Method for step-by-step extraction of phosphorus and rare earth from concentrated sulfuric acid low-temperature roasting phosphorus-containing rare earth concentrate

Abstract

The invention discloses a method for stepwise extraction of phosphorus and rare earth in phosphorus-containing rare earth concentrate through low-temperature roasting by concentrated sulfuric acid. The method comprises: uniformly mixing phosphorus-containing rare earth concentrate and concentrated sulfuric acid according to a ratio, carrying out calcining decomposition at 200-350 DEG C to obtain calcined ore, blending the calcined ore and water, carrying out primary leaching, carrying out filtration and washing to obtain phosphoric acid extract and primary residues, carrying out secondary leaching on the primary residues and a dilute sulfuric acid solution and carrying out filtration and washing to obtain rare earth extract and water leaching residues. The method utilizes the principle ofdifference in solubility of iron phosphate, rare earth phosphate and strontium phosphate and the diffusion rate of rare earth sulfate and phosphoric acid under acidic conditions to extract phosphoricacid step by step, realizes preliminary separation with rare earth and solves the problems in the prior art. .

Description

technical field

[0001] The invention relates to a hydrometallurgical technology, in particular to a method for extracting phosphorus and rare earth step by step by roasting concentrated sulfuric acid at low temperature and containing phosphorus rare earth concentrate. Background technique

[0002] The rare earth minerals in the world are mainly divided into three types: bastnaesite, monazite and weathering crust leaching type rare earth minerals. Among them, the monazite mineral (REPO 4 ) are phosphorus-containing rare earth minerals, which contain rich phosphorus resources in addition to rare earth resources. At present, the concentrated sulfuric acid decomposition process is mainly used to extract rare earths from phosphorus-containing rare earth concentrates, and the concentrated sulfuric acid decomposition process is divided into high temperature and low temperature. In the high-temperature roasting process of concentrated sulfuric acid, the iron in the concentrate and...

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