scholarly journals Hydrodynamic Study Of Column Bioleaching Processes

2015 ◽  
Vol 14 (1) ◽  
pp. 52-61
Author(s):  
Zygmunt Sadowski ◽  
Joanna A. Baranska
Keyword(s):  
Porous Media ◽  
Black Shale ◽  
Copper Recovery ◽  
Experimental Equipment ◽  
Copper Ore ◽  
Bed Porosity ◽  
Heap Bioleaching ◽  
Leaching Solution ◽  
Support Ratio ◽  
Hydrodynamic Study

Abstract The modelling of flow leaching solution through the porous media has been considered. The heap bioleaching process can be tested using the column experimental equipment. This equipment was employed to the hydrodynamic studies of copper ore bioleaching. The copper ore (black shale ore) with the support, inertial materials (glass small balls and polyethylene beads) was used to the bioleaching tests. The packed beds were various composition, the ore/support ratio was changed. The correlation between the bed porosity and bioleaching kinetics, and copper recovery was investigated.

Primary Copper Ore Leaching by Leaching Solution Adjusted Oxidation-Reduction Potential in Column

2015 ◽  
Vol 1130 ◽  
pp. 355-358
Author(s):  
Tatsuya Shinkawa ◽  
Taro Kamiya ◽  
Kazuhiro Kojima ◽  
Tadashi Chida
Keyword(s):  
Sulfuric Acid ◽  
Recovery Rate ◽  
Copper Sulfide ◽  
Copper Recovery ◽  
Copper Ore ◽  
Column Leaching ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Copper Leaching ◽  
Leaching Solution

Copper ore is classified into three groups; primary copper sulfide, copper oxide and secondary copper sulfide. Leaching copper from primary copper sulfide, such as chalcopyrite, with sulfuric acid takes longer time than from copper oxide and secondary copper sulfide. As such, an oxidant is required to extract copper from chalcopyrite. In this study, column leaching tests were carried out using primary copper sulfide ores produced in an iron oxide copper gold (IOCG) deposit and rich in iron in coparison to porphyry copper ores. The columns of 10 cm diameter and 100 cm long had a double tube structure so that the column temperature can be kept at desired temperature by circulating warm water in the outer tube. The oxidation-reduction potential (ORP) of the leaching solutions were adjustedto 400, 450 and 500 mV vs Ag/AgCl. The column leaching test using just pH 2.0 sulfuric acid without adjustment of ORP at 45 °C got a copper recovery rate of 37 % in 400 days. On the other hand, with ORP adjusted leaching solutions of pH 2.0 sulfuric acid containing 500 mg/L Fe, the copper recovery rate reached up to 87 % in 400 days.In addition, it was necessary to keep the temperature above 45 oC to enhance copper leaching by ORP adjusted leaching solution. The result of the column leaching test at room temperature (around 30 °C) using ORP adjusted leaching solution shows that the recovery rate of copper is lower than the result at 45 °C. The ORP adjustment of leaching solution is effective for leaching copper from primary copper sulfide ore, however, the leaching temperature needs to be kept above 45 °C. As a result, it makes clear that copper leaching is enhanced by utilization of ORP adjusted leaching solutions and suggests that the solution ORP control is important to the application of bioleaching.

Effect of Temperature Ramping on Stirred Tank Bioleaching of a Copper Concentrate

2017 ◽  
Vol 262 ◽  
pp. 3-6 ◽  
Author(s):  
Sabrina Hedrich ◽  
Catherine Joulian ◽  
Torsten Graupner ◽  
Axel Schippers ◽  
Anne Gwénaëlle Guézennec
Keyword(s):  
Optimal Control ◽  
Black Shale ◽  
Processing Parameters ◽  
Copper Recovery ◽  
Stirred Tank ◽  
Effect Of Temperature ◽  
Base Metals ◽  
Optimal Temperature ◽  
Copper Ore ◽  
Temperature Ramp

Kupferschiefer-type ore represents an important source for base metals and several studies concerning the bioleaching of black shale ores and Cu concentrates have been carried out with focus on various microbial communities and processing parameters. However, the incomplete dissolution of chalcopyrite remains a key issue for copper ore bioleaching improvement and requires further investigations in order to ensure an optimal control of the process for upscaling. Our study clearly showed that bioleaching tests are characterized by two separate phases with a distinct optimal temperature. A distinct effect of the temperature on the copper recovery and the advantage of temperature ramp in order to enhance copper bioleaching and chalcopyrite dissolution were demonstrated.

Bioflotation of a Black Shale Copper Ore

2007 ◽  
Vol 20-21 ◽  
pp. 358-361 ◽  
Author(s):  
Irena Spasova ◽  
Marina Nicolova ◽  
Stoyan N. Groudev
Keyword(s):  
Black Shale ◽  
Black Shales ◽  
Copper Recovery ◽  
Two Stage ◽  
Copper Ore ◽  
Microbial Pretreatment ◽  
Chemolithotrophic Bacteria ◽  
Silicate Bacteria ◽  
Reducing Bacteria ◽  
Positive Effect

A sample of black shale fraction of copper ore from the Lubin deposit, Poland, was subjected to pretreatment by different microorganisms to improve the copper recovery during the subsequent flotation. Chemolithotrophic bacteria grown on So and S2O3 2- were used to depress pyrite before flotation by means of ethyl xantate as collector. Sulphate-reducing bacteria were used to perform a prior sulphidization of the black shales before flotation by means of the same collector. Two-stage flotation experiments were carried out in which initially the gangue minerals of the ore were depressed by means of “silicate” bacteria and then, during the flotation of the non-floated product from the first stage, the pyrite was depressed by means of pretreatment with So- grown chemolithotrophs. In all these cases the microbial pretreatment had positive effect on the copper recovery.

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.

Influence of particle size on copper recovery from sulfide ore by the moderately thermophilic microorganisms

2019 ◽  
Vol 116 (1) ◽  
pp. 119
Author(s):  
Wen-bo Zhou ◽  
Kai Li ◽  
Yu-guang Wang ◽  
Li-juan Zhang ◽  
Hai-na Cheng ◽  
...  
Keyword(s):  
Particle Size ◽  
Xrd Analysis ◽  
Microbial Interactions ◽  
Copper Recovery ◽  
Mineral Particle ◽  
Copper Ore ◽  
Thermophilic Microorganisms ◽  
Moderately Thermophilic ◽  
Before And After ◽  
Leaching Condition

The bioleaching of copper ore by the defined moderately thermophilic consortium containing Leptospirillum ferriphilum and Acidithiobacillus caldus was carried out in the bench-scale column. Bioleaching experiments showed that the leaching rate was 25% higher than that of a conventional leaching and the acid consumption was reduced by 33% at the optimal leaching condition. Meanwhile, the effect of different particle sizes on the rate of the copper leaching was also investigated, and it was shown that the particle size affects the bioleaching rate significantly in the range of 5–25 mm, in which approximately 89.27% of copper was extracted at 5–10 mm, while only 57.08% at 15–25 mm. The results obtained by X-ray diffraction (XRD) analysis of the mineral samples before and after microbial and chemical leaching revealed that the decrease in particle size of the minerals resulted in an enhancement of complex microbial interactions. Especially for the particle size of 5–10 mm, a significant amount of elemental sulfur and jarosite formed on the surface of the mineral, while it was further confirmed that critical microbe-mineral interactions have taken place on the mineral surface. The results indicated that mineral particle size is an integral factor to improve the copper recovery from ore in heap leaching operation. This will provide a reference to the heap construction for the bioleaching.

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

Development of a Process for Copper Recovering from Galvanic Sludges

2012 ◽  
Vol 730-732 ◽  
pp. 575-580 ◽  
Author(s):  
Cândida Vilarinho ◽  
Fernando Castro ◽  
Filipa Carneiro ◽  
André Ribeiro
Keyword(s):  
Acid Solution ◽  
Sulphuric Acid ◽  
Metal Ion ◽  
Dry Weight ◽  
Sulphuric Acid Solution ◽  
Operating Conditions ◽  
Environmental Benefits ◽  
Copper Recovery ◽  
Leaching Solution ◽  
Iron Scrap

Galvanic coating processes are based on metal plating baths and are responsible for the production of large amounts of wastewaters. Subsequent physical-chemical treatment of the wastewaters generates solid wastes called galvanic sludges. These sludges have a hazardous character and are often disposed, mainly on landfills, without any economical or environmental benefits. The development of alternatives and viable ways to reduce the environmental impact and recover the valuable metals contained in those sludges such as copper, chromium, nickel or zinc, which content might reach 30% (wt.%, dry weight) are of utmost importance. The present work has been developed in the aim of the project VALMETAIS and proposes a hydrometallurgical process for copper recovery from galvanic sludges produced by Ni/Cr plating plants. This procedure has been developed on laboratory scale and is based on leaching of sludges in sulphuric acid solution followed by copper cementation step, using iron scrap as a precipitating agent. The sludge has been characterized for its chemical and physical properties. Chemical analysis showed a copper concentration of more than 10% (dry base). Preliminary leaching tests in both sulphuric acid and ammoniacal media were performed in order to determine the best operating conditions for this step of the process and to assure the best metal recovery conditions in subsequent separation methods. Sulphuric acid yielded much higher metal ion dissolution when compared with ammoniacal leaching. Optimal experimental leaching parameters were defined as follows: sulphuric acid solution 100 g/l, a solid to liquid ratio of 1:10, stirring speed of 400 rpm at room temperature and under atmospheric pressure. It was found that metals dissolution was almost complete in 30 minutes of reaction time. Extraction rates of 99% for Cu and Ni were obtained under the leaching conditions above mentioned. The solid residue separated from the leaching solution is mostly constituted by gypsum (CaSO4), and presents a metal content below 1%. The subsequent extraction of cooper from the obtained solution is achieved by a cementation step with iron scrap. Copper precipitation was performed at a pH of 2 which was achieved through adding new sludge to the filtered leaching solution. Such pH level led to insignificant precipitation of other metals present in the leaching solution, namely chromium. The recovery rate of copper is about 90% and the purity grade of the resulting copper cement enables its application as a commercial product.

Efficiently Utilizing a Low Grade and Complex Copper Ore by Flotation

2013 ◽  
Vol 734-737 ◽  
pp. 929-934
Author(s):  
Qi Nie ◽  
Xiao Si Zhou ◽  
Fen Lan Peng ◽  
Xu Shen ◽  
Zhi Zhang Li
Keyword(s):  
Yunnan Province ◽  
Copper Recovery ◽  
Test Scheme ◽  
Low Grade ◽  
High Quality ◽  
Copper Ore ◽  
Copper Concentrate ◽  
Main Factors ◽  
Complex Copper

Based on the analysis of the properties of the copper ore from Jinggu area in Yunnan province, a suitable technical route was presented for processing of eligible copper concentrate and the main factors i.e. grinding fineness, Na2S dosage and collector dosage, affecting the quality of roughing concentration was investigated. On this basis, a close-circuit flotation test scheme was preceded, which obtained a high quality copper concentrate with Cu grade of 16.08%, copper recovery of 58.52%. The recovery of copper concentrate is much lower than the Cu recovery of roughing concentrate from the condition experiments. This may be contributed to the fact that fine slime carried by middling worsens the separation of copper minerals and gangues. The Mo was enriched in concentrate, which is significantly considered to recovery in further work.

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