Method for recovering phosphorus and rare earth from rare earth-containing phosphate rock

Abstract

The invention discloses a method for recovering phosphorus and rare earth from phosphate rock containing rare earth. The method comprises the following steps: using a mixed acid solution to leach rare earth-containing phosphate rock, filtering to obtain a monocalcium phosphate solution and a phosphate-containing rare earth slag, the main body of the mixed acid solution is phosphoric acid, and the mixed acid solution also contains hydrochloric acid and / or nitric acid; recovering the monocalcium phosphate Phosphorus in calcium solution, and recovery of rare earth in phosphate-containing rare earth slag. The method uses a mixed acid solution to leach rare earth-containing phosphate rock, so that the phosphorus in the phosphate rock forms monocalcium phosphate with high solubility, and at the same time, the rare earth is precipitated and enriched in the slag in the form of rare earth phosphate by adjusting the acidity of the leaching process. The rare earth-containing phosphate rock also contains monazite, which enriches monazite and rare earth phosphate into the slag, and then separates phosphorus and rare earth, simplifies the recovery steps, improves the recovery rate of rare earth, and realizes the purpose of comprehensive recovery of rare earth at low cost.

Description

technical field [0001] The invention relates to the field of rare earth recovery, in particular to a method for recovering phosphorus and rare earth from phosphate rock containing rare earth. Background technique [0002] Rare earth minerals often coexist with barite, calcite, apatite, silicate ore and other minerals in nature. Due to the different mineralization reasons of minerals, the occurrence state and content of rare earth elements in minerals are also different. Among the currently mined rare earth minerals, the grade of rare earth oxides is generally a few percent. In order to meet the needs of rare earth metallurgical production, the rare earth must be separated from other ores by beneficiation before smelting, so that the rare earth minerals can be enriched. The content of rare earth oxides in the rare earth concentrate after beneficiation and enrichment is usually 50% to 70%. [0003] Rare earth minerals mainly include bastnaesite, monazite, xenotime and ion-a...

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Problems solved by technology

(3) Phosphoric acid treatment process of phosphate rock, patent CN201110143415.0 mixes rare earth-containing phosphate concentrate with phosphoric acid solution for reaction, by controlling the process conditions, the rare earth in the phosphate rock is precipitated in the form of fluoride, and more than 85% of the rare earth enters the slag, Then use hydrochloric acid, nitric acid or sulfuric acid to dissolve the rare earth in the recovered slag, but the rare earth grade in the slag is very low, about 1%, and the content of impurities such as phosphorus, calcium, aluminum, silicon, etc. is high, and the rare earth fluoride is difficult to dissolve with acid, and the acid consumption High, large amount of slag, low recovery rate of rare earths; in addition, 15% of rare earths entering the leachate are easy to enter the gypsum slag during the decalcification process and are difficult to recover

When recovering rare earth elements and phosphorus elements in this mixed ore, it is difficult to achieve effective separation of ores by physical beneficiation due to the difficulty of enveloping and dissociation of various substances in the mixed ore

In particular, since the decomposition of monazite requires relatively harsh conditions, such as higher temperature and pH, etc., when using the sulfuric acid method in the prior art to wet treat phosphate rock containing monazite, it is often impossible to completely decompose monazite. can realize its effective recycling

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