Method for extracting lead from waste CRT one glass

Abstract

The invention discloses a method for extracting lead from waste CRT one glass. The method comprises the following steps: putting a granular carbonaceous reducing agent into an upper-layer material distribution device of a vacuum furnace so as to generate carbothermal reduction reaction, putting cone glass into a lower-layer material distribution device, and closing the vacuum furnace; when the pressure of a vacuum chamber is lower than 15Pa and the temperature is higher than 1150 DEG C, maintaining the temperature for 10-120 minutes so as to volatilize lead oxide in the cone glass, wherein volatilized lead oxide generates a carbothermal reaction with the carbonaceous reducing agent while passing through a carbon layer at the upper part of a graphite crucible to generate gaseous lead metal,and gaseous lead metal is condensed in a condensing disc; and after the temperature maintaining is finished, naturally cooling to obtain metal lead in a condensing region, wherein the purity of metallead is higher than 99%, meanwhile, and lead oxide in the residual glass is effectively removed. When the thermal treatment temperature reaches over 1300 DEG C and the temperature maintaining time exceeds 60 minutes, the removal rate of lead oxide can reach over 99%, obtained lead can meet the basic requirements on lead-free glass components or building material components with silicon dioxide asthe main raw material, and the harmless treatment and comprehensive resource utilization of the cone glass can be realized.

Description

technical field [0001] The invention relates to a method for extracting lead from waste CRT cone glass, which belongs to the field of high pollution control and treatment of waste lead-containing glass and comprehensive recovery of secondary resources. Background technique [0002] Especially since entering the 21st century, with the rapid development of electronic technology and the rapid rise of the flat panel display industry, a large number of cathode ray tube (CRT) cone glasses used for display screens and computers have been eliminated, and my country has entered the scrapping of lead-containing CRT cone glass peak period. A forecast study estimates that by 2020, the amount of discarded CRT cone glass across Asia will increase to around 1,500 tons. Moreover, the cone glass mainly contains a large amount of silicon dioxide and lead oxide, among which the content of silicon dioxide is about 50%, and the content of lead oxide is about 20%, so the lead oxide in the cone gl...

AI Technical Summary

Problems solved by technology

At present, the detoxification process and comprehensive recycling technology for secondary resources in conical glass are not mature enough. Therefore, the reasonable method and approach of recycling waste CRT glass has become an urgent problem to be solved in my country and even in the world.

[0003] In recent years, around the principles of environmental protection, economy, and process feasibility, many researchers in my country have proposed a method based on pyrometallurgy cone glass to extract metal lead, which has greatly promoted the secondary recovery and utilization of lead resources in waste CRT cone glass. But there are still many problems, such as low extraction rate of lead, complicated process, environmental pollution problems, etc.

Ma Zhilai and others invented the method and device for recycling metal lead from waste CRT cone glass (application number 201310361538.0, 201320505904.0). This method is to mix the waste CRT cone glass, lead concentrate, lead oxide ore and coke in a certain proportion, and put them in the blast furnace Smelting can get crude lead, slag and soot. The crude lead yield can reach 20%, the lead content in crude lead can reach 98.52%, and the lead content in slag is more than 1%. This process combines cone glass with lead-containing waste Cooperative processing is conducive to the comprehensive treatment of waste, but its lead recovery rate is low, and it will produce a large amount of waste lead-containing slag and smoke (accounting for about 80%)

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