The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time.

The nature of gold (Au) ore deposits plays an essential role in determining the best gold recovery method as an alternative to cyanidation, considering environmental concerns. Thiourea (Tu) leaching of gold is an alternative lixiviant for treating sulfide gold ores and concentrates. The present study investigated the leaching behavior of Au …

It was indicated that microwave energy could have a potential application in comminution, drying, pre-treatment of refractory gold ores, coal desulphurisation, leaching, roasting, carbon reactivation, carbothermic reduction of oxides and waste and slag management.

The depletion of readily amenable gold ores and discovery of complex deposits inspire knowledge improvement and search of commercially effective technique in extracting gold from refractory gold ...

Double refractory gold ores, such as Barrick's Goldstrike ore, contain both pyrite and carbonaceous matter and the latter results in the loss of gold from solution during cyanide leaching.

Mechanical (ultra fine grinding P80 -16µm) and chemical (alkaline, NaOH) pre-treatment and microwave roasting and microwave-assisted cyanide leaching were investigated to increase gold recoveries.

The heap leach cyanidation carbon adsorption electrowinning process developed has proved to be an economical method for exploiting low-grade gold ores and small isolated deposits not suitable for treatment by conventional cyanidation procedures. Heap leaching may be the most profitable method for processing selected gold and …

The information compiled in this chapter demonstrates that microwave energy has the potential for application in mineral treatment and metal recovery processes such as heating, drying, grinding, leaching, roasting, smelting, carbothermic reduction of oxide minerals, pretreatment of refractory gold concentrate or ore, spent carbon …

For carbonaceous gold concentrate or carbonaceous pressure-oxidized gold ore, the gold leaching efficiency by cyanide is relatively low (J. Wang et al., 2019). This is due to the presence of abundant and structurally complex carbonaceous matters in gold ores, which can adsorb gold complexes and trigger "preg-robbing" effect, resulting …

X-ray diffraction data also showed the mineral phase shift from pyrite to hematite or pyrrhotite. A leaching test was conducted for the microwave-treated and untreated gold concentrates using ...

It was indicated that microwave energy could have a potential application in comminution, drying, pre-treatment of refractory gold ores, coal desulphurisation, leaching, roasting, carbon reactivation, carbothermic reduction of …

Overall, this study presents collective information for gold extraction from gold-bearing sulfides based on a leaching process consisting of microwave pretreatment in an inert atmosphere, and ...

The pretreatment of gold ores before cyanidation is a challenging problem due to the world's annual huge waste of refractory gold minerals. Generally, the leaching of gold by cyanidation without any pre-oxidation causes an extraction lower than 90%.

The application of pressure oxidation (POX) followed by thiosulfate gold leaching is an efficient method used to extract gold from double refractory gold ores containing both sulfide and carbonaceous matter. This process is expected to result in high gold recovery rates, as it liberates gold from sulfides and eliminates the preg-robbing …

A review on the negative impact of different elements during cyanidation of gold and silver from refractory ores and strategies to optimize the leaching process

Semantic Scholar extracted view of "Research on gold leaching of carbonaceous pressure-oxidized gold ore via a highly effective, green and low toxic agent trichloroisocyanuric acid" by Huiqun Niu et al.

Pressure oxidation (POX) is an effective method for base metal extraction and a pretreatment of refractory gold ores. A residue from pressure leaching…

This review aims to provide an up-to-date evaluation of thiourea-gold leaching studies from electronic waste, with emphasis on the recent progression from the classic chemical method to a more ...

The roasting is used as a pretreatment for refractory gold ore to increase gold recovery during leaching. The roasting step consumes high energy and produces high sulfur emissions into the atmosphere.

In this paper, the removal of arsenic from arsenic-bearing gold ore through air oxidation and sodium hydroxide leaching with microwave irradiation was studied. Firstly, single-factor experiments were carried out. The results indicated that the removal rate of arsenic was influenced by the sodium hydroxide concentration, ratio of liquid to solid, …

Alkaline pressure oxidation, as a clean and efficient method for strengthening hydrometallurgical leaching, has been used in the pretreatment of complex and refractory materials, such as lead-containing copper matte, refractory gold …

This paper explains a study on microwave-assisted leaching of aluminum from peat clay. Microwave-assisted leaching was undertaken using the Iwaki Pyrex glass reactor in a modified microwave oven.

Generally, these studies demonstrate that roasting, pressure oxidation, bacterial oxidation, chemical oxidation, alkaline oxidation and ultrafine grinding are as pretreatment methods prior to cyanide leaching to …

Microwave roasting and microwave-assisted leaching did not achieve higher recoveries than alkaline pre-treatment or fine grinding. The investigation highlights and confirms that chemical treatment with NaOH is a powerful tool for gold extraction from refractory tailings.

ants [21]. To date, the mechanism of thiourea decomposition by mineral particles remains unclear. Although biological oxidation, chemical ox-idation, pressure oxidation, and roasting could be used to re-move sulfides in gold ores prior to gold leaching, oxidation of

To solve this problem, the present study proposes a two-step process for gold extraction from high arsenopyrite-bearing gold ores: (1) the pre-oxidation of HAsBS using an am-monia solution containing cupric ions, and (2) ammonium thiosulfate leaching of the pre-treated ore to extract gold.

In this paper, the research progress of hydrometallurgical leaching of low-grade complex chalcopyrite is reviewed, and the advantages and disadvantages of mainstream leaching processes such as oxidation leaching, coordination leaching, and biological leaching are analyzed.

Refractory gold ore refers to gold ores with a low leaching rate under conventional leaching conditions, and gold ores with a leaching rate lower than 80% after direct cyanide leaching treatment ...

The results show that pressurized oxidation pretreatment can efficiently liberate gold from the mineral, but causes secondary inclusion of sodium jarosite. The one-step sodium jarosite decomposition treatment of the residue produced by oxygen pressure leach, can effectively liberate gold from the sodium jarosite pHase.

The technology regarded the carbonaceous matter in the carbonaceous gold ore as a raw material, utilized the carbon component to reduce pyrolusite, eliminated the influence of carbonaceous matter on gold, and improved the gold leaching rate.