Method for extracting white carbon black and rare-earth water purifying agent from waste rare-earth polishing powder

Abstract

The invention discloses a method for extracting white carbon black and a rare-earth water purifying agent from waste rare-earth polishing powder. The method comprises the following steps of conducting centrifugal separation of the waste rare-earth polishing powder; leaching and filtering separated fine powder dilute acid; adjusting the pH value and the aluminum-lanthanum ratio of the filtered filtrate, and then drying to obtain polyaluminum lanthanum chloride or aluminum sulfate; leaching filtered filter slag with concentrated sulfuric acid, and then filtering to obtain a cerium sulfate solution and high-acid leaching slag; adjusting the pH value and the cerium-iron ratio of the cerium sulfate solution, and then drying to obtain polymerized ferric sulfate; and separating, washing and drying the high-acid leached slag, and then carrying out jet milling to obtain the white carbon black. According to the method for extracting the white carbon black and the rare-earth water purifying agent from the waste rare-earth polishing powder, the low-content waste rare-earth polishing powder can be prepared into white carbon black and a water purifying agent, and a large part of valuable substances are comprehensively utilized, so that the comprehensive recovery and utilization of the low-content waste rare-earth polishing powder are realized.

Description

technical field [0001] The invention relates to the technical field of solid waste recycling, in particular to a method for extracting white carbon black and rare earth water purifying agent from waste rare earth polishing powder. Background technique [0002] In recent years, with the rapid popularization and replacement of mobile phones and the widespread use of flat screens and car central control screens, the waste rare earth polishing powder solid waste produced every year exceeds 100,000 tons, and it is increasing year by year. Among them, the waste with high rare earth content Polishing powder, the company has applied for a patent, (Application No. 201811404138.2 A method of extracting aluminum, silicon oxide and rare earth from waste rare earth polishing powder), this method mainly fully recovers the rare earth in the high content of waste rare earth polishing powder so that generate value. However, in production practice, some low-content waste rare earth polishing...

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Problems solved by technology

[0004] At present, there are related patents on the recycling of waste rare earth polishing powder, such as the Chinese patent "A Method for Recycling and Reusing Rare Earth Polishing Powder Waste" (publication number: 201910067961.7), which discloses a recycling method for rare earth polishing powder waste , using the method of acid leaching and hydrogen peroxide oxidation, the coagulant can be obtained after mixing and oxidizing the leaching solution and washing water. The solution obtained by this method is actually a mixed acid leaching solution. The fluctuation of the rare earth content in the powder will lead to the fact that the rare earth ion content in the actual acid solution may be higher than the aluminum content, and the lanthanum ion precipitation needs to be around PH 10, which leads to the addition and application of the acid leach solution in wastewater containing heavy metals. When the content of rare earth fluctuates greatly, it is easy to cause secondary pollution of rare earth ions

At the same time, this method is a traditional conventional acid leaching. Under this condition, the cerium dioxide and rare earth fluoride in the waste polishing powder are basically insoluble. The incomplete dissolution of these two not only causes the resources to not be fully utilized, but also leads to oxidation in the acid leaching residue. Silicon content is too low to utilize

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