Extraction of silver from a refractory silver ore by sono-cyanidation

A comprehensive review on the ultrasound-enhanced leaching recovery of valuable metals: Applications, mechanisms and prospects

“…Ultrasound-assisted leaching technology has been extensively applied to extract valuable metals from metal ores, such as vanadium-bearing shale [16] , [19] , chalcopyrite [26] , [49] , scheelite [25] , [50] , [51] , zinc oxide ore [30] , [52] , [53] , nickel laterite ore [17] , rare earth ore [29] , refractory gold ore [27] , [54] , [55] , [56] , [57] , [58] , uranium ore [59] , [60] , K-feldspar [31] , copper-bearing biotite [43] , refractory silver ore [61] , eudialyte [62] , quartz sand [63] , [64] , [65] , [66] , [67] , [68] , poly-metallic sulfide ore [13] , deep-sea nodules [69] , phosphorus-potassium associated ore [21] , sphalerite [32] , and magmatic rocks [70] . In addition, ultrasound-assisted leaching has also been developed with successful enhancement in the leaching efficiency of metals from secondary resources, including metallurgical residues [3] , [15] , [35] , [38] , [39] , [42] , [48] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , spent catalysts [33] , [37] , …”

“…Silver (Ag) is widely adopted in various fields, such as chemical materials and photosensitive materials [61] . The leaching characteristics of Ag from various raw materials with the assistance of ultrasound are summarized and compared, which are displayed in Table 17 .…”

“…Alarcon et al [28] probed the applicability of ultrasound to recover Ag from polymetallic sulfide ores and stated that ultrasound is efficient in increasing the leaching ratio of Ag and the utilization efficiency of cyanide. Cilek et al [61] investigated the ultrasound-assisted leaching recovery of Ag from refractory silver ores in a cyanide system. The outcomes showed that almost equal or better Ag recoveries (up to 15.5%) was obtained at 24 h ultrasound-assisted cyanide leaching than those of 48 h conventional cyanide leaching, indicating that leaching duration could be considerably shortened by 50% with ultrasound assistance.…”

Biooxidation of refractory silver minerals as pretreatment for silver recovery

“…En un estudio de Zhao et al (2020), la biooxidación de concentrado de oro, seguida de lixiviación con tiosulfato, obtuvo buenos resultados. La aplicación de ultrasonidos a mineral de plata refractario, seguida de cianuración, así como el control de otras variables y mediante un diseño experimental estadístico, permitió un aumento significativo de la recuperación de plata (Cilek et al, 2020).…”

Preparation and Mechanism Study of Green Cyanamide Calcium

“…In recent years, the potential value of calcium cyanamide has been exploited and applied in various fields. Calcium cyanamide is also widely used as a precursor for other chemical substances, such as melamine, dicyandiamide, thiourea, unsubstituted and substituted guanidine, and melamine. − At the same time, it can also be used as a raw material for producing pesticides, fertilizers, plastics, and explosives. − In industry, it can be used for the nitridation of steel, the treatment of gold and silver ores, the removal of nitrogen oxides in exhaust gas, the removal of formaldehyde in wastewater, the nitriding of steel, the treatment of gold and silver ores, the removal of nitrogen oxide from waste gas. − It was worth mentioning that the air-stabilized calcium cyanamide-loaded ruthenium (Ru/CaCN 2 ) was an effective and stable catalyst for the synthesis and decomposition of ammonia . Gu et al reported a new synthesis route for the preparation of carbon nitride with a stoichiometric similarity to C 3 N 4 by the reaction of the cyanuric acid chloride with calcium cyanamide at 500–550 °C .…”