Metal recycling method with waste cadmium-nickel battery purified fume

Abstract

The invention relates to a metal recycling method with waste cadmium-nickel battery purified fume, which comprises the steps of obtaining a positive plate, a negative plate, a diaphragm, a battery shell and a lead, shearing the negative plate and the diaphragm into small fragments, cleaning the fragments with water, filtering the cleanout fluids and mixing the filtered cleanout fluids; preparing a SO2 purification fluid by adding the positive fragments into the filtered cleanout fluid, blowing in SO2 fume, adding positive fragments into the purification fluid, stopping blowing in the fume containing SO2 when the solid-to-liquid ratio in the purification fluid reaches 1:6 to 1:5, continuing adding the positive fragments into the purification fluid, stopping adding the positive fragments into the purification fluid when the concentration of SO3<2-> in the purification fluid is detected to be lower than 100mg / l and stopping stirring the purification fluid; soaking the obtained negative fragments after being cleaned in a H2SO4 solution at the temperature of 30-90 DEG C, filtering, then adding the filtrate parallelly flowed with the solution into a reactor, continuing stirring after material fluid is added, aging, filtering, drying the obtained sediment, rewashing the sediment and drying the sediment at the temperature of 110-140 DEG C to prepare cadmium hydroxide; filtering the purification fluid and preparing potassium sulfate in a crystallizing evaporator; and soaking filter residue in the H2SO4 solution, filtering, and adding obtained filtrate parallelly flowed with a KOH solution into a reactor, continuing stirring after the material fluid is added, aging, washing, filtering, drying and then obtaining nickel hydroxide powder.

Description

technical field [0001] The invention relates to a method for recycling metals by using waste batteries to purify flue gas, and belongs to the technical field of environmental protection. Background technique [0002] The emission of sulfur dioxide-containing flue gas from industrial production processes is one of the important causes of air pollution. To eliminate or reduce SO 2 Flue gas emissions pollute the atmospheric environment, and flue gas desulfurization is to prevent SO 2 The basic method of polluting the atmosphere, more than 80 methods have been developed. Among them, for high concentration SO 2 and low concentrations of SO 2 The treatment methods of flue gas are different. high concentration SO 2 Flue gas refers to the flue gas with a sulfur dioxide concentration above 3.5%, which can meet the technical requirements for the production of sulfuric acid by the contact method. Therefore, high-concentration sulfur dioxide flue gas is often used to produce sulfu...

AI Technical Summary

Problems solved by technology

The ammonia method is a more traditional process in the flue gas desulfurization method. This method uses liquid ammonia or ammonia water as the absorbent, which has high absorption efficiency and complete desulfurization. However, ammonia is volatile and consumes a lot of absorbent. In addition, the source of ammonia is affected by the region. More restrictive

The calcium method uses lime water or lime milk to wash the flue gas containing sulfur dioxide. This method has mature technology and low production cost, but the absorption rate is slow and the absorption capacity is small. The generated CaSO 3 and CaSO 4 It is easy to block pipelines and equipment. In addition, this method produces a large amount of waste residue, which causes serious secondary pollution to the environment.

The sodium method uses alkaline substances such as sodium carbonate or sodium hydroxide to absorb sulfur dioxide-containing flue gas. It has large absorption capacity, fast absorption rate, and high desulfurization efficiency. However, the biggest problem is that the raw material sodium alkali is relatively expensive, and the production cost of desulfurization is high.

The above three processes generally have the following common problems: (1) The investment in desulfurization equipment is large; (2) The by-products in the desulfurization process are difficult to use; (3) The environmental protection operation cost is high

The process is complex and the cost of recycling is high

Chinese patent 200710191053.6 reports the fire treatment process of extracting cadmium from waste nickel-cadmium batteries and producing nickel-iron alloy, but this process requires high equipment, is not easy to operate, and the added value of the obtained products is not high

[0004] Scrapped nickel-cadmium batteries still contain a large amount of highly concentrated KOH alkaline electrolyte and oxidizing nickel oxyhydroxide NiOOH. Electrolyte and NiOOH are not well utilized