A process for treating electrolyte of waste and old liquid-rich lead-acid storage battery

Abstract

The present invention discloses a process for treating electrolytes from waste flooded lead-acid batteries, which relates to the technical field of lead-acid batteries and comprises the following steps: S1, utilizing lead oxide-containing waste generated during the processing of lead-acid batteries to react with electrolytes from waste flooded lead-acid batteries; simultaneously, utilizing the positive and negative active materials of waste lean lead-acid batteries to react with the electrolytes from waste flooded lead-acid batteries in a stainless steel container via a stainless steel stirring paddle, and obtaining crude lead sulfate and a filtrate containing sulfuric acid after filter pressing; S2, converting the crude lead sulfate into lead and analytically pure sulfuric acid, and simultaneously neutralizing the filtrate with slaked lime to obtain calcium sulfate. The present invention greatly improves the resource utilization of waste electrolytes, effectively avoids the occurrence of adverse side reactions, makes the operation simpler and more convenient, greatly simplifies the treatment process, improves treatment efficiency, and significantly reduces investment costs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lead-acid batteries, in particular to a waste liquid-rich lead-acid battery electrolyte treatment process. BACKGROUND

[0002] The service life of lead-acid batteries is generally 1-3 years, and hundreds of millions of tons of waste lead-acid batteries are generated each year; lead-acid batteries can be mainly divided into liquid-rich lead-acid batteries and liquid-poor lead-acid batteries, among which the sulfuric acid of waste liquid-poor lead-acid batteries is adsorbed in the AGM separator and the plate, and no free electrolyte is generated during disassembly and smelting. The electrolyte in the liquid-rich lead-acid battery is in a state of excess, and about 20% of the total weight of the battery will generate waste electrolyte after the waste liquid-rich lead-acid battery is disassembled, and the main component is sulfuric acid with a mass concentration of 16-20%. The main treatment method of the traditional waste electrolyte is to prepare calcium sulfate by direct neutralization of quicklime, and then it is treated as solid waste. Some manufacturers also prepare sodium sulfate products, but all have the disadvantages of high investment cost and incomplete treatment.

[0003] Chinese patent CN 114990327A discloses a method for resource utilization of waste lead-acid battery electrolyte, which proposes "a. First, filter the collected waste lead-acid battery electrolyte through an automatic backwashing surface filter to remove impurities and solid particles; b. Add lead-containing materials to the conversion agent A solution for conversion reaction to obtain mixed slurry B; the lead-containing materials in step b are lead dross or lead paste; c. Add the electrolyte filtered in step a to the mixed slurry B obtained in step b for sulfur fixation reaction, and then perform solid-liquid separation to obtain filtrate C and filter residue D; d. Evaporate and concentrate the filtrate C obtained in step c to regenerate the conversion agent A solution, which is returned to step b for recycling; e. Transport the filter residue D obtained in step c to a lead regeneration smelting system to recover lead and sulfur resources".

[0004] Although the sulfur resources in the waste electrolyte and the lead resources in the lead-containing materials are combined and sent to the lead regeneration smelting system for collaborative treatment with other regenerated materials such as lead paste in the prior art, the treatment effect is improved to a certain extent, and the resource utilization of the waste electrolyte is realized, but the prior art still needs to use the conversion agent A solution for conversion reaction, so as to combine the sulfur resources in the waste electrolyte and the lead resources in the lead-containing materials. The process is complex, time-consuming, and prone to adverse side reactions, which has limited effect on reducing the investment cost. At the same time, the prior art only discloses selecting lead dross or lead paste as lead-containing materials, and the degree of resource utilization of the electrolyte is still limited.

[0005] Therefore, a new technical solution is needed to solve the above technical problems. SUMMARY

[0006] The present application aims to provide a kind of waste liquid-rich lead-acid battery electrolyte processing technology, to solve the technical problems of the present stage waste liquid-rich lead-acid battery electrolyte processing technology proposed in the above background art, its process is complex, long time, and extremely easy to cause adverse side reactions occur, while its for input cost reduction and for the degree of resource utilization of waste electrolyte is also limited.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] A kind of waste liquid-rich lead-acid battery electrolyte processing technology, it includes the following steps:

[0009] S1, the lead oxide containing waste material generated in the process of lead-acid battery processing is reacted with waste liquid-rich lead-acid battery electrolyte, at the same time, the positive and negative active material of waste liquid-poor lead-acid battery is reacted with waste liquid-rich lead-acid battery electrolyte in stainless steel container by the action of stainless steel stirring paddle, after pressure filtration, lead sulfate crude product and filtrate containing sulfuric acid are obtained, wherein the weight ratio of waste liquid-rich lead-acid battery electrolyte and the positive and negative active material of waste liquid-poor lead-acid battery is 0.1-0.5:1, the weight ratio of waste liquid-rich lead-acid battery electrolyte and lead oxide containing waste material is 0.1-1:1, the reaction time of the positive and negative active material of waste liquid-poor lead-acid battery and waste liquid-rich lead-acid battery electrolyte, and the reaction time of lead oxide containing waste material and waste liquid-rich lead-acid battery electrolyte are all 20-60 min;

[0010] S2, lead sulfate crude product is converted into lead and analytical pure sulfuric acid, at the same time, the filtrate is neutralized with slaked lime to obtain calcium sulfate.

[0011] Further, the positive and negative active material of waste liquid-poor lead-acid battery is the positive and negative active material mixture with water content less than 5% formed after crushing, sorting and pressure filtration of the positive and negative active material of disassembled waste liquid-poor lead-acid battery, the positive and negative active material mixture contains 35-45% lead dioxide in mass percentage concentration, and the waste liquid-rich lead-acid battery electrolyte is the sulfuric acid solution contained in disassembled waste liquid-rich lead-acid battery with mass percentage concentration of 16-20%;

[0012] Further, in step S2, the specific operation process of converting lead sulfate crude product into lead and analytical pure sulfuric acid is as follows:

[0013] First, lead sulfate crude product is smelted and reduced to obtain lead and flue gas containing sulfur dioxide;

[0014] Then, the flue gas containing sulfur dioxide is separated and treated, and after purification, pure sulfur dioxide is obtained, and the pure sulfur dioxide is oxidized into sulfur trioxide;

[0015] Finally, the fuming sulfuric acid is diluted by pure water to obtain the analytical pure sulfuric acid after sulfur trioxide is absorbed by concentrated sulfuric acid to form the fuming sulfuric acid.

[0016] Compared with the prior art, the application has the beneficial effects that:

[0017] 1. The treatment process provided by the application realizes the recovery treatment of the waste and old rich-liquid type lead-acid battery electrolyte, and realizes the recovery treatment of the lead oxide-containing waste generated in the lead-acid battery processing process and the positive and negative active materials of the waste and old poor-liquid type lead-acid battery, greatly improving the resource utilization degree of the waste electrolyte, and on this basis, the application only needs to use a stainless steel container and a stainless steel stirring paddle, and the positive and negative active materials of the waste and old poor-liquid type lead-acid battery and the waste and old rich-liquid type lead-acid battery electrolyte can be quickly and completely reacted by using the conductive effect, without using a conversion agent in the reaction process, which effectively avoids the occurrence of adverse side reactions, makes the operation more simple and convenient, greatly simplifies the treatment process, improves the treatment efficiency, and greatly reduces the input cost.

[0018] 2. The treatment reagent for the lead sulfate crude product and the filtrate in the application only needs concentrated sulfuric acid and slaked lime, and the addition amount of the treatment reagent is excessive, which has low accuracy requirement, further reduces the input cost, makes the operation more simple and convenient, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the process flow diagram of the application Figure One ;

[0020] Figure 2 is the process flow diagram of the application Figure Two . DETAILED DESCRIPTION

[0021] The following examples are used to further illustrate the content of the application, and do not limit the application of the application.

[0022] The waste and old rich-liquid type lead-acid battery electrolyte used in the application is obtained by separately collecting the waste electrolyte of the disassembled waste and old rich-liquid type lead-acid battery, and the mass percentage concentration of sulfuric acid is 16-20%.

[0023] The lead oxide-containing waste generated in the lead-acid battery processing process used in the application includes the lead oxide-containing waste generated in the production process of the battery, the refining process of lead, and the preparation process of lead alloy.

[0024] Example 1

[0025] Treatment of waste liquid-rich lead-acid battery electrolyte:

[0026] S1, the positive and negative active material of the disassembled waste liquid-poor lead-acid battery is crushed, sorted and pressure filtered to form a positive and negative active material mixture with water content less than 5%. The main components of the positive and negative active material mixture are lead dioxide, lead oxide, etc., and the mass percentage concentration of lead dioxide is 35-45%;

[0027] S2, 1 part of the positive and negative active material is added to a stainless steel container, 0.1 part of waste liquid-rich lead-acid battery electrolyte is added, and the mixture is fully stirred and ground by a stainless steel stirring paddle for 20-60 min to make it fully react. The following chemical reactions occur during stirring:

[0028] PbO2+2H2SO4+Pb=2PbSO4+2H2O

[0029] PbO+H2SO4=PbSO4+H2O,

[0030] When the sulfuric acid content in the reaction mixture liquid is less than 3%, the reaction is considered complete. The obtained mixture is pressure filtered to obtain lead sulfate crude product (lead-containing solid) and filtrate;

[0031] Experiments have found that when using other materials for the reaction container and stirring paddle, the reaction of PbO2 will be very slow or even unable to proceed normally;

[0032] S3, 1 part of the lead oxide-containing waste material is added to the container, 0.1 part of the waste electrolyte is added, and the mixture is fully stirred and ground by the stirring paddle for 20-60 min to make it fully react. The following chemical reactions occur during stirring:

[0033] PbO+H2SO4=PbSO4+H2O,

[0034] When the sulfuric acid content in the reaction mixture liquid is less than 3%, the reaction is considered complete. The obtained mixture is pressure filtered to obtain lead sulfate crude product (lead-containing solid) and filtrate;

[0035] S4, the lead sulfate crude product obtained in steps S2 and S3 is reduced in a side-blown furnace to obtain reduced lead and flue gas containing high-concentration sulfur dioxide. The flue gas containing sulfur dioxide is separated and treated to obtain pure sulfur dioxide, which is then oxidized to sulfur trioxide. Finally, fuming sulfuric acid is formed by absorbing sulfur trioxide with concentrated sulfuric acid (the amount of concentrated sulfuric acid added is in excess), and the fuming sulfuric acid is diluted with pure water to obtain analytical pure sulfuric acid. The relevant chemical reaction equations are as follows:

[0036] PbSO4+CO=PbO+CO2+SO2

[0037] 2SO2+ O2= 2SO3

[0038] SO3+ H2O = H2SO4;

[0039] S5, after the small amount of sulfuric acid in the filtrate obtained from step S2 and S3 is neutralized to form calcium sulfate using slaked lime (the amount of slaked lime added is excessive), solid-liquid separation is carried out by pressure filtration, the separated solid calcium sulfate can be added to the reduction furnace for use as a flux; the remaining filtrate can be sent to the sewage station for treatment, and by adding flocculants and membrane filtration, etc. to remove heavy metals such as lead to meet the discharge standard requirements, as recycled water.

[0040] Example 2

[0041] Treatment of waste and old liquid-rich lead-acid battery electrolyte:

[0042] The treatment process of this example is consistent with example 1, only the formula amount of waste and old liquid-rich lead-acid battery electrolyte in step S2 and step S3 is different, that is: the formula amount of waste and old liquid-rich lead-acid battery electrolyte in step S2 is 0.3 parts, and the formula amount of waste and old liquid-rich lead-acid battery electrolyte in step S3 is 1 part.

[0043] Example 3

[0044] Treatment of waste and old liquid-rich lead-acid battery electrolyte:

[0045] The treatment process of this example is consistent with example 1, only the formula amount of waste and old liquid-rich lead-acid battery electrolyte in step S2 and step S3 is different, that is: the formula amount of waste and old liquid-rich lead-acid battery electrolyte in step S2 is 0.5 parts, and the formula amount of waste and old liquid-rich lead-acid battery electrolyte in step S3 is 0.55 parts.

Claims

1. A process for treating electrolyte of waste flooded lead-acid batteries, characterized in that: The following steps are involved: S1, using lead oxide-containing waste generated during the lead-acid battery processing process to react with the electrolyte of the waste flooded lead-acid battery, and at the same time, using the positive and negative active materials of the waste barren lead-acid battery to react with the electrolyte of the waste flooded lead-acid battery in a stainless steel container through the action of a stainless steel stirring paddle, and obtaining crude lead sulfate and a filtrate containing sulfuric acid after filter pressing; S2. Convert the crude lead sulfate into lead and analytical grade sulfuric acid. Simultaneously, neutralize the filtrate with slaked lime to obtain calcium sulfate.

2. A process for treating electrolyte of waste flooded lead-acid batteries according to claim 1, characterized in that: In step S1, the weight ratio of the electrolyte of the waste flooded lead-acid battery to the positive and negative active materials of the waste starved lead-acid battery is 0.1-0.5:

1.

3. A process for treating electrolyte of waste flooded lead-acid batteries according to claim 2, characterized in that: The positive and negative active materials of the waste starved lead-acid batteries are a mixture of positive and negative active materials with a water content of less than 5% formed by crushing, sorting and filtering the positive and negative active materials of disassembled waste starved lead-acid batteries.

4. A process for treating electrolyte of waste flooded lead-acid batteries according to claim 3, characterized in that: The positive and negative electrode active material mixture contains lead dioxide with a mass percentage concentration of 35-45%.

5. The electrolyte treatment process for waste flooded lead-acid batteries according to claim 1, characterized in that: In step S1, the weight ratio of the electrolyte of the waste flooded lead-acid battery to the lead oxide-containing waste is 0.1-1:

1.

6. The electrolyte treatment process for waste flooded lead-acid batteries according to claim 1, characterized in that: In step S1, the reaction time of the positive and negative active materials of the waste starved lead-acid battery with the electrolyte of the waste flooded lead-acid battery, and the reaction time of the lead oxide-containing waste with the electrolyte of the waste flooded lead-acid battery are both 20 to 60 minutes.

7. The electrolyte treatment process for waste flooded lead-acid batteries according to claim 1, characterized in that: In step S2, the specific operation process of converting crude lead sulfate into lead and analytical grade sulfuric acid is as follows: First, crude lead sulfate is smelted and reduced to produce lead and flue gas containing sulfur dioxide; Then, the flue gas containing sulfur dioxide is separated and treated to obtain pure sulfur dioxide, which is then oxidized into sulfur trioxide; Finally, concentrated sulfuric acid is used to absorb sulfur trioxide to form fuming sulfuric acid, which is then diluted with pure water to obtain analytical grade sulfuric acid.

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