Effects of ultraviolet irradiation on bacteria mutation and bioleaching of low-grade copper tailings

This paper studies the effects of ultraviolet irradiation on the mutation of bacteria (i.e., Acidithiobacillus ferrooxidans LD-1) and on the bioleaching system for low-grade copper tailings. It is shown that ultraviolet irradiation can lead to an obvious LD-1 mutation, can improve bio-activity and bioleaching capability. The mutant LD-1 bacteria, after ultraviolet irradiation for 30 min, had the best oxidation activity, the oxidation rate of ferrous ion (Fe2+) in mutant bacteria culturing medium can reach 100% after 24 h (18 h less than that of the original bacteria under the same leaching conditions). After 30 days, copper extraction with mutant bacteria is increased by about 17%, compared with original bacteria, and by 70% compared to chemical leaching. These results show that the effects of mutant bacteria after ultraviolet irradiation are better than those of the original bacteria and much better than those of chemical leaching. The improved bioleaching rate of the mutant bacteria is attributed to the faster propagation rate and capabilities for stronger sulfuric acid generation. This study shows that mutant bacteria from ultraviolet irradiation have great potential for improving copper recovery from low-grade copper tailings.

This paper describes the effect of ultraviolet irradiation on the mutation of LD-1 bacteria. UV mutation improved bio-activity and bioleaching capability of LD-1 bacteria greatly. The copper extraction with mutant bacteria increases by about 17% as compared to that with original bacteria and 70% higher than that with chemical leaching. This shows that mutant bacteria from ultraviolet irradiation have great potentials for copper recovery from low-grade copper tailings.Figure optionsDownload as PowerPoint slideHighlights
► Ultraviolet irradiation produces an evident mutation in the At.f LD-1 bacteria.
► The mutant LD-1 bacteria have the best oxidation activity with 30 min UV irradiation.
► Ultraviolet irradiation improves the bioleaching properties of the bacteria greatly.
► The mutant LD-1 bacteria are a high efficient method for leaching low-grade copper tailings.