El método de fundición de tantalio
El mineral de tantalio-niobio suele ir acompañado de una variedad de metales. Los pasos principales de la fundición de tantalio son descomponer el concentrado, purificar y separar tantalio y niobio, preparar compuestos puros de tantalio y niobio y, finalmente, preparar metal.
Los minerales se pueden descomponer mediante el método de descomposición del ácido fluorhídrico, el método de fusión del hidróxido de sodio y el método de cloración. El tantalio y el niobio se pueden separar mediante extracción con disolventes (los extractantes comúnmente utilizados son metilisobutilcetona (MIBK), fosfato de tributilo (TBP), sec-octanol y acetamida, etc., cristalización fraccionada e intercambio iónico.
Separation: First, the concentrate of tantalum-niobite is decomposed with hydrofluoric acid and sulfuric acid to form tantalum and niobium into fluorotantalic acid and fluoroniobium acid, which are dissolved in the leaching solution. In the leachate, a strong acid solution with complex composition is formed. The tantalum and niobium leaching solution is extracted with methyl isobutyl ketone to extract tantalum and niobium into the organic phase at the same time, and the trace impurities in the organic phase are washed with sulfuric acid solution to obtain a pure organic phase washing liquid containing tantalum and niobium, and the raffinate is combined, which contains Trace amounts of tantalum, niobium and impurity elements are strong acid solutions and can be comprehensively recovered. The pure tantalum-niobium-containing organic phase is stripped of niobium with a dilute sulfuric acid solution to obtain a tantalum-containing organic phase. Niobium and a small amount of tantalum enter the aqueous phase and then extract the tantalum with methyl isobutyl ketone to obtain a pure niobium-containing solution. The pure tantalum-containing organic phase is back-extracted with water to obtain a pure tantalum-containing solution. The organic phase after stripping the tantalum is returned to the extraction and recycled. Pure fluorotantalic acid solution or pure fluoroniobium acid solution react with potassium fluoride or potassium chloride to form potassium fluorotantalate (K₂TaF₇) and potassium fluoroniobate (K₂NbF₇) crystals, and can also react with ammonium hydroxide to generate hydrogen Tantalum oxide or niobium hydroxide precipitates. The hydroxide of tantalum or niobium is calcined at 9001000 degree to form oxide of tantalum or niobium.