, and the longer the resin layer is, the farther the liquid flow path is, and the more the separation coefficient is obviously improved.
The invention can evenly feed the waste acid liquid into the reverse ion exchange column, and all the resins can completely contact the waste acid liquid, thereby realizing the function of resin separation in a hundred percent.
The waste acid inlet and outlet of the invention are both provided with heat exchangers, and the heat energy in the waste acid discharged from the production line is converted into the heat energy in the acid return system.
The invention can directly desorb acid ions in the ion exchange resin by using clear water without using other chemical agents.
The invention relates to a reverse ion exchange acid recovery device, which aims to simplify the production flow of a steel industry processing plant so as to improve the efficiency of a production line; and the pollution can be reduced, and the resource can be recycled, so that the waste of acid resources is reduced, and the equipment and the operating cost are saved. The following table 1 shows experimental data of the acid solution after the waste acid solution is treated and purified by the acid recovery device,
table 1 spent acid liquor recovery experimental data
Advantageous effects
The invention can evenly feed the waste acid liquid into the reverse ion exchange column, all the resins can completely contact the waste acid liquid, the resin is utilized for separation in percentage, the separation effect is improved, the reverse ion exchange column can also reduce the energy consumption and the resin loss, and the service life of the resin is prolonged. The waste acid inlet and outlet are both provided with heat exchangers, the heat in the waste acid discharged from the production line can be converted into the heat in the acid return system, the energy consumption is greatly reduced, and the temperature of the waste acid before entering the ion exchange column can be reduced, so that the service life of the resin is prolonged. The acid ions in the ion exchange resin can be directly desorbed by using clear water, so that the whole process becomes more environment-friendly and cleaner, and the acidity is also improved.
Drawings
FIG. 1 is a schematic diagram of an acid recovery unit for reverse ion exchange, wherein: 1-a pickling tank, 2-a heat exchanger, 3-a filter, 4-an ion exchange column, 5-a clean water tank, 6-a wastewater station and 7-a valve;
FIG. 2 shows a structure diagram of a reverse waste acid purification and metal recovery apparatus, wherein the drawing shows the following marks: 1-a pickling tank, 2-a heat exchanger, 3-a filter, 4-an ion exchange column, 5-a clean water tank, 6-a wastewater station, 8-a booster pump, 9-an air compressor, 10-an acid liquor recovery tank, 11-an acid liquor recovery pump, 71-a valve I, 72-a valve II, 73-a valve III, 74-a valve IV, 75-a valve V, 76-a valve VI, 77-a valve VII, and 78-a valve VIII;
FIG. 3 shows the test results of the reverse ion-exchange acid recovery method of the present invention for the waste hydrochloric acid solution of iron and steel smelters;
FIG. 4 shows the test results of the conventional acid recovery method for the waste hydrochloric acid solution in the iron and steel smelting plant;
FIG. 5 shows the test results of the acid recovery method of reverse ion exchange for waste hydrochloric acid solution of hot dip galvanizing plating plant according to the present invention;
description of the drawings: any container suitable for the present invention, such as a tank, a pool, a bucket, etc., is collectively referred to as a tank.
Detailed Description
The present invention is further described in detail below with reference to specific examples so that the advantages and features of the present invention may be more readily understood by those skilled in the art, and thus the scope of the present invention is more clearly defined.
As shown in the attached figure 1, the acid recovery device for reverse ion exchange comprises a
The pickle liquor is discharged from
After the acid liquor leaves the filter 3, the acid liquor enters the
As shown in fig. 2, a reverse waste acid purification and metal recovery method and apparatus comprises an apparatus made of corrosion-resistant materials: the system comprises a
the heat energy release inlet of the
the acid
The acid recovery method of reverse ion exchange comprises the following three steps:
the first step is that the waste acid liquid enters an
After the pickling tank of the production line is used for a period of time, the metal content of the acid liquor is increased to reduce the pickling efficiency, at the moment, the automatic control circuit is used for controlling the opening of the valve I71, the valve IV 74, the valve VI 76 and the valve VII 77 and the closing of other valves, the acid liquor with the temperature of over 60 ℃ (also serving as the waste acid liquor) enters the heat exchanger 2 from the pickling tank 1 to release heat energy for cooling, then, the automatic control circuit is used for controlling the booster pump 8 to pressurize the waste acid liquor discharged from the heat exchanger 2 to enter the filter 3 for filtering, and therefore solid suspended matters and insoluble solid particles in the waste acid liquor are filtered; the waste acid solution filtered by the filter 3 enters the bottom of the ion exchange column 4, and the waste acid solution absorbs acid ions by the exchange resin in the process of flowing from the bottom to the top of the ion exchange column 4 at the flow rate of 2-20m/h, so that the resin in the ion exchange column 4 can effectively and averagely contact the waste acid solution; the waste acid is subjected to extremely fine color separation, most heavy metal ions (85-95%) in the waste acid are discharged to a waste water station 6 through a valve IV 74 for metal recovery, and most acid ions (85-98%) in the waste acid are adsorbed and stay in an ion exchange column 4.
The second step is to wash out the acid solution in the
Closing the valve I71, the
the third step is to press out the residual acid solution in the
Closing a
and returning to the first step to operate again after the third step is completed. The automatic control circuit can also set the running times of the equipment device according to the requirements of the production line, thereby achieving the purpose of effectively utilizing resources.
The acid liquor enters the
The invention uses the
Through the mode, the waste acid is adsorbed by the
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