digestion process. However, their acid process does not use liquidliquid extraction.)8 When tin slags are used for the recovery of tantalum, they are sometimes upgraded in an electric furnace process (not shown), yielding a synthetic concentrat The slag is smelted with carbon to reduce the iron, tantalum, and columbium components, which are
Improved solvent extraction recovery of tantalum and niobium oxides from an acid solution of raw materials containing such oxides wherein the charged organic solvent [, MIBK] is washed out (a) with 816N sulfuric acid and then (b) with water or dilute HF. This avoids the use of a second mineral acid addition after digestion by HF of raw materials (and avoids problems .