Purification method of crude scandium oxide

Abstract

The invention discloses a purification method of crude scandium oxide, which comprises the following steps of (1) first-stage acid leaching: adding water into crude scandium oxide to regulate the slurry, adding inorganic acid to regulate the pH value of the slurry to 1.0-3.0, reacting, and filtering to obtain first-stage leaching residues and a first-stage leaching solution, (2) second-stage acidleaching: putting the obtained first-stage leaching residues into an inorganic acid solution, and reacting to obtain a scandium-rich second-stage leaching solution, (3) oxalic acid scandium precipitation: adding an oxalic acid solution into the second-stage leaching solution, adding a back-regulating agent to regulate the pH value of the reaction material to 0.5-2.0, and filtering after reaction to obtain scandium oxalate precipitate; and (4) calcining: drying the obtained scandium oxalate precipitate, and calcining to obtain purified and refined scandium oxide. According to the method, the difference between the acid solubility of the impurities and the acid solubility of scandium oxide is effectively utilized, the impurities and scandium oxide are leached out separately, the impurity separation effect is good, the existing scandium oxide purification process and operation process are greatly simplified, and the operation cost is saved to a certain extent.

Description

technical field

[0001] The invention relates to the field of hydrometallurgy, in particular to a method for purifying crude scandium oxide through segmental leaching. Background technique

[0002] As a rare earth metal element, scandium is widely used in lighting industry, alloy industry, ceramic materials, catalytic materials and other fields. There are few independent deposits of scandium, but they are widely distributed in deposits of cobalt, aluminum, nickel, titanium, tungsten, zirconium, etc. or enriched in some metallurgical waste residues or dust. As an associated ore or by-product, scandium is present in these raw materials Or the content in the waste residue is very low, and the impurities in these raw materials are various and high in content, so the extraction and purification of scandium is particularly difficult.

[0003] Due to the active chemical properties of metal scandium, it is easy to be oxidized, so scandium is generally made into scandium oxide for pr...