阅读说明：本技术 一种氯化钠硫酸钠混盐中去除有机物的方法 (Method for removing organic matters from sodium chloride and sodium sulfate mixed salt ) 是由 魏东红 卢炳杰 李万龙 郑李辉 刘凯华 魏昌鹏 于 2020-06-08 设计创作，主要内容包括：本发明公开了一种氯化钠硫酸钠混盐中去除有机物的方法,针对食品厂、农药厂生产过程产生的含有机物的硫酸钠、氯化钠污盐碳化去除有机物技术,主要是采用低温无氧去除有机物,优化后续制取优质工业盐条件,采用低温无氧碳化的优点有：降低热源提供能耗,从而降低生产运行成本,同时可利用低温条件下有机物的分解获得热能；无氧状态下,减少空气使用量,降低燃烧后烟气处理成本,环保、节能。低温分解有机物获得的碳、氢、氧能及时通过微负压排除,使碳化过程顺利进行,炉体内基本不会产生二次“污染”,缩短碳化时间。(The invention discloses a method for removing organic matters from sodium chloride and sodium sulfate mixed salt, which aims at the technology for removing the organic matters by carbonizing the sodium sulfate and sodium chloride polluted salt containing the organic matters generated in the production process of food factories and pesticide factories, mainly adopts low-temperature anaerobic organic matter removal, optimizes the condition for subsequently preparing high-quality industrial salt, and has the advantages that: the energy consumption provided by a heat source is reduced, so that the production and operation cost is reduced, and meanwhile, heat energy can be obtained by utilizing the decomposition of organic matters under the low-temperature condition; under the anaerobic state, the air consumption is reduced, the flue gas treatment cost after combustion is reduced, and the method is environment-friendly and energy-saving. Carbon, hydrogen and oxygen obtained by decomposing organic matters at low temperature can be discharged in time through micro negative pressure, so that the carbonization process is smoothly carried out, secondary pollution is basically not generated in the furnace body, and the carbonization time is shortened.)

1. A method for removing organic matters from sodium chloride and sodium sulfate mixed salt is characterized by comprising the following steps: the method comprises the following steps:

step 1) mixing organic polluted salt, wherein the mixed salt contains 5-8% of organic matters;

step 2) drying and dehydrating the mixed organic polluted salt, removing free substances, and recovering and treating gas generated in the drying process by adopting a spray tower;

conveying the dried polluted salt in the step 3) into an anaerobic critical carbonization area through conveying equipment, converting organic waste into carbon black at the temperature of 250-550 ℃ and under an anaerobic condition, conveying tail gas into a tail gas treatment system for harmless treatment, and returning the recovered waste heat to the drying system in the step 2) for use;

dissolving and filtering the carbonized mixture in the step 4), wherein carbon particles can be used as a primary filter material or dried and then used as fuel; the filtrate is pure salt or mixed salt solution after harmless treatment, and enters a salt preparation or salt separation process for operation.

2. The method for removing organic matters from the mixed salt of sodium chloride and sodium sulfate as claimed in claim 1, wherein: in the step 1), low-content and high-content organic dirt salt are mixed.

Technical Field

The invention relates to the technical field of organic pollutant separation, in particular to a method for removing organic matters from sodium chloride and sodium sulfate mixed salt.

Background

The current industrial waste salt treatment method mainly comprises the following steps:

firstly, a salt washing method is adopted, and water or a detergent is used for removing impurities or other components in organic waste salt; the method is suitable for treating single waste salt with low impurity content;

secondly, a high-temperature treatment method is adopted, so that the organic impurities in the salt slag are decomposed into gas at high temperature, and then the gas is treated, thereby achieving the purpose of removing the organic impurities; in the high-temperature treatment, the problems of nozzle blockage, abrasion, high-temperature adhesion, crusting, equipment corrosion and the like are easy to occur;

thirdly, a high temperature carbonization method, which is a method for treating organic waste salt proposed in recent years, and which is based on the principle that organic waste salt is carbonized and decomposed at a high temperature to partially decompose organic substances in the waste salt into volatile gas; the scheme has the problems that the carbonization temperature and the surface softening of salt are not easy to control, and the bonding to carbonization equipment is easily formed to influence continuous production;

fourthly, preparing soda ash, namely preparing saturated saline solution from salt residues, introducing nitrogen and carbon dioxide gas under certain conditions to form solid sodium bicarbonate, and preparing soda ash through pyrolysis; the method has the problem that the organic impurities in the waste salt can not be removed completely;

the five-low-temperature fractional carbonization method is characterized in that dried industrial waste salt is combined with hot air flowing at a certain temperature, organic matters in the industrial waste salt form volatile matters and organic carbon through heat transfer carbonization, and industrial salt is obtained after dissolving, washing, filtering and crystallizing treatment are carried out on the organic carbon salt.

Disclosure of Invention

In order to overcome the defects, the invention provides a method for removing organic matters from sodium chloride and sodium sulfate mixed salt, which can solve and cover the problems.

The technical scheme adopted by the invention for solving the technical problem is as follows: a method for removing organic matters from sodium chloride and sodium sulfate mixed salt is characterized in that: the method comprises the following steps:

step 1) mixing organic polluted salt, wherein the mixed salt contains 5-8% of organic matters;

step 2) drying and dehydrating the mixed organic polluted salt, removing free acid radicals and other substances, and recovering and treating gases generated in the drying process by adopting a spray tower, wherein the gases mainly comprise water vapor and a very small amount of other substances, and the dried waste salt has the characteristics of uniform particles and good fluidity;

conveying the dried polluted salt in the step 3) into an anaerobic critical carbonization area through conveying equipment, converting organic waste into carbon black at the temperature of 250-550 ℃ and under an anaerobic condition, conveying tail gas into a tail gas treatment system for harmless treatment, and returning the recovered waste heat to the drying system in the step 2) for use;

dissolving and filtering the carbonized mixture (mainly solid carbon and salt) in the step 4), wherein carbon particles can be used as a primary filter material or dried and then used as fuel; the filtrate is pure salt or mixed salt solution after harmless treatment, and enters a salt preparation or salt separation process for operation.

As a further improvement of the invention, in step 1) low and high organic salts are mixed.

The invention has the beneficial effects that: the invention aims at the technology of removing organic matters by carbonizing the polluted salt of sodium sulfate and sodium chloride containing organic matters generated in the production process of food factories and pesticide factories, mainly adopts low-temperature anaerobic organic matter removal, optimizes the condition of subsequent high-quality industrial salt preparation, and has the advantages of:

1. the energy consumption provided by a heat source is reduced, so that the production and operation cost is reduced, and meanwhile, heat energy can be obtained by utilizing the decomposition of organic matters under the low-temperature condition;

2. under the anaerobic state, the air consumption is reduced, the flue gas treatment cost after combustion is reduced, and the method is environment-friendly and energy-saving.

3. Carbon, hydrogen and oxygen obtained by decomposing organic matters at low temperature can be discharged in time through micro negative pressure, so that the carbonization process is smoothly carried out, secondary pollution is basically not generated in the furnace body, and the carbonization time is shortened.

Drawings

FIG. 1 is a schematic flow chart of the present invention.

Detailed Description

For the purpose of enhancing the understanding of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, which are only used for explaining the present invention and are not to be construed as limiting the scope of the present invention.

FIG. 1 shows a flow of the method for removing organic matters from sodium chloride-sodium sulfate mixed salt, which comprises the following steps:

step 1) mixing organic polluted salt, wherein the mixed salt contains 5-8% of organic matters;

step 2) drying and dehydrating the mixed organic polluted salt, removing free acid radicals and other substances, and recovering gas generated in the drying process by adopting a spray tower;

conveying the dried polluted salt in the step 3) into an anaerobic critical carbonization area through conveying equipment, converting organic waste into carbon black at the temperature of 250-550 ℃ and under an anaerobic condition, conveying tail gas into a tail gas treatment system for harmless treatment, and returning the recovered waste heat to the drying system in the step 2) for use;

dissolving and filtering the carbonized mixture in the step 4), wherein carbon particles can be used as a primary filter material or dried and then used as fuel; the filtrate is pure salt or mixed salt solution after harmless treatment, and enters a salt preparation or salt separation process for operation.

In the step 1), low-content and high-content organic dirt salt are mixed.

Example one

1. Industrial salt produced in a production process of a certain food factory comprises 3.5% of organic matter, 80.8% of sodium chloride, 3.8% of sodium sulfate and 11.89% of water (200 kg); the other contains 9.2% of organic matter, 82.8% of sodium chloride, 1.28% of sodium sulfate and 6.72% of water (200 kg); after the two industrial waste salts are stirred and mixed according to the ratio of 1:1, drying is carried out for 2 hours at the temperature of 100-110 ℃, and the thickness of a salt layer is 1.5-2 cm during drying.

2. After drying, the polluted salt is uniform and has no caking phenomenon, and enters low-temperature carbide in a spiral feeding mode. The carbonization furnace adopts closed and anaerobic operation, the temperature is controlled to be 250-550 ℃, and carbonization is carried out for 5 hours. Cooling after carbonization; the smoke treatment in the carbonization process mainly comprises water vapor and trace dust generated in the carbonization process, cyclone dust collection and cloth bag dust collection are carried out, and hot air is pressurized by a pipeline and then is sent to a drying process for use.

3. And (4) after the carbonized polluted salt is cooled to 70 ℃, sampling (the sample is cooled to room temperature for sample analysis), and dissolving and filtering the rest for subsequent work.

4. Through detection, after low-temperature anaerobic carbonization treatment, the total weight of the solid is 315.277kg, and the content of sodium chloride is as follows: 94.15%, sodium sulfate: 2.85%, carbide: 2.94%, the rest: 0.06 percent.

Example two

1. Industrial salt produced in the production process of a certain pesticide factory comprises 5.5% of organic matters, 88.8% of sodium chloride, 4.8% of sodium sulfate and 13.88% of water (200 kg); the other contains 10.2% of organic matter, 87.5% of sodium chloride, 2.01% of sodium sulfate and 10.72% of water (200 kg); after the two industrial waste salts are stirred and mixed according to the ratio of 1:1, drying is carried out for 2 hours at the temperature of 100-110 ℃, and the thickness of a salt layer is 1.5-2 cm during drying.

2. After drying, the polluted salt is uniform and has no caking phenomenon, and enters low-temperature carbide in a spiral feeding mode. The carbonization furnace adopts closed and anaerobic operation, the temperature is controlled to be 250-550 ℃, and carbonization is carried out for 6 hours. Cooling after carbonization; the smoke treatment in the carbonization process mainly comprises water vapor and trace dust generated in the carbonization process, cyclone dust collection and cloth bag dust collection are carried out, and hot air is pressurized by a pipeline and then is sent to a drying process for use.

3. And (4) after the carbonized polluted salt is cooled to 60 ℃, sampling (the sample is cooled to room temperature for sample analysis), and dissolving and filtering the rest for subsequent work.

4. Through detection, after low-temperature anaerobic carbonization treatment, the total weight of the solid is 350.96kg, and the content of sodium chloride is as follows: 93.09%, sodium sulfate: 3.53%, carbide: 3.28%, the rest: 0.1 percent.

Experiment three

1. Industrial salt produced in the production process of a certain pesticide factory comprises 5.5% of organic matters, 88.8% of sodium chloride, 4.8% of sodium sulfate and 13.88% of water (200 kg); a food factory contains 3.5% of organic matter, 80.8% of sodium chloride, 3.8% of sodium sulfate and 11.89% of water (200 kg); after the two industrial waste salts are stirred and mixed according to the ratio of 1:1, drying is carried out for 2 hours at the temperature of 100-110 ℃, and the thickness of a salt layer is 1.5-2 cm during drying.

2. After drying, the polluted salt is uniform and has no caking phenomenon, and enters low-temperature carbide in a spiral feeding mode. The carbonization furnace adopts closed and anaerobic operation, the temperature is controlled to be 250-550 ℃, and carbonization is carried out for 6 hours. Cooling after carbonization; the smoke treatment in the carbonization process mainly comprises water vapor and trace dust generated in the carbonization process, cyclone dust collection and cloth bag dust collection are carried out, and hot air is pressurized by a pipeline and then is sent to a drying process for use.

3. And (4) after the carbonized polluted salt is cooled to 60 ℃, sampling (the sample is cooled to room temperature for sample analysis), and dissolving and filtering the rest for subsequent work.

4. Through detection, after low-temperature anaerobic carbonization treatment, the total weight of the solid is 316.56kg, and the content of sodium chloride is as follows: 93.29%, sodium sulfate: 4.69%, carbide: 1.95%, the rest: 0.07 percent.