Method for extracting and recovering silver from waste solar cell

Abstract

The invention provides a method for extracting and recovering silver from a waste solar cell, and relates to a technology of solar material washing. The method comprises the following steps: a, washing the surface of a waste solar cell; b, soaking in hydrochloric acid to remove an aluminum back surface field; c, rinsing a silicon wafer subjected to aluminum back surface field removal with pure water, and then soaking in nitrohydrochloric acid to remove a silver electrode on the silicon wafer; d, adding HF into the nitrohydrochloric acid to remove a silicon nitride blue membrane on the surface, thus obtaining a clean silver extraction wafer; e, rinsing the silver extraction wafer with pure water, soaking in mixed acid, and cleaning to obtain clean fragments; and f, adding high-purity iron powder into the nitrohydrochloric acid solution, stirring, filtering silver powder after the reaction is finished, drying, proportioning, and smelting to obtain a high-quality silver ingot. The invention has the following beneficial effects: through the properties of different kinds of acid, the aluminum, silver and silicon nitride on the cell can be subjected to independent treatment, so that the cell can be fully utilized; meanwhile, the silver can be recovered, and about 0.6kg of silver can be recovered from 50kg of cell; and the silicon ingot production cost can be effectively reduced, thereby achieving the synergy purpose.

Description

technical field [0001] The invention relates to the technical manufacturing field of solar single crystal and polycrystalline silicon wafers, in particular to the solar energy cleaning technology. Background technique [0002] The solar energy industry is a sunrise industry. As people pay more attention to environmental protection, the solar energy industry is developing rapidly. Photovoltaic solar silicon-based cells are one of the most popular green energy sources at present. Scrapped cells are produced during the production process, which is caused by equipment, technology, and personnel errors. Scrapped cells cannot meet the standards for casting ingots and must be pickled. . At present, pickling in the market is generally soaked in hydrofluoric acid and ammonium fluoride. The treatment cost is high, and the treatment effect is poor. Casting into the furnace will have a certain impact on the quality of silicon ingots. After soaking in hydrochloric acid, soaking in aqua...

AI Technical Summary

Problems solved by technology

[0003] Each scrap battery contains 0.2 to 0.3g of silver. Currently pickling in the market is generally soaked in hydrofluoric acid and ammonium fluoride, cleaned and put into the furnace for use, but silver cannot be recycled, causing a lot of waste