Provided are: an extractant which is capable of quickly and highly efficiently extracting zirconium from an acidic solution that is obtained by acid leaching a material containing zirconium and scandium such as an SOFC electrode material; and a method for extracting zirconium, which uses this extractant. A zirconium extractant according to the present invention is composed of an amide derivative represented by general formula (I). In the formula, R1 and R2 respectively represent the same or different alkyl groups, each of which may be linear or branched; R3 represents a hydrogen atom or an alkyl group; and R4 represents a hydrogen atom or an arbitrary group other than an amino group, said arbitrary group being bonded, as an amino acid, to the carbon.

The present invention relates to the recovery of rare earths, scandium, niobium, tantalum, zirconium, hafnium, titanium, and the like from ores or concentrates containing fluorine. More specifically, the ores or concentrates are pretreated by carbochlorination to convert the rare earths and other metals into their chlorides and then subjected to dilute hydrochloric acid leaching to recover the valuable rare earths and other metals from the leachate. Niobium, tantalum, zirconium, hafnium, and titanium can be recovered as their chlorides or oxychlorides from the gaseous products of carbochlorination, or converted into their oxides while simultaneously regenerating chlorine.

The present invention relates to the recovery of rare earths, scandium, niobium, tantalum, zirconium, hafnium, titanium, and the like from ores or concentrates containing fluorine. More specifically, the ores or concentrates are pretreated by carbochlorination to convert the rare earths and other metals into their chlorides and then subjected to dilute hydrochloric acid leaching to recover the valuable rare earths and other metals from the leachate. Niobium, tantalum, zirconium, hafnium, and titanium can be recovered as their chlorides or oxychlorides from the gaseous products of carbochlorination, or converted into their oxides while simultaneously regenerating chlorine.

A method for the production of metal powders or metal hydride powders of the elements Ti, Zr, Hf, V, Nb, Ta, and Cr is disclosed, whereby an oxide of the said elements is mixed with a reducing agent and said mixture, optionally with a hydrogen atmosphere (for the production fo metal hydrides), is heated until the reduction reaction commences, the reaction product is quenched, then washed and dried. The oxide used has an average particle size of 0.5 to 20 m, a BET specific surface of 0.5 to 20 m.sup.2/g and a minimum content of 94 wt %.

A method for the production of metal powders or metal hydride powders of the elements Ti, Zr, Hf, V, Nb, Ta, and Cr is disclosed, whereby an oxide of the said elements is mixed with a reducing agent and said mixture, optionally with a hydrogen atmosphere (for the production fo metal hydrides), is heated until the reduction reaction commences, the reaction product is quenched, then washed and dried. The oxide used has an average particle size of 0.5 to 20 m, a BET specific surface of 0.5 to 20 m.sup.2/g and a minimum content of 94 wt %.

A method for producing a metal powder that combines molten reducing metal and metal halide in a space that is substantially free of oxygen and water, wherein the molten reducing metal is sodium and/or potassium, or aluminum (or magnesium or titanium) and is present in a stoichiometric excess to the metal halide which is a solid or liquid, thereby producing metal particles and salt, removing unreacted reducing metal, optionally removing the salt, and recovering the metal powder, is described. A method for producing a metal masterbatch wherein the molten reducing metal is aluminum, magnesium, and/or titanium and after combining molten aluminum (or magnesium or titanium) and metal halide in the reaction space, substantially removing the produced metal salt to obtain the metal masterbatch which comprises at least a portion of the molten aluminum (or magnesium or titanium) and at least one metal also is described.

A method for producing a metal powder that combines molten reducing metal and metal halide in a space that is substantially free of oxygen and water, wherein the molten reducing metal is sodium and/or potassium, or aluminum (or magnesium or titanium) and is present in a stoichiometric excess to the metal halide which is a solid or liquid, thereby producing metal particles and salt, removing unreacted reducing metal, optionally removing the salt, and recovering the metal powder, is described. A method for producing a metal masterbatch wherein the molten reducing metal is aluminum, magnesium, and/or titanium and after combining molten aluminum (or magnesium or titanium) and metal halide in the reaction space, substantially removing the produced metal salt to obtain the metal masterbatch which comprises at least a portion of the molten aluminum (or magnesium or titanium) and at least one metal also is described.

A process for improving the grade and optical quality of zircon, comprising: baking a mixture of a zircon feed and concentrated sulphuric acid at a baking temperature in the range of from 200 up to 400 C., and for a time to form water leachable sulphates with impurities therein including at least iron and titanium; leaching the baked mixture to dissolve the leachable sulphates; and separating the zircon from the leachate containing the leached sulphates, which separated zircon is thereby of improved grade and optical quality.

A process for improving the grade and optical quality of zircon, comprising: baking a mixture of a zircon feed and concentrated sulphuric acid at a baking temperature in the range of from 200 up to 400 C., and for a time to form water leachable sulphates with impurities therein including at least iron and titanium; leaching the baked mixture to dissolve the leachable sulphates; and separating the zircon from the leachate containing the leached sulphates, which separated zircon is thereby of improved grade and optical quality.

A method for processing a heavy mineral concentrate obtained from froth treatment tailings to produce a zirconium concentrated product, including subjecting the heavy mineral concentrate to froth flotation, subjecting a flotation product to initial gravity separation, subjecting an initial gravity separation product to primary dry separation, subjecting a primary dry separation product to finishing gravity separation, and subjecting a finishing gravity separation product to finishing dry separation to produce a finishing dry separation product as the zirconium concentrated product.