CN103374658A - Ultrafine lead oxide prepared from desulfurated lead plaster by means of three-stage process and method thereof - Google Patents

Abstract

A kind of superfine lead oxide prepared by desulfurization lead paste three-stage method and its method, including process Acid leaching of desulfurized lead paste: desulfurized lead paste is reacted with acid, and a reducing agent is added at the same time. After the reaction, the solid and liquid are separated to obtain a lead-containing acid solution; process Preparation of lead carbonate: reaction of lead-containing acid solution with sodium carbonate, solid-liquid separation, washing and drying to obtain lead carbonate; process Roasting: After the lead carbonate is roasted, superfine lead oxide is obtained; the superfine lead oxide can be PbO, Pb ₃ O ₄ , or a mixture of the two, the average particle size is less than 2 μm, and the nanocrystalline particle size is less than 500 nm. Compared with the prior art, the beneficial effects of the present invention are: the active material superfine lead oxide powder compound used in the production of storage battery enterprises can be directly prepared, the lead volatilization amount is small, the smoke rate is low, the lead yield is high, the energy consumption is low and No sulfur dioxide pollution etc.

Description

Ultrafine lead oxide prepared by desulfurization lead paste three-stage method and method thereof

technical field

The invention relates to the field of recycling of waste lead-acid batteries, in particular to reclaiming waste lead paste which pollutes the environment from waste lead batteries through wet leaching and low-temperature roasting processes to directly prepare superfine lead powder, which belongs to the technical field of recycled lead production. the

Background technique

Lead has a wide range of uses, and its annual output ranks fourth among nonferrous metals after aluminum, copper, and zinc. With the increase of the number of automobiles, the lead-acid battery industry has developed rapidly, and the amount of waste lead-acid batteries produced every year is constantly increasing. Lead-acid battery is the battery with the largest output and widest application among all kinds of batteries in the world, and its lead consumption accounts for 82% of the total lead consumption in the world. In order to save limited mineral resources and avoid environmental pollution caused by waste lead materials, the recycling and utilization of waste lead materials are attached great importance both at home and abroad. The governments of various countries strongly support the research on the production of secondary lead and the new technology of secondary lead production by recovering lead from waste lead-acid batteries. the

Lead-containing materials in waste lead-acid batteries include grids and paste. The composition of the grid is lead alloy, containing 90%-95% lead; the composition of lead paste is complex, mainly composed of PbSO ₄ , PbO ₂ , PbO, Pb and a small amount of impurities, containing 60%-80% lead. The furnace types for waste lead plaster pyromelting mainly include reverberatory furnaces, short rotary furnaces, blast furnaces and other professional furnace types. The content of PbSO ₄ in lead paste is generally more than 50%. The melting point of PbSO ₄ is high, and the temperature for complete decomposition should be above 1000 ℃, which is the main reason for the generation of SO ₂ in the smelting process. At the same time, a large amount of lead volatilization loss is caused at high temperature and polluting lead dust is formed. The lead poisoning of operators caused by the volatilization of lead and its compounds is very serious, and the increase in the amount of smoke and dust caused will inevitably lead to the reduction of the direct yield of lead smelting and the pollution of the lead-containing smoke to the environment. In addition, the energy consumption of pyrometallurgy is also relatively high. The energy consumption of 1 ton of lead produced by small domestic secondary lead factories generally consumes 500-600 kg standard coal, and the energy consumption of domestic professional secondary lead enterprises is 130-310 kg/t. The general level of consumption is below 200 kg/t.

In order to solve the environmental problems caused by pyrothermal smelting, some scholars introduced the electrolytic deposition method (referred to as the electrowinning method) to study the hydrometallurgical process of lead-acid batteries. Representative is the RSR process invented by Prengmann and McDonald. The RSR process can be summarized as (NH ₄ ) ₂ CO ₃ -Na ₂ SO ₃ -H ₂ SiF ₄ three-stage wet electrodeposition process according to the typical reagents used in the desulfurization conversion-reduction conversion-electrowinning dissolution and leaching reaction. In addition, there are other similar paste conversion-leaching-electrodeposition hydrometallurgical processes. Introducing the electrowinning hydrometallurgical recovery process solves the problems of SO ₂ emission and lead volatilization at high temperature in the lead paste pyrometallurgy process. However, this process requires a large investment and is only suitable for the construction of large-scale recycling plants. It consumes a lot of energy, even higher than the traditional pyrometallurgical process. Therefore, the problem of high energy consumption remains to be solved.

Both the current wet process and the advanced live process require desulfurization of the lead paste before electrodeposition or pyromelting. The final product is metallic lead ingots. And most of the metal lead is also made into lead powder for the production of new batteries. the

CN1920065A adopts galena as raw material, obtains PbCl ₂ through leaching and crystallization, adds sulfuric acid to lead chloride solution to prepare lead sulfate, and obtains precursor lead carbonate through chemical synthesis of lead sulfate, and finally prepares β-PbO. CN101573461A uses a mixed solution of citric acid and sodium citrate to process lead plaster to prepare superfine lead oxide. At the same time, more citric acid is consumed, the price is higher, and it is difficult to recover sodium sulfate. CN101514395A adopts oxalic acid reduction, filtration, precipitation reacts with nitric acid, precipitation reacts with ammonium carbonate, filtration, precipitation is also added to nitric acid solution, solution reacts with ammonia water, filtration, precipitation thermal decomposition to obtain lead oxide. The process is relatively complicated, and at the same time, volatile agents such as nitric acid and ammonia water are used in the reaction.

To sum up, how to provide a lead-acid battery lead paste treatment method with perfect process, simple process, resource saving, energy saving and no secondary pollution to the environment has become an important research topic for technicians in this field. the

Contents of the invention

The object of the present invention is to provide an ultra-fine lead oxide prepared by a three-stage desulfurization lead paste method. The ultra-fine lead oxide has an average particle size of less than 2 μm and a nanocrystalline particle size of less than 500 nm. The ultrafine lead oxide can be PbO, Pb ₃ O ₄ , or a mixture of both.

The object of the present invention is also to provide the method that utilizes desulfurization lead paste three-stage method to prepare superfine lead oxide, and this method prepares superfine lead oxide powder by the lead paste after the desulfurization of waste lead-acid battery, and its lead powder purity is high, simultaneously its The production process is simple, there is no or very low environmental pollution, the lead recovery rate is high, and the effect of reducing energy consumption and environmental pollution is remarkable. the

脱硫铅膏酸浸出：脱硫铅膏与酸反应，同时添加还原剂，反应结束后，固液分离，得含铅酸溶液；工序

碳酸铅的制备：含铅酸溶液与碳酸钠反应，反应结束后,固液分离、洗涤、干燥得到碳酸铅；工序

焙烧：碳酸铅经过焙烧后，制得超细氧化铅；本发明所述工序

的还原剂为可溶性无机氧化剂。  The technical solution of the invention is divided into several parts: preparation of desulfurized lead paste, leaching of lead paste, preparation of ultrafine lead carbonate, preparation of ultrafine lead powder and recovery of by-products. Including process

Acid leaching of desulfurized lead paste: desulfurized lead paste is reacted with acid, and a reducing agent is added at the same time. After the reaction, the solid and liquid are separated to obtain a lead-containing acid solution; process

Preparation of lead carbonate: react with lead-containing acid solution and sodium carbonate, after the reaction, separate solid and liquid, wash and dry to obtain lead carbonate; process

Roasting: After the lead carbonate is roasted, superfine lead oxide is obtained; the process described in the present invention

The reducing agent is a soluble inorganic oxidizing agent.

的酸为乙酸或者硝酸；所述含铅酸溶液为乙酸铅或者硝酸铅溶液。  Process of the present invention

The acid is acetic acid or nitric acid; the lead-containing acid solution is lead acetate or lead nitrate solution.

中, 脱硫铅膏与酸的投料比例是脱硫铅膏中的铅与酸的摩尔比例为l:2-5, 优选的是1:2.5；脱硫铅膏与含有酸水溶液的质量比例为1:3-30；优选的是1:10；反应温度为室温-50 ℃；反应时间为0.5-3 h，反应时间优选的是1 h。  The process

Among them, the feeding ratio of desulfurized lead paste and acid is that the molar ratio of lead and acid in the desulfurized lead paste is 1:2-5, preferably 1:2.5; the mass ratio of desulfurized lead paste to acid-containing aqueous solution is 1:3 -30; preferably 1:10; the reaction temperature is room temperature-50°C; the reaction time is 0.5-3 h, and the reaction time is preferably 1 h.

中可溶性无机氧化剂为双氧水，脱硫铅膏中的PbO₂与过氧化氢的摩尔比例为1:1-8，优先1:1.5。  Process of the present invention

The medium-soluble inorganic oxidant is hydrogen peroxide, and the molar ratio of _PbO2 and hydrogen peroxide in the desulfurization lead paste is 1:1-8, preferably 1:1.5.

Process of the present invention In the lead-containing acid solution, add sodium carbonate to react, the molar ratio of lead-containing acid solution and sodium carbonate is 1:1.5-3, the reaction time of lead-containing acid solution and sodium carbonate is 0.1-2 h, preferably 0.5 h, the reaction temperature Room temperature -50°C, while ensuring that the pH of the solution is less than 10.

中的含铅酸溶液，加入碳酸钠反应，可以同时加入含铅酸溶液中的铅重量1-5%的结构导向剂聚乙二醇。  Process of the present invention

The lead-containing acid solution in the solution is added with sodium carbonate to react, and the structure-directing agent polyethylene glycol of 1-5% of the lead weight in the lead-containing acid solution can be added at the same time.

中碳酸铅的焙烧温度为250-500 ℃，焙烧时间为0.5-6 h，最后产物为超细氧化铅。  process

The calcination temperature of medium lead carbonate is 250-500 ℃, the calcination time is 0.5-6 h, and the final product is ultrafine lead oxide.

The desulfurized lead paste products used in the present invention can be PbCO ₃ , Pb ₃ (CO ₃ ) ₂ (OH), Pb ₁₀ O(CO ₃ ) ₆ (OH) ₆ , NaPb ₂ (CO ₃ ) ₂ OH, Pb(OH ) ₂ and unreacted Pb, PbO, PbO ₂ , and possibly a small amount of fully reacted lead sulfate and mixtures thereof.

The ultrafine lead oxide powder (PbO) prepared by the method of the present invention has an average particle size of less than 2 μm, a nanocrystalline particle size of less than 500 nm, a purity of greater than 99.8%, and a lead recovery rate of more than 97% in the entire process. the

All the lead compounds in the desulfurized lead paste of the present invention can react rapidly with acetic acid or nitric acid. During the process of step (1) and (2) leaching and conversion in the process, the filtrate can be continuously reused, and when the sodium acetate reaches a certain level, the sodium acetate can be recovered. the

Compared with the prior art, the beneficial effects of the present invention are: it has the advantages of directly preparing the active material superfine lead oxide powder compound used in the production of storage battery enterprises, the lead volatilization is small, the smoke rate is low, the lead yield is high, the energy consumption is low and No sulfur dioxide pollution and other characteristics. the

Description of drawings

Fig. 1 is the XRD figure of lead carbonate product of the present invention. the

Fig. 2 is the SEM figure of lead carbonate product of the present invention. the

Fig. 3 is the XRD pattern of 320 ℃ ultrafine lead oxide of the present invention. the

Fig. 4 is the SEM image (magnification 5000 times) of 320 ℃ ultrafine lead oxide of the present invention. the

Fig. 5 is the SEM image (magnification 20000 times) of 320 ℃ ultrafine lead oxide of the present invention. the

Fig. 6 is the XRD figure of the ultrafine lead oxide of 450 ℃ of the present invention. the

Figure 7 is a SEM image of the 450°C ultrafine lead oxide of the present invention (magnification 5000 times). the

Figure 8 is a SEM image of the 450°C ultrafine lead oxide of the present invention (magnification 20,000 times). the

Detailed ways

The present invention will be further described below. the

Example 1:

(1) Preparation of desulfurized lead paste

After the waste lead-acid batteries are deacidified, they are crushed, sorted, and sieved to obtain the waste lead plaster; the pretreated waste lead plaster is added to the solution with a desulfurizing agent, and the commonly used desulfurizing agents are sodium carbonate, sodium bicarbonate, and ammonium carbonate. After the desulfurization is completed, solid-liquid separation is carried out.

(2) Preparation of lead acetate solution

Add the desulfurized lead paste of (1) into the acetic acid solution, and the feeding ratio of the desulfurized lead paste to acetic acid is 1:2.5 in the molar ratio of lead in the desulfurized lead paste to acetic acid. ₂ reacted with hydrogen peroxide in a molar ratio of 1:1.5, and after reacting for 0.5 h, filtered and separated to obtain lead acetate solution. The possible reaction equation between desulfurized lead paste and acetic acid solution may be:

PbCO ₃ +2CH ₃ COOH→Pb(CH ₃ COO) ₂ +H ₂ O+ CO ₂ (1)

PbO+2CH ₃ COOH→Pb(CH ₃ COO) ₂ +H ₂ O (2)

PbO ₂ +2CH ₃ COOH +H ₂ O ₂ →Pb(CH ₃ COO) ₂ +2H ₂ O+ O ₂ (3)

Pb ₃ (CO ₃ ) ₂ (OH) ₂ +6CH ₃ COOH→3Pb(CH ₃ COO) ₂ +4H ₂ O+2CO ₂ (4)

Pb ₁₀ O(CO ₃ ) ₆ (OH) ₆ +20CH ₃ COOH→10Pb(CH ₃ COO) ₂ +13H ₂ O+6CO ₂ (5)

NaPb ₂ (CO ₃ ) ₂ OH+5CH ₃ COOH→2Pb(CH ₃ COO) ₂ +H ₂ O+2CO ₂ +Na(CH ₃ COO) (6)

Pb(OH) ₂ +2CH ₃ COOH→Pb(CH ₃ COO) ₂ +2H ₂ O (7)

(3) Preparation of lead carbonate

The sodium carbonate added to the lead acetate solution of (2), the molar ratio of lead and sodium carbonate is 1:1.5, the reaction time is 0.5h, the solid-liquid separation, the obtained lead carbonate, the XRD of lead carbonate is shown in Figure 1, SEM See Figure 2 for the picture.

Pb(CH ₃ COO) ₂ +Na ₂ CO ₃ →PbCO ₃ +2Na(CH ₃ COO) (8)

(4) Preparation of superfine lead powder by roasting

Put the dried lead carbonate in (3) into a roasting furnace and roast at 320 °C for 1 h to obtain an ultrafine lead oxide compound product. See Figure 3 for XRD and Figure 4 and Figure 5 for SEM images.

The ultrafine lead oxide powder (PbO) prepared by the method of the present invention has an average particle size of less than 2 μm, a nanocrystalline particle size of less than 500 nm, a purity of greater than 99.8%, and a lead recovery rate of more than 97% in the entire process. the

Example 2:

Difference with embodiment 1 is: leaching agent is nitric acid, and the molar ratio of the lead in the desulfurization lead paste and nitric acid is that the molar ratio of the lead in the desulfurization lead paste and nitric acid is 1:2.5, add reducing agent hydrogen peroxide simultaneously, the lead in the desulfurization lead paste The molar ratio of PbO ₂ and hydrogen peroxide is 1:1.5 to react, after reacting for 0.5 h, filter and separate to obtain lead nitrate solution. The possible reaction equation between desulfurization lead paste and nitric acid solution may be:

PbCO ₃ +2HNO ₃ →Pb(NO ₃ ) ₂ +H ₂ O+ CO ₂ (9)

PbO+2HNO ₃ →Pb(NO ₃ ) ₂ +H ₂ O (10)

PbO ₂ +2HNO ₃ +H ₂ O ₂ →Pb(NO ₃ ) ₂ +2H ₂ O+ O ₂ (11)

Pb ₃ (CO ₃ ) ₂ (OH) ₂ +6HNO ₃ →3Pb(NO ₃ ) ₂ +4H ₂ O+2CO ₂ (12)

Pb ₁₀ O(CO ₃ ) ₆ (OH) ₆ +20HNO ₃ →10Pb(NO ₃ ) ₂ +13H ₂ O+6CO ₂ (13)

NaPb ₂ (CO ₃ ) ₂ OH+5HNO ₃ →2Pb(NO ₃ ) ₂ +3H ₂ O+2CO ₂ + NaNO ₃ (14)

Pb(OH) ₂ +2HNO ₃ →Pb(NO ₃ ) ₂ +2H ₂ O (15)

Sodium carbonate added to the lead nitrate solution, the molar ratio of lead to sodium carbonate is 1:1.5, the reaction time is 0.5h, and solid-liquid separation is performed to obtain lead carbonate. The reaction equation is 16

Pb(NO ₃ ) ₂ +Na ₂ CO ₃ →PbCO ₃ +2NaNO ₃ (16)

The final product of other substances is ultrafine lead oxide powder, the utilization rate of raw materials is 98.3%, and the yield is 99.0%. Others are the same as in Example 1, and the main process parameters are shown in Table 1.

Example 3:

The difference from Example 1 is that the calcination temperature is 450°C, and finally a red ultrafine lead oxide compound product is obtained. XRD is shown in Figure 6, SEM is shown in Figure 7 and Figure 8, the utilization rate of raw materials is 98.0%, and the yield is 99.2%. . Others are the same as in Example 1, and the main process parameters are shown in Table 1.

Embodiment 4:

The difference from Example 1 is that the dosage of acetic acid during acid leaching is the molar ratio of lead and acetic acid in the desulfurization lead paste is 1:3, the solid-liquid ratio is 1:15 during desulfurization, and finally superfine lead oxide powder is obtained The product has a raw material utilization rate of 98.1%, and a yield of 95.6%. Others are the same as in Example 2, and the main process parameters are shown in Table 1.

Claims (8)

1. a ultra-fine lead oxide that utilizes the preparation of desulfurization lead plaster three-stage process is characterized in that described ultra-fine lead oxide can be PbO, Pb ₃O ₄, perhaps both mixtures, its average grain granularity is less than 2 μ m, and nanocrystalline particle diameter is less than 500 nm.

2. one kind is utilized the desulfurization lead plaster three-stage process to prepare the ultra-fine lead oxide method, it is characterized in that: comprise operation

The desulfurization lead plaster Ore Leaching: desulfurization lead plaster and acid-respons, add simultaneously reductive agent, after reaction finished, solid-liquid separation got leaded acid solution; Operation The preparation of lead carbonate: leaded acid solution and yellow soda ash reaction, solid-liquid separation, washing, drying obtain lead carbonate; Operation Roasting: lead carbonate makes ultra-fine lead oxide through after the roasting; Described operation Reductive agent be solubility inorganic oxidizer.

3. utilize as claimed in claim 2 the desulfurization lead plaster three-stage process to prepare the method for ultra-fine lead oxide, it is characterized in that: described operation

Acid be acetic acid or nitric acid; Described operation

Leaded acid solution be lead acetate or lead nitrate solution.

4. as described in claim 2 or 3, utilize the desulfurization lead plaster three-stage process to prepare the method for ultra-fine lead oxide, it is characterized in that: described operation In, desulfurization lead plaster with acid ingredient proportion be in the desulfurization lead plaster lead with acid molar ratio be l:2-5; Desulfurization lead plaster is 1:3-30 with the mass ratio that contains aqueous acid; Temperature of reaction is room temperature-50 ℃; Reaction times is 0.5-3 h, and the reaction times is 1 h preferably.

5. as described in claim 2 or 3, utilize the desulfurization lead plaster three-stage process to prepare the method for ultra-fine lead oxide, it is characterized in that: operation

Middle solubility inorganic oxidizer is hydrogen peroxide, the PbO in the desulfurization lead plaster ₂With the molar ratio of hydrogen peroxide be 1:1-8, preferential 1:1.5.

6. as described in claim 2 or 3, utilize the desulfurization lead plaster three-stage process to prepare the method for ultra-fine lead oxide, it is characterized in that: operation

In leaded acid solution, add the yellow soda ash reaction, the molar ratio of leaded acid solution and yellow soda ash is 1:1.5-3, leaded acid solution and yellow soda ash reaction times are 0.1-2 h, preferred 0.5 h, temperature of reaction is room temperature-50 ℃.

7. as described in claim 2 or 3, utilize the desulfurization lead plaster three-stage process to prepare the method for ultra-fine lead oxide, it is characterized in that: operation

In leaded acid solution, add the yellow soda ash reaction, add simultaneously the structure directing agent polyoxyethylene glycol of the plumbous weight 1-5% in the leaded acid solution.

8. as described in claim 2 or 3, utilize the desulfurization lead plaster three-stage process to prepare the method for ultra-fine lead oxide, it is characterized in that: operation The maturing temperature of middle lead carbonate is 250-500 ℃, and roasting time is 0.5-6 h, and final product is ultra-fine lead oxide.

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