The present invention provides a method which is capable of more strictly controlling the oxygen partial pressure required during the melting of a starting material, thereby being capable of recovering a valuable metal more efficiently. A method for recovering valuable metals (Cu, Ni, Co), said method comprising the following steps: a step for preparing, as a starting material, a charge that contains at least phosphorus (P), iron (Fe) and valuable metals; a step for heating and melting the starting material into a melt, and subsequently forming the melt into a molten material that contains an alloy and slag; and a step for recovering the alloy that contains valuable metals by separating the slag from the molten material. With respect to this method for recovering valuable metals, the oxygen partial pressure in the melt is directly measured with use of an oxygen analyzer when the starting material is heated and melted.

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.

A process for nickel concentration and extraction from non-sulfidic iron-bearing nickeliferous resources is disclosed. The process includes an atmospheric acid-based leaching treatment of the non-sulfidic iron-bearing nickeliferous resources by oxalic acid to produce a nickel concentrate comprising distinct nickel oxalate particles. The nickel concentrate is technically amenable to further chemical and physical processing to obtain various high-grade nickel products.

Provided is a method for recovering valuable metals contained in waste batteries, wherein valuable metals can be efficiently recovered while suppressing a reduction in recovery rate. The method according to the present invention for recovering valuable metals from waste batteries comprises: a roasting step S1 for roasting a waste battery; a crushing step S2 for inserting an obtained roasted material into a crushing container, and crushing the roasted material using a chain mill; and a sieving step S3 for sieving an obtained crushed material and separating the crushed material into sieve upper material and sieve lower material. A chain mill equipment that is used in the crushing process is provided with: a rotating axial rod vertically erected with respect to a bottom surface of a crushing container; and a chain attached to a side surface of the rotating axial rod.

Provided is a smelting method capable of effectively promoting a reduction reaction on pellets formed using nickel oxide ore as starting material to obtain a ferronickel alloy with a high nickel grade of at least 4%. The present invention is a method for smelting nickel oxide ore wherein ferronickel alloy with a nickel grade of at least 4%, the method comprising a pellet-producing step S1 for producing pellets from nickel oxide ore, and a reducing step S2 for reduction-heating of the obtained pellets in a smelting furnace. In the pellet-producing step S1, the pellets are produced by mixing nickel oxide ore with a specified amount of a carbonaceous reducing agent as starting materials. In the reducing step S2, the produced pellets are charged in a smelting furnace in which a carbonaceous reducing agent (furnace bottom carbonaceous reducing agent) has been spread over the entire furnace bottom and reduction-heating is performed.

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 hydrometallurgical process of recovering Ni from nickel oxide ore using a high pressure acid leaching, in which abrasion of the facilities caused by an ore slurry is suppressed, the amount of a final neutralized residue is reduced, and impurity components are separated and recovered for recycling. The hydrometallurgical process includes, as steps of the high pressure acid leaching, at least one step selected from step (A): separating and recovering chromite particles in the ore slurry; step (B-1): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH).sub.2; and step (B-2): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH).sub.2, and then recovering hematite particles.

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.

There is provided a process for treating particulate scrap material. The process includes emplacing the particulate scrap material and a reagent material within a calcining zone with effect that a reactive process is effected such that a calcined metal material product is obtained, and carbonylating a carbonylation precusor material with effect that a carbonylated product is obtained, wherein the carbonylation precursor material is derived from the calcined metal material product.

Provided is a method that allows for efficient removal of an impurity metal, and further, the recovery of a valuable metal with high efficiency. The method for recovering a valuable metal (Cu, Ni, and Co) includes the steps of: preparing a charge comprising at least a valuable metal as a raw material; heating and melting the raw material to form an alloy and a slag; and separating the slag to recover the alloy containing the valuable metal, wherein the heating and melting of the raw material comprises charging the raw material into a furnace of an electric furnace equipped with an electrode therein, and further melting the raw material by means of Joule heat generated by applying an electric current to the electrode, or heat generation of an arc itself, and thereby separating the raw material into a molten alloy and a molten slag present over the alloy.