Green extraction method of ionic rare earth ore calcium salt system

Abstract

The invention discloses a green extraction method of an ionic rare earth ore calcium salt system. Calcium salt is taken as an ore leaching agent, calcium oxide is taken as a purification impurity removal agent, and calcium oxide is taken as a precipitant; the ore leaching agent, chlorine removal and heavy metal elements are recovered in a form of Friedel's salt; no ammonia nitrogen and high-salt wastewater is discharged in the whole process, the process is smooth, the product impurity content is low, and after ore closing, the mining area environment influence is small, and green and environment-friendly mining of ionic rare earth can be implemented. In addition, the method takes calcium chloride as a main component, a small amount of acid regulators such as aluminum chloride, ferric chloride and ammonium chloride are added, the formed composite salt ore leaching agent is a main component of ore soil, and compared with an ore leaching system with ammonium salt, magnesium salt, sodium salt and potassium salt as main components, the composite salt ore leaching agent has almost no influence on the environment, the leaching rate and the leaching peak concentration of rare earth can beeffectively improved, the tailing phenomenon of the ore leaching agent is reduced, the ore leaching time is shortened, and the ore leaching efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of rare earth hydrometallurgy, in particular to a green extraction method of ion-type rare earth ore calcium salt system. Background technique [0002] The rare earth in the ionic rare earth ore is adsorbed on the surface of the clay mineral in an ionic state, and the rare earth ions can be exchanged with a strong electrolyte. Therefore, according to the characteristics of the ionic rare earth ore, my country has invented an ionic rare earth extraction process. The ionic rare earth extraction process has successively gone through the stages of sodium chloride pool leaching process, ammonium sulfate pool leaching process, ammonium sulfate heap leaching process, ammonium sulfate in-situ leaching process and magnesium sulfate leaching process. Industrial system laid the foundation. The in-situ leaching technology of ammonium sulfate leaching-ammonium bicarbonate crystallization precipitation has been applied f...

AI Technical Summary

Problems solved by technology

However, basic magnesium salts such as magnesium oxide, magnesium hydroxide, and magnesium carbonate are insoluble in water, while soluble magnesium bicarbonate is extremely unstable, the process is difficult to control, and the content of magnesium impurities in rare earth products is high.

[0006] In addition, after the mine is closed, the amount of wastewater remaining in the mine is large, mainly from the recovered ore leaching tailings, impurity removal and sedimentation wastewater, etc. The content of valuable elements is low, and the cost of treatment and recovery is high, so it is often directly discharged into the mine without treatment. in the surrounding environment

The high content of salt in the wastewater causes acidification and compaction of the soil in the rare earth mining area and the surrounding soil, and the cost of ecological restoration is high

The waste water also contains low-concentration ore leaching agent, and the direct discharge causes a waste of resources, and the waste water contains a small amount of heavy metals such as lead, zinc, copper, etc. If the discharge is not treated, the content of heavy metal elements in the surrounding environment will exceed the standard.

Images