increasingly on lower grade more complex and refractory ores as well as smaller deposits As a result the level of sophistication that needs to be built into the design and operation of the heap leaching process also increases The heap leaching of copper ores is an example of such a trend where heap leaching
This review examines the acid and ferric sulfate bioleaching of uranium from low grade ores The review traces back the progression of the technology from the time the role of microorganisms was
Since then heap leaching has been adopted successfully by many mines across the world Heap leaching occurs after the mining and crushing of low grade ores usually in an opencast mine High grade ores and ores not amenable to cyanide leaching at coarse particle sizes require further processing to recover the gold values These processing
Heap leaching accounts for approximately 17% of global gold and 21% of global copper production respectively Marsden and Botz 2017; Basov 2015 It is the only economic technology available to extract value metals from low grade ores; however the slow rate of recovery is a major drawback and in most cases is related to heap permeability Petersen
Petersen J Heap Leaching as a Key Technology for Recovery of Values from Low Grade Ores—A Brief Overview Hydrometallurgy 2016 165 206 212 [Google Scholar] Abzalov Sandstone Hosted Uranium Deposits Amenable for Exploitation by In Situ Leaching Technologies Appl Earth Sci 2012 121 55 64 [Google Scholar]
Heap leaching has been implemented in different mining operations in order to recover copper gold and uranium It has been especially cost effective for treating low grade ores [1 2 3 4] In particular the heap leaching method to treat copper ores has been used in Chile since the 1980s It currently produces over Mt/year of cathodes
Heap bioleaching of low grade chalcopyrite CuFeS2 was carried out in 1000 tons scale over a time period of 383 days Bacterial solution was prepared and re‐circulated in specially designed
It can be performed via heap leaching vat leaching or agitated leaching [2 3]; however heap leaching is mostly adopted by local people because of its simple design low operating costs June
Heap leaching is a low cost technology used in industrial mining to recover precious metals such as gold and uranium along with several other highly sought after metals like copper from their primary resources ores and minerals For many decades there has been a growing demand for heap leaching due to its environmental benefits Heap leaching provides
With the gradual depletion of high grade uranium resources in southern China it is necessary to recover uranium from low grade complex and refractory uranium resources However the traditional acid mining process has certain drawbacks such as high acid consumption low uranium recovery and potential environmental pollution There is an urgent
1 Introduction Heap leaching is an industrial method to process low grade ores consisting of percolating an acid or alkaline leaching solution through a 4 to 10 meter high heap of crushed ore Ghorbani et al 2016 This technique is used to process several ores such as uranium copper or nickel laterites and is based on fluid rocks interactions at the heap scale
In order to better understand the heap leaching process of uranium ore agglomerates a multi scale approach based on 10 cm and meter scale columns was used to achieve a Representative Elementary Volume REV of packed agglomerates Heap leaching is an industrial method to process low grade ores consisting of percolating an acid or
In acid heap leaching of low grade ores such as copper nickel and uranium containing a large number of fines and clays the agglomeration process has been widely used to prevent fine particle
Heap leaching Fig 18 is suited for low grade ores abandoned tailings and discard stockpiles that cannot be economically processed via other beneficiation processes Papangelakis and
The agglomeration process represents a way used by nickel copper and uranium industries to enhance acid heap leaching of low grade ores containing large amount of fines and clays Dhawan et al 2013 This industrial technology consists in increasing ore particle size distribution by gathering fines to improve the heap permeability and stability and also
and uranium from low grade ores as well as in the pre treatment o f refractory gold ores respectively Dresher 2004; Gonzalez et al 2004 ; Rawlings and Johnson 2007 It is proposed
Dump leaching Heap and in situ leaching characteristics are combined in dump leaching Depending on the dump location an impermeable layer may or may not be employed in a dump leach The ore is dumped to allow similar processing to heap leaching but the geological conditions of the area allow a valley or pit to act as the sump Vat leaching
We evaluated uranium bioleaching from low grade granite type uranium ore using mixed acidophilic microbes from uranium mine leachate A 4854 ton plant scale heap bioleaching process achieved sustained leaching with a uranium leaching efficiency of % using a pH of and an Fe3 dosage of g/L Acid consumption amounted to g H2SO4
Heap leaching technology is finding increasingly widespread application to recover values from low grade ores especially in the gold and copper industry The particular attractiveness of the process is the relatively low cost recovery of the target metal at site without the need for energy intensive comminution providing the process can be combined with a
In 2006 SOMAIR decided to increase the uranium production by 50% using heap leaching for the treatment of low grade ores These ores which come from different lodes with various properties have Expand
Although heap leaching using sulfuric acid was introduced to the uranium industry in the 1950s sodium carbonate bicarbonate alkaline heap leaching of low grade Ca carbonate rich uranium ores has recently gained popularity This study presents the results of two column tests on a calcrete type uranium vanadium carnotite ore using a mixture of sodium carbonate
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