A New Method for Preparing Rare Earth Chloride from Baiyun Obo Rare Earth Concentrate

Abstract

The invention relates to a new method for preparing rare earth chloride by using Baiyunebo rare earth concentrate and belongs to the field of wet-process metallurgy. The invention comprises the following steps: performing thermal decomposition, wherein a raw material used is Baiyunebo mixed rare earth concentrate with a grade of 60 to 80 percent; leaching in hydrochloric acid, namely leaching oreobtained after thermal decomposition in hydrochloric acid; performing alkaline decomposition, namely decomposing filter residue obtained after leaching in hydrochloric acid with solution of sodium hydroxide; washing, namely washing the ores obtained after alkaline decomposition with water till the pH value is 7 to 9, and recovering fluorine and phosphorus from washing solution; performing primaryneutralization, namely mixing hydrochloric acid leachate and water washing residue, and neutralizing till the pH value is 0.5 to 2.5; and performing secondary neutralization, namely neutralizing the filtrate obtained by the primary neutralization till the pH value is 4 to 5, wherein the filtrate of the secondary neutralization is solution of rare earth chloride. The method has the advantages of facilitating recovery of other elements, avoiding waste gas, waste water and waste residue, along with small alkali consumption, stable process and high rare earth recovery rate of more than or equal to 95 percent.

Description

technical field [0001] The invention relates to a new method for preparing rare earth chloride from Baiyun Obo rare earth concentrate, which belongs to the field of hydrometallurgy. Background technique [0002] The Baiyan Obo Mine is by far the largest rare earth mine in my country and even in the world. This kind of rare earth mine mainly exists in the form of bastnaesite and monazite mixed ore, which is a typical mineral that is difficult to select and smelt. In industrial production, there are two main smelting processes for this mineral: concentrated sulfuric acid roasting process and sodium hydroxide decomposition process. Concentrated sulfuric acid roasting process is the earliest and most mature smelting process for Baiyun Obo mine. The biggest advantage of this process is its strong adaptability to minerals, but there are also many serious defects. Although in the long-term application process, these Some improvements have been made to the defects, but due to the l...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a new method for preparing rare earth chloride from Baiyun Obo rare earth concentrate. This process can effectively solve the problem of three wastes pollution in the rare earth smelting process, the recovery rate of rare earth is high, and the synthesis of other useful elements can be realized. recycle and re-use

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