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Bioleaching of low grade copper sulphide ores in the column

Name: ภาวิณี ศิลาเกษ

Organization : มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

keyword: Bioleaching

; Thiobacillus ferrooxidans

; Copper

; Column leaching

Abstract: Adsorption of Thiobacillus ferrooxidans on low grade copper sulphide ore particleswas studied in shake flask experiments at 30 ‘C and pH 2.8. The adsorption rate was found to befast in comparison with the bioleaching rate. This result indicated that the bacterial adsorptionwas at equilibrium during the leaching process. The adsorption equilibrium data were correlatedby the Langmuir equilibrium isotherm, which was used to predict the number of bacteriaadsorbed on the ore particles.Experiments in a batch reactor and a pilot-scale column system were carried out to studythe effect of T. ferrooxidans on the solubilization rate of copper contained in ores. The columnexperiment was carried out for a period of 3 16 days. The experiment was set up by packing 25kg of ores in a 1 IO-cm high acrylic column. The leaching solution was fed through the column,collected in a reservoir, and then returned to the top of the column. Concentrations of bacteriaand copper ion in the solution were analyzed. Ore samples, taken from different positions in thecolumn, were analyzed for the number of bacteria adsorbed on the ore particles. The results werecompared with the number of bacteria adsorbed on the ore particles calculated using Langmuirisotherm. It was found that the concentraion of adsorbed bacteria measured was higher than thatcalculated using Langmuir isotherm. This could be the effect of the bacteria deposited on the oresamples. The deformation of ore particles from the original size was also observed. Theseresults indicated that leaching solution might not truly flow throughout the column andchanneling flow occurred in the column. The measuring results of concentrations of bacteriaadsorbed on the ore particles at different heights indicated that oxygen was not a limiting factor.The rate of copper solubilization was related to the number of bacteria adsorbed on the) ore particles. The result was compared with the initial rates of copper solubilization by bacteriain batch experiments. 5.8% (w/w) of copper was leached from the column during the first 120days. The low number of adsorbed bacteria on the ore surfaces could cause this low leachingrate. To increase the concentration of bacteria in the column, 25 (mg/l) of bacteria were addedto the total of reservoir. The leaching rate was found to be increased after the bacteria wereadded. Total of 11.6%(w/w) of copper was leached from the column after 3 16 days of theexperiment. The specific rate of copper extraction (mg. Cu/mg Prot./min) in the column wasfound to be only about 2% of the specific rate of copper extraction in the batch experiments

มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

Address: กรุงเทพมหานคร (Bangkok)

Email: info.lib@mail.kmutt.ac.th

Name: ผศ.ดร.ไพทิพย์ ณีรเวชญาณ

Role: อาจารย์ที่ปรึกษา

Created: 2541

Issued: 2005-10-17

Modified: 2006-05-30

วิทยานิพนธ์/Thesis

ISBN: 9746244523

CallNumber: BIT258

tha

DegreeName: วิทยาศาสตรมหาบัณฑิต

Level: ปริญญาโท

Descipline: เทคโนโลยีชีวภาพ

Grantor: มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

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ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	BIT258.pdf	18.28 MB	73	2022-10-08 16:48:49
2	BIT258ab.pdf	118.61 KB	23	2018-05-13 04:22:12
3	BIT258ab.smi	2.87 KB	10	2018-05-13 04:22:12

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