CN103757378A

CN103757378A - Leaching method of nickel-cadmium waste battery positive-negative electrode mixed material

Info

Publication number: CN103757378A
Application number: CN201310736577.4A
Authority: CN
Inventors: 龙炳清; 刁剑; 曾凡芸
Original assignee: Sichuan Normal University
Current assignee: Sichuan Normal University
Priority date: 2013-12-29
Filing date: 2013-12-29
Publication date: 2014-04-30

Abstract

The invention provides a leaching method of a nickel-cadmium waste battery positive-negative electrode mixed material, which comprises the following steps: putting a positive-negative electrode mixed material subjected to roasting pretreatment separated from nickel-cadmium waste batteries into a pressure-resistant sulfuric-acid-corrosion-resistant container, pumping sulfuric acid into the container, sealing the container, pumping a Na2SO3 solution into the container by using a filling pump, closing the Na2SO3 solution inlet valve, and leaching.

Description

The leaching method of waste nickel-cadmium batteries anode and cathode mixed materials

Technical field

The present invention relates to a kind of leaching method of waste nickel-cadmium batteries anode and cathode mixed materials.

Background technology

Nickel-cadmium cell is the widely used battery of a class, and this battery will produce a large amount of refuse batteries after using and scrapping.Because this class battery contains plurality of heavy metal, if abandon into environment, will environment be produced to very large direct and potential hazard.Waste nickel-cadmium batteries anode and cathode mixed materials is nickeliferous, cobalt and cadmium mainly, and three's total content is up to 60% left and right, has very much a recovery value.Have very much a recovery value.The technique that reclaims at present nickel, cobalt and cadmium from waste nickel-cadmium batteries anode and cathode mixed materials mainly contains thermal process and wet processing.The product that thermal process obtains is alloy material, nickel, cobalt and cadmium that very difficult acquisition is purer.Wet processing becomes more readily available purer nickel, cobalt and cadmium.Leaching is a requisite process in wet processing.The leaching method of waste nickel-cadmium batteries anode and cathode mixed materials mainly contains hydrochloric acid leaching process, sulfuric acid leaching, nitric acid lixiviation process and nitration mixture (sulfuric acid adds nitric acid) lixiviation process at present.Hydrochloric acid leaching process, equipment corrosion is large, the large and contaminate environment of acid mist generation.The oxygenant (as hydrogen peroxide etc.) that sulfuric acid leaching consumption is more expensive.The nitric acid consumption of nitric acid lixiviation process is large, and can produce a large amount of oxynitride, contaminate environment.All there is the problem that improves how economically leaching velocity, raising metal leaching rate, reduces acid consumption and other supplementary product onsumption in all wet processings.Although nitric acid processing industry pure oxygen lixiviation process and nitration mixture processing industry pure oxygen lixiviation process have solved the problems referred to above preferably, but leaching plant is more complicated, and the required industrial pure oxygen amount of refuse battery leaching is little, refuse battery is processed enterprise, and manufacture pure oxygen is personal uneconomical on the spot, and the storage of industrial pure oxygen, transportation and use are cumbersome.Development equipment corrosion is little, leaching velocity is fast, leaching yield is high, acid consumes and other supplementary product onsumption is low, easy to use, the leaching method of the waste nickel-cadmium batteries anode and cathode mixed materials of basic non-environmental-pollution has larger practical value.

Summary of the invention

The problem leaching for current waste nickel-cadmium batteries anode and cathode mixed materials, the object of the invention is to find a kind of metal leaching rate high, leaching velocity is fast, leaching yield is high, acid consumption and other supplementary product onsumption are low, easy to use, need not expensive reductive agent, the leaching method of the waste nickel-cadmium batteries anode and cathode mixed materials of basic non-environmental-pollution, it is characterized in that anode and cathode mixed materials isolated from waste nickel-cadmium batteries and that obtain through roasting pretreatment to put into withstand voltage and container sulfuric acid corrosion resistant, and sulfuric acid is pumped into this container, sealed vessel then, and with injection pump by Na ₂sO ₃solution pumps into container, after this closes Na ₂sO ₃solution pumps into valve and leaches, and after leaching finishes, carries out liquid-solid separation, obtains required infusion solution.Temperature of reaction is 40 ℃～80 ℃, and the sulfuric acid starting point concentration of leaching is 1mol/L～4mol/L, and extraction time is 1h～3h, and leaching process stirs, and stirring velocity is 30r/min～120r/min.Sulphuric acid is to add 110%～150% of sulfuric acid theoretical consumption that in the anode and cathode mixed materials of reaction vessel, all metals leach.Na ₂sO ₃add-on for by positive electrode material all high-valency metals be reduced to the Na of metal at a low price ₂sO ₃105%～120% of theoretical consumption.

The object of the present invention is achieved like this: at airtight and Na ₂sO ₃under the condition existing, after roasting pretreatment, waste nickel-cadmium batteries anode and cathode mixed materials is when (nickel in material, cobalt and cadmium are metal oxide form to sulfuric acid leaching), and following main chemical reactions occurs leaching process:

NiO?+?H ₂SO ₄?=?NiSO ₄?+H ₂O

Ni ₂O ₃?+?2H ₂SO ₄?+?Na ₂SO ₃?=?2NiSO ₄?+?Na ₂SO ₄?+?2H ₂O

CoO?+?H ₂SO ₄?=?CoSO ₄?+?H ₂O

Co ₂O ₃?+?2H ₂SO ₄?+?Na ₂SO ₃?=?2CoSO ₄?+?Na ₂SO ₄?+?2H ₂O

H ₂SO ₄?+?Na ₂SO ₃?=?H ₂SO ₃?+?Na ₂SO ₄

H ₂SO ₄?+?Na ₂SO ₃?=?NaSO ₄?+?SO ₂?+?H ₂O

Ni ₂O ₃?+?H ₂SO ₄?+?H ₂SO ₃?=?2NiSO ₄?+?2H ₂O

Ni ₂O ₃?+?H ₂SO ₄?+?SO ₂?=?2NiSO ₄?+?2H ₂O

Co ₂O ₃?+?H ₂SO ₄?+?H ₂SO ₃?=?2CoSO ₄?+?2H ₂O

Co ₂O ₃?+?2H ₂SO ₄?+?SO ₂?=?2CoSO ₄?+?2H ₂O

CdO?+?H ₂SO ₄?=?CdSO ₄?+?H ₂O

Due to Na ₂sO ₃reducing power more much better than than the reducing power of the hydrogen peroxide generally using in existing leaching method, and need under strong acidic environment, could reduce, can reduce like this acidity of leaching process, the consumption of minimizing sulfuric acid and reductive agent, raising speed of response.Na ₂sO ₃can thoroughly destroy the laminate structure of high oxide in positive electrode material, improve the leaching yield of valuable metal.Na ₂sO ₃with H ₂sO ₄reaction generates H ₂sO ₃and SO ₂, these resultants and Ni ₂o ₃and Co ₂o ₃reaction is consumed, due to SO ₂in the aqueous solution, there is certain solubleness, be released in the SO in reactor upper space ₂less, and along with the carrying out reacting, SO ₂to constantly be consumed, so carry out under pressure-fired in whole reaction.

With respect to existing method, outstanding advantages of the present invention is to adopt Na ₂sO ₃make reductive agent and leach waste nickel-cadmium batteries anode and cathode mixed materials, speed of response is fast, and such as reaction acidity is lower, and the consumption of sulfuric acid and reductive agent is little; In anode and cathode mixed materials, the laminate structure of high oxide is destroyed thoroughly, can improve metal leaching rate; In leach liquor subsequent disposal, do not need to neutralize a large amount of acid, cost is lower; Na ₂sO ₃wide material sources, low price.The waste amount producing in leach liquor subsequent disposal is few, and lower pollution abatement costs, has obvious economic benefit and environmental benefit.

specific implementation method

embodiment 1: it is in the stainless steel cauldron of 1L that 100g waste nickel-cadmium batteries anode and cathode mixed materials (nickeliferous 30.5%, cobalt 1.6%, cadmium 28.1%) is added to volume, adds the sulfuric acid 650ml of 1.5mol/L, adds Na ₂sO ₃37g (180ml solution) stirs (stirring velocity 80r/min) and leaches 2.5h at 40 ℃～50 ℃, after leaching finishes, carries out liquid-solid separation, obtains 800ml infusion solution (containing leached mud washing water).The leaching yield of nickel, cobalt and cadmium be respectively 98.9%, 98.2% and 99.0%(by entering nickel in infusion solution and leached mud washings, cobalt and cadmium, calculate).

Embodiment 2: it is in the stainless steel cauldron of 5L that 500g waste nickel-cadmium batteries anode and cathode mixed materials (nickeliferous 30.5%, cobalt 1.6%, cadmium 28.1%) is added to volume, adds the sulfuric acid 1900ml of 3.0mol/L, adds Na ₂sO ₃200g (900ml solution), at 70 ℃～80 ℃, stir (stirring velocity is 70r/min) and leach 1.0h, after finishing, leaching carries out liquid-solid separation, obtain 2700ml infusion solution (containing leached mud washing water), the leaching yield of nickel, cobalt and cadmium be respectively 99.6%, 99.1% and 99.6%(by the nickel, cobalt and the cadmium that enter in infusion solution and leached mud washings, calculate).

Claims

1. the leaching method of a waste nickel-cadmium batteries anode and cathode mixed materials, it is characterized in that anode and cathode mixed materials isolated from waste nickel-cadmium batteries and that obtain through roasting pretreatment to put into withstand voltage and container sulfuric acid corrosion resistant, and sulfuric acid is pumped into this container, then sealed vessel, and with injection pump by Na ₂sO ₃solution pumps into container, after this closes Na ₂sO ₃solution pumps into valve and leaches, after finishing, leaching carries out liquid-solid separation, obtain required infusion solution, temperature of reaction is 40 ℃～80 ℃, and the sulfuric acid starting point concentration of leaching is 1mol/L～4mol/L, and extraction time is 1h～3h, leaching process stirs, stirring velocity is 30r/min～120r/min, and sulphuric acid is to add 110%～150% of sulfuric acid theoretical consumption that in the anode and cathode mixed materials of reaction vessel, all metals leach, Na ₂sO ₃add-on for by positive electrode material all high-valency metals be reduced to the Na of metal at a low price ₂sO ₃105%～120% of theoretical consumption.