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Percolation bacterial leaching of low-grade chalcopyrite using acidophilic microorganisms
Karanam Srinivasa Rao,Amrita Mishra,Devbrata Pradhan,Gautam Roy Chaudhury,Birendra Kumar Mohapatra,Trupti Das,Lala Bihari Sukla,Barada Kanta Mishra 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.3
Bioleaching studies were carried out in percolation columns using low-grade copper containing rock (granite). The lixiviant consisted of acidified ferric sulfate containing acidophilic microorganisms. The iron oxidizing strain was isolated from Malanjkhand mine water and after adaptation the iron oxidation observed to be 500 mg/L/h. Leaching parameters studied were lixiviant flow rate, particle size and bed height. It was observed that leaching efficiency increased with decrease of particle size and lixiviant flow rate. The precipitation of iron during leaching observed to be low as pH was maintained at 2. Based on the leaching kinetics, a unified rate equation was developed and shown as ra(dp)[−0.61 (F)−0.76 (Hb)0.97.]수식
Lala Bihari Sukla,Mousumi Mishra,Sradhanjali Singh,Trupti Das,Rabi Narayana Kar,Karanam Srinivasa Rao,Barada Kanta Mishra 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.3
Bioleaching involves the use of iron and sulfur oxidizing microorganisms to catalyze the dissolution of valuable metals. In this investigation, lagoon material contains 0.39% Cu, in which the major copper bearing mineral is chalcopyrite associated with other minerals present as minor phase. Leaching experiments were carried out using an adapted strain of Acidithiobacillus ferrooxidans with various parameters such as presence/absence of iron, pH, pulp density and temperature. Base of the medium was 9 K (without ferrous) Bio-dissolution of copper was found to be maximum, i.e., 80.9% with 9 K+ (with ferrous) at pH-2.0, 10% pulp-density and 35 oC within an incubation period of 30 days.
Sandeep Panda,Srabani Mishra,Danda Srinivas Rao,Nilotpala Pradhan,Umaballava Mohapatra,Shivakumar Angadi,Barada Kanta Mishra 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.4
Copper slag was subjected to in-depth mineralogical characterization by integrated instrumental techniquesand evaluated for the efficacy of physical beneficiation and mixed meso-acidophilic bioleaching tests towardsrecovery of copper. Point-to-point mineral chemistry of the copper slag is discussed in detail to give better insight intothe association of copper in slag. Characterization studies of the representative sample revealed the presence of fayaliteand magnetite along with metallic copper disseminated within the iron and silicate phases. Physical beneficiation of thefeed slag (~0.6% Cu) in a 2 L working volume flotation cell using sodium isopropyl xanthate resulted in Cu beneficiationup to 2-4% and final recovery within 42-46%. On the other hand, a mixed meso-acidophilic bacterial consortiumcomprised of a group of iron and/or sulfur oxidizing bacteria resulted in enhanced recovery of Cu (~92-96%) from theslag sample. SEM characterization of the bioleached slag residue also showed massive coagulated texture with severeweathered structures. FE-SEM elemental mapping with EDS analysis indicated that the bioleached residues were devoidof copper.
Bio-hydrometallurgical processing of low grade chalcopyrite for the recovery of copper metal
Sandeep Panda,Lala Behari Sukla,Chinmaya Kumar Sarangi,Nilotpala Pradhan,Tondepu Subbaiah,Barada Kanta Mishra,Gur Lal Bhatoa,Mullukutlashivram Prasad,Subrat Kumar Ray 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.6
A process flowsheet was developed to recover copper metal from the lean sulfide ore of copper available at Malanjkhand, Hindustan Copper Limited (HCL), India. Copper pregnant leach solution (PLS) obtained from bio-heap leaching of chalcopyrite containing 0.3% copper was purified through solvent extraction (SX) and the copper recovered by electrowinning (EW). The copper-free raffinate obtained from SX stripping unit was returned back to the bioleaching circuit. The purity of the electrolytic copper produced at pilot scale was found to be 99.96%. During electrowinning,the effect of flow rate of electrolyte on current efficiency and energy consumption was also studied.
Aqueous processing of nickel spent catalyst for a value added product
Abdul Rauf Sheik,Malay Kumar Ghosh,Kali Sanjay,Tondepu Subbaiah,Barada Kanta Mishra,Abdullahi Aalafara Baba 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.2
Nickel was recovered from a fertilizer industry spent catalyst by leaching with nitric acid followed by nickel hydroxide precipitation. The optimization of temperature, initial acid concentration and particle size for leaching of the spent catalyst was done through 23 factorial design. A maximum extraction of 91.9% was achieved at 90 oC, 1.5M HNO3 and 62.5 μm particle size. Temperature and acid concentration showed positive effect, while particle size showed no effect. A regression equation was developed and employed to predict conditions for 100% extraction which were experimentally tested. Nickel hydroxide was electrochemically precipitated from the leach liquor and its maximum discharge capacity was found to be 155 mAh/g. A 3-stage counter current leaching circuit was designed to obtain a leach liquor of suitable pH. XRD characterization of the precipitated Ni(OH)2 shows to consist of both α- and β-forms.
Smaranika Mohapatra,Chandan Sengupta,Bansi Dhar Nayak,Lala Bihari Sukla,Barada Kanta Mishra 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.5
Experimental investigation made previously on microbiological leaching of nickel and cobalt from the laterite nickel ore of Sukinda Valley reveals that the recovery was not very much promising under any favorable conditions. Therefore, in order to improve the efficiency for bioleaching, the homogenized lateritic ore in palletized form is thermally pretreated by roasting at different temperatures. The parameters studied for the bioleaching experiments were the four types of pretreated ore which were roasted at different temperatures, i.e., 300 oC, 400 oC, 600 oC and 800 oC, in shake flask by using a mixed mesophilic acidophilic bacterial consortium consisting predominantly of the Acidithiobacillus ferrooxidans strain. It was observed that the pretreated ore at 600 oC with 10% (w/v) pulp density showed maximum recovery of nickel and cobalt, i.e., 59.18% (4.556 ppm) and 65.09% (0.546 ppm), using 10% (v/v) (2.5×108 cells/ ml) consortium concentration at 1.5 pH, 30 oC, and 150 rpm after an incubation period of 31 days.
Biological leaching of nickel and cobalt from lateritic nickel ore of Sukinda mines
Smaranika Mohapatra,Chandan Sengupta,Bansi Dhar Nayak,Lala Bihari Sukla,Barada Kanta Mishra 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.1
In the present study lateritic nickel ore was used for bacterial leaching using a mixed consortium of mesophilic acidophiles. The microorganisms were adapted to 1 gram nickel/L prior to leaching. For the experiments, lateritic ore in different forms such as raw, roasted, roasted ore presoaked in dilute sulphuric acid and palletized pretreated roasted (400℃ and 600℃) ore were taken. The leaching experiments were conducted in 9 K+ with 40 L capacity bioreactor using 10% (v/v) inoculum concentration at 10% (w/v) pulp density. The aeration was maintained at 2-3 L/min and the speed of agitator and temperature at 400-500 rpm and 35℃. The maximum extraction of nickel and cobalt was observed with pretreated ore (600℃) at 10% pulp density (77.23% and 73.22%) respectively within 31 days at pH 1.5 and least extraction in case of raw ore i.e., 9.47% nickel and 41.12% cobalt respectively.
Sandeep Panda,Pradeep Chandra Rout,Chinmaya Kumar Sarangi,Srabani Mishra,Nilotpala Pradhan,Umaballav Mohapatra,Tondepu Subbaiah,Lala Behari Sukla,Barada Kanta Mishra 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3
Bioleaching studies for chalcopyrite contained ball mill spillages are very scarce in the literature. We developeda process flow sheet for the recovery of copper metal from surface activated (600 oC, 15 min) ball mill spillagethrough bio-hydrometallurgical processing route. Bioleaching of the activated sample using a mixed meso-acidophilicbacterial consortium predominantly A. ferrooxidans strains was found to be effective at a lixiviant flow rate of1.5 L/h, enabling a maximum 72.36% copper recovery in 20 days. Mineralogical as well as morphological changesover the sample surface were seen to trigger the bioleaching efficiency of meso-acidophiles, thereby contributing towardsan enhanced copper recovery from the ball mill spillage. The bio-leach liquor containing 1.84 g/L Cu was purified throughsolvent extraction using LIX 84I in kerosene prior to the recovery of copper metal by electrowinning. Purity of thecopper produced through this process was 99.99%.
Recovery of copper values from bio-heap leaching of low grade Malanjkhand chalcopyrite ore
Lala Behari Sukla,Kailash Chandra Nathsarma,Joystna Rani Mahanta,Sradhanjali Singh,Snehasis Behera,Karanam Srinivas Rao,Tondepu Subbaiah,Barada Kanta Mishra 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6
M/S Hindustan Copper Limited (HCL), India generates large amounts of lean sulfide ores of copper. The current production of lean copper ores in India is 0.55 million tons with ~0.3% average copper content. Heap-bioleaching of the lean copper ores in 15 and 30 ton scales was undertaken at IMMT, Bhubaneswar. The leaching study showed 0.09% dissolution of copper from the ore body per day. The leach liquor was processed through solvent extraction and electrowinning. Extraction of copper from the actual leach liquor was carried out with 1.5% LIX 622N in kerosene with zero co-extraction of iron. The copper-free raffinate was fed back to the leaching unit. Stripping of copper from the loaded organic was carried out with 180 kg/㎥ H2SO4. The copper pregnant electrolyte was passed through a carbon column to make it free from entrained organic and was fed to the electrowinning unit. The increase in current efficiency was due to the increase in the concentration of electrolyte. The energy consumption was 1.7 kWh/kg at a flow rate of 4.5 L/h. Smooth and bright sheets of copper of 99.99% purity were obtained.
Lala Behari Sukla,Sunil Kumar Behera,Prangya Parimita Panda,Sandeep Kumar Saini,Nilotpala Pradhan,Barada Kanta Mishra 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.2
Oxalic acid is a prominent metabolite secreted by several fungi under specific conditions, which acts as a metal chelating agent. Amongst different fungal species, Aspergillus niger is favored as the best option for microbial production of oxalic acid. The present study deals with the oxalic acid over production by A. niger in response to manganese supplement to its growth medium, which in turn improves the recovery of nickel from pre-treated chromite overburden(COB) during fungal bioleaching. The metabolic pathway in oxalate bio-synthesis by A. niger involves one prominent cytoplasmic enzyme oxaloacetate acetylhydrolase (OAH), which catalyzes the breakdown of oxaloacetate metabolic intermediate to oxalate and acetate. Oxalic acid production was increased due to supplement of manganese to the culture medium of the A. niger. Manganese acts as cofactor for OAH enzyme; further, it enhances the catalytic activity of OAH to produce more oxalate. With oxalic acid production by A. niger, nickel recovery from pre-treated COB was improved. During the study, a maximum of nickel recovery was achieved up to 38.6% from pre-treated COB by adding 80 ppm of manganese to the culture media, whereas 24.0% of nickel was recovered without supplement of manganese (experiments were performed at 30 oC and the COB pulp density 2% w/v).