Waste battery piece recycling process

Abstract

A waste battery piece recycling process includes the following steps that an aluminum layer is removed, a silver layer is removed, silver powder is recycled, a silicon nitride layer is removed, and a pure silicon wafer is recycled. The waste battery piece recycling process is provided in the invention, alkali liquor and a hydrofluoric acid solution which are used are both discarded liquor discharged by a solar battery production line, further use is conducted, the production cost is reduced, and meanwhile the optimal temperature of the reaction in each step is regulated and controlled. Utilization of energy can also be considered on the premise of ensuring efficiency, the recycled silver powder and the recycled silicon wafer have very high economic value, the recycling rate of silicon of the recycled silicon wafer reaches 99% or above, and the recycling rate of silver can also reach 95% or above. These materials can be used for manufacturing silicon wafer batteries again, the production cost is reduced, environment friendliness is achieved, pollution is little, and the waste battery piece recycling process has very high popularization value.

Description

technical field [0001] The invention belongs to the field of recycling silicon wafers of solar batteries, and in particular relates to a recycling process of waste battery wafers. Background technique [0002] Solar energy is a renewable energy with the ideal characteristics of sustainable development. It has no noise, no carbon dioxide during power generation, flexible scale, and simple operation and maintenance. It has shown considerable attractiveness. Crystalline silicon solar cell components mainly include photovoltaic glass, silicon cells and backsheets. Silicon cells are mainly composed of silicon wafers, silver paste, and aluminum paste. A certain number of fragments and substandard cells will appear during the production process of silicon cells or the lamination process of components. Poor disposal of waste silicon cells is not only a waste, but also brings environmental pollution. The recovery rate of copper and glass is low, and the possibility of reusing the f...

AI Technical Summary

Problems solved by technology

Poor disposal of waste silicon cells is not only a waste, but also brings environmental pollution

The recovery rate of copper and glass is low, and the possibility of reusing the finished product is also low. Therefore, even if the recycling cost is low, it is not valued because of the low benefit. However, the silver powder and silicon wafer in crystalline silicon solar cells still have a high cost. recycling value

[0003] There are two methods for removing the aluminum back field from crystalline silicon solar panels: acid solution and alkaline solution. Patent CN106629738A discloses a method for extracting silver from crystalline silicon solar panels, including dismantling solar energy from crystalline silicon solar panels. Battery sheet, remove the aluminum layer with sodium hydroxide solution, leach silver with a mixed solution of organic acid and hydrogen peroxide and electrolyze silver to obtain silver powder, remove impurities with hydrofluoric acid, and obtain high-purity silicon materials; but the quality is used Fraction is the sodium hydroxide solution of 20-40%, has produced alkaline waste liquid after reaction again, is unfavorable for the protection of environment, and the lye used in the present invention is that the concentration that the solar cell production line discharges is 3-5% Soak the crystalline solar cell chip with waste lye, not only can use the waste liquid, but also do not generate excess waste liquid

[0004] CN105436191A provides a method for recovering high-purity silicon in waste solar cells. The waste solar cells are sequentially subjected to hydrochloric acid to remove aluminum, nitric acid to remove silver, sodium hydroxide to remove aluminum-silicon alloy layers, and hydrofluoric acid to remove silicon nitride anti-reflection layers. , sodium hydroxide to remove the phosphorus diffusion layer and hydrochloric acid, hydrofluoric acid or a mixed acid composed of hydrofluoric acid and nitric acid to remove surface metal impurities and obtain high-purity silicon, but only the recovery of silicon is considered in the invention, and this The recycling process is more complicated, and the cost of recycling increases

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