CN103757322A

CN103757322A - Method for leaching positive pole material of waste nickel-metal hydride battery

Info

Publication number: CN103757322A
Application number: CN201310736514.9A
Authority: CN
Inventors: 龙炳清; 李贵; 林春
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 adding the positive pole material which is separated from the waste nickel-metal hydride battery and is subjected to roasting pretreatment, and napier grass powder into a reaction kettle which is resistant to pressure and the corrosion of sulfuric acid and nitric acid, adding a mixed solution of sulfuric acid and nitric acid, and leaching while stirring under closed conditions.

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 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-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 by positive electrode material isolated from waste nickel-metal hydrogen batteries and that obtain through roasting pretreatment and≤the napier grass powder of 1.5mm adds withstand voltage, in the reactor of resistance to sulfuric acid and nitric acid corrosion, the mixing solutions that adds sulfuric acid and nitric acid, and carry out in confined conditions agitation leach.After leaching finishes, carry out liquid-solid separation, obtain required infusion solution.Temperature of reaction is 50 ℃～80 ℃, and the sulfuric acid starting point concentration of leaching is 1mol/L～4mol/L, and the starting point concentration of nitric acid is that 5g/L～10g/L extraction time is 2h～4h, and leaching process stirs, and stirring velocity is 30r/min～120r/min.Sulphuric acid is to add 110%～140% of sulfuric acid theoretical consumption that in the positive electrode material of reaction vessel, all metals leach.The add-on of napier grass powder is counted 60%～75% of nickel in positive electrode material, cobalt total mass with butt.

The object of the present invention is achieved like this: airtight and have under the condition that napier grass powder and nitric acid exists, the waste nickel-metal hydrogen batteries positive electrode material of sulfuric acid leaching after roasting pretreatment is when (nickel and cobalt in material are oxide form), and following main chemical reactions occurs leaching process:

NiO?+?H ₂SO ₄?=?NiSO ₄?+?H ₂O

CoO?+?H ₂SO ₄?=?CoSO ₄?+?H ₂O

nC ₆H ₁₀O ₅?+?nH ₂SO ₄?=n(C ₅H ₁₁O ₅)HSO ₄

n(C ₅H ₁₁O ₅)HSO ₄?+?nH ₂O?=?nC ₆H ₁₂O ₆?+?nH ₂SO ₄

C ₆H ₁₂O ₆?+?8HNO ₃?=?8NO?+?6CO ₂?+?10H ₂O

nC ₆H ₁₀O ₅?+?8nHNO ₃?=?8nNO?+?6nCO ₂?+?9nH ₂O

3Ni ₂O ₃?+?6H ₂SO ₄?+?2NO?=?6NiSO ₄?+?2HNO ₃?+?5H ₂O

3Co ₂O ₃?+?6H ₂SO ₄?+?2NO?=?6CoSO ₄?+?2HNO ₃?+?5H ₂O

Ni ₂o ₃and Co ₂o ₃total reaction be:

12nNi ₂O ₃?+?nC ₆H ₁₀O ₅?+?24nH ₂SO ₄?=?24nNiSO ₄?+?6nCO ₂?+?29nH ₂O

12nCo ₂O ₃?+?nC ₆H ₁₀O ₅?+?24nH ₂SO ₄?=?24nCoSO ₄?+?6nCO ₂?+?29nH ₂O

Other organism in napier grass powder also generates NO, CO with nitric acid reaction ₂and H ₂o, the NO of generation and Ni ₂o ₃and Co ₂o ₃by previous reaction, generate NiSO ₄, CoSO ₄, HNO ₃and H ₂o.

Because the speed of response of nitric acid and napier grass powder is very fast, the NO of generation and Ni ₂o ₃and Co ₂o ₃reaction also very fast, accelerate thus whole leaching process, and realize Ni ₂o ₃and Co ₂o ₃leach more completely.NO can thoroughly destroy the laminate structure of high oxide in positive electrode material, improves the leaching yield of valuable metal.

With respect to existing method, outstanding advantages of the present invention is to adopt napier grass powder to make reductive agent, and nitric acid is made to leach accelerator and leached waste nickel-metal hydrogen batteries positive electrode material, and speed of response is fast, and such as reaction acidity is lower, and the consumption of sulfuric acid and reductive agent is little, and napier grass powder is cheap; 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; The waste amount producing in leach liquor subsequent disposal is few, has reduced pollution abatement costs, has obvious economic benefit and environmental benefit; Process is carried out in confined conditions, the environmental pollution of having avoided NO to overflow and produce.

specific implementation method

embodiment 1: by 100g waste nickel-metal hydrogen batteries positive electrode material (nickeliferous 56.4%, cobalt 5.9%) and≤to add volume be in the lining titanium pressure reaction still of 2L to 1.5mm napier grass powder 37.5g, adding sulfuric acid concentration is the mixed acid solution 850ml that 1.5mol/L, concentration of nitric acid are 5g/L, at 50 ℃～60 ℃, 4.0h is leached in airtight stirring (stirring velocity 80r/min), after leaching finishes, carry out liquid-solid separation, obtain 820ml infusion solution (not containing leached mud washing water).The leaching yield of nickel and cobalt be respectively 98.7% and 98.4%(by entering nickel in infusion solution and leached mud washings and cobalt, calculate).

Embodiment 2: by 500g waste nickel-metal hydrogen batteries positive electrode material (nickeliferous 56.4%, cobalt 5.9%) and≤to add volume be in the lining titanium pressure reaction still of 5L to 1.5mm napier grass powder 230g, adding sulfuric acid concentration is the mixed acid solution 2500ml that 3.0mol/L, concentration of nitric acid are 10g/L, at 70 ℃～80 ℃, 2.0h is leached in airtight stirring (stirring velocity 70r/min), after leaching finishes, carry out liquid-solid separation, obtain 2300ml infusion solution (not containing leached mud washing water).The leaching yield of nickel and cobalt be respectively 99.6% and 99.3%(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 by positive electrode material isolated from waste nickel-metal hydrogen batteries and that obtain through roasting pretreatment and≤the napier grass powder of 1.5mm adds withstand voltage, in the reactor of resistance to sulfuric acid and nitric acid corrosion, the mixing solutions that adds sulfuric acid and nitric acid, and carry out in confined conditions agitation leach, after finishing, leaching carries out liquid-solid separation, obtain required infusion solution, temperature of reaction is 50 ℃～80 ℃, the sulfuric acid starting point concentration leaching is 1mol/L～4mol/L, the starting point concentration of nitric acid is that 5g/L～10g/L extraction time is 2h～4h, leaching process stirs, stirring velocity is 30r/min～120r/min, sulphuric acid is to add 110%～140% of sulfuric acid theoretical consumption that in the positive electrode material of reaction vessel, all metals leach, the add-on of napier grass powder is counted nickel in positive electrode material with butt, 60%～75% of cobalt total mass.