Method for synergistically recovering platinum / palladium-containing waste catalyst and lead-acid battery waste lead plaster based on ore phase reconstruction

Abstract

The invention relates to the technical field of solid waste recycling, in particular to a method for synergistically recycling a platinum / palladium-containing waste catalyst and lead-acid battery waste lead plaster based on mineral phase reconstruction. The method comprises the following steps: mixing the lead-acid battery waste lead plaster with platinum / palladium-containing waste catalyst powder, then carrying out oxidizing roasting, carrying out mineral phase reconstruction on Pt / Pd metal elementary substances in the platinum / palladium-containing waste catalyst powder by using PbO, PbO2 and Pb components in the lead-acid battery waste lead plaster, converting the Pt or Pd metal elementary substances into a composite oxide which is easily dissolved in hydrochloric acid, and then directly leaching through hydrochloric acid, the sponge platinum / palladium is finally obtained through the steps of ammonium chloride precipitation, ammonia water complexing, hydrochloric acid precipitation, hydrazine hydrate reduction and the like, a basic lead chloride product is obtained after the lead ion leaching solution is precipitated through sodium hydroxide, the recovery rate of Pt or Pd and Pb is 96% or above, the addition of a leaching oxidizing agent and the generation of toxic gas Cl2 are avoided, and the recovery rate is high. Synergistic resource utilization of solid waste is achieved, the process is simple, and industrial application is easy.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource utilization, and in particular to a method for collaboratively recovering waste platinum / palladium-containing catalysts and waste lead paste of lead-acid batteries based on mineral phase reconstruction. Background Art

[0003] At present, the main methods for recovering platinum and palladium from waste catalysts include pyrometallurgy and hydrometallurgy. Pyrometallurgy has problems such as large equipment investment and high energy consumption. Chloride leaching in hydrometallurgy has been the most studied, however, it is often necessary to add strong oxidants such as Cl2, H2O2, HNO3, etc. to promote the dissolution of precious metals such as platinum and palladium in hydrochloric acid solution. The addition of these oxidants will produce toxic and corrosive gases such as Cl2, posing serious risks to production operations and the environment. Therefore, it is particularly important to develop a green recovery process that does not require the addition of oxidants.

[0004] Lead-acid batteries are the most widely used storage batteries in the world with the largest production and market share. With the scarcity of lead resources, the recovery of lead resources in waste lead-acid batteries has become particularly important. In addition, if waste lead-acid batteries are not properly handled, they will also cause serious harm to the environment and human body. If a technical solution can be designed to achieve the joint treatment of lead-acid batteries and waste catalysts containing platinum / palladium and the coordinated recycling of metals, it will be of great technical significance. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The present invention is to mix waste lead paste of lead-acid batteries with waste catalyst powder containing platinum / palladium and then perform oxidative roasting, and then directly leach the roasted product through a hydrochloric acid solution to obtain a leachate containing platinum / palladium and lead ions, and then through ammonium chloride precipitation, ammonia complexation, hydrochloric acid precipitation, hydrazine hydrate reduction and other steps to finally obtain sponge platinum / palladium, and the lead ion leachate is precipitated by sodium hydroxide to obtain a basic lead chloride product.

[0006] To achieve the above object, the present invention adopts the following technical solution: a method for synergistically recovering waste catalyst containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction, comprising the following steps:

[0007] (1) fully mixing the crushed platinum / palladium-containing waste catalyst powder and the crushed lead-acid battery waste lead paste, and then oxidizing and roasting them to obtain a roasted product;

[0008] (2) adding the calcined product into a hydrochloric acid solution for immersion and filtering to obtain a leaching solution containing platinum / palladium and lead ions;

[0009] (3) adding ammonium chloride to the leachate and stirring continuously until no precipitation is generated, and performing solid-liquid separation after standing to obtain a crude platinum / palladium product and a lead-containing leachate;

[0010] (4) adding aqueous ammonia to the crude platinum / palladium product to dissolve it, then adding hydrochloric acid to precipitate it and collecting the filter residue; adding aqueous ammonia to the filter residue to dissolve it again, then adding hydrazine hydrate to reduce it, and filtering it to obtain sponge-like platinum / palladium;

[0011] Sodium hydroxide powder is added to the lead-containing leaching solution and stirred continuously. After standing, solid-liquid separation is performed to obtain solid precipitated basic lead chloride.

[0012] As a further improvement of the method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction:

[0013] Preferably, in step (1), the equipment used for oxidative roasting is a tubular furnace, the gas introduced is air, the temperature of oxidative roasting is 500-900° C., and the time is 1-12 h.

[0014] Preferably, in step (1), the temperature of the oxidative roasting is 600-800° C., and the roasting time is 1-8 hours.

[0015] Preferably, in step (1), the mass ratio of waste platinum / palladium-containing catalyst to waste lead paste of lead-acid batteries is (4-20):1.

[0016] Preferably, in step (1), the mass ratio of waste platinum / palladium-containing catalyst to waste lead paste of lead-acid batteries is (5-10):1.

[0017] Preferably, in step (2), the device used for leaching the hydrochloric acid solution is a water bath or a stainless steel reactor.

[0018] Preferably, in step (2), the concentration of the hydrochloric acid solution is 1-12 mol / L, the leaching temperature is 50-120° C., the leaching time is 1 h-5 h, and the mass ratio of the volume of the hydrochloric acid solution to the roasting product is 10-50 mL / g.

[0019] Preferably, in step (2), the concentration of the hydrochloric acid solution is 3-12 mol / L, the leaching temperature is 80-120° C., the leaching time is 2h-4h, and the mass ratio of the volume of the hydrochloric acid solution to the roasting mixture is 20-50 mL / g.

[0020] Preferably, in step (4), sodium hydroxide powder is added to the lead-containing leachate at a molar ratio of lead ions to sodium hydroxide of (0.5-1.2):1 and stirred continuously for 30-60 minutes, and the solid precipitate obtained after solid-liquid separation is basic lead chloride PbOHCl.

[0021] Preferably, in step (4), the crude platinum / palladium product is ammonium chloroplatinate / ammonium chloropalladate, and ammonia water is added to the ammonium chloroplatinate / ammonium chloropalladate product to dissolve it, and then hydrochloric acid is added to precipitate and the filter residue is collected; ammonia water is added to the filter residue again to dissolve it, and finally hydrazine hydrate is added to reduce it, and sponge-like platinum / palladium is obtained after filtering.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The present invention provides a method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste from lead-acid batteries based on mineral phase reconstruction, wherein " / " represents the meaning of "or". The technical solution comprises the following steps: mixing waste lead paste from lead-acid batteries with waste catalyst powder containing platinum / palladium and then oxidizing and roasting the mixture, and then directly leaching the roasted product through a hydrochloric acid solution to obtain a leachate containing platinum / palladium and lead ions, and then precipitating the mixture through ammonium chloride, complexing with ammonia water, precipitating the mixture through hydrochloric acid, reducing the mixture with hydrazine hydrate, and finally obtaining sponge platinum / palladium. The lead ion leachate is precipitated through sodium hydroxide to obtain a basic lead chloride product.

[0024] The principles of the present invention are as follows: 1) Pb in waste lead paste will be oxidized to PbO2 and Pb3O4 at high temperature, and then further decomposed into stable PbO. PbO2 will also decompose into stable PbO at high temperature; 2) PbO can reconstruct the mineral phase of Pt or Pd, converting the Pt element into composite oxides PbPt2O4 and Pb2PtO4 that are easily soluble in hydrochloric acid, and converting the Pd element into composite oxides PbPdO2 that are easily soluble in hydrochloric acid, thereby promoting the direct leaching of Pt or Pd metal in hydrochloric acid solution; 3) Oxidative roasting removes organic matter and carbon in waste platinum / palladium catalysts, thereby eliminating the agglomeration between platinum / palladium metal particles.

[0025] 2) At present, the dissolution of platinum / palladium metal in hydrochloric acid solution often requires the addition of strong oxidants such as Cl2, H2O2, HNO3, etc. to strengthen it. The addition of these oxidants will produce highly toxic and corrosive gases such as Cl2, which poses a serious risk to production operations and the environment. The most lead-containing and most valuable part of waste lead-acid batteries is waste lead paste, whose main components are lead sulfate (50-60wt%), lead dioxide (20-30wt%), lead oxide (5-15wt%) and single lead (1-2wt%). The method for collaboratively recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction of the present invention utilizes PbO, PbO2 and Pb components in waste lead paste of lead-acid batteries to carry out mineral phase reconstruction of Pt / Pd metal elements in waste catalyst powder containing platinum / palladium, converts Pt or Pd metal elements into composite oxides that are easily soluble in hydrochloric acid, and then directly leaches with hydrochloric acid, thereby avoiding the addition of leaching oxidants such as H2O2 and aqua regia, thereby avoiding the generation of toxic gas Cl2, which is of great significance for alleviating environmental pollution; valuable metals in waste catalysts containing platinum / palladium and waste lead-acid batteries can also be recovered at the same time, thereby realizing collaborative resource utilization of solid wastes. The recovery rates of Pt or Pd and Pb in waste catalysts containing platinum / palladium of the method of the present invention are all above 96%, the process is simple, and it is easy to be industrially applied, and it is a green recovery method. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart for collaboratively recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction as described in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] This embodiment provides a method for collaboratively recovering waste platinum-containing catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction, which specifically comprises the following steps:

[0030] (1) The crushed Pt / Al2O3 waste catalyst powder and the crushed lead-acid battery waste lead paste were fully mixed in a mass ratio of 5:1, placed in a tube furnace, and oxidatively roasted in an air atmosphere at a roasting temperature of 700° C. for 6 h to obtain a roasted product;

[0031] (2) adding the calcined product into the inner tank of a reactor, adding 12 mol / L hydrochloric acid solution according to a mass ratio of the volume of the hydrochloric acid solution to the calcined product of 20 mL / g, immersing at 100° C. for 2 h, and then filtering to obtain a leachate containing platinum and lead ions;

[0032] (3) adding ammonium chloride to the leachate and stirring continuously until no precipitation is generated, and performing solid-liquid separation after standing to obtain ammonium chloroplatinate precipitation and lead-containing leachate;

[0033] (4) adding ammonia water to ammonium chloroplatinate to dissolve it, then adding hydrochloric acid to precipitate it and collecting the residue; adding ammonia water to the residue to dissolve it again, then adding hydrazine hydrate to reduce it, and filtering it to obtain sponge-like platinum;

[0034] According to the molar ratio of lead ion to sodium hydroxide being 1.0, sodium hydroxide powder is added to the lead-containing leaching solution and stirred continuously for 30 minutes. After standing, solid-liquid separation is performed to obtain solid precipitated basic lead chloride.

[0035] Example 2

[0036] This embodiment provides a method for synergistically recovering platinum-containing waste catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The specific steps are referred to in Example 1, except that the mass ratio of Pt / Al2O3 waste catalyst powder to lead-acid battery waste lead paste in step (1) is changed from 5:1 to 20:1. Other conditions are exactly the same as in Example 1.

[0037] Example 3

[0038] This embodiment provides a method for synergistically recovering waste platinum-containing catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The specific steps are referred to in Example 1, with the only difference being that the leaching temperature in step (2) is changed to 80°C, and the other conditions are exactly the same as in Example 1.

[0039] Example 4

[0040] This embodiment provides a method for synergistically recovering waste platinum-containing catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The specific steps are referred to in Example 1, with the only difference being that the leaching time in step (2) is changed to 3 hours, and the other conditions are exactly the same as in Example 1.

[0041] Example 5

[0042] This embodiment provides a method for synergistically recovering waste platinum-containing catalysts and waste lead paste from lead-acid batteries based on mineral phase reconstruction. The specific steps are referred to in Example 1, except that the concentration of the hydrochloric acid solution in step (2) is changed to 9 mol / L. The other conditions are exactly the same as in Example 1.

[0043] Example 6

[0044] This embodiment provides a method for the coordinated recovery of platinum-containing waste catalysts and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The specific steps refer to those of Example 1, with the only difference being that the Pt / Al2O3 waste catalyst in step (1) is replaced with a Pt / C waste catalyst. The other conditions are exactly the same as those of Example 1.

[0045] Example 7

[0046] This embodiment provides a method for collaboratively recovering waste palladium-containing catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction, which specifically comprises the following steps:

[0047] (1) The crushed Pd / Al2O3 waste catalyst powder and the crushed lead-acid battery waste lead paste were fully mixed in a mass ratio of 5:1, placed in a tube furnace, and oxidatively roasted in an air atmosphere at a roasting temperature of 600° C. for 2 h to obtain a roasted product;

[0048] (2) adding the calcined product into the inner tank of a reactor, adding 9 mol / L hydrochloric acid solution according to a mass ratio of the volume of the hydrochloric acid solution to the calcined product of 20 mL / g, immersing at 100° C. for 2 h, and then filtering to obtain a leachate containing palladium and lead ions;

[0049] (3) adding ammonium chloride to the leachate and stirring continuously until no precipitation is generated, and performing solid-liquid separation after standing to obtain ammonium chloropalladate precipitation and lead-containing leachate;

[0050] (4) adding ammonia water to ammonium chloropalladate to dissolve it, then adding hydrochloric acid to precipitate it and collecting the filter residue; adding ammonia water to the filter residue again to dissolve it, then adding hydrazine hydrate to reduce it, and filtering it to obtain sponge-like palladium;

[0051] According to the molar ratio of lead ion to sodium hydroxide being 1.0, sodium hydroxide powder is added to the lead-containing leaching solution and stirred continuously for 30 minutes. After standing, solid-liquid separation is performed to obtain solid precipitated basic lead chloride.

[0052] Example 7

[0053] This embodiment provides a method for the synergistic recovery of palladium-containing waste catalyst and lead-acid battery waste lead paste based on mineral phase reconstruction. The specific steps refer to Example 6, the only difference is that the oxidation roasting temperature in step (1) is changed to 700°C, and the other conditions are exactly the same as in Example 6.

[0054] Example 8

[0055] This embodiment provides a method for the coordinated recovery of palladium-containing waste catalyst and lead-acid battery waste lead paste based on mineral phase reconstruction. The specific steps refer to Example 6, the only difference is that the concentration of the hydrochloric acid solution in step (2) is changed to 3 mol / L, and the other conditions are exactly the same as those in Example 6.

[0056] Example 9

[0057] This embodiment provides a method for the synergistic recovery of palladium-containing waste catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The specific steps refer to those of Example 6, with the only difference being that the leaching temperature of the hydrochloric acid solution in step (2) is changed to 80°C, and the other conditions are exactly the same as those of Example 6.

[0058] Example 10

[0059] This embodiment provides a method for the coordinated recovery of palladium-containing waste catalyst and waste lead paste of lead-acid batteries based on mineral phase reconstruction. The specific steps refer to Example 6, the only difference is that the leaching time of the hydrochloric acid solution in step (2) is changed to 3 hours, and the other conditions are exactly the same as those in Example 6.

[0060] Embodiment 11

[0061] This embodiment provides a method for the coordinated recovery of palladium-containing waste catalyst and lead-acid battery waste lead paste based on mineral phase reconstruction. The specific steps refer to Example 6, the only difference is that the Pd / Al2O3 waste catalyst in step (1) is replaced by Pd / C waste catalyst, and the other conditions are exactly the same as those in Example 6.

[0062] The sponge-like platinum / palladium and basic lead carbonate products obtained in Examples 1-11 were digested and then detected by inductively coupled plasma optical emission spectroscopy (ICP-OES), and the recoveries of Pt / Pd and Pb were calculated. The results are shown in Table 1 below:

[0063] The calculation formula of the recovery rate of metal elements is as follows:

[0064]

[0065] Table 1 Recovery of Pt / Pd and Pb in Examples 1-11

[0066]

[0067] According to Examples 1-12, the method of the present invention for collaboratively recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction can simultaneously recover valuable metals in waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries, thereby realizing collaborative resource utilization of solid wastes. In addition, the method of the present invention for collaboratively recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction, using PbO, PbO2 and Pb components in waste lead paste of lead-acid batteries to perform mineral phase reconstruction on Pt / Pd metal elements in waste catalyst powder containing platinum / palladium, and then directly leaching by hydrochloric acid, can obtain a higher leaching rate of valuable metals, avoid the addition of leaching oxidants such as H2O2 and aqua regia, and thus avoid the generation of toxic gas Cl2, which is of great significance to alleviating environmental pollution.

[0068] Those skilled in the art should understand that the above are only some specific embodiments of the present invention, rather than all embodiments. It should be noted that for those of ordinary skill in the art, many modifications and improvements can be made, and all modifications or improvements that do not exceed the scope of protection of the present invention should be regarded as the scope of protection of the present invention.

Claims

1. A method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction, characterized in that: The following steps are involved: (1) fully mixing the crushed platinum / palladium-containing waste catalyst powder and the crushed lead-acid battery waste lead paste, and then oxidizing and roasting them to obtain a roasted product; (2) adding the calcined product into a hydrochloric acid solution for immersion and filtering to obtain a leaching solution containing platinum / palladium and lead ions; (3) adding ammonium chloride to the leachate and stirring continuously until no precipitation is generated, and performing solid-liquid separation after standing to obtain a crude platinum / palladium product and a lead-containing leachate; (4) adding aqueous ammonia to the crude platinum / palladium product to dissolve it, then adding hydrochloric acid to precipitate it and collecting the filter residue; adding aqueous ammonia to the filter residue to dissolve it again, then adding hydrazine hydrate to reduce it, and filtering it to obtain a sponge-like platinum / palladium; Sodium hydroxide powder is added to the lead-containing leaching solution and stirred continuously. After standing, solid-liquid separation is performed to obtain solid precipitated basic lead chloride.

2. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (1), the equipment used for oxidation roasting is a tubular furnace, the gas introduced is air, the temperature of oxidation roasting is 500-900° C., and the time is 1-12 hours.

3. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (1), the temperature of oxidative roasting is 600-800° C., and the roasting time is 1-8 hours.

4. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (1), the mass ratio of the waste catalyst containing platinum / palladium to the waste lead paste of lead-acid batteries is (4-20):

1.

5. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (1), the mass ratio of waste catalyst containing platinum / palladium to waste lead paste of lead-acid batteries is (5-10):

1.

6. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (2), the device used for leaching the hydrochloric acid solution is a water bath pot or a stainless steel reactor.

7. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (2), the concentration of the hydrochloric acid solution is 1-12 mol / L, the leaching temperature is 50-120° C., the leaching time is 1 h-5 h, and the mass ratio of the volume of the hydrochloric acid solution to the roasted product is 10-50 mL / g.

8. The method for collaboratively recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (2), the concentration of the hydrochloric acid solution is 3-12 mol / L, the leaching temperature is 80-120° C., the leaching time is 2h-4h, and the mass ratio of the volume of the hydrochloric acid solution to the roasting mixture is 20-50 mL / g.

9. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (4), sodium hydroxide powder is added to the lead-containing leachate according to a molar ratio of lead ions to sodium hydroxide of (0.5-1.2):1 and stirred continuously for 30-60 minutes. The solid precipitate obtained after solid-liquid separation is basic lead chloride PbOHCl.

10. The method for synergistically recovering waste catalysts containing platinum / palladium and waste lead paste of lead-acid batteries based on mineral phase reconstruction according to claim 1, characterized in that: In step (4), the crude platinum / palladium product is ammonium chloroplatinate / ammonium chloropalladate, and ammonia water is added to the ammonium chloroplatinate / ammonium chloropalladate product to dissolve it, and then hydrochloric acid is added to precipitate and the filter residue is collected; ammonia water is added to the filter residue again to dissolve it, and finally hydrazine hydrate is added to reduce it, and sponge-like platinum / palladium is obtained after filtering.

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