CN1120592A

CN1120592A - Method for extracting zinc and manganese dioxide from waste dry cell

Info

Publication number: CN1120592A
Application number: CN94111199A
Authority: CN
Inventors: 包智香
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-10-08
Filing date: 1994-10-08
Publication date: 1996-04-17

Abstract

The process for extracting Zn and MnO2 from waste dry battery whose Zn and MnO2 contents are over 20% includes roasting, granulating, dissolving, removing Cl and Fe ions and electrolysis and features saving electricity by 60%, decreasing acidic fog by 6 times, high recovery (over 80%) and high quality of products.

Description

Method for extracting zinc and manganese dioxide from waste dry battery

The invention relates to a method for extracting metal zinc and manganese dioxide from waste dry batteries.

China is a big country for producing zinc-manganese dry batteries, the annual consumption is about 75 hundred million, and the batteries are almost thrown away as garbage after being used, so that zinc and manganese dioxide in the dry batteries are wasted, and the dry batteries contain various chemical substances harmful to human beings and can cause environmental pollution. An effective recycling method has not been found so far, and how to recycle is a problem which people are concerned and studied.

The invention aims to provide a method for extracting zinc and manganese dioxide from waste dry batteries, which is suitable for industrial application, so as to solve the problems of environmental pollution and waste of zinc and manganese resources caused by the waste dry batteries.

The purpose of the invention is realized by adopting the following method:

firstly, the collected waste dry batteries are reduced and roasted in an oxygen-deficient container, and granulated after sorting,removing chloride ions and adding waste electrolyte to the pelletsRemoving iron ions, adding Ca (oH) into electrolyte containing zinc sulfate and manganese sulfate₂Or Ba (OH)₂Adjusting the pH value to 3.8-5.2 to obtain Fe⁺³Precipitating with other heavy metal impurity ions, and filtering to remove precipitate; finally, electrolysis is carried out, an aluminum plate is used as a cathode, a lead (silver) alloy or titanium plate is used as an anode, and zinc and manganese dioxide are electrolyzed. The overall reaction formula is: 。

the invention is further described below with reference to the accompanying drawings:

FIG. 1 is a process flow diagram of the present invention: referring to the attached drawings, the process for extracting zinc and manganese dioxide by using the waste dry battery comprises the following steps: 1. reduction roasting, heating the collected waste dry batteries to 550-750 ℃ in an oxygen-deficient container, keeping the temperature for 1-2 hours, continuously stirring the waste dry batteries to ensure that hydrocarbon in the batteries is incompletely combusted, ammonium chloride is sublimated, graphite acetylene is in a red hot state, water is evaporated and vaporized, and the state is very beneficial to the generation of a reduction atmosphere₂MnOOH(manganite) is reduced into soluble MnO under the action of various reducing agents; the zinc compound is decomposed into ZnO, and part of the metal zinc is also H in red heat state₂O，CO₃，NH₃Oxidation to ZnO, Zn₃N₂。

2. Sorting: while sieving the reduced roasted material, removing metallic iron by an electromagnetic method, removing part of zinc (for neutralization), and sorting out carbon rods for recovery.

3. Granulating to remove chloride ion (CL)^-): slowly adding concentrated sulfuric acid into the powder subjected to sorting, continuously stirring to enable the powder to be in a wet granular shape with the weight ratio of ≈ 1: 1, standing for 0.5-1.5 hours, and allowing the concentrated sulfuric acid to be coatedThe powder is fully absorbed and reacted. The main reaction is as follows:

and finally, introducing hot air, continuously stirring, keeping the temperature at 150-250 ℃ for 0.5-2 hours, and then heating to 350-500 ℃ for 20 minutes to 1.5 hours to completely volatilize HCL gas, wherein HCL can be absorbed by water.

4. Dissolving: adding the waste electrolyte into the granules, and continuously stirring to accelerate the dissolution of the sulfate and the reaction until the zinc is completely dissolved and no hydrogen is generated.

The reaction formula is as follows: ；

5. fe with iron removed⁺³: in the solution (apparent Fe)⁺²If necessary, small amounts of oxidizing agents, e.g. KMnO₄) Addition of Ca (OH)₂Or Ba (OH)₂And (3) neutralizing, adjusting the pH value of the solution to be 3.8-5.2, cooling to room temperature, and reacting in the solution as follows:

other impurities in the solution will then react with Fe (OH)₃And (4) co-precipitating, and adding a domestic third coagulant if the sedimentation speed is increased.

6. Purifying and filtering: adding zinc powder into the solution according to the proportion of 50-70 Kg per ton of electrolytic zinc, heating to 45-55 ℃, keeping for 1-1.5 hours, further purifying the solution and filtering.

7. Electrolysis: heating the purified electrolyte to 80 ℃ and putting the electrolyte into an electrolytic cell, using an aluminum plate as a cathode, using a lead-silver alloy or a titanium plate as an anode, wherein the concentration of the electrolyte is as follows: zn: 60 to 1OO g/l, H₂SO₄: 15-60 g/l, electrolyte temperature: 80-95 ℃, current density: 80-12 OA/M²And the cell voltage is 2.6-2.8V, and the cathode and the anode respectively generate the following reactions during electrolysis:

cathode:

anode:

and (3) total reaction:

the results of the electrolysis were: zinc is deposited on a cathode aluminum plate, manganese dioxide is deposited on an anode lead plate, and the deposition ratio is as follows: zn: MnO₂The product has the advantages of ≤ 1: 13, current efficiency of more than 85%, 60% of electricity consumption, 6 times of acid mist reduction, and recovery rate of more than 80% compared with conventional method for separately extracting zinc and manganese dioxide.

The invention has the advantages that: 1. the method has simple process, rich raw materials, low cost and good benefit; 2. the quality of the zinc and the manganese dioxide extracted by the method can reach the national first-grade product standard, and the power consumption is reduced by 60 percent compared with the conventional single extraction; 3. the raw material of the method is the waste dry battery, the utilization of the method not only avoids the pollution of the waste battery to the environment and is beneficial to the health of people, but also recycles the waste zinc and manganese dioxide, changes waste into valuable and saves the resources of nonferrous metals for China.

Claims

1. A method for extracting zinc and manganese dioxide from waste dry batteries is characterized in that: firstly, reducing and roasting the waste dry batteries in an oxygen-deficient container while stirring; screening to detect carbon rods and zinc blocks, and removing iron (Fe) by an electromagnetic method; then concentrated sulfuric acid H is added₂SO₄Slowly adding the powder into the sorted powder, continuously stirring to obtain wet granular powder, and introducing hot air into the placed granular powder for heating to volatilize HCL gas; then adding waste electrolyte to dissolve the granules; then Ca (OH) is added₂Or Ba (OH)₂Neutralizing to ensure that the pH value of the solution is 3.8-5.2; and finally, heating the solution subjected to the displacement and purification treatment by using zinc powder to 80 ℃, putting the solution into an electrolytic bath, carrying out electrolysis simultaneously, and depositing zinc and manganese dioxide on the cathode and the anode respectively.

2. The method of claim 1, wherein: the roasting temperature of the waste dry battery in the oxygen-deficient container is 550-750 ℃ and the roasting time is 1-2 hours.

3. The method of claim 1, wherein: the weight ratio of concentrated sulfuric acid to powder added in the process of granulating and removing chloride ions is 1: 1, hot air is introduced after 0.5-1.5 hours of placement after granulation, the temperature is kept at 150-250 ℃ for 0.5-2 hours, then the temperature is raised to 350-500 ℃ for 20 minutes-1.5 hours, and the HCL gas is completely volatilized.

4. The method of claim 1, wherein: during electrolysis, an aluminum plate is used as a cathode, a lead-silver alloy plate or a titanium plate is used as an anode, and the specific conditions are as follows: electrolyte concentration Zn: 60 to 100 g/l, H₂SO₄: 15-60 g/L; temperature of the electrolyte: 80-95 ℃; current density: 80-120A/M²(ii) a Cell voltage: 2.6-2.8V.