The present invention relates to a method for extracting base and precious metals, all contained in refractory minerals, using aqueous media. The aim is to replace the current flotation/smelting-method for extracting minerals in Chilean and global mining or classical leaching with a method comprising a simple and robust pre-treatment that leads to solubilisation of the refractory matrices thereof. The method consists of mixing the mineral (Cu2S, CuS,CuFeS2, Cu5FeS4, FeS2, FeAsS.NiS, (Ni,Fe)xSy), ground to an appropriate size (2.5 centimetres), with a specific dose of solid reagent in a rotary agglomeration drum and then adding slightly acidified water to obtain a defined water content (5-8%) depending on the type of gangue contained in the metal-containing solid, thereby forming an agglomerate that will form a heap, which is subsequently allowed to stand for a period of several days (20-60 days), during which the conditions required to transform the refractory matrix into a highly soluble solid will be generated. Finally, appropriately regulated irrigation is applied, thus resulting in extraction of the metal by simple aqueous washing. In essence, the method achieves maximum transformation of the original refractory mineral into a highly soluble solid salt during a step prior to the conventional leaching process. Thus, the metal will be contained in a solid with a much higher solubility than the original matrix, therefore the dissolution thereof will be faster, more efficient and require a minimal use of consumables and reagents.

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 extraction of pure iron (III) oxide from bulk iron ore is provided that includes crushing and grinding, using a crushing machine, raw hematite ore, where a milled ore is formed, water-washing the milled ore by rinsing under continuous stirring conditions, dilute acid-washing the milled ore with diluted hydrochloric acid under continuous stirring conditions, immersing the dilute acid-washed milled ore in concentrated acid under the continuous stirring conditions, and applying heat, treating the heated and immersed milled ore with an alkali to form a precipitate, washing with water the precipitate to purify the precipitate, and drying the purified precipitate, and igniting the purified dry precipitate to extract a pure iron (III) oxide from a bulk iron ore.

A method of extraction of pure iron (III) oxide from bulk iron ore is provided that includes crushing and grinding, using a crushing machine, raw hematite ore, where a milled ore is formed, water-washing the milled ore by rinsing under continuous stirring conditions, dilute acid-washing the milled ore with diluted hydrochloric acid under continuous stirring conditions, immersing the dilute acid-washed milled ore in concentrated acid under the continuous stirring conditions, and applying heat, treating the heated and immersed milled ore with an alkali to form a precipitate, washing with water the precipitate to purify the precipitate, and drying the purified precipitate, and igniting the purified dry precipitate to extract a pure iron (III) oxide from a bulk iron ore.

Residuals, such as slag particles, from iron- and/or steel-making, and/or water-leached eluates thereof, are added directly to a conventional or multi-staged anaerobic digester or other sewage sludge or biosolid handling process. The slag particles or other residuals sorb, sequester, immobilize, or otherwise promote the removal of phosphorus and/or sulfur from wastewater, sludge, or biosolids being treated, such that the associated aqueous phase concentrations of phosphorus and sulfur are significantly reduced.

Residuals, such as slag particles, from iron- and/or steel-making, and/or water-leached eluates thereof, are added directly to a conventional or multi-staged anaerobic digester or other sewage sludge or biosolid handling process. The slag particles or other residuals sorb, sequester, immobilize, or otherwise promote the removal of phosphorus and/or sulfur from wastewater, sludge, or biosolids being treated, such that the associated aqueous phase concentrations of phosphorus and sulfur are significantly reduced.

A method of leaching copper-containing ores includes leaching copper-containing ores or concentrates or tailings of the ores or concentrates with a leach liquor in the presence of an additive that enhances the dissolution of copper from copper minerals in the ores and concentrates by forming a complex between (a) sulfur, that has originated from copper minerals in the ores, and (b) the additive. A method of leaching copper-containing ores includes leaching copper-containing ores or concentrates or tailings of the ores or concentrates with a leach liquor includes leaching copper-containing ores or concentrates or tailings of the ores or concentrates with a leach liquor in the presence of a nitrogen-containing organic complexing additive that forms a complex between sulfur, that has originated from copper minerals in the ores, and the additive.

A method of leaching copper-containing ores, such as chalcopyrite ores, with a leach liquor in the presence of silver and an activation agent that activates silver whereby the silver enhances copper extraction from copper ores.

A method of leaching copper-containing ores, such as chalcopyrite ores, with a leach liquor in the presence of silver and an activation agent that activates silver whereby the silver enhances copper extraction from copper ores.

The present invention refers to an agglomeration drum and to a procedure for the agglomeration of mineral inside said drum for the pretreatment of minerals, both of them mainly used in hydrometallurgy. Said drum and procedure use a system and a phase of recirculation of gases as part of the invention. Additionally, in the agglomeration procedure the process of chemical reactions occurring inside the agglomeration drum is included. The agglomeration drum, agglomeration procedure and the reactive process allow to obtaining uniform, stable and poorly degradable agglomerates that have a bigger agglomerate-reagent contact surface. The agglomerates or aggregates produced in the agglomeration drum and according to the process of the invention increase the extractive yield of the later leaching process, thus reducing the creation of preferred ways for the leaching solution in the leaching piles. In addition, the drum and procedure of the invention allow preventing the release of gases to the environment, having a gas recirculation system, which by being closed keeps gases inside the agglomeration drum and process. This recirculation of gases not only allows preventing the release of said gases to the environment, but it also reduces the operating costs by using the recirculated gases as part of the agglomeration process.