TORONTO, CANADA -- (Marketwire) -- 01/26/09 -- BacTech Mining Corporation ("BacTech" or the "Company")(TSX VENTURE: BM) is pleased to report significantly improved metal recoveries from the concentrate test work currently being done on the sample of tailings material taken from the Castle Mine tailings deposit located in Gowganda near Cobalt, Ontario.
Highlights of this round of test work include substantially improved recoveries of arsenic, with tests achieving over 92% recovery into the concentrate. In addition, gold, silver, and cobalt recoveries averaged in excess of 76%, much higher than the initial results the Company reported on November 10, 2008 (see table below). Readers should also note the first mention of gold recovery from the tailings, although these are only present as minor values in the sample being used for test work.
The metallurgical work is being done as a precursor to BacTech's plan to build a bioleaching plant near Cobalt, Ontario, to neutralize the arsenic-laden tailings prevalent in the area, while also recovering the significant quantities of cobalt, nickel, and silver also present in the tailings. The Castle Mine tailings are owned by Gold Bullion Development Corp. (TSX VENTURE: GBB).
The objective of the metallurgical test work is to test the effects of using both gravity and flotation techniques to upgrade the tailings to produce concentrates suitable for bioleach test work. Of particular note is that the mass pull has been reduced, while recoveries have been improved over the November results. Mass pull is defined as the amount of original tails which reports to the concentrate, so, by example, a 7% mass pull means that 70 kg of concentrate is produced for every tonne of tailings processed. The initial study focused on the use of gravity techniques. The current round of testing included the use of flotation in combination with gravity. Test work examining the possible use of flotation on its own, without gravity, is also being undertaken. The test work is being conducted at SGS Lakefield Metallurgical Laboratory in Lakefield Ontario.
At this stage, BacTech has yet to use any expensive grinding of the tails to obtain these results. An assessment of the potential application of grinding and its effects on recoveries at relevant stages may be undertaken.
Concentrates have also been produced by SGS Lakefield which have been shipped to SGS Oretest in Perth, Australia, and to the University of Toronto for the purpose of initiating bioleach and diagnostic leach testing, together with downstream metal recovery tests. Initial results from this work are expected by April.
The high retention of arsenic in the concentrate, which was one of the main objectives of the test work, is very encouraging from an environmental rehabilitation perspective. BacTech's patented bioleaching technology is a proven and effective technology for producing a stable form of arsenic, which makes this both an environmental reclamation project and a metal recovery project. The technology is able to process concentrates with high arsenic values which would normally be considered unacceptable for conventional processing methods such as smelting or roasting.
The cost of bioleaching is directly related to the amount of concentrate that has to be processed.
