It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores.
The results of the stage test showed that it is advisable to use a two-stage scheme for ore processing. The first stage of concentration in the grinding cycle (ore size 60–70%– 0.071 mm), the second at the final size (80%–0.071 mm). According to the GRG test, the ore is efficiently con-centrated by centrifugal methods.
Abstract. Double refractory gold ore (DRGO) not only include ppt levels of gold grains locked in sulfide minerals but also a problematic amount of carbonaceous matter. This causes a significant …
The limestone sample of zinc oxide ore with 6 per cent Zn was collected from a lead and zinc mine in Yunnan, China. It was processed with jaw crusher, double-roll crusher and vibration screen into ...
In 1029 1030 K.S. FRASER et al. the simplest of terms, a refractory ore is one where gold recovery by cyanidation alone is well below normally accepted levels. One definition, although somewhat arbitrary, has defined a refractory ore as one where gold recovery is less than 80% after conventional cyanidation.
The advantages of chloride leaching using copper(II) or iron(III) as oxidant are fast leaching kinetics and the possibility to process more complex raw materials. In this dissertation, chloride and chloride-bromide based processing of free-milling gold ore as well as refractory and double refractory gold concentrates was investigated.
As a kind of refractory gold ore resources, carbonaceous gold ore containing carbonaceous matter and sulfide minerals is generally considered as double-refractory [4,5]. Its processing is relatively complicated due to “preg-robbing†and the inhibition of the dissolution of gold by carbonaceous matter [6].
A notable example of such a double-refractory carbonaceous sulfide ore is at Barrick's Goldstrike Mine where gold occurs in pyrite in refractory sulfide ore and double-refractory sulfidic/ carbonaceous ore. These ores are pretreated by autoclave and roaster prior to cyanide leaching (Thomas et al., 2000; Wickens et al., 2003). In the Jinya
Microorganisms can play a beneficial role in all facets of minerals processing, from mining to waste disposal and management. Some of the applications, such as biologically assisted leaching of copper sulfide ores, uranium ores, and biooxidation of refractory sulfide gold ores, are now established on the scale of commercial processes.
However, refractory and double refractory ores are not easily treated by cyanidation because gold is locked within the sulfide minerals in refractory ores (Natarajan, 2018;Norgate and Haque, 2012 ...
Refractory gold ore is usually affected by the associated carbonaceous matter through the preg-robbing effect, which is eliminated by oxidation roasting, followed by leaching, to achieve a satisfactory gold …
During the roasting process of double-refractory ores in the presence of oxygen, the main reactions are the combustion of the carbonaceous material and sulfides. It is estimated that 81–89% of the TCM content in the ore is oxidized, producing carbon dioxide (about 96% of the carbon by weight) and carbon monoxide (about 4% of the …
The initial results for the cyanide leach gold recoveries were very poor on a high-grade primary sulphide ore of 6.2 g/t Au with no silver. Subsequent mineralogy showed the ore …
There are a number of factors that cause refractory behaviour in gold ores. Typically when we start investigating these ores the first step would be to undertake a mineralogical analysis that will tell you if your ore is sulphide refractory (and the grain size you are needing to target for liberation), if you have pregnant solution robbers or if you have a …
Processing proposal. The results of this investigation constitute a novel technical process for recovering gold from double refractory ores. As indicated on the flow diagram (Fig. 6), sulfides in flotation concentrate are subjected to biooxidation using the chemolithotrophic bacteria T. thiooxidans, T. ferrooxidans and L. ferrooxidans. The ...
Several pre-cyanidation treatment methods have been developed for double refractory gold ores, such as flotation and depression, blanking, the use of activated …
Presently, there are two approaches to enhance the process parameters of refractory ore processing technology. The first approach involves the inclusion of …
It is shown that the reasonable new process technology of combining mineral processing of Zn oxides after sulfides and hydrometallurgy could realize efficient recovery of the zinc minerals in the ...
The pyrite contains 43.36% Fe and 41.26% S. The occurrence of gold in the different phases of the sulfide refractory gold ore is shown in Fig. 2, which indicates that 93.94% Au is encapsulated, especially, sulfide-encapsulated gold up to 80.85%. The X-ray diffraction (XRD) pattern of the sulfide refractory gold ore and pyrite is shown in Fig. 3.
The treatment process of a low-grade refractory gold ore containing sulfide minerals and carbonaceous matters was studied in this work. ... R. H. Walton, and J. A. Wells, "Processing of refractory gold ores," Minerals Engineering, 4 (7–11 ... "Microwave pretreatment of a double refractory gold ore," Minerals Engineering, 20 (11) (2007 ...
1 Introduction. Nevada Gold Mines (NGM) processes Carlin-type ores that are difficult to float due to challenging regional mineralogy and that are increasingly …
processing of refractory sulphide carbon-bearing gold ores and float concentrates extracted from them include pressure oxidation and bacterial oxidation enabling the liberation of dispersive gold ...
Zinc processing, the extraction of zinc from its ores and the preparation of zinc metal or chemical compounds for use in various products. Zinc (Zn) is a metallic element of hexagonal close-packed (hcp) crystal structure and a density of 7.13 grams per cubic centimetre. It has only moderate.
A reactor to improve the leaching kinetics of refractory gold ores.. •. The Jetleach reactor is designed to propagate micro-cavitation in a chamber filled with oxygen. •. This reactor can improve the gold recovery while decreasing the leaching time. •. The Jetleach is a potential solution to the cyanidation problems of refractory ores.
Cyanide-refractory ores constitute 30 % of the world's gold mineral resource base. With the global decrease in the availability of high-grade and free-milling ores, low-quality ores, including ...
This has a significant effect on the environmental footprint of gold production as refractory ores cannot be easily treated by simple cyanidation treatment. In refractory ores, gold is typically encapsulated inside a sulfide matrix (pyrite, arsenopyrite) that must be decomposed to liberate the gold for leaching (Marsden and House Citation 2005).
A comprehensive mineralogical and physico-chemical examination of two refractory gold ores and concentrates from the Ghanaian gold province was conducted to gain a better understanding of the differences in performance of gold cyanidation. Both ore were mainly silicates, carbonates, oxide, phosphate and sulphides.
Refractory is generally defined as the ore thatyields <80 wt.% Au after standard physicochemical leaching conditions [11].Au-refractory ores, in most cases, contain elevated concentrations of arsenic, mainly with the form of arsenian pyrite (FeS 2), arsenopyrite (FeAsS), realgar (As 4 S 4), and orpiment (As 2 S 3).The entire …
The main contributions are described as follows: (1) A complete process of gold recovery from sulfide refractory gold ore was proposed and the gold was effectively recovered; (2) Pyrite was first used to enhance the chlorination roasting; (3) Thermodynamic analysis and laboratory experiments verified the feasibility and reliability …
Refractory ores are generally regarded as those where the gold is in some way locked 1 in the sulphide fraction. Approximately 10% of world gold production is from refractory ores (Yen et al ...
A simplified system boundary is also observed in Fig. 2, showing various stages from comminution to electrowinning for producing 1 kg gold from double refractory ores in a roasting process plant. A roasting facility in Nevada was developed to process 12,000 t of double refractory ore daily (Thomas et al., 1997; Thomas and Cole, 2016).
Carbonaceous gold-bearing ores of the type that occur in north central and northeastern Nevada were investigated by the Bureau of Mines as part of its Heavy Metals Program. Specific objectives were to identify the carbon and organic compounds that prevent adequate gold recovery from the ore by cyanidation, and to develop an …
Double refractory gold ores (DRGO) are becoming increasingly attractive as a source of gold, owing to the depletion of easier to process ores. The double refractory behavior is a consequence of the preg-robbing of dissolved Au species (Au(CN) 2 − ) by carbonaceous matter and encapsulation of the gold in sulfide minerals such as pyrite and ...
Gold ores are considered refractory if gold extractions from a conventional cyanidation process are less than 80% even after fine grinding. 1) Arsenic-bearing refractory gold ore has stones extremely difficult to deal with. In the stones, gold is locked up in arsenic mineral matrix as the form of microscopic or submicroscopic lattice.
1. Introduction. Cyanide leaching has been used conventionally to extract gold from ores for more than 100 years (Wang et al., 2013).The common steps in the cyanidation process are crushing and grinding, leaching, loading gold by activated carbon, gold elution from loaded activated carbon, and electrowinning (Khaing et al., …
1. Introduction. Cyanidation has been the predominant leaching method for gold ores since 100 years ago [1].Despite the success of cyanidation, its applicability is limited by some gold mineralization [2].This method's main limitation is in dealing with refractory gold ores in which sulphide minerals surround gold particles [3].The major …
Mekanism provides 4 tiers of systems to process ores and obtain two to five ingots from 1 ore. The complexity of the systems rises with each tier and at the higher tiers various secondary machines are required to produce consumables for the main ore processing line. The following page shows the layout of these systems as well as some in-game …
