A smelting method capable of obtaining an iron-nickel alloy having a high nickel grade of 4% or higher by effectively facilitating a reduction reaction of pellets formed using a nickel oxide ore as a raw material. The present invention is a method for smelting a nickel oxide ore, by which an iron-nickel alloy is obtained by forming pellets from a nickel oxide ore and reducing and heating the pellets. In the pellet production step S1, a mixture is obtained by mixing raw materials that contain at least a nickel oxide ore and a carbonaceous reducing agent. In the reduction step S2, a furnace floor carbonaceous reducing agent is laid on the floor of the smelting furnace in advance when placing the obtained pellets in the smelting furnace and the pellets are placed on the furnace floor carbonaceous reducing agent and then reduced and heated.

Provided is a method for producing a pellet capable of suppressing heat shock-induced crack occurrence, when nickel oxide ores are made into pellets and placed in a reducing furnace in a smelting process. In the method for producing a pellet from a nickel oxide ore, a nickel oxide ore, a binder and a carbonaceous reducing agent are mixed, the mixture is made into a lump, and then the resulting lump is subjected to a preheat treatment at a temperature of 350 C. to 600 C. In this preheat treatment, the lump more preferably undergoes the preheat treatment at a temperature of 400 C. to 550 C.

Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, and leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution.

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 as well as some copper, and the cathode material comprising lithium and nickel. The method of extracting metals carried out by an arrangement that is suitable for use in the method.

Disclosed in the present invention is a method for extracting valuable metal from low-matte nickel converter slag. The method comprises: mixing low-matte nickel converter slag and quicklime then calcinating, obtaining a calcinated material; grinding and magnetically separating the calcinated material, obtaining silicate and iron-rich slag; adding a strong alkali solution to the iron-rich slag to perform leaching processing, and performing solid-liquid separation, obtaining a filtrate and a residue; mixing the residue with an acid solution, performing oxygen pressure acid leaching, and performing solid-liquid separation, obtaining a leachate and iron oxide; introducing hydrogen sulfide gas into the leachate, adjusting the pH, and performing solid-liquid separation, obtaining a copper sulfide precipitate and a nickel-cobalt-containing filtrate. In the present invention, first, removing silicon dioxide is removed by means of calcination to prepare silicate, then iron oxide is prepared by means of acid leaching, and finally metal separation is performed on the leachate, causing various components of the converter slag to be effectively utilized. The process flow of the present invention is short and effectively utilizes each component of the low-matte nickel converter slag, waste is turned into valuable material, and the loss of valuable metal elements is reduced.

Provided is a method for producing valuable metal from raw materials including, for example, waste lithium ion batteries by a pyrometallurgical method, said method making it possible to efficiently separate manganese included in the raw materials from metal into slag without lowering the valuable metal recovery rate. The present invention is a method for producing valuable metal from raw materials comprising: a reduction melting step for subjecting the raw materials to a reduction melting process so as to obtain a reduction product containing slag and molten metal that contains valuable metal; a slag separation step for recovering the molten metal from the reduction product; and an oxidation purification step for adding silicon dioxide (SiO.sub.2) as flux to the recovered molten metal and performing an oxidation melting process. In the oxidation purification step, SiO.sub.2 is added as the flux such that the SiO.sub.2/MnO weight ratio is 0.4-1.0 in the slag.

Systems and methods for sequestering carbon, evolving hydrogen gas, producing iron oxide as magnetite, and producing magnesium carbonate as magnesite through sequential carbonation and serpentinization/hydration reactions involving processed olivine- and/or pyroxene-rich ores, as typically found in mafic and ultramafic igneous rock. Precious or scarce metals, such nickel, cobalt, chromium, rare earth elements, and others, may be concentrated in the remaining ore to facilitate their recovery from any gangue material.

Provided is a hydrometallurgical process for nickel oxide ore effectively reducing the amount of sulfuric acid used in the leaching step and the amount of a neutralizer such as slaked lime used in the final neutralization step without reducing nickel yield. The present invention is a method for pre-treating ore slurry to be submitted for leaching treatment in a hydrometallurgical process for nickel oxide ore, the method comprising: a separating step for separating the ore slurry into a coarse particle fraction, in which particles having a particle diameter of less than 45 m are 30 mass % of the solids or less, and a fine particle fraction, and feeding said fine particle fraction to the leaching process; and a vibration sieving step for separating the separated coarse particle fraction into oversize particles and undersize particles using vibration sieving and feeding the ore slurry of said undersize particles to the leaching process.

Oxygen is injected into the windbox of a fluidized bed ore roaster to form a fluidizing and oxidizing gas stream of elevated oxygen content which is fed into only the feed zone into which the ore to be fluidized is fed.

Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, and leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution.