A kind of method for producing mixed rare earth chloride from Baiyun Obo rare earth concentrate

Abstract

The invention discloses a method for preparing mixed rare earth chloride from Baiyan Obo rare earth concentrate, comprising: mixing Baiyan Obo rare earth concentrate with concentrated sulfuric acid at a mass ratio of 1:(0.7-1.5) and performing three-stage roasting to obtain rare earth roasting ore; after leaching and removing impurities, the obtained rare earth roasted ore is filtered and slag removed, and the filtered filtrate is extracted and transformed to obtain raffinate and loaded organic phase; the loaded organic phase is back-extracted with hydrochloric acid to obtain mixed rare earth chloride solution. The invention adopts low-temperature external heat roasting and the heat source and materials move countercurrently, effectively reducing energy consumption; the three-stage roasting method can further promote the full decomposition of rare earth concentrates, avoid materials sticking to the kiln, and at the same time make the materials roast more fully and effectively reduce tail gas discharge; continuous leaching and countercurrent impurity removal can effectively improve the recovery rate of rare earth concentrate.

Description

technical field [0001] The invention belongs to the technical field of rare earth mineral smelting, and in particular relates to a method for preparing mixed rare earth chloride from Baiyun Obo rare earth concentrate. Background technique [0002] Rare earth is a new material of great significance in high-tech fields such as national defense, aerospace, electronics, metallurgy, permanent magnets, high-energy optics and batteries. China is a big country in the reserve and production of rare earth resources. The production and sales of rare earth resources account for more than 90% of the world. In the field of domestic rare earth concentrates, the storage and production of Baotou Baiyun Obo rare earth concentrates account for the total domestic rare earth concentrate reserves and 83% of total production. At present, the method commonly used in the domestic Baiyun Obo rare earth concentrate smelting process is the rotary kiln high-temperature sulfuric acid roasting method, bu...

AI Technical Summary

Problems solved by technology

[0003] (1) The problem of material sticking to the kiln during the roasting process can only be solved by adding excessive sulfuric acid or external cleaning, and the required sulfuric acid is 1.5 to 2 times the theoretical value;

[0004] (2) The temperature of high-temperature roasting reaches 800 ℃ ~ 1000 ℃, and the energy consumption is large. The standard coal consumption per ton of concentrate is 300kg ~ 500kg, and the standard coal consumption of some concentrates even exceeds 600kg;

[0005] (3) Internal combustion roasting is adopted and a large amount of sulfuric acid is consumed, so that the gas and flue gas are mixed and discharged. The temperature of the mixed gas is high and the composition is complex, which makes it difficult to process the mixed gas, and the environmental pollution caused by the flue gas is difficult to solve;

[0006] (4) The ammonium bicarbonate precipitation or extraction transformation is used in the post-treatment stage, which produces a large amount of wastewater, a wide variety of salt components in the wastewater and a low concentration of a single salt, which makes the structure of the wastewater treatment and recovery device complex and high investment

[0007] The sulfuric acid high-temperature treatment method of internal combustion rotary kiln is difficult to meet the current situation of energy saving and emission reduction of environmental pollution. The recovery and treatment of waste water and flue gas has become a difficult problem that plagues Baiyun Obo Rare Earth Mine. Looking for a road of energy saving, environmental protection and clean production It is the key to the current rare earth concentrate smelting enterprises