The tank bioleaching of metal sulphides is an established technology. Commercial success started with the treatment of refractory gold concentrates using mesophilic micro-organisms, followed by the development of tank bioleaching processes for the treatment of base metal concentrates. This was initially a mesophilic process treating secondary copper sulphides, …
Read MoreTo study the feasibility of a potential bioleaching project, we used the BIOX™ project, a process for the treatment of refractory gold concentrates, as an example (D.E. Rawlings). The bio-oxidation section contributes to more than 50 percent of the total BIOX™ plant equipment cost. The BIOX™ reactors and agitator are the brunt of this cost.
Read MoreBioleaching commonly refers to biomining technology applied to base metals; whereas, biooxidation is normally applied to sulfidic-refractory gold ores and concentrates.
Read MoreDuring bioleaching of arsenic-rich gold concentrates, the density of the mutant bacterial cells reached to 1.13 × 10 8 cells/mL at 15 days, more than 10 times compared with that of the original culture. The extraction of iron reached to 95.7% after 15 days, increased by 9.9% compared with that of the original culture.
Read MoreThis pilot will aim to recover metals from the surface using multi drills in which bioleaching fluids will be circulated. Phase II will be proposed as a pilot project in a follow-up EU call 2018. This new in-situ bioleaching technology is also expected to decrease the number of worker accidents in the mining industry compared to traditional ...
Read MoreThe invention relates to a method for recovering gold from a sulphidic concentrate, particularly one containing arsenopyrite and/or pyrite, hydro-metallurgically. The concentrate is first subjected to leaching with a concentrated solution of alkali chloride and copper (II) chloride, by means of which the copper minerals and some of the gold in the concentrate are made to …
Read Morethe bacteria for arsenic-rich gold concentrates bioleaching [11, 12]. In this paper, the bacterial flora enriched in acid mine drainage of Dexing copper mine, Jiangxi Province,
Read Moreconcentrates, iron precipitation, nickel concentrate, pH, pulp density Bioleaching and bio-oxidation are used to extract metals from low-grade, low-quality and complex ores and ore concentrates such as arsenic-containing and refractory gold concentrates. In this thesis, the bio-oxidation of a refractory gold flotation concentrate
Read MoreThe bioleaching of mineral sulfide pulps in a bench-scale rotating-drum reactor was studied. The reactor contained horizontal paddles on the inner wall for lifting the mineral pulp. The performance of the reactor was tested by bioleaching a refractory pyritic gold concentrate in the presence of pure Thiobacillus ferrooxidans (ATCC 19859). The concentrate was …
Read MoreGold bioleaching mediated by iodide oxidizing bacteria (IOB) has been proposed as a sustainable alternative to conventional technologies such as cyanidation. This study evaluated the ability of two IOB sourced from a commercial culture collection, Roseovarius (R.) tolerans DSM 11457T and R. mucosus DSM 17069T, to bioleach gold from electronic waste …
Read MoreThe bioleaching of the concentrate before cyanide leaching increased the gold extraction from 32 to 95% and that of silver from 48 to > 98%. INTRODUCTION It is known that many of the gold and silver deposits are often associated with sulfide minerals, especially pyrite.
Read MoreBiooxidation of gold ores or concentrates could be a very attractive alternative to pressure oxidation (POX) or roasting to liberate the gold grains from various sulfides. Crushed heap bioleaching was successful in US and many operations using tank bioleaching of gold concentrate are currently running around the world.
Read MoreMany studies on mutation breeding of bioleaching bac-teria have been done all over the world, but few focused on the bacteria for arsenic-rich gold concentrates bioleaching [, ]. In this paper, the bacterial ora enriched in acid mine drainage of Dexing copper mine, Jiangxi Province, China, was used to be mutated and for arsenic-rich gold ...
Read MoreFor bioleaching of gold ore concentrate with R. tolerans, triiodide concentrations were higher in one-step and two-step leaching than in the bacterial control (bacteria without ore concentrate) and spent medium leaching as shown in Figure 2 a. On the other hand, ...
Read MoreBioleaching experiments were conducted in 250 mL flasks containing 100 mL 9 K liquid medium and 10% (v/v) of bacterial flora. The pulp density of arsenic-rich gold concentrates was 5% (w/v), and the initial pH of the culture was adjusted to 2.0 with 5 mol/L H 2 SO 4.Flasks were incubated at 40°C and 160 rpm in a rotary shaker.
Read MoreAgitated Tank Bioleaching. Bioleaching processes in mechanically-agitated tanks are usually applied for the treatment of flotation concentrates derived from sulfidic ores. The valuable components in these concentrates can be gold, uranium and a variety of base metals such as copper, nickel, zinc and cobalt. Bioleaching is an attractive option ...
Read MoreAbstract. Bioleaching is a simple and effective technology for metal extraction from low-grade ores and mineral concentrates. Metal recovery from sulfide minerals is based on the activity of chemolithotrophic bacteria, mainly Thiobacillus ferrooxidans and T. thiooxidans, which convert insoluble metal sulfides into soluble metal sulfates.Non-sulfide ores and minerals can …
Read Morebioleaching of refractory gold concentrates has since found widespread application in South America, Asia, Africa and Australia. An industrial bioleaching plant for the treatment of a refractory gold concentrate. At the Beaconsfield Gold Mine in Tasmania, Australia, about 70 t per day of a refractory pyrite-arsenopyrite concentrate per day are
Read MoreThe plant was designed for treating gold and silver bearing concentrates, but it can be used for the bioleaching of copper, zinc, nickel and other base-metal concentrates (Anonymous, 2002c). Another ongoing project is a heap bioleaching plant to treat zinc sulphide concentrates that is being developed in the Kumba's Rosh Pinah mine in Namibia ...
Read MoreIn this thesis, the bio-oxidation of a refractory gold flotation concentrate (from the Agnico-Eagle, Suurikuusikko mine site, Kittilä, Finland) and the bioleaching of two nickel- and cobalt-containing flotation concentrates (from Mondo Minerals Oy Talc Mining Site, Sotkamo) were studied.
Read MoreBioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used ...
Read MoreThe results showed that bioleaching had markedly increased the extraction recovery of gold and silver compared with direct cyanidation of the pyrite concentrate without bioleaching. The latter approach achieved only 32% and …
Read MoreMorin D, 011iver P, Toromanoff I et al. Bioleaching of gold refractory arsenopyrite rich sulfide concentrate: laboratory and pilot case studies. In: Gaskell PR, ed. EPD Congress Proceedings. The Minerals, Metals and Materials Society, 1991: 577–589. Google Scholar
Read MoreAbstract. Natural bioleaching has been taking place for almost as long as the history of the world, but it is only in the last few decades that we have realized that bioleaching is responsible for acid production in some mining wastes, and that this bacterial activity can be used to …
Read MoreDuring bioleaching of arsenic-rich gold concentrates, the density of the mutant bacterial cells reached to 1.13 × 10⁸ cells/mL at 15 days, more than 10 times compared with that of the original culture. The extraction of iron reached to 95.7% after 15 days, increased by 9.9% compared with that of the original culture.
Read MoreInnovations in Copper: Mining & Extraction: Producing ...
Read MoreBioleaching gold recovery. Download Now. Download. Download to read offline. Environment. Nov. 30, 2015. 6,379 views. This is an ancient process which involves the alloying of the gold particles with metallic mercury to form amalgam and then the separation of the gold from the mercury by heating in Pressure oxidation: Utilizes oxygen and heat ...
Read MoreThe gold in refractory ores is encapsulated as fine particles (sometimes at a molecular level) in the crystal structure of the sulfide (typically pyrite with or without arsenopyrite) matrix. This makes it impossible to extract a significant amount of refractory gold by cyanidation since the cyanide solution cannot penetrate the pyrite/arsenopyrite crystals and dissolve gold particles, even ...
Read MoreBioleaching has been applied to copper and uranium deposits for many years, but more recently has been applied to gold ore refractory and refractory concentrates. This process involves the oxidation of sulfide, ferrous, and sometimes carbon containing minerals in order to liberate the gold trapped within.
Read MoreBioleaching of gold–copper concentrate The bioleaching experiments in shaken flasks were carried out using various solid concentrations. The range of solid concentration was between 12% and 25%. The results of the leaching of gold–copper concentrate are shown in Fig. 1. As can be seen the best results were obtained at 12% and …
Read MoreBioleaching of refractory gold concentrates at high pulp densities in a nonconventional rotating-drum reactor. M. N. Herrera, B. Escobar, N. Parra, C. Gonzalez, T. Vargas, G. Rossi 1 & T. Vargas 2 Mining, Metallurgy & …
Read MoreAbstract: S-11 adhesive was used to paste gold concentrate around low-grade primary ore and the column bioleaching was compared with traditional column bioleaching.The concentration of Fe2+,pH,Eh,attached bacteria concentration on the surface of ore,free bacteria concentration in leaching solution,oxidation rates of arsenic and sulfur and cyaniding leaching efficiency were …
Read MoreBioleaching of gold by metabolic products of microorganisms has received less attention, but also offers opportunities for industrial application, especially if future regulations restrict the use of cyanide. This paper reviews recent progress in the use of microorganisms tooxidize the sulfidic matrix in refractory gold ores (bio-oxidation) and ...
Read More