scholarly journals Investigation of Affecting Parameters on Heap Leaching Performance and Reducing Acid Consumption of Low Grade Oxide-Sulfide Copper Ore

2017 ◽  
Vol 2 (4) ◽  
pp. 40 ◽  
Author(s):  
Mohsen Azmayandeh
Keyword(s):  
Heap Leaching ◽  
Low Grade ◽  
Copper Ore ◽  
Acid Consumption

Insights into Heap Bioleaching at the Agglomerate-Scale

2017 ◽  
Vol 262 ◽  
pp. 185-188 ◽  
Author(s):  
Alison Cox ◽  
Christopher G. Bryan
Keyword(s):  
Interstitial Cell ◽  
Cell Concentration ◽  
Low Grade ◽  
Dissolved Metals ◽  
Copper Ore ◽  
Cell Numbers ◽  
Liquid Phases ◽  
Heap Bioleaching ◽  
Cell Concentrations ◽  
The Difference

Previous agglomerate-scale heap bioleaching studies have outlined the variations in cell numbers of the liquid and attached phases during colonisation of sterilised ore by a pure culture. In this study, a mixed mesophilic culture was used in agglomerate-scale columns containing non-sterilised low-grade copper ore. Over a six - month period, columns were harvested at various intervals to provide snapshots of the metal distribution and the quantity, location, and ecological variations of mineral-oxidizing microbes within the ore bed. The initial colonisation period in this experiment was dissimilar to previous work, as the indigenous community was retained within the ore-bed throughout acid agglomeration. The overall colonisation phase lasted for approximately 1,000 hours until cell concentrations stabilised. In each column, less than 0.05% of the total cells were found in the leachate, 15-20% in the interstitial phase and the remaining ~80% were attached to the mineral surface. Once cell numbers had stabilised, interstitial cell concentrations were approximately 2,000× greater than those in the leachate. This difference persisted for the duration of the experiment. Copper concentrations in the two liquid phases generally decreased over time, but were on average 50× higher in the interstitial phase. Iron concentrations were more stable, but again were 30× higher in the interstitial phase. This demonstrates that that the difference in cell concentration between the leachate and interstitial phases cannot be explained through diffusion gradients within the system as it is much greater than those observed for the dissolved metals. It also shows that the specific environmental conditions of the interstitial and attached cells are very different to those inferred through analysis of leachates alone.

scholarly journals Effects of Fe+2 and Fe+3 in Pretreatment and Leaching on a Mixed Copper Ore in Chloride Media

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 866
Author(s):  
María E. Taboada ◽  
Pía C. Hernández ◽  
Aldo P. Padilla ◽  
Nathalie E. Jamett ◽  
Teófilo A. Graber
Keyword(s):  
Chloride Concentration ◽  
Solution Concentration ◽  
Copper Extraction ◽  
Curing Time ◽  
Ferrous Ions ◽  
Copper Ore ◽  
Second Stage ◽  
Acid Consumption ◽  
Nacl Concentration ◽  
Leaching Solution

A study of the pretreatment stage and subsequent leaching of a mixed copper ore with different chloride solutions containing iron was carried out. The first stage considered pretreatment tests to decide the best conditions. Two levels of each factor were analyzed, 20 and 50 kg/t of NaCl, 17 and 25 kg/t of H2SO4, 0 and 25 kg/t of Fe2(SO4)3·9.2H2O, 0 and 25 kg/t of Fe2SO4·7H2O, and a curing time of 15 and 30 days. The results showed a significant effect of NaCl and curing time on the extraction, and less effect was found with the variation of acid and iron salts. The second stage included column leaching using a solution with 0.5 g/L of Cu+2, 80 g/L of Cl−, 10 g/L of H2SO4, and variable concentrations of ferric and ferrous ions (0 and 2 g/L). The best copper extraction of 80.2% was found considering a pretreatment of 30 days, 25 kg/t of H2SO4, 50 kg/t of NaCl, and a leaching solution concentration described previously with 2 g/L of Fe+2. The results showed the leaching of all copper oxide species and 20% of the copper sulfide species. In addition, there was a reduction in the acid consumption as the resting time increases. Furthermore, to evaluate a possible decrease in time and acid in pretreatment and chloride in leaching, tests including 10 and 25 kg/t of H2SO4 and 1, 15, and 30 days of curing and a diminution of the NaCl concentration to 20 g/L (content from seawater) were executed. The results showed a significant effect on curing time below 15 days. Furthermore, the slight influence of the decrease of acid on copper extraction gives cost reduction opportunities. The diminution of chloride concentration (80 to 20 g/L) in leaching solution decreases the extraction from 79% to 66.5%. Finally, the Mellado leaching kinetic model was successfully implemented.

Bioleaching of Low-Grade Copper Sulfide Ore Using a Colum Reactor

2009 ◽  
Vol 71-73 ◽  
pp. 409-412
Author(s):  
Wen Qing Qin ◽  
Yan Sheng Zhang ◽  
Shi Jie Zhen ◽  
Jun Wang ◽  
Jian Wen Zhang ◽  
...  
Keyword(s):  
Iron Concentration ◽  
Mixed Cultures ◽  
Copper Recovery ◽  
Low Grade ◽  
Leaching Rate ◽  
Ministry Of Education ◽  
Copper Ore ◽  
Copper Leaching ◽  
Pure Cultures ◽  
Mixed Bacteria

The effects of several variables on the column bioleaching of copper sulphide ore have been investigated. The copper ore contained chalcopyrite as the main sulfide minerals and bornite and chalcocite as the minor minerals. The experiment was carried out using bench-scale column leach reactors designed in Key Lab of Biometallurgy of Ministry of Education, which were inoculated with the pure mesophile bacteria (Acidithiobacillus ferrooxidans) and thermophile bacteria (Sulfobacillus), respectively, and the mixed bacteria which contain both iron- and sulfur-oxidizing bacteria. The results show that the mixed cultures were more efficient than the pure cultures alone and the maximum copper recovery 53.64% was achieved using the mixed cultures after 85 days. The leaching rate of chalcopyrite tended to increase with the increased dissolved ferric iron concentration. The effect of particle size on the rate of the copper leaching was also investigated, and it was shown that the copper bioleaching rate decreases as the amount of fines increase, which limits the permeability, thus decreases leaching rate. Jarosite and elemental sulphur formed in the column were characterized by the X-ray and EDS.

Hypochlorite pretreatment in heap leaching of a low grade carbonaceous gold ore

1991 ◽  
Vol 8 (1) ◽  
pp. 27-31
Author(s):  
M. Ahmadiantehrani ◽  
J. L. Hendrix ◽  
G. Ramadorai
Keyword(s):  
Heap Leaching ◽  
Low Grade ◽  
Gold Ore

scholarly journals Copper Recovery from Silicate-Containing Low-Grade Copper Ore Using Flotation Followed by High-Pressure Oxidative Leaching

2017 ◽  
Vol 64 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Baisui HAN ◽  
Batnasan ALTANSUKH ◽  
Kazutoshi HAGA ◽  
Yasushi TAKASAKI ◽  
Atsushi SHIBAYAMA
Keyword(s):  
High Pressure ◽  
Copper Recovery ◽  
Low Grade ◽  
Copper Ore ◽  
Oxidative Leaching

Biological Production of Copper Sulfide Concentrate from Flotation Tailings and Low Grade Ore

2017 ◽  
Vol 262 ◽  
pp. 202-206 ◽  
Author(s):  
Víctor J. Zepeda ◽  
Ivan Nancucheo ◽  
Milton Guillen ◽  
Enrique Becerra ◽  
Camila Escuti ◽  
...  
Keyword(s):  
Copper Sulfide ◽  
Mine Drainage ◽  
Mining Industry ◽  
Low Grade ◽  
Copper Ore ◽  
Flotation Reagents ◽  
Selective Precipitation ◽  
Flotation Tailings ◽  
Fine Grained ◽  
Fine Chemistry

Flotation tailings are hazardous due to physical and chemical instability and are currently considered one of the main pollution concerns of mining industry. Most of these tailings are fine-grained residues with low copper content (0.1-0.8%) and include toxic compounds, such as heavy metals, arsenic, and flotation reagents, among others. Another hazard is the generation of acid mine drainage (AMD) due to biological oxidation of tailings. On the other hand, low-grade ore is challenging the mining industry to commercially produce copper.The main objective of this work was to assess the use of flotation tailings and low-grade ore to produce a biologically-produced copper sulfide, as a product for further pyrometallurgical or fine chemistry processing. Low-grade ore and flotation tailings were first agglomerated at different proportions and leaching tests were performed in 1m columns, using either industrial or synthetic raffinate solution. Then, the PLS solution obtained from the column tests was subjected to selective precipitation of copper by using biogenic hydrogen sulfide (H2S) generated by a mixed culture of neutrophilic sulfate reducing bacteria (SRB), enriched from sediments of Caracarani river (located at 4,600 m over sea level in northern Chile).Over 91% of the copper soluble present in the PLS was recovered as copper sulfide in 28 days, while ferrous iron, other metals and arsenic remained in solution. Analysis performed by XRD confirmed the presence of copper in the precipitate (58% as covellite). This work demonstrates the possibility to apply bioleaching and bio-precipitation technologies to treat tailings and low-grade copper ore to produce a high quality copper sulfide.

Bio-Heap Leaching of Primary Copper Sulfide Ore by JOGMEC

2017 ◽  
Vol 262 ◽  
pp. 99-102
Author(s):  
Tatsuya Shinkawa ◽  
Tadashi Chida ◽  
So Furukawa ◽  
Taro Kamiya
Keyword(s):  
Copper Sulfide ◽  
Heap Leaching ◽  
Sulfide Ores ◽  
High Iron Content ◽  
Iron Oxidizing Bacteria ◽  
Acid Consumption ◽  
Sulfide Ore ◽  
Leaching Solution ◽  
Sulfur Oxidizing ◽  
Copper Sulfide Ore

JOGMEC has been carrying out the study on primary copper sulfide ores leaching for recovering copper economically and efficiently by heap leaching. In our study, we have been using the primary copper sulfide ore produced in an IOCG deposit. The ore is characterized by high iron content and high acid consumption in leaching. For the optimization of the leaching, the conditions such as ore size, agglomeration, pH and irrigation rate of leaching solution were examined with column leach tests. The best result was over 80 % extraction of copper in 150 days with leaching solution of 1 M sulfuric acid and temperature of 45 °C. In this experiment, the fines of the ore sample were removed before putting it into the column to keep the permeability of the ore bed. In these column leach tests, the Fe2+/total-Fe ratio of PLS decreased gradually by the activity of naturally grown iron-oxidizing bacteria. The bacteria in PLS, which have the ability of iron-oxidizing and sulfur-oxidizing, were identified by next-generation sequencing as Acidithiobacillus caldus and Sulfobacillus thermosulfidooxidans. We also carried out bench-scale tests with about 200 tons of the primary copper sulfide ores. Iron-oxidizing and sulfur-oxidizing bacteria were identified in the leaching solution as same with column leach tests. It is considered that the bacteria worked in the leaching solution and on the surface of the ores.

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