Oxidation of sulfide mineral and metal extraction analysis in the microwave-assisted roasting pretreatment of refractory gold ore

Sulfuric Acid Baking and Fe(III)-Cl─-H2SO4 Leaching Behavior of Ni- and Cu-Containing Sulfide and Silicate Rich Suhanko Concentrate

“…27,28 Raw material including PGMs bearing ores, PGM concentrate, and PGM bearing matte are generally treated with a pressure leaching process using halides, H 2 SO 4 , or cyanide lixiviant with O 2 , Cl 2 , or HNO 3 oxidant followed by a recovery process including precipitation, metal cementation, carbon adsorption, ion exchange (IX), solvent extraction (SX), electrowinning (EW), or SX-EW. 29−31 To improve the leaching efficiency from refractory ores, especially high silicate bearing ores, many pretreatment processes such as roasting, 32,33 bio-oxidation, 34,35 and baking 36 have been used to either activate or passivate the targeted phases. Among these processes, baking with sulfuric acid is the most common process used to pretreat high silicate bearing ores like calamine and manganite, as it allows the conversion of acid-soluble silicate into an insoluble form at relatively low temperatures (25−300 °C), controlling the leaching of Si.…”

“…To improve the leaching efficiency from refractory ores, especially high silicate bearing ores, many pretreatment processes such as roasting, , bio-oxidation, , and baking have been used to either activate or passivate the targeted phases. Among these processes, baking with sulfuric acid is the most common process used to pretreat high silicate bearing ores like calamine and manganite, as it allows the conversion of acid-soluble silicate into an insoluble form at relatively low temperatures (25–300 °C), controlling the leaching of Si .…”

Evaluation of the Efficiency of Using an Oxidizer in the Leaching Process of Gold-Containing Concentrate

“…A significant part of the gold in the concentrate is finely interspersed and associated with pyrite and arsenopyrite, which makes it difficult to directly cyanide the enrichment products. Processing of persistent gold-containing raw materials is carried out according to technologies based on the use of pre-oxidative roasting, autoclave and bacterial oxidation, and ultrafine grinding with subsequent cyanidation [15][16][17][18][19]. The most common method of opening fine gold associated with pyrite and arsenopyrite and implemented in the practice of processing resistant gold-containing raw materials is oxidative roasting [20,21].…”