Environmental effects on bacterial copper extraction from low-grade copper sulfide ores

1967 ◽  
Vol 9 (4) ◽  
pp. 471-485 ◽  
Author(s):  
H. L. Ehrlich ◽  
Sally I. Fox
2013 ◽  
Vol 825 ◽  
pp. 344-347 ◽  
Author(s):  
Ai Xiang Wu ◽  
Bao Hua Yang ◽  
Jin Zhi Liu ◽  
Xiu Xiu Miao

Heap bio-leaching technology is extensively applied to recover metals from low-grade complex ores in the mining industry, particularly the copper sulfide ores. Understanding the effect of bio-leaching process on the pore structure of packed particle beds is important to enhance the percolation and leaching performances with respect to design and operation of heap leaching system. The porosity, pore size distribution and degree of pore connectivity are the three most important features correlated with fluid flow in heap leaching operation. In this study, a spiral X-ray CT scanner, combined with 3D imaging and analysis, was used to characterize the complex pore structure of the packed ore particle beds before and after bioleaching copper sulfide ores. The results indicate that the pore structure has temporal and spatial variations during bio-leaching process.


2014 ◽  
Vol 21 (2) ◽  
pp. 728-734 ◽  
Author(s):  
Jun Wang ◽  
Shan Zhu ◽  
Yan-sheng Zhang ◽  
Hong-bo Zhao ◽  
Ming-hao Hu ◽  
...  

2017 ◽  
Vol 262 ◽  
pp. 233-236 ◽  
Author(s):  
Denis W. Shiers ◽  
David M. Collinson ◽  
Helen R. Watling

In this study, a dynamically-controlled column was used to evaluate two ores known to cause heap overheating. This enabled the simulation of heap self-heating under controlled conditions. The lixiviant was inoculated with a consortia of mesophilic and moderately thermophilic microorgaisms, and the impact of rapid temperature increases on biological activity and cell numbers was evaluated. During the leaching of ore sample A, the temperature lagged for 29 days before increasing rapidly from 26 to 88 °C. Cell numbers and solution potential increased concomitantly, before both were reduced as the temperature increased past maximum microbial tolerances. Cell numbers began increasing again within 10 days of reaching temperatures that would facilitate mesophilic growth being restored. During the leaching of ore B, the temperature lagged for 4 days before exhibiting a rapid increase in temperature, increasing from 30 to 76 °C over a six-day period. Cell numbers were reduced with the sudden temperature increase, and did not recover over the remainder of the experiment.


2013 ◽  
Vol 825 ◽  
pp. 396-400 ◽  
Author(s):  
Bo Wei Chen ◽  
Liu Lu Cai ◽  
Biao Wu ◽  
Xue Liu ◽  
Jian Kang Wen

Shake flask bioleaching of a low-grade nickel-cobalt-copper sulfide ore from Lao was investigated to test the technical feasibility to recovery metals from this ore. The mineralogical results indicated that the valuable minerals were disseminated finely and the ore had a low content of sulfur and high content of iron and magnesium, which was very harmful for bioleaching. The effects of different parameters such as the amount of acid addition, inoculation volume, initial pH, temperature and leaching time on the bioleaching performance of the ore were evaluated after pre-leaching with dilute acid. The results showed that nickel, cobalt, copper leaching rates reached 81.61%, 80.75%, 70.97% at 33 °C and 83.40%, 82.13%, 70.34% at 45 °C. The mineralogical analysis of the leaching residues revealed that the leaching rate of nickel sulfide was more than 92% and the unleached nickel was mainly present as nickel silicate.


2017 ◽  
Vol 262 ◽  
pp. 202-206 ◽  
Author(s):  
Víctor J. Zepeda ◽  
Ivan Nancucheo ◽  
Milton Guillen ◽  
Enrique Becerra ◽  
Camila Escuti ◽  
...  

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.


2017 ◽  
Vol 262 ◽  
pp. 99-102
Author(s):  
Tatsuya Shinkawa ◽  
Tadashi Chida ◽  
So Furukawa ◽  
Taro Kamiya

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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