|Antimony ores are concentrated by flotation and gravity methods. The element is extracted mostly by pyrometallurgical method which is precipitation of the fusion with iron. Alternatively partially oxidized ores as well as for ores containing precious metals are subject of oxidizing roasting with sublimation. It may be applied for Sb2O3, which on the next step is processed by reduction smelting. In both cases Na2CO3, Na2SO4 or NaCl are used as flux. Roast-reaction smelting based on reaction Sb2S3 + 2Sb2O3 : 6Sb + 3SO2, soda fusion 2Sb2S3 + 6Na2CO3 + 3C : 4Sb + 6Na2S + 6CO2, and alkaline fusion are also used for this purposehydromatallurgical method: leaching by Na2S NaOH solution with following electrolysis, applied, especially for copper-antimony concentrates. |
Fire refining include removing of iron and copper affecting on them by Sb2S3 or sulphur, alkaline refining from Arsenic and sulphur, purification from sodium by SiO2. Fire refining include removing of iron and copper affecting on them by Sb2S3 or sulphur, alkaline refining from Arsenic and sulphur, purification from sodium by SiO2 and pouring under the molten burah layer or NaSbO2 ("asteriated slag"). For gold, silver and lead removing electrolytic refining is applied using sulphate-fluoride-potassium-alkaline solutions. High-purity antimony is recovered via intermediate compounds such as SbCl3 or SbH3, which are passed through rectification, for instance. Electrolytic refining with glycerol-alkaline or xylitol-alkaline electrolytes also works. The refining process is completed by zone melting or other crystallization methods are used.