"Direct" leaching of attached bacteria would mean a direct electron transfer from the sulfide mineral to cell surface compounds (e.g. cytochromes), and further to molecular oxygen. Evidence for this direct electron transfer was provided by bioleaching experiments with At. ferrooxidans in "iron-free" medium and using metal sulfides such ...

The bacteria proliferation is accompanied by the oxidation process of ferrous and sulfide ions, which in turn catalyzes the gradual dissolution of copper sulfide minerals (Shiers et al., 2016). During the reaction process, the macroscopic bacterial concentration and the copper leaching rate are important indicators used to evaluate bacterial ...

Oxygen pressure sulfuric acid leaching is used to directly recover nickel, copper and cobalt from mechanically activated complex sulfide ore in the early stage, but the application of the process is limited by high-level equipment and high maintenance costs.8 Mixed nitric-sulfuric acid leaching at ambient temperature and atmospheric …

The Zaldívar open-pit, heap-leach copper mine, 175 km southeast of Antofagasta, is currently in the process of transitioning to chloride leaching operations with Cuprochlor. The project, which …

process, unlike other copper sulphide leaching methods, has several advantages: One of these advantages is the short heap leaching times, which range from 100 to 110 days [

In 2008, Antonijevic proposed copper recovery from Bor copper mine tailings through acid leaching. The tailings had around 21% sulfide content and 0.2% copper, with a particle size of approximately 0.074 mm. He used a 1-L beaker with mechanical and magnetic agitators, employing 500 mL of leaching solution and 100 g of …

Activation energy for the process of copper(I) sulphide leaching was determined by using the kinetic equations of Ginstling-Brounshtein, Spenser-Topley and Wadsworth (Sohn and Wadsworth, 1979). By applying these equations, it can be concluded that experimental results of the temperature influence on leaching degree (Fig. 2) are …

Yet primary-sulfide leaching offers a pathway to recover copper from material that is currently below mill head grade and considered waste. ... For major mining companies, the new technologies mentioned, such as coarse particle recovery, sulfide leaching, and process optimization with machine learning, highlight the importance and …

The bioleaching experiments show that the order of the copper bioleaching rates of four copper sulphide minerals, regardess of whether the optimum conditions or the initial ferrous iron ...

Research on chalcopyrite leaching represents a great challenge, given its importance as one of the most abundant copper minerals and its significant role in global copper extraction. This study aimed to evaluate the effects of different parameters on chalcopyrite leaching by hydrogen peroxide as a strong oxidizing reagent in sulfuric …

The method used to extract copper from its ores depends on the nature of the ore. Sulfide ores such as chalcopyrite ( CuFeS2 C u F e S 2) are converted to copper by a different method from silicate, carbonate or sulfate ores. Chalcopyrite (also known as copper pyrites) and similar sulfide ores are the commonest ores of copper.

Nuton will continue to test the application of its copper heap-leach related technology to the primary sulphide component of the Cactus Mine and Parks/Salyer Projects, in Arizona, through column leaching and scoping out capital and operating costs and design parameters, it added.

A typical heap leaching circuit is shown in Figure 1. This process is conducted in leaching piles, where their typical height is between 4 and 10 m, although in some cases, they can reach 18 m [ 28]. In addition, the largest sizes generally range between 10 and 40 mm in heap leaching, and sizes less than 6 mm are unacceptable.

The remaining water with Fe 3+ is used again in the leaching process after adjusting the pH to 2.0 with the help of H 2 SO 4. An outline of microbial leaching of copper is illustrated in Fig. 12.2. Bioleaching of copper has been used in the United States, Australia, Canada, Mexico, South Africa, Portugal, Spain and Japan.

The rapid leach kinetics and high copper recoveries place FL ROL's process economics on par with stirred-tank leaching of secondary copper sulphide concentrates. The key to the high performance of the process is the use of very low energy, inter-stage or intra-stage attrition along with the activation of the mineral to …

Inoculating the bacterial community with ferric iron (Fe 3+) under shaking conditions resulted in rapid copper recovery from bornite, leaching 40% of the Cu content after 10 days of cultivation. The addition of ferrous iron (Fe 2+) instead promoted Cu recovery of 30% at day 48, clearly delaying the leaching process. More efficiently, the ...

With this leaching process that could change, points out Muchnik, especially at sulphide mines that already have existing electrowinning infrastructure at their operations. Work continues to optimise the Cuprochlor-T ® process and, crucially, its cost, says Abraham Backit. One focus of attention is the energy used to heat the heap.

For example, acid leaching has been successfully used to process oxidized and mixed ores, pressure oxidation is usually used to process sulfide concentrates, and bioleaching is widely used to process low-grade sulfide ores (heap bioleaching) and finds limited use for processing substandard copper concentrates [18,19,20,21,22,23,24,25]. …

One typical chloride-based leaching is the CLEAR process, which is described for example in US patents 3,879,272 and 4,545,972. ... One of the important subject in copper sulfide leaching, Ore ...

This study focuses on the development of a hydrometallurgical process for efficient copper extraction from complex carbonaceous sulfide ore which contains chalcopyrite, carbonates (dolomite and calcite), and carbonaceous gangue minerals. ... Matuska et al. (2018) applied direct pressure leaching on the complex copper sulfide …

The feasibility of processing low-grade copper-nickel ores by heap bioleaching was investigated. It was found that an iron-oxidizing strain of acidophilic microorganisms, Acidithiobacillus ferrivorans, is effective in the leaching of sulfide ores from the deposits in Russia's Murmansk region. Sulfide mineralization of the studied …

ore composition. The use of this biochemical method in the copper leaching process resulted in a significant reduction in sulfuric acid consumption, by 40%, and a copper recovery rate of 87.2%. Keywords: copper leaching; sulfuric acid consumption; acid-intensive minerals; bio-oxidation 1. Introduction

Nickel resources are broadly classified as nickel sulfide ore and laterite ore, with nickel sulfide ore accounting for only about 30% of total nickel resources. However, at the moment, more than 50% of nickel products come from nickel sulfide ore. ... The nitric acid pressure leaching process employs nitric acid instead of sulfuric acid as the ...

The cost of the heap leaching process is low, making this process an attractive option from a financial standpoint. ... Analysis of heat conservation during copper sulphide heap leaching. Hydrometallurgy …

Among them, chalcopyrite (CuFeS 2) is one of the most abundant and widely distributed copper-bearing minerals, accounting for more than 70% of the earth's copper reserves [], and belongs to primary copper sulfide minerals.Although about 80% to 85% of the world's copper output is produced by means of pyrometallurgical processes, the …

The main disadvantage of sulfide (bio)leaching is that the process is considered slow compared to the pyrometallurgical process and other high-intensity hydrometallurgical processes ... microbial strains that are accustomed to the metals/metalloids in the waste is commonly used in the bioleaching of copper. During …

The use of ammoniumâˆ'thiosulfate solutions to leach gold and silver from the oxidizing leaching residue of copper sulfide concentrates was reported by BEREZOWSKY and SEFTON in 1979 [25]. ... (0âˆ'12 g/L) [105]. It was reported that in the process of leaching sulfide ores containing 4.3 g/t gold with copperâˆ'ammonia∠...

Extrapolations of copper sulphide grain exposure data indicate that the portion of copper available for leaching decreases to 10% when the ore particle size is increased to between 100 and 200 mm. In terms of kinetics, the observed leaching rate is a product of the chemical reaction rate itself and various transport processes such as for …

Dissolution of sulfide ores requires oxidative leaching conditions, then ISR can be conducted by applying bacterial leaching, a technology which is established in the copper industry for the treatment of copper sulfide ores in heaps and dumps (Ghorbani et al., 2016; Petersen, 2016).

The passivation layer forms on the surface of chalcopyrite and other primary sulfide minerals, preventing leaching from occurring effectively. In the study, Jetti's team used electrochemical analysis to discover that chalcopyrite is an n-type semiconductor in an accumulation state, not in a depletion state as has been commonly assumed to date.