-
-
اتصل بالوكيل
The viability of thiocyanate leaching was confirmed in 1989, 9 and subsequent studies have reported gold recovery ranging from 93% (oxide concentrate in 0.6 M NH 4 SCN in the presence of glycine and 0.05 M Fe 3+, pH 2) to 95% (hard arsenopyrite in 0.4 M KSCN, pH 2–5). 11,14 Many studies have investigated thiocyanate leaching using 99.9% pure gold discs …
Relationship of gold recovery to sulfide oxidation required for ore A and concentrate to be amendable to cyanidation. A significant contemporary challenge for gold mining companies is to...
The rauc-condestable iron oxide copper-gold deposit, central coast of peru: Ore and related hydrothermal alteration, sulfur isotopes, and thermodynamic constraints. Econ. Geol. 104, 365–384 (2009).
Many sulfide ores, including Carlin-type gold ores 7 Arsenic sulfide ores Gold occurs as liberated particles and inclusions, and submicroscopic gold in arsenopyrite and oxidized products. Giant Yellowknife, Campbell Mine (Canada), Sao Bento (Brazil) and Carlin-type ores 8 Antimony sulfide ores Gold occurs mainly as native gold, with minor
In the light of mentioned above, pyrolysis pretreatment of sulfide gold ore can expose the encapsulated gold. Meanwhile, the pyrolysis products of pyrite are self-generating thiosulfate at atmospheric pressure by our proposed scheme, and applying it to the green extraction of gold has become a reality (Ou et al., 2022).Hence, the specific aim of this study is …
Double refractory gold ore, meaning significant gold is locked in sulfides and being "preg-robbed" by carbonaceous material, presented a new challenge in which pretreatment by oxidation was …
Iron oxide-copper-gold (IOCG) deposits are highly valuable concentrations of copper, gold and uranium ores. ... Sulfide ores are processed via froth floatation to obtain copper concentrate. Copper ...
There are two main types of copper ore that are of interest: copper oxide ores and copper sulfide ores. Both ore types can be economically mined, but they are processed in different...
A rock with 1% pyrite may contain 50 g/t gold, or 5, and there is no way to tell without an assay. Silver and platinum-group element mines have similar problems. ... Common ore typing problems include the presence of a mixed zone where oxide and sulfide ores coexist, a frequent feature of copper, cobalt, zinc, nickel, and a few other metals ...
The use of thiosulfate to extract gold from refractory ores is promising because of its non-toxicity and high selectivity. Sulfide minerals (i.e., pyrite, arsenopyrite, chalcopyrite), major gold carriers in refractory gold ores, …
The samples from three areas studied consisted of: (a) the massive sulfide deposit from Commonwealth Main with high gold (2.41–11.6 g/t), silver (545–1080 g/t), zinc (6.6–10 wt%) and lead (2 ...
Oxide copper–gold ores: The presence of clay minerals prevents flotation of these ores. Ester-modified xanthates have been used, with some success, to treat gold-containing oxide copper ores, using a sulphidization method. ... Theory and Practice Flotation of Sulfide Ores. Elsevier B.V., Petersborough, Ontario, Canada (2007), 10.1016/B978-0 ...
T he copper mining industry is reaching a turning point. Surface oxide deposits are depleting and copper miners are turning their attention to untapped sulfide ores found deeper underground. However, sulfides require more expensive processing techniques since they are not responsive to standard technologies that are used in oxide heap leaching.
There are different types of sulfide minerals. Selenides, tellurides and antimonides are just a few of the classes that sulfide minerals have. Second, sulfides differ from oxides through their …
An oxide gold ore was subjected to chloride/hypochlorite leaching at room temperature. The effects of three factors, including Ca(OCl) 2 vs. NaOCl, OCl − concentration, and HCl concentration on gold leaching performance were investigated. Due to formation of CaOCl + complex in solution and hence less reactivity, calcium hypochlorite produces a …
estimates for different methods of pretreatment were prepared and these estimated costs and ore sulfide grades then used to compare the process economics. 250 ... The majority of gold ores are classified refractory because the gold mineralogy is contained in sulphides. This type of gold is typically very fine gold or locked in solid
However, recovery rates and ore grade can affect profitability. The capital intensity for sulfide projects tends to be higher. Sulfide projects often come with by-product credits like gold or silver. While it's possible to extract these from oxide deposits, it typically requires a secondary leaching process and is less common.
Iron oxide copper-gold (IOCG) deposits are a diverse family of mineral deposits characterized by the following features: ... Chalcopyrite ore VS gold Chalcopyrite (a type of copper-iron sulfide) has properties very similar to pyrite. Its hardness (3.5 to 4) and specific gravity (4.1 to 4.3) are lower than those of pyrite, in addition ...
The leaching behavior of gold from an oxide gold ore using copper–tartrate–thiosulfate solutions has been investigated. Experimental parameters, including temperature, initial pH, and concentrations of copper tartrate and thiosulfate, were systematically studied. The capability of gold leaching using copper–tartrate–thiosulfate solutions is …
Gold processing - Mining, Concentrating, Refining: The nature of the ore deposit determines the mining and mineral processing techniques applied. Oxide ore deposits are frequently of such low grade (e.g., 3 to 10 parts per million) that extensive mineral processing cannot economically be justified. In this case they are merely shattered by explosives and then …
Gold is present in refractory sulfide gold ores mainly in arsenian pyrite and arsenopyrite, where it occurs in both the chemically bonded state and as nano-size grains of metallic gold. During roasting or pressure oxidation, the sulfide matrix is destroyed and essentially all the gold is converted to the metallic form. The liberated gold is readily dissolved in conventional cyanide …
The pretreatment of refractory gold ore is a complex chemical process. In addition to the oxidation of pyrite, some side reactions also occur. The phase changes of refractory gold ore before and after pretreatment are shown in Fig. 11. The main phases of refractory gold ore include quartz (SiO 2), pyrite (FeS 2), and dolomite (CaMg(CO 3) 2 ...
Recovering gold from sulfide refractory gold ore has been an important guarantee for the sustainable development of gold industry, while there are many challenges in the …
Types of copper ore: Oxides. As mentioned, copper oxide ores are not as attractive an exploration target as copper sulfide ores due to their lower grade. However, in some cases low-grade copper oxide ores can still be economically mined because they can be processed at a lower cost than copper sulfide ores. Oxidized copper orebodies may be
The temperatures needed are too high to be economic. Instead, it is extracted by electrolysis. The ore is first converted into pure aluminum oxide by the Bayer Process, and this is then electrolyzed in solution in molten cryolite - another aluminum compound. The aluminum oxide has too high a melting point to electrolyse on its own.
Microbial enhanced sulfide oxidation is one of the alternatives to roasting or pressure oxidation (POX). High grade whole ores or upgraded sulfide concentrates can be processed using POX or roasting processes but the high capital and operating costs often prohibit to process lower grade materials using these process methods.
Oxidized gold ores are relatively easier to treat using cyanide leaching than the sulfide ores because the oxidation process reduces the size of the sulfide matrix and liberates the gold particles.
Basically, refractory gold ores (gold recovery efficiency of <50% in average using direct cyanidation) are classified into sulfide, tellurium and carbon ores. Sulfide gold ores account for a large proportion of refractory gold ores, therefore, it is very meaningful to recover gold from sulfide gold ores (Ubaldini and Vegliò, 2000, Saba, 2011 ...
The effect of bio-oxidation and neutral atmospheric oxidation pre-treatment of refractory gold concentrates on gold and silver extraction during cyanidation was investigated. A series of pre-treatment experiments was conducted on three high sulfur (> 9%) refractory concentrates with 0.92–1.25 g/t gold and 64–90 g/t silver. Cyanidation of the pre-treated …
Gold in sulfide ores and technogenic formations after their processing is concentrated in the form of micro-dispersed particles. This article presents a study on the composition of the ultrafine ...
Globally, copper, silver, and gold orebody grades have been dropping, and the mineralogy surrounding them has become more diversified and complex. The cyanidation process for gold production has remained dominant for over 130 years because of its selectivity and feasibility in the mining industry. For this reason, the industry has been adjusting its methods …
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 behavior of carbonaceous matter. …
Abstract—Gold and silver are capable of forming stable natural compounds with different elements. For gold 36 minerals are known: 10 in the class "Native metals, intermetallic compounds" and 26 in the class "Sulfides (selenides, tellurides, arsenides, antimonides, bismuthides)." For silver, 194 minerals are registered in the MMA, presented in 8 classes. …
Problem with gold recovery from sulphide ore: How may a mill get the maximum recovery of gold from a sulphide ore, at the least capital cost and at the same time obtain the highest net return.This latter point is most important. In many cases a gold mill using an all-cyanide flowsheet with fine grinding of all the ore will report very low gold content in the tailings …
Gold ores are classified "free-milling" and "refractory" based on their response to cyanide dissolution. Bioprocessing can be used to treat refractory gold-bearing sulfide ores as well as carbonaceous gold ores. It is essential to characterize different types of gold ores to understand the extent and nature of gold-entrapment in different associated mineral phases before an …
Small particles of gold, a metal of higher interest, are mostly found in a matrix of sulfide-based minerals and not affordably recovered with conventional approaches encompassing cyanidation, pyrometallurgy, extreme heating (roasting), oxidation of ore …
pressure within a gold operation to reach the highest percent recovery, no matter what kind of ore is presented for treatment. For double refractory gold ores, the most crucial unit operation is performed by the roaster by creating a high temperature oxidation of the ore. An efficient roasting operation creates a
Copper processing is a complicated process that begins with mining of the ore (less than 1% copper) and ends with sheets of 99.99% pure copper called cathodes, which will ultimately be made into products for everyday use.The most common types of ore, copper oxide and copper sulfide, undergo two different processes, hydrometallurgy and pyrometallurgy, respectively, …