Developing Environment-Friendly Technologies
The Group is endeavoring to develop technologies that reduce environmental impact as a part of efforts to secure the sustainable development of both society and the economy. Guided by the overarching goal to develop environment-friendly technologies, JX Nippon Mining & Metals Corporation established the joint venture company BioSigma S.A. with the Chilean state-owned Corporacion Nacional del Cobre de Chile (CODELCO) to pursue the development of bio-leaching technologies in 2002. In the following section, we introduce the initiatives undertaken by BioSigma in the field of bioleaching technology development.
What is Bio-leaching Technology?
Bio-leaching is a hydro-metallurgical process that extracts value-bearing metals from their ores through the use of bacteria. In recent years, demand for copper has risen dramatically. On this basis, the effective application of lowgrade copper ore, which was previously discarded as tailings, has become an increasingly pressing issue. Since 1990, bioleaching technology has been employed to extract copper from low-grade secondary copper sulfide ore at certain mines. Focusing not only on secondary copper sulfide ore, BioSigma is working to further harness the potential of the bacteria found in nature to develop a technology that will efficiently leach and refine copper from primary copper sulfide ore, long thought to be a difficult process.
Under the bio-leaching process, bacteria perform the action of oxidizing iron and sulfur. In order to procure the energy required to spur bacterial growth, both iron and sulfur oxidizing bacteria draw on electrons found in the iron and sulfur, respectively. As a result, the iron and sulfur oxidize. Copper, with which bacteria cannot be used, remains unoxidized. That is to say, copper is a by-product of the bioleaching process. Previously discarded tailings serve as a resource while the bio-leaching technology also contributes to improved economic benefits by accelerating the speed of leaching in the hydro-metallurgical process.
Copper Recovery Process utilizing Bio-leaching Technology
Manufacture of Bio-leaching Refined Copper at the Pilot-scale Test Level
Left: View of the pilot-scale facility at the Andina Mine
Right: Refined copper manufactured utilizing the bio-leaching technology
Pilot-scale tests were launched at CODELCO's Andina Mine to validate BioSigma's bio-leaching technology. Refined copper is currently being successfully produced using this technology.
Strengthening Bio-leaching Technology
Strengthening Functional Analysis and Specified Performance Reinforcement of Bio-leaching Microorganisms (Biotechnology Development)
BioSigma's research laboratory, which is located in the suburbs of the city of Santiago, identifies and develops the cultivation methods for the bacteria used in its bio-leaching technologies. At the same time, BioSigma has entered into a cooperative research agreement with Keio University's Institute for Advanced Biosciences, which itself possesses leading-edge biotechnologies. Under the agreement, both parties engage in metabolome analysis as well as genome analysis. The results of this research are then applied in the functional analysis of bacteria. Furthermore, in order to realize efficient and stable bio-leaching processes, experimental column leaching trials are being undertaken to facilitate optimal condition searching. By strengthening these forms of research and development, promoting the application of the most optimal bio-research, and strengthening the qualities of bacteria essential to bio-leaching, every effort is being made to enhance the leaching performance.
