CN1221052C

CN1221052C - Alkaline leaching of wasted dry battery

Info

Publication number: CN1221052C
Application number: CNB021280037A
Authority: CN
Inventors: 严逊; 严明英; 张尚斌
Original assignee: Chongqing iron and steel research institute; Chongqing Iron and Steel Group Co Ltd
Current assignee: Chongqing iron and steel research institute; Chongqing Iron and Steel Group Co Ltd
Priority date: 2002-12-06
Filing date: 2002-12-06
Publication date: 2005-09-28
Anticipated expiration: 2022-12-06
Also published as: CN1416185A

Abstract

The present invention provides a new alkaline leaching method. The present invention prepares ammonia leaching solution by using ammonia (NH3. H2O), ammonia bicarbonate (NH4HCO3) or ammonia chloride (NH4Cl); zinc crusts of ordinary zinc-manganese dry batteries and calamine cream of alkaline zinc-manganese dry batteries are used as the raw materials of ammonia leaching; air blown in the solution as oxidant; a small amount of cobaltammine or cupric ammine complexes or the combination of the two complexes are added in the ammonia leaching solution as additive. The present invention can greatly enhance the oxidizing leaching speed of zinc for reaching the requirements of industrialization production.

Description

The alkalescence of scrap dry battery leaches

Technical field:

The alkalescence that the present invention relates to the processing of scrap dry battery, particularly scrap dry battery leaches.

Background technology:

The recycling of scrap dry battery worldwide all belongs to a difficult problem, is exactly because two basic problems and why become a difficult problem: the one, and the control of the mercury in the recycling process and harmless treatment, the 2nd, the cost of recycling.Obviously, the cost of recycling depends on the control and the innoxious process for treating of mercury to a great extent.Comparatively promising in numerous processing methods should be the wet treatment technology, because the secondary pollution of mercury relatively easy to control in the wet treatment process, materials such as the zinc in the scrap dry battery, manganese can obtain recycling comparatively simply, make the recycling of scrap dry battery be able to sustainable development.What the most effective application prospect was comparatively wide in wet treatment should be alkaline leaching-out technique, pollution is less because alkalescence leaches, condition is controlled easily, and mercury easily forms the mercury ammino-complex under alkali condition, make mercury not volatile in processing, does not pollute.

In alkalescence leached, adopting ammonia to soak was comparatively effective solution.The ammonia soaking technology is a kind of optionally extract technology, and it can optionally leach zinc, copper, mercury and cadmium in the dry cell.Other component does not then enter ammonia leaching solution, and this just can reach the purpose (such as separating of zinc and manganese dioxide, iron and other nonmetal things) of initial gross separation.By further control techniques, get final product purifying zinc, copper, harmless treatment mercury, cadmium etc.

Yet the leaching of soaking zinc under the condition at ammonia is comparatively difficult, and leaching velocity is very slow, is unfavorable for payable recycling.The leaching of so-called zinc is actually that zinc is oxidized to be dissolved in the ammonia solution, and the key that influences the oxidation dissolution speed of zinc is its oxidation rate.Under ammonia soaks condition, the reaction of zinc and oxygen belongs to " gas-solid-liquid " multinomial reaction, its reactions steps is roughly: the oxygen that enters in the solution spreads to the metal surface, on the metal surface, generate metal oxide then with metal reaction, metal oxide again with solution in ammonia or ammonium hydrogencarbonate reaction generate metal complex and enter solution.Soak under the treatment temperature at the ammonia that adopts usually, the solubility of airborne oxygen in leachate very low (being about 0.004g/l), low oxygen content like this, add the active low of the slow and reactant of the low oxygen diffusion speed that causes of solution temperature, and the heterogeneity of solid metallic in solution, make that the crash response chance of oxygen molecule and metallic atom is relatively low, whole reaction speed is just very slow.As if therefore, oxygen is made oxidant in the ammonia soaking system and test limitation is clearly, and if adopt other oxidant not have economy and can say.

Summary of the invention:

The present invention proposes a kind of alkaline extract technology of zinc, adopts ammoniacal liquor (NH ₃H ₂O), ammonium hydrogencarbonate (NH ₄HCO ₃) or sal-ammoniac (NH ₄Cl) the preparation ammonification soaks solution, the cadmia of common zinc-maganese dioxide dry cell and the calamine cream of alkaline zinc-manganese dioxide dry cell are that ammonia soaks raw material, in solution, blast air as oxidant, soak at ammonia and to add minor amounts of additives in the solution, make the oxidation leaching velocity of zinc increase substantially, reach industrial production requirement.Being added on the additive that ammonia soaks in the solution is the combination of cobalt ammonia complex or cupric ammine complex or these two kinds of complex compounds.The high price complex ion of these two kinds of complex compounds and low price complex ion are evenly distributed in the ammonia leaching solution, and both current potentials are all between the current potential of the metal of aerobicization and oxygen, its high price complex ion is the solid metallic in the oxidation leachate easily, and the low price complex ion after being reduced can be become the high price complex ion by the dioxygen oxidation in the solution at an easy rate, quicken the oxidation rate of metallic zinc thus, improved the leaching velocity of zinc.Obviously, above-mentioned two kinds of complex compounds are actual in leaching process, and what play a part is to deliver oxygen, thereby significantly improves the oxidation leaching velocity of zinc.

Ammonia of the present invention soaks solution, mainly by ammoniacal liquor (NH ₃H ₂O), ammonium hydrogencarbonate (NH ₄HCO ₃) or sal-ammoniac (NH ₄Cl) formulated, can add ammoniacal liquor (NH separately ₃H ₂O), ammonium hydrogencarbonate (NH ₄HCO ₃) or sal-ammoniac (NH ₄The mixture that Cl), also can add above-mentioned two or three material.Wherein, ammonia (NH ₃) addition be 10g/l-150g/l, be advisable with 30g/l-80g/l; Ammonium hydrogencarbonate (NH ₄HCO ₃) addition be 10g/l-100g/l, be advisable with 30g/l-70g/l; Sal-ammoniac (NH ₄Cl) addition is 5g/l-60g/l, is advisable with 10g/l-30g/l.Above-mentioned three kinds of total additions of material are controlled at 50g/l-120g/l and are advisable.

Additive of the present invention mainly is the combination of cobalt ammonia complex or cupric ammine complex or these two kinds of complex compounds, in fact when adding cobalt or copper, might not add with the form of ammino-complex, the ion that can add cobalt or copper is allowed to condition at ammonia and soaks formation cobalt ammonia complex or cupric ammine complex in the solution.Obviously, the ion that adds cobalt or copper can have many kinds of methods, as adding inorganic salts, oxide or the hydroxide etc. of cobalt or copper.Add the ionometer of the content of cobalt ammonia complex or cupric ammine complex with cobalt or copper: the addition of cobalt ions can be 0.01g/l-1.00g/l, is advisable with 0.05g/l-0.80g/l; The addition of copper ion is 0.01g/l-0.90g/l, is advisable with 0.05g/l-0.60g/l.Obviously also can add cobalt or copper ion mixture, its total content is advisable at 0.05g/l-0.80g/l.

Add that ammonia soaks cobalt in the solution or the inorganic salts of copper can be oxalates, sulfate, carbonate or the chloride of cobalt or sulfate, carbonate or the chloride of copper.

Specific embodiments:

The invention will be further described below in conjunction with some examples:

Example one (Comparative Examples):

Raw material is the inner core (only using the calamine cream part) of 10 spent alkaline zinc-maganese dioxide dry cells, and total weight is 33 grams, and wherein mercury content is about 0.2%, and KOH is about 10%, and surplus is zinc and a spot of water.Each material of leachate consists of: NH ₄HCO ₃80g/l; NH ₃, 60g/l; H ₂The about 2000ml of O, the concentration of maintenance ammonia and carbonic hydroammonium in the course of reaction.(air quantity is 0.05m in the normal temperature air blast ³) leach, leaching in the reactor that is reflected at a sealing and carry out, tail gas is derived back dilute sulfuric acid (H ₂SO ₄+ H ₂O) and potassium permanganate (KMnO ₄) absorb.Reaction has been carried out about 150 hours, and the leaching rate of zinc has 5% approximately.Can think and not react basically.

Example two:

Raw material, auxiliary material and reaction condition and process are the same, and different is the cobalt ions (form with cobalt oxalate adds) that adds about 0.10g/l in the reaction beginning forward direction leachate.Reaction has been carried out 24 hours, and the leaching rate of zinc is about 99%, the leaching rate of mercury about 87%.

Example three:

Raw material, auxiliary material and reaction condition and process are the same.Different is the cobalt ions (form with cobalt oxalate adds) that adds about 0.05g/l in the reaction beginning forward direction leachate.Reaction has been carried out 30 hours, and the leaching rate of zinc is about 99%.The leaching rate of mercury about 85%.

Example four:

Raw material is the cadmia of waste and old common zinc-maganese dioxide dry cell, 10, and gross weight 170g, mercurous about 0.02%, leachate condition and reaction condition add the cobalt ions (form with cobalt oxalate adds) of 0.05g/l with 1 in the reaction forward direction leachate.Reaction has been carried out about 24 hours, and the leaching rate of zinc is about 99%, the leaching rate of mercury about 90%.

Example five:

Raw material is the cadmia of waste and old common zinc-maganese dioxide dry cell, 10, and gross weight 170g, mercurous about 0.02%, leachate condition and reaction condition add the copper ion (form with copper sulphate adds) of 0.05g/l with 1 in the reaction forward direction leachate.Reaction has been carried out about 24 hours, and the leaching rate of zinc is about 99%, the leaching rate of mercury about 90%.

By above-mentioned example as can be seen, can improve the oxidation dissolution speed of zinc in ammonia leaching solution greatly behind adding cobalt ammonia complex or the cupric ammine complex, also promptly improve the leaching velocity of zinc greatly, handle the industrialness of scrap dry battery for the ammonia lixiviation process and implement to have created condition.

Claims

1, a kind of scrap dry battery alkalescence leaching method adopts mainly by ammoniacal liquor (NH ₃H ₂O), ammonium hydrogencarbonate (NH ₄HCO ₃) or sal-ammoniac (NH ₄Cl) solution that is mixed with leaches, and the employing air is an oxidant, it is characterized in that: above-mentioned ammonia soak in the solution add cobalt ammonia complex or cupric ammine complex or above-mentioned two kinds of complex compounds combination as additive.

2, according to the described leaching method of claim 1, it is characterized in that: additive cobalt ammonia complex or cupric ammine complex are that the form with inorganic salts, oxide or the hydroxide that adds cobalt or copper adds.

3, according to the described leaching method of claim 1, it is characterized in that: the concentration that ammonia soaks cobalt ions when only adding cobalt complex in the solution is 0.05g/l-0.80g/l; The concentration of copper ion is 0.05g/l-0.60g/l when only adding copper complex; Total ion concentration is 0.05g/l-0.80g/l when adding the two mixture.

4, according to the described leaching method of claim 2, it is characterized in that: add that ammonia soaks cobalt in the solution or the inorganic salts of copper are oxalates, sulfate, carbonate or the chloride of cobalt or sulfate, carbonate or the chloride of copper.