Method of selectively recovering yttrium from CRT fluorescent powder for doping preparation of ternary composite oxide catalyst

Abstract

The invention belongs to the technical field of environmental catalysis, and especially relates to a method of selectively recovering yttrium from CRT fluorescent powder for doping preparation of ternary composite oxide catalyst, which includes the steps of: 1) performing initial treatment to the waste CRT fluorescent powder and performing high temperature alkali melting to prepare an alkali molten product; 2) leaching the alkali molten product with ammonia water and performing solid liquid separation to removal a major impurity, zinc; 3) performing extraction with diluted hydrochloric acid and enriching and recovering rare earths through a two-step precipitation method, and performing secondary extraction with diluted hydrochloric acid to obtain a rare earth extract liquid; 4) preparing yttrium oxalate by combining photochemical method and chemical precipitation method; 5) performing coprecipitation to obtain the ternary composite oxide catalyst. The method can high-effectively separate and extract and fully utilize the rare earths in the waste CRT fluorescent powder. By doping the yttrium, low temperature denitration performance of the catalyst is significantly improved. The method reduces production cost of the catalyst and actually achieves treating waste by waste.

Description

technical field [0001] The invention belongs to the technical field of environmental catalysis, and in particular relates to a method for selectively recovering yttrium in CRT fluorescent powder for doping to prepare a ternary composite oxide catalyst. Background technique [0002] Nitrogen oxides (NO X ) In addition to directly damaging human health as a primary pollutant, it will also produce a variety of secondary pollution (such as acid rain, photochemical smog). NO X Control technology and countermeasures have been included in the key environmental science and technology issues for regional air pollutant control. my country's current NO X The emissions mainly come from automobiles, boiler combustion, industrial production, etc. Different fuels have different effects on NO X The contribution of emissions is different. According to statistics, among various fuels, coal combustion is the most X The largest source of emissions, accounting for more than 60% of total emi...

AI Technical Summary

Problems solved by technology

Catalyst is the biggest core of denitrification technology. At present, coal-fired power plants are widely using V 2 o 5 -WO 3 / TiO 2 SCR denitrification technology is a catalyst, which has high denitrification efficiency, strong anti-poisoning, and can meet environmental protection requirements, but the production cost is high and the activation temperature is high (300-430°C). The following flue gas treatment capacity is limited, and V 2 o 5 Toxic and easy to cause secondary pollution

Iron-based SCR catalysts have the advantages of cheap development, non-toxicity, and low pollution, but they also have the problem of low denitrification activity at low temperatures, which limits their large-scale industrial application.

Rare earth elements themselves have certain catalytic properties. Existing studies have found that the addition of rare earths cerium, lanthanum, and yttrium can improve the performance of the catalyst, but the addition of rare earths will also increase the cost of the catalyst.