Cleaning production technique for directly transforming rare earth sulfate bake ore to extract rare earth

Abstract

The invention belongs to the field of rare earth wet metallurgy and industrial chemistry, and relates to a clean production technology for roasting rare earth concentration to leach rare earth by the sulphate method. Aiming at the prior roasting production technology by the sulphate method taking Baotou rare earth concentration as raw materials, the technological process of the clean production technology realizes direct transformation production from sulphate to carbonate by the transformation technology of double decomposition reaction in chemical process and according to the principle of mutual transformation between solid substances with different solubility products. Non-rare-earth compounds (such as ammonium sulphate and ammonium carbonate) and the like are fully recovered with low cost; simultaneously, water can be fully recycled and used; the intermediate impurity removing technology is adopted to recover non-rare-earth substances such as Ca from rare earth ore. Therefore, the purpose of full-recycling and clean production in rare earth leaching process by the sulphate roasting method is realized. The technology has the advantages that the production process of rare earth ore sulphate method fully recovers rare earth elements and valuable elements from mineral products with lower cost, and clean production without sewage emission is realized.

Description

technical field [0001] The invention belongs to the field of rare earth hydrometallurgy and chemical industry, and relates to a clean production process for extracting rare earth by roasting rare earth concentrate with concentrated sulfuric acid. Background technique [0002] The most representative mineral of China's rare earth resources - Baotou Baiyun Obo rare earth mine, due to the special complexity of its mineral composition, is quite difficult in the technical process of mineral beneficiation, decomposition, transformation and separation. The Baiyun Obo Mine in Baotou is a rare multi-element symbiotic mine such as iron and rare earth in the world. There is no such mineral in foreign countries, and there is no similar extraction and separation technology. [0003] At present, the smelting process of Baotou rare earth mine is mainly based on the "concentrated sulfuric acid method", supplemented by the "caustic soda method". The "concentrated sulfuric acid method" proce...

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Problems solved by technology

However, due to the low solubility of rare earth sulfate, the concentration of the solution is too low, which not only affects the yield of rare earth, but also produces a large amount of extremely rare and impurity-containing ammonium salt wastewater, which makes it very difficult to treat the end.

[0012] (2) Substitute ammonium bicarbonate with sodium carbonate as the precipitant for producing rare earth carbonate. This method can avoid the problem of ammonia nitrogen water, but the cost is too high, and the product yield is low, and the process control also has certain difficulties, and it cannot reduce and Avoid massive sulfate efflux

However, this move does not meet the underground discharge standards for industrial wastewater, nor does it meet the river discharge standards, and the total salt content is far beyond the standard, and ultimately cannot enter the environment

[0014] (4) If using P 507 The extraction system must be saponified. If it is saponified with ammonia, it is meaningless. If it is saponified with sodium, calcium, and magnesium, it will discharge a large amount of sulfate solution. There are also the above environmental problems.

[0015] (5) At home and abroad, the production wastewater generated by the rare earth extraction and separation process is mixed and then treated at the end. The total salt content of this part of the wastewater exceeds the standard when it is discharged, and the relevant clean production technology that organically combines the production process with environmental protection and governance has not been developed. Research

However, in the process of rare earth separation process, there are no reports on the process of recovering all the waste water salts and the process of full recycling of waste water.

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