Ammtec

Bacterial Leaching

AMMTEC is pleased to be able to offer, in association with Pacific Ore Limited [POL], advanced bacterial leaching test facilities covering bench scale test-work through to continuous pilot plant campaigns. Pacific Ore Limited has extensive experience in all areas of bioleaching through to the design, construction, commissioning and operation of full scale bacterial leach plants.

Pacific Ore Limited - The Company

The use of bacteria for leaching metals is becoming an increasingly important and economically viable supplement to conventional extraction processes for the mining industry. In addition, with the ever-increasing environmental pressure on pyrometallurgical processes, bacterial leaching has the potential to supplement and eventually replace roasting and smelting operations across the globe.

Pacific Ore Limited has significantly expanded the potential application of bacterial leaching through the development of BioHeap™, its patented leach process. BioHeap™ has been developed for the treatment of base metal sulphide ores in which the metal values are leached into solution via bacterially assisted chemical reactions. The process involves the innovative combination of bacterial leaching and the use of pre-prepared heaps for base metal extraction.

The Company’s highly experienced technical and management team have been involved in the development of BioHeap™ for over 15 years.

Dr. Colin Hunter (BSc, PhD)

Dr Colin Hunter has a BSc Honours [Metallurgy] and was awarded a PhD from Brunel University for his work on the froth flotation of sulphide minerals. Colin has worked extensively on the bio-leaching of refractory gold nickel and other base metals.

Colin was a founding director of Bio Hydro Metallurgy Ltd, which was established to develop what has developed into the BioHeap™ process for the bio-leaching of chalcopyrite, zinc and other sulphide minerals. Since 2000 Colin has directed the technical activities of Pacific Ore Limited.

Graham Marshall (MPD)

Mr Marshall is a Master Project Director with experience in the fields of engineering and construction gained through exposure to design and construction, engineering and project management, commercial and contract management, business development and marketing across the resources, industrial and utility sectors.

Graham was the Owner’s Representative on the Bulong Nickel Project, spent 5 years as General Manager for a leading West Australian design, engineering & construction company and was Senior Project Manager of the structural, mechanical and piping components of the crushing circuit on the Telfer Gold Mine expansion project.

Jason Fewings (BSc (Hons)

Mr Jason Fewings has a BSc Honours degree in Chemistry, Mineral Science (Extractive Metallurgy) and Process Control. Jason’s honours project focused on the atmospheric leaching of mixed base metal sulphides.

Jason spent 2 years working for BacTech (Australia) Ltd before joining Titan Resources Ltd as part of the design and commissioning team for the Mt Scholl heap leach project. Since then Jason has focused on data analysis and process modelling of heap leaching systems.

Pacific Ore Limited laboratory affiliations

For many years the POL team has had close ties with the Research and Productivity Council [“RPC”] laboratories of New Brunswick, Canada. Part of the original development of what has developed into BioHeap™ occurred at the RPC laboratories.

AMMTEC has entered into an agreement with Pacific Ore Limited to carry out all of their Southern Hemisphere test-work with the Research and Productivity Council laboratories continuing to be responsible for most of POL’s test-work in the Northern Hemisphere.

AMMTEC brings to POL an internationally recognised and respected testing facility with extensive experience in bioleaching.

Why Should Clients Look Closely at Pacific Ore Limited?

It is AMMTEC's belief that POL Limited is significantly ahead of the competition in the field of bacterial leaching. POL has developed the BioHeap™ process using its own mesophilic and thermophilic bacteria, capable of operating at temperatures up to and in excess of 60°C. This brings about a significant improvement in the kinetics and thereby reduces capital and operating costs.

The superiority of BioHeap™ is evident in the response of the notoriously hard to leach mineral, chalcopyrite, to its process. Other providers of bacterial oxidation systems can seldom achieve copper dissolution in excess of 60% from chalcopyrite ores, and even this only after prohibitively long leach times or after ultra fine grinding. The chalcopyrite concentrates that have been tested to date using the Pacific Ore Bioheap™ process have all yielded essentially complete copper dissolution in comparatively short times.

There is a huge potential for this technology in the treatment of chalcopyrite rich, copper-gold ores. Bacterial leaching would remove copper from the ore leaving behind a gold concentrate which would be treated in a conventional cyanide leach. In this way the full value of the copper and gold is realised by the deposit holder. Currently, depending on the values involved, traditional methods do not give the deposit holder the full value of the gold credits. Realisation of these credits is also considerably quicker via the bacterial leaching route.

Further, where concentrate production is problematic, heap leaching may provide a viable alternative. Chalcopyrite heap leaching would be of particular interest to existing mines treating oxide or supergene copper deposits by conventional heap leaching methods, where the deposit is underlain by fresh sulphide copper.

There is potential for bacterial leaching in the treatment of copper-molybdenum ores where POL has developed a technique for removing unwanted copper from the molybdenum concentrate.

In nickel bacterial leaching POL has developed a flexible process capable of treating both high and low grade feed stocks by either tank or heap leaching. The Gencor BioNIC® nickel leaching process is limited to relatively high grade feed stocks. The potential for the BioHeap™ process lies in the treatment of low-grade ores, ores that do not concentrate well and remote ores where high transport costs reduce the economics of the deposit. BioHeap™ will liberate nickel into solution on site where it can be turned into finished metal with no threat to the environment. There are deposits that, although they upgrade well, contain high levels of arsenic and are therefore unacceptable as feed to most smelters. BioHeap™ will take the arsenic into solution along with the nickel allowing the precipitation of the arsenic as a safe and environmentally acceptable compound.

Apart from chalcopyrite associated copper/gold, copper/molybdenum and copper/nickel ores, the BioHeap™ technology is also applicable to complex lead/zinc ores where the less noble zinc mineral sphalerite can be leached from a bulk concentrate, for direct electrowinning to zinc metal, leaving behind a high grade lead concentrate. This is particularly important where the metals are in a finely disseminated form and the normal differential flotation process cannot produce sufficiently clean concentrates. Where there is an assemblage of sulphide minerals, at least one of which is capable of being oxidised to a soluble sulphate, then there is scope for the development of a bio-leaching process. Mineral deposits have been identified, and are continually being identified, that cannot be treated by conventional metallurgical means. Ores with complex metallurgy that cannot be separated into saleable concentrates, or deposits which contain impurities such as arsenic or mercury making the concentrates unsaleable, are suitable applications for the BioHeap™ bacterial leach process.

For more information contact:

Graham Marshall

graham@pacificore.com.au

Jason Fewings

jason@pacificore.com.au

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