Baja Mining Corp. said today that a key milestone has been achieved towards manganese metal production at its Boleo project in Baja, Mexico.
Staff at the University of British Columbia’s Hydrometallurgy Research Laboratory have successfully demonstrated that manganese metal can be manufactured from Boleo manganese carbonate using conventional hydrometallurgical processing steps, the company reported.
A sample of manganese carbonate produced during the 2006 demonstration pilot plant at SGS Lakefield was used as feedstock for the tests which were done under the supervision of Thomas Gluck, Baja’s manager for process technology, and David Dreisinger, Baja’s vice president for metallurgy.
The Baja property, scheduled to come on line in 2012, is expected to produce copper, cobalt and zinc metal, as well as manganese, zinc sulphate products and perhaps minor metals such as indium, gallium and germanium.
The key features of the Boleo manganese metal process are:
- Boleo manganese carbonate is leached to greater than 99% efficiency in the manganese leach solution (electrolyte from the manganese plating cell).
- Minor impurities present in solution are removed using sulfide precipitation and clarification.
- The purified solution is electrolyzed in a conventional manganese electrowinning cell. A smooth grey deposit of manganese metal was plated over a six-hour period at a current efficiency of 65%. This represents typical commercial performance, the company said.
- The manganese metal is plated without the addition of selenium — a condition that ensures a higher quality product.
“Being able to produce manganese metal without adding selenium will differentiate Boleo manganese metal from the majority of the product available in the market,” Gluck said. “This is something our Korean partners are particularly interested in.”
Korean investors
Last July Baja sold 30% of Boleo to a Korean consortium for $294 million in cash plus project funding. The Korean firms include Kores, LS-Nikko Copper Inc., Hyundai Hysco Co. Ltd., , SK Networks Co. Ltd. and Iljin Copper Foil Co. Ltd.
“Today’s result provides added confidence in our ability to produce manganese metal at Boleo once the copper, cobalt and zinc circuits are up and running and could add significantly to the economics of the project,” said John Greenslade, Baja’s president and CEO.
Boleo is the world’s sixth-largest manganese deposit. Current Boleo mining and processing plans would allow for the production of up to 100,000 tonnes (220 million pounds) of manganese metal per year.
Manganese metal is used in alloying applications in the steel, aluminum and non ferrous alloy industries. Annual production of manganese metal is estimated to be over 800,000 tonnes worldwide. The spot price for electrolytic manganese metal containing selenium (manufactured in China) is currently $1.00 per pound and the Boleo product would sell at a premium to this price.
More studies needed
Further work on plating of Boleo manganese is ongoing at UBC and with other development partners toward the goal of producing a fully integrated flow sheet for converting Boleo manganese carbonate to manganese metal in the most efficient way possible, Baja said.
This ongoing work is being conducted as part of a “manganese action plan” that is overseen by the Minera y Metalurgica del Boleo (MMB) Manganese Action Committee and includes the evaluation of alternate uses for Boleo manganese carbonate. MMB is the Mexican subsidiary of Baja and a Korean Consortium
and 100% owner of the Boleo project. The Manganese Action Committee is made up of nominated representatives from Baja and the Korean Consortium. A next key milestone in the action plan is the completion of a pre-feasibility study for manganese metal production.
A 2007 definitive feasibility study projected an average annual production for the first four years of 56,000 tonnes of copper cathode, 1,500 tonnes of cobalt cathode and 20,000 tonnes of zinc sulphate, Baja said.
The project has proven and probable reserves that support a mine life of more than 25 years. Anticipated cash costs in the first five years are $0.27 per pound of copper, net of by-product credits for cobalt and zinc and with no credit for manganese.
