Effect of SX on microbial populations inhabiting in solutions of a heap bioleaching process
Today there is hardly any information available on the impact that the solvent extraction process ( SX) has on the microbial populations growing in heap bioleaching. The SX process involves fast changes in several physicochemical parameters of the solution ( pH, H + , Cu + ) , agitation and contact of the solutions with organic reagents. The aim of this work is to investigate this impact by monitoring the microbiology of feed solutions (pregnant leaching solution, PLS) and the solutions coming out of the SX process ( Raffinate) in an industrial bioheap leaching plant treating low-grade copper ROM ( runof-mine) ore at Minera Escondida Ltda. The SX plant was the traditional mixer-settler with three extraction stages and two stripping stages. Monitoring techniques includes Real Time-PCR of prokaryotes, most probable number of sulfur and iron oxidizing microorganisms, and oxidation activity tests. Modifications in the mean and median of the bacterial populations coming in and out of the SX process reached even three orders of magnitude (10 to 102 cell/mL). A statistical analysis was performed using exploratory and Hypothesis Test and graphical tools ( boxplot and dispersion). The hypothesis tests indicated that there was indeed a significant reduction in the microbial populations due to the impact of the SX process. Data mining was used as well for data understanding. We get new insights to discuss about the inoculation capacity of the Raffinate solutions. In addition, we investigated the occurrence, the characterization and the abundance of eukaryotic microorganisms associated to the SX process. The DNA extraction, the PCR with universal primers for amplifying ITS region, the genetic library and the sequencing were performed from industrial samples. Once the eukaryotic microorganisms were identified, they were quantified from the industrial samples by Real Time-PCR. The results showed a preliminary relation between crud formation and the abundance of a Candida related sequence.
bioleaching SX solvent extraction
Cecilia Demergasso Victor Iturriaga Pedro A. Galleguillos Sergio Davis
Centra de Biotecnologfa Profesor Alberto Ruiz, Universidad Catolica del Norte and Centra de Inves Minera Escondida Limitada, Antofagasta, Chile
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
712-717
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）