Method for treating lead plaster of waste lead-acid storage battery to recover lead

Abstract

The invention relates to a method for recycling lead by treating lead plaster of a waste lead-acid storage battery, and belongs to the technical field of lead secondary resource recycling. The method comprises the following steps: (1) slurrying lead paste with water to obtain slurry; adding sodium carbonate and sodium sulfite into the slurry, heating and then carrying out reduction-conversion reaction under a certain temperature condition to obtain a reaction mixture containing a lead-containing solid and a liquid phase; (2) carrying out solid-liquid separation on the reaction mixture obtained in the step (1) under the condition that the temperature is not lower than 40 DEG C to obtain a lead-containing solid; (3) drying the lead-containing solid obtained in the step (2) to obtain a dried lead-containing material; and (4) the dried lead-containing material obtained in the step (3) is subjected to high-temperature reduction smelting, and metal lead is obtained. According to the method, a wet process and a pyrogenic process are adopted, the used raw materials such as sodium carbonate, sodium sulfite and pea coal are cheap and easy to obtain, the whole technological process is short, operation is easy, the lead recovery rate is high, and industrial large-scale application and popularization are facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lead secondary resource recycling, and particularly relates to a method for treating and recycling lead from lead paste of waste lead-acid storage battery. BACKGROUND

[0002] In recent years, various new types of batteries such as lithium batteries and nickel-hydrogen batteries have developed very rapidly, but lead-acid storage batteries still account for a large proportion of the storage battery market. A lead-acid storage battery is composed of a shell, a separator, an electrode, lead paste and sulfuric acid. After being used for a period of time, the performance of the lead-acid storage battery is greatly reduced due to the increase of lead sulfate crystals, thereby leading to the scrap of the lead-acid storage battery. A large number of lead-acid storage batteries are scrapped due to the expiration of the service life in China every year. The recycling of lead secondary resources (mainly lead paste) in waste lead-acid storage batteries has important significance and role. For the lead paste of the waste lead-acid storage battery, the lead resources are usually recycled by fire smelting and wet treatment.

[0003] The fire smelting treatment of the lead paste mainly mixes the lead paste with lead concentrate, and then converts the lead paste into lead-rich slag through top blowing and bottom blowing smelting, and then reduces the lead-rich slag to obtain metallic lead by using side blowing reduction technology. The fire smelting requires high temperature in the whole process, and has large energy consumption, and a large amount of SO2 gas is generated in the process, thereby increasing the investment of environmental protection treatment. In addition, considering the economy, it is usually required that the raw materials are sufficient and the scale reaches a certain size to generate benefits.

[0004] There are many wet treatment process schemes, and the more representative ones include ore pulp electrolysis and lead oxide preparation processes. The ore pulp electrolysis has complex equipment and devices, high technical difficulty, and is difficult to be industrialized and popularized. The preparation of lead oxide needs to go through the processes of conversion, reduction, nitric acid leaching, sulfuric acid lead precipitation, caustic soda desulfurization and drying and calcination, so as to prepare lead oxide. The process flow is long, the lead recovery rate is not ideal, a large amount of hazardous waste liquid is generated, the treatment cost is high, and the popularization and application are limited.

[0005] In view of the defects of the current lead paste treatment method, how to provide a recycling method with short process, simple operation, good economy, high lead recovery rate and suitable for industrialized popularization and application has been pursued by the technical personnel in the field. SUMMARY

[0006] To solve or partially solve the problems in the related art, the present application provides a method for treating and recycling lead from lead paste of waste lead-acid storage battery. PbSO4 in the lead paste is converted into PbCO3 by using a wet method, and PbO2 is reduced into PbO at the same time, so that the lead-containing materials in the lead paste are changed into a mixture of PbCO3, PbO and Pb. The mixture of PbCO3, PbO and Pb is reduced by fire at high temperature, and metallic lead is obtained.

[0007] The method for treating and recycling lead from waste lead-acid battery paste comprises the following steps: (1) slurry the lead paste with water to obtain a slurry; add sodium carbonate and sodium sulfite to the slurry, and perform a reduction-conversion reaction at a certain temperature after warming to reduce lead dioxide in the lead paste into lead oxide precipitate and convert lead sulfate into lead carbonate precipitate to obtain a reaction mixture containing lead-containing solids and a liquid phase; Specifically, after adding sodium carbonate and sodium sulfite to the slurry and warming, the following reactions occur: PbSO4+Na2CO3→Na2SO4+PbCO3↓ PbO2+Na2SO3→Na2SO4+PbO↓ The lead-containing solids include PbCO3, PbO, Pb and a small amount of impurities. (2) perform solid-liquid separation on the reaction mixture obtained in step (1) at a temperature not lower than 40°C to obtain lead-containing solids; (3) dry the lead-containing solids obtained in step (2) to obtain dried lead-containing materials; (4) perform high-temperature reduction smelting on the dried lead-containing materials obtained in step (3) to obtain metallic lead.

[0008] Further, the liquid-solid ratio of the lead paste to water in step (1) is 4-5:1, the temperature of the reduction-conversion reaction is 80-95°C, the time is 1-3h, the stirring speed is 200-600rpm, the excess coefficient of Na2CO3 is 1.1-2.0, and the excess coefficient of Na2SO3 is 1.5-3.0.

[0009] Further, the reaction mixture in step (1) is directly subjected to hot filtration without cooling.

[0010] Further, the step of slurry washing the lead-containing solids obtained in step (2) with water is further included, and the liquid-solid ratio of the slurry washing is 5-10:1, the stirring speed is 200-400r / min, and the time is 1-4h.

[0011] Further, the drying temperature in step (3) is 105-200°C, and the drying time is 3-6h.

[0012] Further, the temperature of the high-temperature reduction smelting in step (4) is 1250-1400°C, the time is 6-12h, the reducing agent is coal particles with a particle size of <150μm, and the addition amount of the reducing agent is 1.05-1.5 times the theoretical amount. Specifically, the following reactions occur during the high-temperature reduction smelting: PbCO3→PbO+CO2↑ 2C+O2→2CO PbO + C → Pb + CO↑ PbO + CO → Pb + CO2↑ Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses a wet process to convert PbSO4 in lead paste into PbCO3 and reduce PbO2 to PbO, so that the lead-containing materials in lead paste are converted into a mixture of PbCO3, PbO and Pb. This mixture can be reduced to metallic lead in one step of pyrometallurgical reduction at high temperature. The whole process is short, simple to operate and easy to control, achieving the goals of green environmental protection and high lead recovery rate.

[0013] (2) The present invention adopts a wet process followed by a pyrometallurgical process, which avoids the disadvantages of high energy consumption and large amount of SO2 gas generated by pure pyrometallurgical smelting, which require additional environmental protection treatment, making it more green and environmentally friendly.

[0014] (3) The present invention adopts a wet process followed by a pyrolysis process, which avoids the problems of complex equipment and high technical difficulty in the slurry electrolysis technology in the whole wet process, and the difficulty in industrialization and promotion. At the same time, it avoids the disadvantages of the wet process for preparing lead oxide, which requires conversion, reduction, nitric acid leaching, sulfuric acid precipitation, caustic soda desulfurization, drying and calcination, etc., which are long process, unsatisfactory lead recovery rate, and high environmental protection cost of the large amount of hazardous waste liquid generated.

[0015] (4) The present invention adopts a wet process followed by a fire process. The raw materials used in the process, such as sodium carbonate, sodium sulfite and granular coal, are cheap and readily available. The reagent cost is low. The entire process is short and easy to operate, and the lead recovery rate is high. This method is easy to promote and apply on an industrial scale. Detailed Implementation

[0016] The embodiments of this application will now be described in more detail with reference to the examples. While embodiments of this application are shown in the examples, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0017] Example 1 The method for recycling lead from waste lead-acid battery lead paste mainly includes the following steps: Step 1: Take 200g of lead paste (PbSO4 content 49.69%, PbO2 content 33.94%, PbO content 8.86%, Pb content 2.61%, the remainder being impurities), slurry it with 800ml of water, Na2CO3 excess coefficient 1.5, Na2SO3 excess coefficient 2.0, reaction temperature 80℃, stirring speed 350r / min, reaction time 2h, to obtain mixture I.

[0018] Step 2, the mixture I obtained in step 1 is directly filtered by a vacuum filtration device to obtain precipitate I, the filtering temperature is 65-75℃, the filtering time is 15 min, and no Na2SO4 crystal appears.

[0019] Step 3, 1000 ml of water is added to the precipitate I obtained in step 2, the stirring speed is 300 r / min, and the time is 1 h to obtain mixture II.

[0020] Step 4, the mixture II obtained in step 3 is placed for 1 h, and then filtered by a vacuum filtration device to obtain precipitate II, the filtering time is 30 min, and no Na2SO4 crystal appears.

[0021] Step 5, the precipitate II obtained in step 4 is uniformly dispersed on an evaporating dish, and then dried in a hot air drying oven to obtain material I, the drying temperature is 150℃, and the time is 4 h.

[0022] Step 6, the material I obtained in step 5 is uniformly mixed with coal particles and loaded into a clay crucible, and then placed in a heating furnace for high-temperature reduction smelting, the temperature is 1300℃, the time is 8 h, the reducing agent is coal particles (with a particle size of less than 10 mm), and the addition amount is 1.2 times of the theoretical value of complete reduction.

[0023] It is calculated that the lead recovery rate reaches 96.2% from the lead paste treatment to the obtained lead.

[0024] Example 2 The method for treating and recovering lead from the waste lead-acid battery lead paste mainly includes the following steps: Step 1, 200 g of lead paste (PbSO4 content 49.69%, PbO2 content 33.94%, PbO content 8.86%, Pb content 2.61%, and the rest is impurities) is slurried with 800 ml of water, the Na2CO3 excess coefficient is 1.2, the Na2SO3 excess coefficient is 2.0, the reaction temperature is 90℃, the stirring speed is 350 r / min, and the reaction time is 2 h to obtain mixture I.

[0025] Step 2, the mixture I obtained in step 1 is directly filtered by a vacuum filtration device to obtain precipitate I, the filtering temperature is 65-73℃, the filtering time is 15 min, and no Na2SO4 crystal appears.

[0026] Step 3, 900 ml of water is added to the precipitate I obtained in step 2, the stirring speed is 300 r / min, and the time is 1 h to obtain mixture II.

[0027] Step 4, the mixture II obtained in step 3 is placed for 1 h, and then filtered by a vacuum filtration device to obtain precipitate II, the filtering time is 30 min, and no Na2SO4 crystal appears.

[0028] Step 5, the precipitate II obtained in Step 4 is uniformly dispersed on an evaporation dish, and dried in a hot air drying oven to obtain material I, the drying temperature is 160℃, and the drying time is 6h.

[0029] Step 6, the material I obtained in Step 5 is uniformly mixed with coal particles and loaded into a clay crucible, and placed in a heating furnace for high-temperature reduction smelting, the temperature is 1350℃, the time is 8h, the reducing agent is coal particles (the particle size is <10mm), and the addition amount is 1.2 times of the complete reduction theoretical value.

[0030] It is calculated that the lead recovery rate reaches 95.24% from the lead paste treatment to obtain the metal lead.

[0031] Example 3 The method for treating and recovering lead from the waste lead-acid battery lead paste mainly includes the following steps: Step 1, take 200g of lead paste (PbSO4 content 49.69%, PbO2 content 33.94%, PbO content 8.86%, Pb content 2.61%, and the rest is impurities), slurry with 1000ml of water, Na2CO3 excess coefficient 1.5, Na2SO3 excess coefficient 2.5, reaction temperature 95℃, stirring speed 350r / min, reaction time 2h, to obtain mixture I.

[0032] Step 2, the mixture I obtained in Step 1 is directly filtered by a vacuum filtration device to obtain a precipitate I, the filtering temperature is 75-82℃, the filtering time is 15min, and no Na2SO4 crystal appears.

[0033] Step 3, 1200ml of water is added to the precipitate I obtained in Step 2, the stirring speed is 300r / min, and the time is 1h to obtain mixture II.

[0034] Step 4, the mixture II obtained in Step 3 is placed for 1h, and filtered by a vacuum filtration device to obtain a precipitate II, the filtering time is 40min, and no Na2SO4 crystal appears.

[0035] Step 5, the precipitate II obtained in Step 4 is uniformly dispersed on an evaporation dish, and dried in a hot air drying oven to obtain material I, the drying temperature is 180℃, and the drying time is 5h.

[0036] Step 6, the material I obtained in Step 5 is uniformly mixed with coal particles and loaded into a clay crucible, and placed in a heating furnace for high-temperature reduction smelting, the temperature is 1290℃, the time is 10h, the reducing agent is coal particles (the particle size is <10mm), and the addition amount is 1.4 times of the complete reduction theoretical value.

[0037] It is calculated that the lead recovery rate reaches 97.02% from the lead paste treatment to obtain the metal lead.

[0038] Example 4 The method for treating and recycling lead from waste lead-acid battery paste mainly comprises the following steps: Step 1, take 200g of lead paste (PbSO4 content 49.69%, PbO2 content 33.94%, PbO content 8.86%, Pb content 2.61%, and the rest is impurities), slurry with 900ml water, Na2CO3 excess coefficient 1.5, Na2SO3 excess coefficient 2.0, reaction temperature 95℃, stirring speed 400r / min, reaction time 2.5h, to obtain mixture I.

[0039] Step 2, the mixture I obtained in step 1 is directly filtered with a vacuum filtration device to obtain precipitate I, the filtration temperature is 77-75℃, the filtration time is 15min, and no Na2SO4 crystal appears.

[0040] Step 3, add 1500ml water to the precipitate I obtained in step 2, stir at a speed of 300r / min for 1.5h to obtain mixture II.

[0041] Step 4, the mixture II obtained in step 3 is left to stand for 2h, and then filtered with a vacuum filtration device to obtain precipitate II, the filtration time is 50min, and no Na2SO4 crystal appears.

[0042] Step 5, evenly disperse the precipitate II obtained in step 4 on an evaporating dish, and dry in a hot air drying oven to obtain material I, the drying temperature is 160℃, and the time is 4h.

[0043] Step 6, mix the material I obtained in step 5 with coal particles uniformly and load into a clay crucible, and place it in a heating furnace for high-temperature reduction smelting, the temperature is 1380℃, the time is 10h, the reducing agent is coal particles (the particle size is <10mm), and the amount of addition is 1.5 times of the theoretical value of complete reduction.

[0044] It is calculated that the lead recovery rate reaches 97.2% from the treatment of lead paste to the obtained lead metal.

[0045] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications, or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A method for treating and recycling lead from waste lead-acid battery lead paste, characterized in that, Includes the following steps: (1) The lead paste is slurried with water to obtain a slurry; sodium carbonate and sodium sulfite are added to the slurry, and after heating, a reduction-conversion reaction is carried out under certain temperature conditions to reduce the lead dioxide in the lead paste to lead oxide precipitate and convert lead sulfate to lead carbonate precipitate, so as to obtain a reaction mixture containing lead solid and liquid phase. (2) The reaction mixture obtained in step (1) is subjected to solid-liquid separation at a temperature not lower than 40°C to obtain lead-containing solid; (3) The lead-containing solid obtained in step (2) is dried to obtain a dried lead-containing material; (4) The dry lead-containing material obtained in step (3) is subjected to high-temperature reduction smelting to obtain metallic lead.

2. The method for treating and recovering lead from waste lead-acid battery lead paste according to claim 1, characterized in that, In step (1), the liquid-solid ratio of lead paste to water is 4-5:1, the temperature of the reduction-conversion reaction is 80-95℃, the time is 1-3h, the stirring speed is 200-600rpm, the excess coefficient of Na2CO3 is 1.1-2.0, and the excess coefficient of Na2SO3 is 1.5-3.

0.

3. The method for treating and recovering lead from waste lead-acid battery lead paste according to claim 1, characterized in that, The reaction mixture in step (1) is directly subjected to hot filtration without cooling.

4. The method for treating and recovering lead from waste lead-acid battery lead paste according to claim 1, characterized in that, It also includes a step of adding water to wash the lead-containing solid obtained in step (2), and the liquid-solid ratio during the water washing is 5-10:1, the stirring speed is 200-400r / min, and the time is 1-4h.

5. The method for treating and recovering lead from waste lead-acid battery lead paste according to claim 1, characterized in that, In step (3), the drying temperature is 105-200℃ and the drying time is 3-6h.

6. The method for treating and recovering lead from waste lead-acid battery lead paste according to claim 1, characterized in that, In step (4), the high-temperature reduction smelting temperature is 1250-1400℃, the time is 6-12h, the reducing agent is coal particles with a particle size <150μm, and the amount of reducing agent added is 1.05-1.5 times the theoretical ratio.