阅读说明：本技术 一种铅膏铵法脱硫副产物硫酸铵溶液的净化、干燥处理方法及装置 (Purification and drying treatment method and device for ammonium sulfate solution as byproduct of ammonium lead plaster desulphurization ) 是由 吴光辉 王振云 范伟 刘伟 单欢乐 王觉群 于 2019-11-14 设计创作，主要内容包括：本发明一种铅膏铵法脱硫副产物-硫酸铵溶液净化及干燥处理的方法为：步骤一,脱硫滤液精滤；步骤二,重金属沉淀过滤；步骤三,调节pH；步骤四,进一步精滤；步骤五,蒸发结晶；步骤六,母液喷雾干燥。本发明所采用的装置包括硫酸铵溶液储罐,沉淀剂添加设备,第一袋式过滤器,沉淀絮凝反应罐,絮凝剂添加设备,硫酸添加设备,压滤机,调节罐,净化后硫酸铵储罐,蒸发结晶系统,离心机,离心母液罐,喷雾干燥器,分离器,第二袋式过滤器15。本发明对蒸发母液定期外排,避免系统中腐蚀性离子过度累积,对设备造成损害,延长设备使用寿命,达到资源的高效回收利用和清洁生产的目的,既环保又经济。(The invention relates to a method for purifying and drying ammonium sulfate solution which is a byproduct of ammonium lead plaster desulphurization, which comprises the following steps: firstly, fine filtering the desulfurization filtrate; precipitating and filtering heavy metal; regulating the pH value; step four, further fine filtering; step five, evaporating and crystallizing; and step six, spray drying the mother liquor. The device adopted by the invention comprises an ammonium sulfate solution storage tank, a precipitator adding device, a first bag filter, a precipitation flocculation reaction tank, a flocculating agent adding device, a sulfuric acid adding device, a filter press, a regulating tank, a purified ammonium sulfate storage tank, an evaporative crystallization system, a centrifuge, a centrifugal mother liquor tank, a spray dryer, a separator and a second bag filter 15. The invention discharges the evaporation mother liquor regularly, avoids the excessive accumulation of corrosive ions in the system and the damage to equipment, prolongs the service life of the equipment, achieves the aims of high-efficiency recycling of resources and clean production, and is environment-friendly and economical.)

1. A method for purifying and drying a byproduct ammonium sulfate solution generated by ammonium lead plaster desulphurization is characterized by comprising the following steps:

step one, fine filtering of desulfurization filtrate: pumping a byproduct ammonium sulfate filtrate generated after the lead plaster is desulfurized into a first bag type filter, filtering fine lead oxide and lead carbonate particles through fine filtration, and then entering a precipitation flocculation reaction tank;

step two, heavy metal precipitation and filtration: adding a heavy metal capture agent into the precipitation flocculation reaction tank, stirring for 5-15 minutes, adding a flocculating agent polyacrylamide, stirring for 5-15 minutes, standing for 10-20 minutes, pumping into a filter press to filter precipitated impurities, and then feeding into an adjusting tank;

step three, adjusting the pH: neutralizing the excessive ammonium bicarbonate in the regulating tank with dilute sulfuric acid;

step four, further fine filtering: filtering the adjusted filtrate by a second bag filter, and then feeding the filtrate into a purified liquid storage tank;

pumping the ammonium sulfate solution in the purifying solution storage tank into an evaporative crystallization system for evaporative crystallization, separating by a centrifuge to obtain high-purity ammonium sulfate crystals and crystallization mother liquor, continuously feeding the crystallization mother liquor into the evaporative crystallization system, and discharging the mother liquor when the impurity content of the mother liquor is enriched to a certain degree to influence the salt quality and the evaporation performance;

step six, spray drying of mother liquor: and (4) pumping the mother liquor discharged from the middle and outer rows in the step five into a centrifugal spray drying system while the mother liquor is hot, so as to obtain ammonium sulfate crystals with lower purity.

2. The method for purifying and drying the ammonium sulfate solution as the byproduct of ammonium patented lead plaster desulfurization according to claim 1, wherein in the second step, diatomite is added while polyacrylamide as a flocculant is added.

3. The method for purifying and drying the ammonium sulfate solution as the byproduct of ammonium lead plaster desulfurization, according to claim 1, wherein the pH value after neutralization is 4-6 in the third step.

4. The method for purifying and drying the ammonium sulfate solution as the byproduct of ammonium diachylon desulphurization according to claim 1, wherein in the second step, the time for stirring twice is 10 minutes.

5. The utility model provides a lead plaster ammonium method desulfurization accessory substance ammonium sulfate solution purifies, drying process device which characterized in that has connected gradually through the pipeline:

the device comprises an ammonium sulfate solution storage tank, a first bag filter, a precipitation flocculation reaction tank, a filter press, an adjusting tank, a second bag filter, a purified ammonium sulfate storage tank, an evaporative crystallization system, a centrifuge mother liquor tank and a centrifugal spray drying system.

6. The apparatus for purifying and drying ammonium sulfate solution as a byproduct of ammonium lead plaster desulfurization, according to claim 5, wherein the centrifugal spray drying system comprises a spray dryer and a separator.

7. The ammonium diachylon desulphurization byproduct ammonium sulfate solution purification and drying treatment device according to claim 5, wherein the precipitation flocculation reaction tank is connected with a precipitator adding device and a flocculant adding device, and discharge ports of the precipitator adding device and the flocculant adding device are connected with the precipitation flocculation reaction tank through pipelines.

8. The device for purifying and drying the ammonium sulfate solution as the byproduct of ammonium lead plaster desulphurization according to claim 5, it is characterized in that a discharge port of the ammonium sulfate solution storage tank is connected with the precipitation flocculation reaction tank through a pump, a pipeline and the first bag filter, the sedimentation flocculation reaction tank is connected with the adjusting tank through a filter press and a pipeline, the pipeline of the adjusting tank is communicated with the purified ammonium sulfate storage tank through a pump, a pipeline and the second bag type filter, the purified ammonium sulfate storage tank is communicated with the evaporative crystallization system through a pump and a pipeline, the evaporative crystallization system is connected with the centrifuge through a pump and a pipeline, the centrifuge is communicated with the centrifuge mother liquor tank through a pipeline, and the centrifuge mother liquor tank is respectively communicated with the evaporative crystallization system and the centrifugal spray drying system through a pump and a pipeline.

Technical Field

The invention relates to the technical field of resource recovery and utilization processes, in particular to a method and a device for purifying and drying ammonium sulfate solution which is a byproduct of ammonium lead plaster desulphurization.

Background

In the secondary lead industry, lead plaster is the most difficult to treat and the highest content of components in waste lead-acid storage batteries, and accounts for 35% -45% in a pregnant solution battery and 55% -65% in a barren solution battery. The traditional method is to convert the lead-containing substance in the lead plaster into reduced lead by pyrometallurgy at high temperature (1100-1200 ℃). However, high-temperature smelting needs to consume a large amount of energy, auxiliary materials and equipment investment, the lead recovery rate is low, a large amount of waste residues are generated, the production environment is relatively severe, the content of sulfur dioxide in flue gas is high, and the environment is greatly threatened. With the development of the technology and the support of national policy, the wet-fire combined smelting becomes one of the important technical processes for recovering waste lead plaster, and the technology firstly carries out wet pre-desulfurization on the lead plaster and then carries out low-temperature smelting (about 900 ℃). Mainly taking sodium carbonate as a desulfurizing agent, converting lead sulfate in the lead plaster into lead carbonate by a wet method, and then smelting and recovering lead by a pyrogenic process; the pre-desulfurization byproduct is sodium sulfate solution, and sodium sulfate is prepared after purification and crystallization. The purification method of heavy metals in sodium sulfate solution is usually purification and crystallization, so that heavy metal ions are continuously concentrated and enriched in an evaporation crystallizer, and the quality of sodium sulfate products is continuously reduced. Meanwhile, the additional value of the by-product sodium sulfate is not high, the sodium sulfate is difficult to sell, and even related units need to be entrusted with the treatment in the form of solid waste, so that the economic benefit of lead plaster recycling is reduced to a certain extent.

Aiming at the defects of the sodium carbonate method pre-desulfurization, the inventor develops an ammonium method pre-desulfurization technology, adopts ammonium bicarbonate as a desulfurizer, and produces a byproduct of ammonium sulfate. The ammonium sulfate is mainly used as a fertilizer, is suitable for various soils and crops, can also be used in the aspects of textile, leather, medicine and the like, and has better economic benefit. However, the ammonium sulfate solution generated by ammonium desulfurization contains more heavy metal impurities and more types of heavy metals, and the purification treatment of the ammonium sulfate solution to obtain high-purity ammonium sulfate becomes a very important link in the pre-desulfurization process. At present, for a purification method of ammonium sulfate solution, which is a byproduct of ammonium lead plaster desulfurization, a patent with application number of CN201811535603.6 is proposed by my company in 2018, 12 and 14 months. In a patent with application number CN201811535603.6, which is proposed by my company in 2018, 12, month and 14, ammonia water has a large smell, redundant ammonium sulfide is easy to generate hydrogen sulfide during neutralization, mother liquor is continuously circulated, corrosive ions are continuously accumulated, the service life of equipment is influenced, the salt discharge quality of ammonium sulfate is influenced, and customers cannot accept the ammonium sulfate.

Disclosure of Invention

The invention aims to: provides a method and a device for purifying and drying ammonium sulfate solution which is a byproduct of ammonium lead plaster desulphurization and has high salt yield quality.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for purifying and drying ammonium sulfate solution which is a byproduct of ammonium lead plaster desulphurization is characterized by comprising the following steps:

step one, fine filtering of desulfurization filtrate: pumping a byproduct ammonium sulfate filtrate generated after the lead plaster is desulfurized into a first bag type filter, filtering fine lead oxide and lead carbonate particles through fine filtration, and then entering a precipitation flocculation reaction tank;

step two, heavy metal precipitation and filtration: quantitatively adding a heavy metal capture agent into the precipitation flocculation reaction tank, stirring for 5-15 minutes, then quantitatively adding a flocculating agent polyacrylamide, stirring for 5-15 minutes, standing for 10-20 minutes, pumping into a filter press to filter precipitated impurities, and then entering into an adjusting tank;

step three, adjusting the pH: neutralizing the excessive ammonium bicarbonate in the regulating tank with dilute sulfuric acid;

step four, further fine filtering: filtering the adjusted filtrate by a second bag filter, and then feeding the filtrate into a purified liquid storage tank;

pumping the ammonium sulfate solution in the purifying solution storage tank into an evaporative crystallization system for evaporative crystallization, separating by a centrifuge to obtain high-purity ammonium sulfate crystals and crystallization mother liquor, continuously feeding the crystallization mother liquor into the evaporative crystallization system, and discharging the mother liquor when the impurity content of the mother liquor is enriched to a certain degree to influence the salt quality and the evaporation performance;

step six, spray drying of mother liquor: and (4) pumping the mother liquor discharged from the middle and outer rows in the step five into a centrifugal spray drying system while the mother liquor is hot, so as to obtain ammonium sulfate crystals with lower purity.

Further, in the second step, a certain amount of diatomite is added at the same time of adding the flocculating agent polyacrylamide.

Further, in the third step, the pH value after neutralization is 4-6.

Furthermore, in the second step, the time for stirring twice is 10 minutes.

Further, the following components are sequentially connected through a pipeline:

the device comprises an ammonium sulfate solution storage tank, a first bag filter, a precipitation flocculation reaction tank, a filter press, an adjusting tank, a second bag filter, a purified ammonium sulfate storage tank, an evaporative crystallization system, a centrifuge mother liquor tank and a centrifugal spray drying system.

Further, the centrifugal spray drying system comprises a spray dryer and a separator.

Furthermore, a precipitator adding device and a flocculant adding device are connected to the precipitation flocculation reaction tank, and discharge ports of the precipitator adding device and the flocculant adding device are connected with the precipitation flocculation reaction tank through pipelines.

Further, ammonium sulfate solution storage tank discharge gate pass through pump, pipeline and first bag filter with deposit flocculation retort and connect, deposit flocculation retort pass through pressure filter and pipeline and regulating tank pipe connection, the regulating tank pipeline pass through pump, pipeline and second bag filter with purify back ammonium sulfate storage tank intercommunication, purify back ammonium sulfate storage tank pass through pump and pipeline with evaporation crystallization system intercommunication, evaporation crystallization system pass through pump and pipeline with centrifuge is connected, centrifuge pass through the pipeline with centrifuge mother liquor tank intercommunication, centrifuge mother liquor tank pass through pump and pipeline respectively with the evaporation knotThe crystal system and the centrifugal spray drying system are communicated。

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

the invention discharges the evaporation mother liquor regularly, avoids the excessive accumulation of corrosive ions in the system and the damage to equipment, prolongs the service life of the equipment, achieves the aims of high-efficiency recycling of resources and clean production, and is environment-friendly and economical.

Drawings

FIG. 1 is a process flow diagram of a purification and drying treatment method of ammonium sulfate solution as a byproduct of ammonium lead plaster desulfurization;

FIG. 2 is a schematic structural diagram of a purification and drying treatment device for a byproduct ammonium sulfate solution generated by ammonium lead plaster desulphurization.

In the drawings: 1. an ammonium sulfate solution storage tank; 2. a precipitant addition device; 3. a first bag filter; 4. a sedimentation flocculation reaction tank; 5. a flocculant addition device; 6. a sulfuric acid addition device; 7. a filter press; 8. a conditioning tank; 9. a purified ammonium sulfate storage tank; 10. an evaporative crystallization system; 11. a centrifuge; 12. centrifuging the mother liquor tank; 13, a spray dryer; 14. a separator; 15. a second bag filter.

Detailed Description

Embodiments of the present invention are further described below with reference to the accompanying drawings.

As shown in FIGS. 1-2, the apparatus of the present invention comprises an ammonium sulfate solution storage tank 1, a precipitant addition apparatus 2, a first bag filter 3, a precipitation flocculation reaction tank 4, a flocculant addition apparatus 5, a sulfuric acid addition apparatus 6, a filter press 7, a conditioning tank 8, a purified ammonium sulfate storage tank 9, an evaporative crystallization system 10, a centrifuge 11, a centrifuge mother liquor tank 12, a spray dryer 13, a separator 14, and a second bag filter 15.

Wherein, ammonium sulfate solution storage tank 1, first bag filter 3, deposit flocculation retort 4, pressure filter 7, adjusting tank 8, second bag filter 15, ammonium sulfate storage tank 9 after purifying, evaporation crystallization system 10, centrifuge 11, centrifugal mother liquor jar 12, spray drier 13 and separator 14 connect gradually through pump and pipeline to centrifugal mother liquor jar 12 still has a pipeline to lead to evaporation crystallization system 10. The sedimentation flocculation reaction tank 4 is also respectively connected with a precipitator adding device 2 and a flocculating agent adding device 5 through pipelines, and the adjusting tank 8 is connected with a sulfuric acid adding device 6 through a pipeline.

The process flow of the invention is as follows:

firstly, pumping a byproduct ammonium sulfate filtrate generated after the lead plaster is desulfurized into a first bag filter 3 from an ammonium sulfate solution storage tank 1, filtering fine lead oxide and lead carbonate particles through fine filtration, and then feeding the fine lead oxide and lead carbonate particles into a precipitation flocculation reaction tank 4.

Secondly, a heavy metal catching agent is quantitatively added into the precipitation flocculation reaction tank 4 through a precipitator adding device 2, then the mixture is stirred for 5-15 minutes, in the embodiment, the optimal stirring time is 10 minutes, the heavy metal catching agent can be fully dissolved into the solution, the time is saved, diatomite can be added as a filter aid in the process, then a flocculating agent polyacrylamide is quantitatively added through a flocculating agent adding device 5, the mixture is stirred for 5-15 minutes, in the embodiment, the optimal stirring time is 10 minutes, the flocculating agent polyacrylamide can be fully dissolved into the solution, the time is saved, then the mixture is statically placed for 10-20 minutes, a filter press 7 is pumped, and the precipitated impurities are filtered and then enter an adjusting tank 8.

Thirdly, dilute sulfuric acid is added into the adjusting tank 8 through a sulfuric acid adding device 6 to neutralize the excessive ammonium bicarbonate in the adjusting tank, and the pH value of the neutralization is 4-6.

Fourthly, the adjusted filtrate in the adjusting tank 8 is filtered by a second bag filter 15 and then enters a purified ammonium sulfate storage tank 9.

Fifthly, pumping the purified ammonium sulfate solution in the ammonium sulfate storage tank 9 into an evaporative crystallization system 10 for evaporative crystallization, and separating by a centrifuge 11 to obtain high-purity ammonium sulfate crystals and crystallization mother liquor. The high-purity ammonium sulfate crystal is mainly used as a fertilizer, is suitable for various soils and crops, can also be used in the aspects of textile, leather, medicine and the like, has good economic benefit, the crystallization mother liquor continuously enters the evaporative crystallization system 10, and when the impurity content of the mother liquor is enriched to a certain degree, and the salt yield quality and the evaporation performance are influenced, the mother liquor is discharged.

Sixthly, pumping the externally discharged mother liquor in the fifth step into a spray dryer 13 while the mother liquor is hot, and then feeding the mother liquor into a separator 14 to obtain ammonium sulfate crystals with lower purity.

The ammonium sulfate product obtained by the method of the invention accords with the superior products of the national standard of ammonium sulfate (GB/T535-.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.