CN103757254A

CN103757254A - Method for leaching positive pole material of waste nickel-metal hydride battery

Info

Publication number: CN103757254A
Application number: CN201310736496.4A
Authority: CN
Inventors: 龙炳清; 舒曼; 曾伟
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 discloses a method for leaching a positive pole material of a waste nickel-metal hydride battery. The method comprises the steps of putting the positive pole material which is separated from the waste nickel-metal hydride battery and is subjected to roasting pretreatment into a vessel which is resistant to pressure and the corrosion of sulfuric acid, pumping sulfuric acid into the vessel, then, sealing the vessel, pumping a Na2SO3 solution into the vessel by using an injection pump, then, closing a Na2SO3 solution pumping valve, and leaching.

Description

The leaching method of waste nickel-metal hydrogen batteries positive electrode material

Technical field

The present invention relates to a kind of leaching method of waste nickel-metal hydrogen batteries positive electrode material.

Background technology

Nickel metal hydride battery 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.The main nickeliferous and cobalt of waste nickel-metal hydrogen batteries positive electrode material, both total contents are up to 50～70%, have very much a recovery value.The technique that reclaims at present nickel, cobalt from waste nickel-metal hydrogen batteries positive electrode material mainly contains thermal process and wet processing.The product that thermal process obtains is alloy material, the nickel that very difficult acquisition is purer and cobalt.Wet processing becomes more readily available purer nickel and cobalt.Leaching is a requisite process in wet processing.The leaching method of waste nickel-metal hydrogen batteries positive electrode material 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 more expensive reductive agent of sulfuric acid leaching consumption (as hydrogen peroxide etc.), and leaching velocity is slower, and acid consumption is high.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 storage, transportation and the use of industrial pure oxygen 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-metal hydrogen batteries positive electrode material of basic non-environmental-pollution has larger practical value.

Summary of the invention

The problem leaching for current waste nickel-metal hydrogen batteries positive electrode material, 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, basic non-environmental-pollution the leaching method of waste nickel-metal hydrogen batteries positive electrode material, it is characterized in that putting into withstand voltage and container sulfuric acid corrosion resistant by isolate positive electrode material isolated and that obtain through roasting pretreatment from waste nickel-metal hydrogen batteries, 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, 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 positive electrode material of reaction vessel, all metals leach.Na ₂sO ₃add-on be 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, during the waste nickel-metal hydrogen batteries positive electrode material (nickel and cobalt in material be oxide form) of sulfuric acid leaching after roasting pretreatment, there is following main chemical reactions in 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

Due to Na ₂sO ₃reducing power more much better than than the reducing power of hydrogen peroxide of 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 whole reaction is carried out under pressure-fired.

With respect to existing method, outstanding advantages of the present invention is to adopt Na ₂sO ₃make reductive agent and leach waste nickel-metal hydrogen batteries positive electrode material, speed of response is fast, and such as reaction acidity is lower, and the consumption of sulfuric acid and reductive agent is little; In positive electrode material, 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 pressure reactor of 2L that 100g waste nickel-metal hydrogen batteries positive electrode material (nickeliferous 56.4%, cobalt 5.9%) is added to volume, adds the sulfuric acid 850ml of 1.5mol/L, adds Na ₂sO ₃70g (350ml solution), at 40 ℃～50 ℃, 2.5h is leached in airtight stirring (stirring velocity 80r/min), after leaching finishes, carries out liquid-solid separation, obtains 1150ml infusion solution (containing leached mud washing water).The leaching yield of nickel and cobalt be respectively 98.5% and 98.1%(by entering nickel in infusion solution and leached mud washings and cobalt, calculate).

Embodiment 2: it is in the stainless steel pressure reactor of 5L that 500g waste nickel-metal hydrogen batteries positive electrode material (nickeliferous 56.4%, cobalt 5.9%) is added to volume, adds the sulfuric acid 2500ml of 3.0mol/L, adds Na ₂sO ₃380g (1700ml solution), at 70 ℃～80 ℃, 1.0h is leached in airtight stirring (stirring velocity 70r/min), after leaching finishes, carries out liquid-solid separation, obtains 4000ml infusion solution (containing leached mud washing water).The leaching yield of nickel and cobalt be respectively 99.5% and 99.4%(by entering nickel in infusion solution and leached mud washings and cobalt, calculate).

Claims

1. the leaching method of a waste nickel-metal hydrogen batteries positive electrode material, it is characterized in that putting into withstand voltage and container sulfuric acid corrosion resistant by isolate positive electrode material isolated and that obtain through roasting pretreatment from waste nickel-metal hydrogen batteries, 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 positive electrode material of reaction vessel, all metals leach, Na ₂sO ₃add-on be 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.