An aqueous cobalt chloride solution purification method, in which impurities can be efficiently removed from a cobalt salt solution, includes bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a substitution reaction, in which the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5. Since the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5, a passive film on a surface of the metallic nickel can be effectively removed, and the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, so that an impurity more noble than the metallic nickel can be precipitated by the substitution reaction. The metallic nickel is only brought into contact with the aqueous solution containing cobalt chloride, and the impurity can be easily removed.

An aqueous cobalt chloride solution purification method, in which impurities can be efficiently removed from a cobalt salt solution, includes bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a substitution reaction, in which the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5. Since the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5, a passive film on a surface of the metallic nickel can be effectively removed, and the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, so that an impurity more noble than the metallic nickel can be precipitated by the substitution reaction. The metallic nickel is only brought into contact with the aqueous solution containing cobalt chloride, and the impurity can be easily removed.

Provided is a method for recovering a valuable metal from a material including waste lithium ion batteries or the like. The method comprises: a preparation step for preparing a material including at least Li, Al, and a valuable metal; a reduction and melting step for carrying out a reduction and melting process on the material to obtain a reduced product including a slag and an alloy containing a valuable metal; and a slag separation step for separating the slag from the reduced product to recover the alloy. In the preparation step and/or the reduction and melting step, a flux containing Ca is added. In the reduction and melting step, the reduction and melting process is performed such that the mass ratio of aluminum oxide/(aluminum oxide+calcium oxide+lithium oxide), in the generated slag, is set to 0.5-0.65, and the slag heating temperature is set to 1400-1600? ? C.

A wet smelting method for nickel oxide ores from which nickel, cobalt, etc. are recovered is provided with which it is possible to reduce the consumption of an acid in leaching, such as sulfuric acid, and to recover valuable metals. The method comprises: step (A) in which nickel oxide ores as a raw material are separated into a limonite-type ore having a low magnesium content and a saprolite-type ore having a high magnesium content; step (B) in which the saprolite-type ore is subjected to normal-pressure leaching under given standardized leaching conditions using the pressure leachate obtained by pressure leaching in step (C); and step (C) in which the limonite-type ore obtained in step (A) is mixed with the normal-pressure leaching residue obtained in step (B) and the mixture is reacted with sulfuric acid in an acidic atmosphere having a high temperature and a high pressure, thereby conducting pressure leaching.

A process for thermal treatment of a sulfur-containing ore in which the ore is calcined at temperatures of between 600 and 1200? C. in the presence of oxygen in a reactor so that between 1 and 90% by weight of sulfur contained in the ore is burned to sulfur dioxide and impurities contained are driven off in gaseous form. The exhaust gas being produced and containing the sulfur dioxide is fed into a gas purification comprising at least one component and/or the calcined ore is fed into at least one further process stage. An exhaust gas from the gas purification and/or the process stage and/or a gas used for cooling within the gas purification or for cooling within a further process stage is at least partially returned back into the reactor as recycling gas having a temperature of >100? C.

A mineral processing facility is provided that includes a cogen plant to provide electrical energy and waste heat to the facility and an electrochemical acid generation plant to generate, from a salt, a mineral acid for use in recovering valuable metals.

A mineral processing facility is provided that includes a cogen plant to provide electrical energy and waste heat to the facility and an electrochemical acid generation plant to generate, from a salt, a mineral acid for use in recovering valuable metals.

The invention relates to a method and apparatus for recovering metals from metalliferous starting materials comprising steps of i) leaching the metalliferous starting material in chloride-based leaching liquor, ii) withdrawing from the leaching step i) aqueous chloride solution with dissolved metals, iii) recovering metal value from the aqueous chloride solution in a metal recovery process step, iv) neutralizing hydrogen chloride content of the aqueous chloride solution in the metal recovery process step with adding hydrolyzed ammonia to the process solution so as to form ammonium chloride, v) withdrawing ammonium chloride containing process solution to an ammonium regeneration step where calcium-containing reagent is added to generate calcium chloride and ammonia gas and recycling ammonia back to the metal recovery process step iii), vi) regenerating the CaCl.sub.2-solution with H.sub.2SO.sub.4 so as to provide a aqueous HCl solution for recycling to the leaching step i).

In an embodiment, a method of fabricating a leached polycrystalline diamond (PCD) body is disclosed. The PCD body includes bonded diamond grains defining interstitial regions at least a portion of which include at least one interstitial constituent disposed therein. The method includes leaching the PCD body with a leaching agent to remove at least a portion of the at least one interstitial constituent therefrom. The leaching agent includes a mixture having hydrofluoric acid in a first concentration of about 10 weight % to about 50 weight %, nitric acid in a second concentration of about 5 weight % to about 25 weight %, and water in a third concentration of about 25 weight % to about 85 weight %. Further embodiments relate to different leaching methods and different leaching agent compositions.

A method for extracting metals from the black mass of lithium-ion batteries, the black mass containing the anode and cathode materials of the batteries, wherein the cathode material comprises lithium, nickel, and cobalt. The method is carried out by an arrangement that is suitable for use in the method.