CN1303234C

CN1303234C - Environmental protection method for extracting lead in waste storage battery

Info

Publication number: CN1303234C
Application number: CNB2004100213254A
Authority: CN
Inventors: 李东红; 张正洁; 金重阳; 陈曦; 许增贵
Original assignee: ENVIRONMENT PROTECTION DANGEROUS ARTICLE TREATMENT ENGINEERING TECHNOLOGY (SHENYANG) CENTER
Current assignee: ENVIRONMENT PROTECTION DANGEROUS ARTICLE TREATMENT ENGINEERING TECHNOLOGY (SHENYANG) CENTER; Shenyang Academy Environmental Sciences
Priority date: 2004-03-02
Filing date: 2004-03-02
Publication date: 2007-03-07
Anticipated expiration: 2024-03-02
Also published as: CN1664132A

Abstract

The present invention provides an environmental protection method for extracting lead in a waste storage battery, which solves the technical problems that a reverberatory furnace mixing method is mainly used in China for recovering lead in the waste storage battery, lead dust, lead steam, lead slag, sulphur dioxide, etc., which are generated because of a high temperature cause serious environment pollution and the method has a low lead recovery rate. In foreign countries, a melting method that desulphurization is carried out firstly and then reduction is carried out in a pyrogenic mode is used for recovering lead, and has the disadvantages of larger investment and environment pollution in the working process. The essential points of the present invention comprises preprocessing desulphurization, electrolytic deposition, the recovery of a desulfurizing agent, wherein the desulfurizing agent is sodium carbonate, a reducing agent is sodium nitrite or sodium sulfite. The present invention has the advantages that the integral technological process is carried out in a humid environment at normal temperature; the lead dust, the lead steam, the lead slag and the sulfur dioxide pollution can not be generated; water can be circularly used; simultaneously, lead obtained through electrolysis has the advantages of high purity and large value.

Description

Green lead extraction method for waste storage battery

Technical Field

The invention relates to a method for extracting lead from waste storage batteries.

Background

The recovery of lead from used batteries has been a difficult problem. At present, the domestic method for recovering lead from waste storage batteries is mostly carried out by adopting a reverberatory furnace mixing method, the smelting temperature is high and is about 1200 ℃, lead dust, lead steam, lead slag, sulfur dioxide and the likegenerated at high temperature cause serious pollution to the environment, and meanwhile, the method also has the problem of low recovery rate of a pot, which can only reach about 80 percent generally.

At present, the smelting method of firstly desulfurizing and then reducing by a pyrogenic process is mostly adopted to recover lead abroad, but the method has large equipment investment, needs various equipment such as a blower, a reverberatory furnace, an electric furnace, a converter and the like, and still can favor the environment to pollute the environment in the working process.

Disclosure of Invention

The invention aims to provide a green lead extraction method for waste storage batteries, which can effectively overcome the defects, has simple working equipment and small environmental pollution.

The invention provides a green lead extraction method of waste storage batteries, which comprises the following steps:

1. pretreatment desulfurization

1.1, after acid pouring of the storage battery, cutting off an upper cover by a cutting machine, pouring out a polar plate, washing the polar plate with acid, sending the polar plate to a rod mill, and screening after the rod mill to obtain a grid plate and a filler;

1.2, directly casting a grid plate into a finished alloy ingot, feeding filler into a ball mill, finely grinding the filler to be more than 80 meshes, feeding the filler into a desulfurization reaction kettle for desulfurization, and adding a desulfurizing agent and a reducing agent for desulfurization and reductive conversion;

1.3, filtering the filler by a plate and frame filter after the filler is converted, and recovering the desulfurization solution after 4-6 times of desulfurization of the filtrate.

2. Electrolytic deposition

2.1, using fluorosilicic acid to obtain electrolyte from filter residues in a leaching tank, wherein the leaching conditions are as follows: the temperature is 35-45 ℃, the time is 30-60min, and the ratio (volume ratio) of liquid to solid is 3.0-3.5: 1;

2.2, the electrolyte enters the electrolytic cell through the circulating cell and the elevated tank for electrolysis, and the current density during electrolysis is160-240A/m²The temperature of the electrolyte is 25-45 ℃;

and 2.3, returning the electrolyzed barren electrolyte to the leaching tank for leaching.

3. Recovery of desulfurizing agent

And adding the filtrate obtained by the pretreatment desulfurization into an evaporation kettle for recovery.

Compared with the prior art, the whole process is carried out in a normal-temperature wet environment, lead dust, lead steam, lead slag and sulfur dioxide pollution are avoided, water can be recycled, and lead obtained by electrolysis is high in purity and value.

Drawings

The invention is further described with reference to the following figures and examples.

FIG. 1 is a process flow diagram of a first embodiment of the present invention.

FIG. 2 is a process flow diagram of a second embodiment of the present invention.

Detailed Description

The first embodiment is as follows: see FIG. 1

As shown in fig. 1, the present embodiment includes three parts: pretreatment desulfurization, electrolytic deposition and desulfurizer recovery.

1. Pretreatment desulfurization

1.1 after acid pouring of the storage battery, cutting off an upper cover by a cutting machine, pouring out a polar plate, washing the polar plate with acid, sending the polar plate to a rod mill, and screening after the rod mill to obtain a grid plate and a filler;

1.2 the grid plate is directly casted into finished alloy ingot, the filler enters a ball mill to be finely ground to be larger than 80 meshes, then enters a desulfurization reaction kettle to be desulfurized, a desulfurizing agent and a reducing agent are added to carry out desulfurization and reduction conversion, the desulfurizing agent is sodium carbonate, the reducing agent is sodium nitrite, and the reaction formula is

1.3 after the filler is converted, filtering by a plate and frame filter, and recovering the desulfurization solution after 4-6 times of desulfurization of the filtrate.

2. Electrolytic deposition

2.1 the filter residue is leached in a leaching tank by fluosilicic acid to obtain electrolyte, and the leaching conditions are as follows: the temperature is 35-45 ℃, the time is 30-60min, the ratio (volume ratio) of liquid to solid is 3.0-3.5: 1, and the reaction formula is

2.2 the electrolyte enters the electrolytic cell through the circulation cell and the head tank for electrolysis, and the current density during electrolysis is 160-240A/m²The temperature of the electrolyte is 25-45 ℃;

2.3 returning the electrolyzed barren electrolyte to the leaching tank for leaching.

3. Recovery of desulfurizing agent

Pretreating desulfurization stationThe obtained desulfurization solution is mainly Na₂SO₄By-product Na is recovered in winter₂SO₄·10H₂O, recovery of anhydrous Na in summer₂SO₄。

3.1 in winter, the desulfurizing liquid enters a crystallizing pond and is frozen to be below 0 ℃ under natural conditions, namely Na is contained₂SO₄·10H₂Separating out the O crystal, and returning the solution for use;

3.2 in summer, the desulfurization solution enters an evaporator, is heated to evaporate water, is cooled to 40 ℃ and enters a centrifugal filter to be filtered, and a byproduct of anhydrous Na is obtained₂SO₄。

Example two: see FIG. 2

The difference from the first embodiment is that: in the pretreatment desulfurization stage, sodium sulfite is used as a reducing agent, and the reaction formula is as follows:

PbO₂+Na₂SO₃＝PbO+Na₂SO₄

the rest is the same as the first embodiment.

Claims

1. The green lead extracting method for waste accumulator is characterized by comprising the following steps:

(1) pretreatment desulfurization

(1.1) after acid pouring of the storage battery, cutting off an upper cover by a cutting machine, pouring out a polar plate, washing the polar plate with acid, sending the polar plate to a rod mill, and screening after the rod mill to obtain a grid plate and a filler;

(1.2) directly casting the grid plate into a finished alloy ingot, feeding the filler into a ball mill to be finely ground to be more than 80 meshes, feeding the filler into a desulfurization reaction kettle to be desulfurized, adding a desulfurizing agent sodium carbonate and a reducing agent sodium nitrite to perform desulfurization and reduction conversion, wherein the reaction formula is

；

(1.3) filtering the filler by a plate and frame filter after the filler is converted, and recovering the desulfurization solution after 4-6 times of desulfurization of the filtrate;

(2) electrolytic deposition

(2.1) using fluosilicic acid to obtain electrolyte from filter residue in a leaching tank, wherein the leaching conditions are as follows: the temperature is 35-45 ℃, the time is 30-60min, the ratio of liquid to solid is 3.0-3.5: 1, and the reaction formula is

；

(2.2) the electrolyte enters the electrolytic cell through the circulation cell and the head tank to carry out electrolysis, andthe current density during electrolysis is 160-240A/m²The temperature of the electrolyte is 25-45 ℃;

(2.3) returning the electrolyzed barren electrolyte to a leaching tank for leaching;

(3) recovery of desulfurizing agent