摘要:
The process comprises the following steps: (a) leaching with fluorosilicic acid with a minimal H2SiF6 concentration of 10% to 40% and greater to which a strong mineral acid, either HCl or H2SO4, may be added; (b) separation of Nb and/or Ta from the aqueous acid medium by liquid-liquid extraction using a suitable organic extractant; (c) recovery of the niobium and/or tantalum from the organic phases by re-extraction in aqueous phase followed by precipitation by a base, and subsequent calcination; (d) purification of the tantalum and/or niobium compounds to remove other undesirable elements, in particular silica, by carbochlorination.
摘要:
A thermite process for producing a metal or alloy by charging a reactor furnace with a mixture primarily containing a powdered metallic oxide and a reducing agent such as powdered aluminum, wherein a batch of the mixture of the starting materials is divided into a plurality of loading lots. The amount of heat generated by each of the loading lots of the starting materials is so regulated that it differs from any of the others and the loading lots are sequentially arranged. The lots are loaded into a furnace to form so may layers for thermite reaction in an ascending order in terms of the level of heat generation.
摘要:
Die vorliegende Erfindung betrifft aus Agglomeraten bestehende Erdsäuremetallpulver, insbesondere Niob und Tantal, für pulvermetallurgische Anwendungen zur Herstellung von Sinterkörpern, Verfahren zu ihrer Herstellung sowie deren Verwendung.
摘要:
Du tantale ou du niobium en poudre ou en morceaux contenant des impuretés volatiles, p.ex. de la poudre de tantale sodiothermique, est d'abord transformé en du métal coulé brut par fusion au moyen d'une torche à plasma et le métal coulé brut est ensuite affiné par fusion par bombardement d'électrons.
摘要:
Metallic niobium or metallic tantalum is produced by a process which comprises bringing a fluorine containing com pound of niobium or tantalum: (A) into contact with a gas comprising hydrogen at a temperature of at least 400°C; or (B) into contact with metallic aluminium, metallic magnesium or metallic lead, at a temperature of at least 300°C; to convert the fluorine containing compound into the corres ponding metal.