Rare-earth enrichment recovery method from phosphorite

Abstract

The invention discloses a method for enriching and recovering rare earth from phosphorite, which drives a large quantity of rare earth elements to be enriched into a phosphate system and be separated and recovered by inhibiting loss of the rare earth in phosphogypsum through optimizing the technological conditions and adding a calcium sulphate crystal seed and / or an active additive on the premise of not changing the wet-method phosphate process. Compared with the prior art, the method controls proper technological conditions and particularly adds the calcium sulphate crystal seed and / or the active additive, can improve the crystalline morphology of the phosphogypsum, reduce the eutectic effect and the adsorption effect of phosphate rare earth and calcium sulphate, reduce enrichment of the phosphate rare earth and the calcium sulphate to the phosphogypsum, make the enrichment ratio of the rare earth in phosphate reach more than 80 percent, and be favorable for recovering the rare earth from the phosphate. Moreover, the method can meet the requirements of wet-method phosphate production, has simple technique and high content of rare earth in the phosphate, and can adopt proper technology to recover rare earth from the phosphate and realize effective combination of rare earth recovery technology and phosphorization technology.

Description

technical field [0001] The invention relates to a method for enriching and recovering rare earths from phosphate rocks, in particular to a method for enriching and recovering rare earths from phosphate rocks during the process of decomposing rare earth-containing phosphate rocks with sulfuric acid to produce phosphoric acid. Background technique [0002] In addition to the occurrence of rare earth elements in various rare earth ores, a considerable part of the rare earth elements in nature is symbiotic with apatite and phosphorite ores. The total reserves of phosphate rocks in the world are about 100 billion tons. According to the average rare earth content of 0.05%, the total reserves of associated rare earths in the world's phosphate rocks can be 50 million tons. As a potential source of rare earths, the recovery of rare earths in phosphate rock is of great significance. [0003] At present, according to the type of acid used in the production of wet-process phosphoric ac...

AI Technical Summary

Problems solved by technology

In order to achieve uniform recovery of metals such as uranium and rare earths from phosphoric acid solution, when sulfuric acid decomposes phosphate rock, introducing aluminum ions, iron ions, silicon ions or their mixed ions into the pulp can increase the solubility of rare earths in the solution. The highest enrichment degree is only 56%, and because the introduced silicon plasma is a harmful impurity in the production process of phosphoric acid, it directly affects the subsequent process of wet phosphoric acid

[0006] In short, the problems in the process of recovering trace rare earths from phosphate rocks are: extracting rare earths from phosphogypsum is technically feasible, but the process is very complicated and economically difficult; recovery of rare earths from phosphoric acid, phosphoric acid Rare earth enrichment is low, the current research level is only about 60%, which does not meet the technical and economic requirements