Leaching copper and precious metals from fragmented ore in heaps, mine stripping waste dumps, and caved workings is rapidly expanding in the western United States, and its economic value now...
The fines produced in crushing or slimes contained in the ore interfere with leaching and lowers extraction due to channeling of solution through the coarser segregated particles. Channeling can be …
A summary of recent studies indicates that uranium ore is mainly treated by stacking, heap leaching, stope, and in situ biological leaching. Because uranium deposits contain rare earth elements, future bioleaching applications are likely to focus increasingly on these deposits, allowing for the full exploitation of metallic resources [93, 95 ...
The findings of column leaching tests demonstrated that permeability was substantially improved by the surfactant. In the later period of leaching, the permeability coefficient was two times higher than that of the control group. Meanwhile, the ore extraction rate increased by approximately 10%.
Copper heap leaching is a rate-dependent process sensitive to copper mineralogy (copper oxides > secondary sulfides > hypogene sulfides), driven by the pH of the leach solution, the activity of ferric iron (Fe3+ (aq)) …
The chemical binder is one of the critical factors affecting ore agglomeration behavior and leaching efficiency. In this study, we investigated the effect of the type of binder and mass fraction of the H 2 SO 4 solution used on the curing, soaking, and leaching behavior of agglomerations.
POX in a copper heap leach circuit. Figure 2. Simplified ferric leaching flowsheet. Figure 3. Copper chloride leach process. Leaching Chemistry As outlined earlier, the leaching chemistry that takes place within a total POX autoclave is very complex and will vary from case to case according to the mineralogy of the concentrate fed to the
Leachable copper is the true head grade for heap leaching, and the orebody should be modelled accordingly. Select the appropriate leachable copper assay procedure. Better to start correctly than ...
Almost all of the copper oxide and sulfide minerals encountered in such deposits are leachable by this method, since the leach cycle is measured in years. Heap leaching is used primarily to extract …
Only few heap bioleaching plants, such as Zijinshan copper mine accumulated enough acid and iron in cycling solution during leaching under the excessive pyrite oxidation [ 9, 12 ]. So for most heap bioleaching plants, accelerating of the pyrite oxidation can reduce the cost of sulfuric acid addition to the heap irrigation solution.
Ambient temperature, pressure and even humidity can affect leaching testwork, especially with sulphides. Therefore pay attention to any difference in ambient conditions between the testwork...
A common hydrometallurgical method for producing copper is to "heap leach" a low grade ore. Coarse ore is stacked in heaps and irrigated with an acidic solution to leach the copper minerals. In sulfate medium copper minerals are …
Fig. 1a: Industrial Column Leaching – Oxide Ore Leach time is 70% of control 34% more copper leached 28ppm LixTRA™ Control Results From Figure 1 (a-d) the beneficial effect of using LixTRA™ can be observed when leaching; a) an oxide ore b) a secondary sulfide ore, c) a mixed oxide/primary sulfide ore and d) an agglomerated mixed oxide ...
The objectives of any copper heap bacterial leaching should encompass the following main points: 1) Characterise ore for particle size, elemental composition, mineralogy, acid consumption...
Agglomeration through geopolymerization can produce agglomerates suitable for acid heap leaching, which can solve the permeability problem of low-grade copper …
Heap bioleaching has been used for copper/nickel/cobalt/zinc/uranium bioleaching and in the biooxidation of complex refractory gold ores (Brierley and Brierley 2001;Jia et al. 2019;Kaksonen...
When processing copper through heap leaching, vast quantities of ore and overburden are mined. The overburden is separated and either hauled to the waste site …
Oxidation of pyrite can provide the essential sulfuric acid and oxidant Fe 3+ for copper sulfide dissolution during heap bioleaching of copper sulfides. So, if the ore …
As heap leaching is a process that involves many physical and chemical aspects (dissolution, diffusion, convective and dispersive transport, chemical reactions, among others), it is difficult...
Sulfuric acid solution containing ferric iron is the extractant for industrial heap bioleaching of copper sulfides. To start a heap bioleaching plant, sulfuric acid is usually added to the irrigation solution to maintain adequate acidity (pH 1.0–2.0) for copper dissolution. An industrial practice of heap bioleaching of secondary copper …
Heap leaching is a simple means of recovering copper from oxide and oxide-sulfide ores. Although this method requires relatively low capital investment, it suffers from low copper recoveries and relatively …
Ore particles, especially fine interlayers, commonly segregate in heap stacking, leading to undesirable flow paths and changeable flow velocity fields of packed beds. Computed tomography (CT), COMSOL Multiphysics, and MATLAB were utilized to quantify pore structures and visualize flow behavior inside packed beds with segregated …
Heap bioleaching has been used for copper/nickel/cobalt/zinc/uranium bioleaching and in the biooxidation of complex refractory gold ores (Brierley and Brierley …
In situ leaching does not include dump or heap leaching where the ore is blasted and/or dug and placed in areas specially prepared for leaching, but is reserved for the process where chemical solutions are circulated through the ore body. Although the ore may be blasted to increase permeability for in situ leaching, it is not transported.
The chemical binder is one of the critical factors affecting ore agglomeration behavior and leaching efficiency. In this study, we investigated the effect of the type of binder and mass fraction of the H2SO4 solution used on the curing, soaking, and leaching behavior of agglomerations. The results revealed that Portland cement (3CaO·SiO2, …
Currently, the technologies of choice are heap or dump leaching, both of which have been commercialised on very large scales for the leaching of copper sulfide ores [30,164] but historically, in situ and in stope bioleaching have received considerable attention for the extraction of copper [232,233] and uranium [162,234]. Investigations of the ...
test heap, poor copper extraction, only 2% in 500 days compared with a nickel recovery of 92%. The test heap at Radio Hill was constructed using copper-nickel ore from the Mt Sholl deposit. The results obtained from this test heap prompted the studies described in the present paper and are thus summarised specifically. 1.1. Copper-nickel ore ...
A summary of recent studies indicates that uranium ore is mainly treated by stacking, heap leaching, stope, and in situ biological leaching. Because uranium deposits contain rare earth elements, future …
Heap leach operations typically employ some form of modelling and forecasting tools to predict cash flow margins and project viability. However, these vary from simple spreadsheets to phenomenological models, with more complex models not commonly employed as they require the greatest amount of time and effort. Yet, accurate …
The alkaline residue allows immediate application of cyanide leaching of gold and silver in ores where there is an economic precious metal content after removal of high cyanide consuming metals such as copper. Typical Capital and Operating Costs for Copper Heap Leaching An analysis of the economics of the AmmLeach® process compared with
Because a high pulp density significantly inhibits microbial activity, when the pulp density was greater than 15%, it had a great influence on the leaching rate of copper and zinc [ 35, 42 ]. 2.2.4. …
This report describes laboratory permeability leaching tests conducted on three clayey ores (two uranium and one copper), employing both alkaline and acidic leach solution. Clay-swelling tests and zeta …
To solve the problem of low permeability and lower extraction rates of high-mud ores, a surfactant was added as a penetrant to the pregnant leaching solution during column leaching tests. On the basis of the theories of physical chemistry and seepage flow mechanics, the mechanism by which seepage is enhanced under the effects of the …
Heap leaching is done on ores of semilow grade—that is, high enough to be brought to the surface for treatment. This method is increasing in popularity as larger tonnages of semilow-grade ore are mined. The ore …
