Method for extracting scandium oxide from tungsten steel slag

Abstract

The invention relates to a method for extracting scandium oxide from tungsten steel slag. The method includes the steps: firstly, using a fine ball mill to crush the steel slag prior to performing main processes of inorganic acid leaching, organic solvent extraction, oxalate precipitation and the like, and enabling scandium in the tungsten steel slag to leach by the aid of sulfuric acid; secondly, allowing leaching liquor to stand to precipitate titanyl sulfate, filtering and removing titanyl sulfate, diluting mother liquor by slag washing water, and using the diluted mother liquor as feed liquor 1 of the extracted scandium; thirdly, dissolving the filtered titanyl sulfate solids by the slag washing water, and using filtrate with insoluble impurities as feed liquor 2 of the extracted scandium; fourthly, extracting the feed liquor 1 and the feed liquor 2, performing back extraction for a loaded organic phase by NaoH solution, and using sulfuric acid to dissolve hydroxide obtained after back extraction; fifthly, removing titanium by water, subjecting scandium-rich liquor with the titanium removed to secondary extraction according to conditions, washing the loaded organic phase by sulfuric acid solution containing Nacl and H2O2, then using NaoH solution for back extraction, and performing filtering, ignition and hydrochloric acid dissolving for scandium hydroxide obtained after back extraction; and finally, precipitating scandium oxalate from oxalate, and then converting the scandium oxalate to the scandium oxide by means of ignition.

Description

technical field [0001] The invention relates to a method for recovering scandium from a mixture containing scandium, titanium, zirconium, etc. by sulfuric acid leaching, organic solvent extraction and oxalic acid precipitation, especially a method for separating and recovering scandium from tungsten steel slag. Background technique [0002] At present, the ways to recover scandium from ilmenite and its products include: recovery from the hydrolysis mother liquor of titanium dioxide production and recovery from the chlorination fume of Ticl4 production, while the recovery of Sc2O3 from tungsten steel slag has not been reported in China. The existing technology for extracting scandium from titanium white mother liquor has low acidity (6N) and low TiO2 content (about 4 g / L), while the scandium content in tungsten steel slag is about 250 g / ton After leaching with sulfuric acid, the TiO2 content in the acid leaching solution is as high as 50-80 g / L, and the acidity is above 18N. ...

AI Technical Summary

Problems solved by technology

The existing technology for extracting scandium from titanium white mother liquor has low acidity (6N) and low TiO2 content (about 4 g / L), while the scandium content in tungsten steel slag is about 250 g / ton After leaching with sulfuric acid, the TiO2 content in the acid leaching solution is as high as 50-80 g / L, and the acidity is above 18N. Therefore, it is difficult to extract scandium oxide from tungsten steel slag with the existing method of extracting scandium from titanium white mother liquor , but must explore a method suitable for extracting scandium from said tungsten steel slag

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