A method of recovering iron from a zinc sulfate solution according to an embodiment of the present disclosure is associated with recovering iron from a zinc sulfate solution produced by a leaching process in which zinc ore is dissolved in sulfuric acid. The method comprises a conditioning process including a step of reducing a conditioning process input solution, which is the zinc sulfate solution, and an iron precipitation process for recovering iron as hematite, including a step of pressurizing and oxidizing an iron precipitation process input solution discharged from the conditioning process. The iron precipitation process is performed at a temperature ranging from 135° C. to 150° C. and a pressure ranging from 5 barg to 10 barg.

Provided is a method of inhibiting degradation of an extractant by an anhydrous environment avoiding and metal stripping, the method including the steps of: (a) stopping the addition of soda ash (Na.sub.2CO.sub.3) to an extracting reaction tank; (b) starting solution recirculation and stopping solvent recirculation of a settler; (c) supplying a solvent from a loaded organic tank to a scrubbing reaction tank, in which the scrubbing reaction tank, stripping reaction tank and extracting reaction tank are connected for circulation and operating stirrers of the scrubbing reaction tank, stripping reaction tank and extracting reaction tank; (d) supplying a sulfuric acid solution having a controlled concentration with a diluting solution to the stripping reaction tank; (e) transferring the solvents of the settler, the loaded organic tank and all the pipes to the scrubbing reaction tank; and (f) stopping the step (e) and initiating solvent recirculation.

Provided is a method for inhibiting extractant degradation by a diluent and an extractant input manner, the method including steps of: (a) determining and analyzing the total volume of the DSX solvent when the diluent and the extractant, which are the DSX solvents, are added in the DSX process and identifying the concentration of the extractant; (b) calculating an extractant concentration according to an amount of the diluent to be added based on the analysis value of step (a), and then adding the extractant; (c) determining the ratio between the extractants through analysis after adding the extractants; (d) adding the extractant to be needed when the ratio between extractants is out of the range; and (e) adding the diluent and analyzing the ratio between the extractants.

A method of extracting metals from polymetallic sulphide ores or concentrates comprising at least Cu, Zn, Pb and Ag, comprising a first step of atmospheric leaching in sulphate medium in the presence of recycled silver for extracting Cu and Zn and a second step of atmospheric leaching in chloride medium for extracting Pb and Ag.

Provided is a method for measuring the concentration of bis(2,4,4-trimethylpentyl) phosphinic acid using ICP-OES, the method including the steps of: (a) decomposing and dissolving an organic solvent into an acid; (b) preparing a phosphorus reference solution and producing a calibration curve using the phosphorus reference solution; and (c) measuring the phosphorus concentration (mg/L) of the solution of step (a) using the calibration curve of step (b) and calculating the concentration (v/v %) of bis(2,4,4-trimethylpentyl) phosphinic acid in the organic solvent using the phosphorus concentration.

A vertical low-pressure reactor with stirred tank for leaching polymetal minerals and concentrates of lead, copper, zinc, iron and/or the mixtures thereof, in a solid-gas-liquid three-phase suspension system. The low-pressure vertical reactor with stirred tank consists of: a cylindrical vertical container with three or four deflectors evenly distributed across the 360; a stirring system made up of two impellers coupled to a rotary shaft, that provides adequate reaction and interaction of the metal species of interest; a space of the volume of the reactor, corresponding to 20% to 35% of the total volume of the container, located at the top of the reactor and which acts as a gas chamber that provides a continuous feed of oxygen; and a system of coils placed on the outside or inside surface of the reactor to ensure efficient heat-transfer reactions and controlled kinetics.

A process for leaching a mineral particulate material comprising the steps of feeding the mineral particulate material to a leaching step (10) in which at least one valuable metal in the mineral particulate material is leached into a leach solution to form a pregnant leach liquor and a solid residue containing undissolved mineral matter, the leaching step being conducted under conditions such that elemental sulphur is formed in the leaching step, wherein beads or particles that take up elemental sulphur are added to the leaching step such that elemental sulphur is taken up by or collects on the beads or particles, and separating the beads or particles from the pregnant leach liquor and the solid residue. The beads or particles may be treated to remove sulphur and the beads or particles are returned to the leaching step. Alternatively the mineral doesn't need to comprise a soluble component and can be a refractory sulphide of iron and/or arsenic containing precious metals that require oxidation before downstream conventional processes such as cyanidation.

A method of selectively leaching a metal such as nickel from an ore or ore processing intermediate comprising the metal and cobalt. The ore or ore processing intermediate is contacted with an acidic leach solution comprising an amount of an oxidising agent sufficient to oxidise a major portion of the cobalt to thereby cause it to be stabilised in the solid phase while a major portion of the metal is dissolved for subsequent recovery.

A hydrometallurgical process for the treatment of polymetallic ores and sulphide concentrates of copper and zinc, and by-products of lead and zinc from smelting plants, treated independently and/or as mixtures thereof, which contain relevant amounts of lead, copper, zinc, iron, gold and silver, such as the matte-speiss mixture of lead foundries, and copper cements from the purification processes of electrolytic zinc plants. The process allows the recovery of metallic copper, zinc, copper as copper and zinc basic salts, which may be hydroxides, carbonates, hidroxysulphates or mixtures thereof; the production of stable arsenic residues; and the effective and efficient recovery of Pb, Au and Ag as a concentrate of lead sulphide and/or lead, Au, and Ag sulphate.

A vertical autoclave according to an embodiment of the present disclosure is a vertical autoclave including an inlet port through which a process solution is introduced, an outlet port through which the process solution is discharged, an oxygen inlet port through which oxygen is supplied to the process solution, an agitator configured to mix the process solution, an inner wall, an acid-resistant brick layer lined on a lower portion and a side portion of the inner wall, and an acid-resistant metal layer lined on an upper portion of the inner wall. A method of removing salt from an autoclave includes raising a surface level of a solution in the autoclave from a first level to a second level such that salt in the autoclave is immersed in the solution, and maintaining the surface level of the solution at the second level. The salt is dissolved in the solution while the surface level of the solution is maintained at the second level.