JPS61261443A - Method for separating and recovering valuables from waste dry battery - Google Patents

Abstract

PURPOSE:To separate and recover iron, zinc, Mn, copper, etc., from waste dry battery advantageously from economic standpoint, by leaching out with sulfuric acid powdery substance composed mainly of oxides of zinc and Mn in which iron and chlorine are removed by magnetic separation and water washing respectively after roasting of waste dry battery and electrolyzing the leached liquid. CONSTITUTION:Waste dry battery is crushed finely by crusher, to expose zinc or MnO2, etc., contg. mercury in dry battery. The crushed powder is roasted by roasting furnace, and mercury is vaporized, cooled and recovered. Calcined slag in which metals excluding mercury are remaining is charged in magnetic separator to separate and recover iron pieces, then sieved to separate and recover brass pieces. The obtd. powdery substance is washed with water to remove chlorine ion, and the powdery substance composed mainly of zinc and MnO2 is obtained. This is leached with sulfuric acid, MnO2 is added to leached liquid to oxidize it and remove iron, and copper is removed by zinc powder substitution method. Electrolysis is carried out using the obtd. leached clean liquid contg. ZnSO4 and MnSO4 as electrolyte, and anode lead plate, cathode Al plate, zinc and MnO2 obtd. at cathode and anode respectively are scraped off and recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for separating and recovering valuable materials such as iron, zinc, manganese, copper, etc. from waste dry batteries efficiently and economically and without harming the environment.

[Prior art]

Conventionally, there have been two types of techniques for separating and recovering the metals that make up waste dry batteries.

■The waste dry battery is roasted to volatilize the mercury contained therein, and then the mercury-containing gas phase is cooled to condense the mercury. A method to recover only mercury.

■ Waste dry batteries are reduced and roasted in the same way as the dry zinc smelting process.
A method to recover only n as metal.

■By roasting waste dry batteries, the volatile mercury is collected by cooling and condensing, and the melted and condensed zinc is separated and collected. The remaining liquid is then roasted again, the iron is separated using magnetic separation, and the remaining powder is wet-processed to recover it as a zinc hydroxide and manganese sulfate solution.

■There was a method to obtain a ferromanganese raw material by roasting waste dry batteries to separate and recover mercury, separating iron and zinc by sieving, and then treating the residue with a chloride roasting method to separate zinc.

[Problem that the invention seeks to solve]

Methods ■ or ■ mentioned in the prior art section are as follows.

The only metals that can be separated and recovered are mercury and zinc; many other metals are not recovered and are discarded.
There are problems in terms of effective use of resources.

On the other hand, methods ① and ① recover most of the main constituent metals of dry batteries.

It requires high-temperature roasting twice, and the process is complicated, which is economically disadvantageous, and the metal recovered once is only a secondary raw material for the metal recovery.

As mentioned above, the conventional technology has problems in terms of effective use of resources, economical processing, and the form of recovered materials.

[Structure of the invention]

The present invention was made for the purpose of separating and recovering the constituent metals, namely iron, zinc, manganese, and copper, from waste dry batteries, and in accordance with this purpose, the present inventors conducted two different types of research. result.

He has made the following inventions that solve problems such as advantageous use of resources, economic efficiency of processing, and added value to recovered materials.

In other words, the waste dry batteries are crushed and then roasted to obtain slag from which mercury has been volatilized and separated. Iron pieces are removed from the sintered slag by magnetic separation, chlorine is removed by washing with water, and zinc and manganese are removed. a separation step to obtain a powder mainly composed of oxides;
A leaching liquid purification process in which powder mainly consisting of zinc and manganese oxides is leached with sulfuric acid, trace amounts of iron and copper are removed from the leached liquid to obtain a liquid containing zinc sulfate and manganese sulfate, and zinc sulfate. We were able to establish a method for separating and recovering valuables from waste dry batteries, which consists of an electrolytic process in which zinc is electrolytically deposited on the cathode and manganese dioxide is electrolytically deposited on the anode from a solution containing manganese sulfate.

The present invention will be described in detail below.

In order to recover the mercury contained in waste dry batteries, first,
The material is pulverized using a crusher to expose zinc or manganese dioxide containing mercury inside the battery. This crushed powder is roasted in a roasting furnace at a temperature between 500°C and 800°C, preferably about 600°C for several hours.

Preferably roast for about 3 hours. At this time, more than 99.9% of the mercury contained in the dry cell volatilizes and transfers to the gas phase.
By cooling this gas phase, mercury can be condensed and recovered. When roasting.

Metals other than mercury remain intact.

The residue obtained from Gongxingang blood roasting includes metal iron pieces and brass pieces. First, a magnetic separator is used to separate and collect the iron pieces as magnetic substances. Next, the brass pieces are separated and collected by sorting using a 2 to 0.5 m+ sieve. The nonmagnetic powder thus obtained is washed with water to remove the chlorine ions contained therein. By efficiently removing chlorine ions, manganese dioxide can be efficiently recovered. Further, consumption of the lead electrode can be prevented. After that, solid-liquid separation is performed by filtration.

A powder containing zinc and manganese oxides as main components can be obtained.

Hawk 1 color group]: The powder obtained in the step separation process is leached with sulfuric acid. The leachate obtained here mainly contains ZnSO4 and MnSO4, but also contains iron and copper as impurities. In the post-process, this iron and copper have a negative effect, so MnO2 is added to adjust the pH to 4.5 to 5.5, and the iron is removed by oxidation to make it trivalent, and the copper is removed by a zinc powder replacement method. , separated and removed from the liquid.

Electrolysis process Electrolysis is performed using the solution containing Zn5O* and Mn5O obtained in the leaching and purification process as an electrolyte. Appropriate electrolysis conditions at this time include a liquid temperature of 80 to 100°C, an anode lead plate, a cathode aluminum plate, an anode current density of 0.5 to 3 A/drrr, and a cathode current density of 1 to IOA/drrr. By electrolysis, zinc is deposited on the cathode and manganese dioxide is simultaneously deposited on the anode. High purity zinc and manganese dioxide can be recovered by periodically stripping these off. Further, in this case, in order to reduce the amount of sludge generated, it is preferable that the amounts of zinc and manganese to be treated are 2 equivalents. The electrolytic zinc is remelted and a trace amount of Mn is removed to obtain an ingot.

〔effect〕

(1) Waste dry batteries can be disposed of in an environmentally friendly manner by using wet methods in many of the processes.

(2) Electrolytic zinc and manganese dioxide can be efficiently obtained in the same electrolytic cell.

(3) In the treatment of waste dry batteries, the batteries are charged so that the zinc and manganese in the treatment solution in the final electrolysis step are equal in amount.

It is possible to reduce the amount of sludge and efficiently obtain electrolytic zinc and manganese dioxide.

〔Example〕

250 g of a mixture of commercially available AA-size manganese dry batteries and alkaline manganese dry batteries (ratio 8:2) was crushed to a maximum particle size of 10 square meters using a rotary shear type crusher. This crushed powder (composition Zn 20%, Mn 13%
, Fe 21%, Cu 1%, (1,16%,
Hg 0.17%) was roasted at 600°C for 3 hours in a rotary kiln. At this time, air was added to the kiln by 0.5 Q.
About 0.3 g of mercury could be solidified and recovered in the form of metal by flowing at a flow rate of /min and cooling the outlet air to room temperature. Furthermore, the outlet air containing trace amounts of mercury can be washed with chlorinated water to extremely reduce the amount of mercury escaping into the outside air (5 μg
/rn') can be controlled.

When the slag obtained here was magnetically separated using a magnetic separator, it weighed 47g.
Got a piece of iron. When further sorted with an Ig sieve,
4 g of brass pieces were obtained on the sieve.

When the powder under the sieve was washed with 3Q of water, the chlorine concentration in the residue decreased from 6% to 0.6%.

By leaching the powder obtained here with 150 mQ of 165 g/Ω sulfuric acid, Zn 60 g/Q, Mn 4
0g/Q, Fe70mg/Q, Cu70
A solution of mg/Q and pH 2 was obtained. This solution contains MnO,
Ig was added and further neutralized to pH 5 with Ca(OH)a to precipitate and remove Fe in the solution. Furthermore, 1 g of zinc powder was added to this solution to reduce and precipitate copper ions dissolved in the solution. As a result, Fe in the liquid,
Both Cu concentrations were below 5■/Q.

Using this solution as an electrolyte, the solution temperature was 90°C and the anode lead plate was used.

Using a cathode aluminum plate, the anode current density IA/d rr
r.

Cathode current density 3A/dn? When electrolyzed, manganese dioxide was used as the anode and zinc was used as the cathode, and the current efficiency was 95%.
and 92% precipitated.

The electrolytic zinc obtained had a high quality of 99.95%.

Furthermore, high-grade manganese dioxide was also obtained. The total amount of impurities in the obtained manganese dioxide was 0.1% or less.

The amount of sludge was also extremely small, resulting in highly efficient electrolysis.

Claims (1)

[Scope of Claims] A roasting step of crushing a waste dry battery and roasting it to obtain slag from which mercury has been volatilized and separated, removing iron pieces from the slag by magnetic separation, and further removing contained chlorine by washing with water. , a separation process to obtain powder mainly composed of oxides of zinc and manganese, leaching the powder mainly composed of oxides of zinc and manganese with sulfuric acid, and removing trace amounts of iron and copper from the leached solution. A leaching liquid purification process to obtain a solution containing zinc sulfate and manganese sulfate, and an electrolysis process in which zinc sulfate and manganese dioxide are electrodeposited on the cathode and manganese dioxide on the anode by electrolysis from the solution containing zinc sulfate and manganese sulfate. A method for separating and recovering valuable materials from waste dry batteries.