A simple method to extract manganese dioxide from dry batteries

Firstly, the waste dry battery is reduced and roasted in an oxygen-poor container, and stirred while burning;

Then the carbon rod and zinc block were detected by sieve, and the iron (Fe) was removed by electromagnetic method;

Then the concentrated sulfuric acid H2SO4 is slowly added to the powder after sorting and stirring continuously, the powder is in the form of moist granules, and then hot air is introduced into the placed pellets to heat to volatilize the HCl gas; After that, the waste electrolyte is added to dissolve the granules; Ca(OH)2 or BA(OH)2 is then added to neutralize the solution so that the pH value of the solution is 3 8 5 2;Finally, the purified solution is replaced with zinc powder, heated to 80 and placed in the electrolytic cell, and electrolyzed at the same time, and zinc and manganese dioxide are deposited on the cathode and anode respectively.

Knowing that it is already the simplest, it is a standard laboratory method, and I can't think of a simple one. Besides, if it were that simple, waste batteries wouldn't be a public nuisance, right?

The impurities in it mainly include chloride ions, zinc, zinc ions, ammonium ions, and some organic matter precipitation.

Crush the material inside, wash it with water, filter it, repeat it two or three times, wash away water-soluble substances such as chloride ions, zinc ions, ammonium ions, precipitation, etc. to get a crude product.

Mainly using chemical reactions:

1) The dry battery is divided into carbon and alkaline batteries and then crushed, the crushed material can be placed in the leaching tank, and 100-120g l of dilute sulfuric acid is added for leaching to obtain zinc sulfate solution, and then metal zinc is obtained by electrolysis;

2) After separating the copper grease and carbon rod, the remaining manganese dioxide residue and water manganese stone are calcined to obtain manganese dioxide.

Manganese dioxide (found in nature as pyrolite). Physical properties: black amorphous powder, or black orthorhombic crystal. Solubility: insoluble in water, weak acid, weak alkali, nitric acid, cold sulfuric acid, soluble in concentrated hydrochloric acid to produce chlorine.

Acid zinc-manganese dry cell battery.

Negative electrode: zn-2e zn2+

Positive electrode: 2NH4 2E 2NH3 H2

The H2 produced is oxidized by Mno2: H2+2Mno2=Mn2O3+NH3 produced by H2O, which in turn reacts with ZnCl2: Zn2++4NH3=[Zn(NH3)4]2+

The function of starch paste is to increase the migration rate of anions and cations in the two electrodes.

The total reaction formula of the battery: 2Zn+4NH4Cl+4MNO2 [ZN(NH3)4]Cl2+ZNCL2+2MN2O3+2H2O

Manganese dioxide is used as a depolarizing agent.

Hydrogen gas is produced, which adheres to the carbon rods. Due to the large resistance of hydrogen, it occurs when the battery is working"Polarization"--- generates a considerable amount of voltage in the vicinity of the battery, causing the road-end voltage to drop. So manganese dioxide is added to the battery as"Depolarizing agents"）

Alkaline zinc-manganese dry battery in:

Negative electrode reaction Zn+2OH--2E=Zn(OH)2 positive electrode reaction 2mNO2+2H2O+2E=2MnoOH +2OH-total reaction Zn+2mNO2+2H2O=Zn(OH)2+ 2MnoOH manganese dioxide as an oxidant.

Manganese dioxide is the cathode material, that is, the oxidant in the galvanic battery. Because the dry battery is a zinc-manganese battery, it is a galvanic battery with manganese dioxide as the positive electrode, zinc as the negative electrode, and ammonium chloride aqueous solution as the main electrolyte. The reason why it is a dry battery is because the battery uses flour, starch, etc., to make the electrolyte a gel and does not flow.

The total reaction formula of the battery is: 2mNO2 Zn 2NH4Cl 2mNO(OH) Zn(NH3)2Cl2

There are two types of manganese hydroxide:

Dumn(OH)2 and MN(OH)3

mn(oh)2

Consists of soluble manganese salts with hydrogen and oxygen.

Sodium DAO, potassium hydroxide or ammonia are reacted back to prepare:

mnso4+2naoh=mn(oh)2+na2so4mn(oh)3

Manganese dioxide and concentrated sulfuric acid are heated to 383K to form manganese(III) sulfate

4mnO2+6H2SO4 (concentrated) = 2mn2(SO4)3+6H2O+O2 A small amount of sodium hydroxide solution was added to manganese sulfate (III) to prepare Mn(OH)3:

mn2(so4)3+6naoh=2mn(oh)3+3na2so4

1. It is prepared by reduction and roasting of pyromanganese, and the reaction products are cooled under the condition of isolated air.

2. Any other manganese oxide is prepared by heating it in hydrogen.

3. It can also be prepared by manganese hydroxide, manganese carbonate, and air isolation and heating, pay attention to control the reaction conditions, and the products are generally not pure.

Potassium permanganate. After the oxygen is produced, the manganese dioxide is purified.

Steps:1Dissolve the mixture.

2.Filtration. 3.Wash solids.

4.Dry solids.

If the pants are thick, the steps of potassium manganate are.

1.Dissolve the mixture.

2.Filtration. 3.Evaporate the solution.

Coarse salt purification. Steps (there are four steps): four of them use the Glass Brigade Pure Calling Stick.

1.Stir to dissolve.

2.Transfer liquids.

3.Drainage. 4.Stir to prevent liquid from spilling.

a. Jars for containing fiber solid drugs, so A is correct;

B. Take the manganese dioxide solid generic medicine spoon, so B is correct;

c. Suck a small amount of liquid with a rubber head dropper, so C is wrong;

d. The graduated cylinder cannot be used as a reaction vessel, so D is wrong

Therefore, ab is chosen