Method for recycling valuable metals in waste lithium ion batteries

Abstract

The invention discloses a method for recycling valuable metals in waste lithium ion batteries. The method comprises the following steps: mixing waste lithium ion batteries with carbon powder, feeding into a rotary kiln for low-temperature reduction roasting, and controlling the roasting temperature to be less than 900 DEG C during low-temperature reduction roasting, so as to obtain a roasting product, wherein the amount of the carbon powder is not greater than 30% of that of the waste lithium ion batteries; mixing the roasting product with a slag former, so as to obtain a mixed material, wherein the mass of the roasting product accounts for at least 10% of that of the mixed material; feeding the mixed material into an electric furnace for smelting, so as to obtain an alloy with valuable metals and slag with CaO and SiO2. The method has the remarkable advantages of simple equipment, low investment operation cost, easiness in popularization, remarkable process energy consumption reduction, high valuable metal recycling rate and the like.

Description

technical field [0001] The invention belongs to the technical field of resource recovery and environmental protection, and in particular relates to a method for recovering valuable metals in lithium ion batteries. Background technique [0002] The recycling process of waste lithium-ion batteries is mainly divided into two categories: wet method and fire method. At present, domestically developed waste lithium-ion battery recycling and treatment technologies are mainly focused on wet treatment processes, and the specific process is "discharge-dismantle-physical sorting-wet leaching-extraction separation and recovery of Co and Ni". This process requires a pretreatment process of mechanically dismantling waste lithium-ion batteries. Due to the risk of explosion safety or the risk of environmental pollution due to the volatilization of organic compounds in this process, dismantling in a protective atmosphere or low-temperature freezing is currently generally used. However, , wh...

AI Technical Summary

Problems solved by technology

This process has the advantages of being able to process various types of battery waste and avoiding the risk of safety explosion and environmental pollution in the process of battery dismantling. However, it uses a special shaft furnace for smelting, and its construction process is complicated and the construction cost is high, which is not conducive to application. to promote

[0004]In addition, four patents (publication numbers CN103370427A, CN103459623A, CN103380218A, CN103459624A) applied by Sumitomo Corporation of Japan proposed a battery pre-disassembly-low temperature oxidation Roasting-high-temperature electric furnace smelting process. Although this method uses mature rotary kiln and electric furnace equipment, it is easy to popularize and apply. However, the rotary kiln roasting process has the following problems: (1) In order to achieve high oxidation of reducing substances in battery materials, The roasting temperature is as high as 1000°C, and the energy consumption is high; (2) The two-stage roasting method can effectively reduce the explosion safety risk of the battery, but it increases the complexity of the equipment

In addition, under the slag-type conditions used in electric furnace smelting, a large amount of reducing substances (aluminum and carbon) need to be oxidized during the roasting stage of the rotary kiln, which makes it impossible to fully utilize the reduction of metal aluminum to generate a large amount of energy during the electric furnace smelting process, resulting in Excessive energy consumption