Method for leaching niobium, scandium and rare earth elements from tailings

Abstract

The invention discloses a method for leaching niobium, scandium and rare earth elements from tailings and relates to the technical field of hydrometallurgy. The method comprises the following steps: S1, adding calcium hydroxide and sodium chloride into iron ore dressing, rare earth and fluorite tailings, uniformly mixing to obtain a mixture, and roasting the mixture to obtain roasted ore; S2, performing ball-milling treatment on the roasted ore; S3, mixing the roasted ore subjected to ball-milling treatment with hydrochloric acid, heating for leaching, and filtering an extract to obtain a leaching residue I and a leaching liquor I rich in rare earth and scandium; and S4, drying the leaching residue I, leaching the leaching residue I by adoption of a concentrated sulfuric acid heating leaching method, and filtering an extract to obtain a leaching residue II and a leaching liquor II rich in niobium. The method is simple to operate, low in energy consumption, green and environmentally friendly, and low in process cost, can effectively leach niobium, scandium and rear earth in the iron ore dressing, rare earth and fluorite tailings, and is high in leaching rate of niobium, scandium and rear earth.

Description

technical field [0001] The invention relates to a method for leaching niobium, scandium and rare earth elements from tailings, and relates to the technical field of hydrometallurgy. Background technique [0002] The iron, rare earth and fluorite tailings of Baiyan Obo Mine can be recovered by weak magnetic separation and strong magnetic separation, and niobium, scandium and rare earth can be recovered by flotation. The final content of niobium and scandium in the tailings reaches 0.36% and 0.03%, which is about 3 times the content of niobium and scandium in raw ore. The resources of niobium and scandium have been effectively enriched and have a high recovery value. In addition, there are a small amount of rare earth elements that cannot be recovered in the flotation process and still exist in the tailings, with a content of about 2.14%. The full recovery of rare metals such as niobium, scandium and rare earths in the tailings is of great significance for the comprehensive u...

AI Technical Summary

Problems solved by technology

The disadvantage is that the performance of the current niobium beneficiation agent has not yet passed the test. The flotation concentrate not only contains a lot of impurities, but also the recovery rate of niobium minerals is too low. A large part of niobium minerals still remain in the tailings, and the amount of minerals entering the leaching process is relatively small , will affect the final recovery rate of niobium and scandium

In addition, the scandium-containing minerals obtained by magnetic separation also have the same problem. In addition, the pressure acid leaching process requires high equipment strength and corrosion resistance, which increases the process cost. Secondary recycling of resources

[0005] In addition, there are many methods for effectively leaching niobium and scandium minerals, but all of them have certain shortcomings or limitations

For example, the method of sulfuric acid to decompose niobium minerals at low temperature can only be used for easily decomposed niobium minerals, and consumes a large amount of acid; the hydrofluoric acid method of decomposing niobium minerals will produce toxic gas HF; Corrosion and environmental pollution are serious, and the operating environment is poor; the method of leaching scandium in sodium hydroxide solution or potassium hydroxide solution makes the solid-liquid separation difficult in the filtration process, and the cost is high; the method of directly leaching scandium in concentrated hydrochloric acid takes too long to react , the leaching rate is low, and the high concentration of hydrochloric acid is highly volatile, and the operating conditions of this process are relatively poor

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