Method for preparing high pure scandium oxide from hydrochloric acid mother liquid for producing zirconium oxychloride

Abstract

The invention belongs to the field of wet metallurgy, and particularly relates to a method for preparing high pure scandium oxide from a hydrochloric acid mother liquid for producing zirconium oxychloride. The method comprises the following steps of (1) extracting the hydrochloric acid mother liquid, separating by centrifugation to remove water phase from an organic phase and for demulsification and washing with acid; (2) subjecting an organic phase loaded in the acid solution to reverse extraction and filtration, discharging the filtrate, dissolving filter residues with acid and extracting; (3) subjecting the organic phase to reverse extraction and filtration, discharging the filtrate, and dissolving the filter residues with acid; (4) regulating a pH value of the acid solution, adding oxalic acid to precipitate scandium, filtering, roasting the filter residues, then dissolving the roasted residues with acid and filtering; (5) regulating a pH value of the filtrate, adding oxalic acid to precipitate scandium again, filtering, roasting the filter residues again, boiling the roasted residues in an acid water, regulating the pH, filtering, washing with water, roasting and drying to obtain a product. The method is used for preparing the high pure scandium oxide from an acid liquid solution with complex components, and changes wastes into valuables. A separation technology employing a baffle-free type self-flow extraction tank, a variable frequency technique and a centrifugal extractor is used to solve technical problems of difficult phase separation and serious emulsification in the extraction technology, and conditions for recovering valuable metals from the complex material liquid are provided.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy, in particular to a method for preparing high-purity scandium trioxide from hydrochloric acid mother liquor for producing zirconium oxychloride. Background technique [0002] Adding sodium hydroxide to alkali-fused zircon sand, washing with water to remove silicon, adding hydrochloric acid to filter, and concentrating and crystallizing the filtrate to produce zirconium oxychloride products will produce a large amount of mother liquor of zirconium oxychloride hydrochloride. The content of scandium is generally 800-1200ppm, which is several orders of magnitude higher than the content of scandium in the waste acid of the titanium dioxide industry, but other harmful elements are also extremely high. The elements that seriously affect the quality of scandium include zirconium, hafnium, titanium, rare earth, Thorium et al. [0003] When the material liquid is neutralized with alkali, the yield of dry res...

AI Technical Summary

Problems solved by technology

Although the long-term static phase separation is adopted, it is still difficult to complete the phase separation, and the entrainment is serious, resulting in a large loss of the organic phase and the product quality cannot meet the standard. Although the product is purified many times, it is still difficult to reach the standard. The main elements exceeding the standard are zirconium, hafnium, titanium, and thorium. , rare earth, etc.

During the purification process of scandium, the loss of scandium is serious, although the extraction rate is high, the total recovery rate of scandium is low