Preparation of rare earth chloride from long-chain fatty acid extracting transformation and back-extraction process thereof

Abstract

The present invention uses rare earth sulfate obtained by using sulfuric acid to roast immersion liquor magnesia to regulate pH value to 3-4 and removing iron and impurity as raw material, and uses long-chain fatty acid, cosolvent and sulfonated kerosene to form orgnaic phase, the long-chain fatty acid is dehydrated on non-dehydrated ricinus oil fatty acid, and uses ammonia water, sodium hydroxide, ammonium hydrogen carbonate or sodium carbonate to make saponficiation, and adopts multi-stage extraction and washing processes to obtain the invented rare earth chloride solution whose concentration is greater than 200 g / l, acidity pH is 1-2 and sulfuric acid radical is less than 0.02%, and the rare earth yield is greater than 99%.

Description

1. Technical field: [0001] The invention belongs to the processing field of metallurgical rare earth metals, and in particular relates to a long-chain fatty acid extraction transformation to prepare rare earth chloride and its stripping process. 2. Background technology: [0002] The annual production capacity of Baotou rare earth concentrate is 80,000 tons. At present, the rare earth industry mainly adopts the high-temperature roasting and decomposition process of concentrated sulfuric acid. The roasted ore is leached with water to obtain a leaching solution containing rare earth and impurities such as iron and calcium. Magnesium oxide is used to adjust the pH to 3-4 to remove iron, etc. Rare earth sulfate solution is obtained after impurity. There are two follow-up processes in the industry to prepare rare earth chloride for the rare earth sulfate solution. The first process is to precipitate with ammonium bicarbonate, and obtain rare earth carbonate products through centri...

AI Technical Summary

Problems solved by technology

[0002] The annual production capacity of Baotou rare earth concentrate is 80,000 tons. At present, the rare earth industry mainly adopts the high-temperature roasting and decomposition process of concentrated sulfuric acid. The roasted ore is leached with water to obtain a leaching solution containing rare earth and impurities such as iron and calcium. Magnesium oxide is used to adjust the pH to 3-4 to remove iron, etc. Rare earth sulfate solution is obtained after impurity. There are two follow-up processes in the industry to prepare rare earth chloride for the rare earth sulfate solution. The first process is to precipitate with ammonium bicarbonate, and obtain rare earth carbonate products through centrifugation, and then use it as needed. The rare earth chloride solution obtained by dissolving hydrochloric acid is used to separate a single rare earth product. The intermittent operation of this process is discontinuous. The high sulfate content in the rare earth carbonate is not conducive to subsequent separation operations, and produces acidic wastewater containing a large amount of ammonium salts to pollute the environment. The second The process is to use P204 extraction and back extraction with hydrochloric acid to prepare rare earth chloride solution. On the one hand, this process requires high acidity of stripping to strip rare earth and a small amount of iron. The obtained rare earth chloride solution has high acidity and cannot be directly used for subsequent separation. The feed liquid of a single rare earth needs to be adjusted in acidity, and the process is discontinuous. After a period of production and operation, the iron in the extractant accumulates, which reduces the extraction capacity of the organic phase. On the other hand, P204 is an acidic phosphate lipid extractant. It is not easy to degrade, has certain toxicity, and produces a large amount of waste water containing organic phosphorus to pollute the environment, and the process flow is discontinuous

Images