Duluth Metals acquires Platsol(TM) technology license for Nokomis Project
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TORONTO, Jan. 15 /PRNewswire-FirstCall/ - Duluth Metals Limited ("Duluth
Metals") (TSX: DM) (TSX:DM.U) today announced the Company has signed a
Platsol(TM) technology license with International PGM Technologies Ltd for
processing copper, nickel and platinum group metals ("PGM") from future Duluth
Metals operations on their Minnesota Properties. The Platsol(TM) patented
technology will allow for the recovery of base metals and precious metals,
including platinum, palladium, gold and silver, in a cost effective single
phase, environmentally enhanced, hydrometallurgical extraction process. The
use of hydrometallurgical extraction eliminates the need for a conventional
smelter with all of its associated environmental issues.
In 2007, SGS Lakefield successfully tested the Platsol(TM) process
technology in a detailed metallurgical test based on a 252 kg composite ore
sample of drill core from Duluth Metals' Nokomis Deposit (October 3, 2007
Duluth Metals press release). Platsol(TM) provided the highest
hydrometallurgical recovery levels when compared against other available
technologies. Additionally, Platsol(TM) proved to be the most economic
process, using conventional processing chemicals at relatively low levels of
heat and pressure. While the process still needs to be optimized for Duluth
Metals, preliminary comparative analysis indicates that use of the Platsol(TM)
process may save 10 to 40 percent on capital costs, 5 to 15 percent on
refining costs and improve payable metal recoveries by 10 to 25 percent,
depending on the alternative approach chosen. Further testing will be
conducted to verify these results, and for optimization of the system and
preliminary design of a full scale plant for the Nokomis Project.
The Platsol(TM) hydrometallurgical process is an environmentally superior
method of recovering base and precious metals from combined base and precious
metals concentrate. One advantage of the Platsol(TM) process technology is
that sulphur associated with the sulphides is used as the fuel source to
generate heat and the base metal leaching agent. The technology also relies on
the addition of a small amount of chloride (salt) to the "total oxidation"
autoclave leach to cause the precious metals to dissolve at the same time that
the copper, nickel and cobalt sulphides are oxidized in a standard acid leach.
The addition of the chloride to the autoclave feed represents an incremental
change in autoclave chemistry that effectively permits simultaneous leaching
and recovery of the valuable PGMs and gold and silver in a single step with
the base metals. The technology allows for the recovery of:
- Copper, nickel and cobalt in solution so that they can be electro-won
and processed into metal cathode or hydroxide salts for sale;
- PGMs, gold and silver as a 'precious metals cake' that can be shipped
to a conventional precious metals refinery for final recovery and
sale; and
- Sulphides to be utilized as a heat source and leaching agent, and
sulphur oxidized in the autoclave is precipitated and neutralized as
synthetic gypsum, eliminating long-term environmental concerns.
The Duluth Metals Metallurgical Study, available on our web-site at
www.duluthmetals.com, reported that significant high extraction and recovery
rates were returned from the metallurgical test of the Nokomis Deposit copper
- nickel - PGM ores. Flotation-concentration recoveries of 95.3% for copper
and 72.4% for nickel, and 86.0%, 87.0% and 73.0% for platinum, palladium and
gold, respectively, producing a bulk Cu-Ni concentrate were achieved using
conventional flotation-concentration techniques. Hydrometallurgical testing
using the Platsol(TM) process on the bulk Cu-Ni concentrate produced
extraction efficiencies of 99.6%, 99.2%, 97.6%, 98.1%, and 84.1%, respectively
for Cu, Ni, Pt, Pd and Au under typical Platsol(TM) conditions. Combined
flotation-concentration and Platsol(TM) testing achieved recoveries of 94.9%
for copper and 71.8% for nickel, and 83.9%, 85.4% and 61.3% for platinum,
palladium and gold, respectively.
Additional Duluth Metals samples, totaling approximately 1,230 kg
utilizing the core reject from 12 selected holes in the Nokomis Deposit are
presently at SGS Lakefield being prepared for the next series of testing and
optimization studies. In addition, another 30 tonnes of samples are being
obtained for bulk metallurgical testing from the current 200,000+ drill
program conducted this winter and into 2008.
David Oliver, P. Geo. and Duluth Project Manager is the Qualified Person,
in accordance with NI 43-101 of the Canadian Securities Administrators, and is
responsible for the technical content of this press release and quality
assurance of the data and analytical results.
About Duluth Metals
Duluth is committed to acquiring, exploring and developing copper, nickel
and platinum group metal (PGM) deposits. Duluth's principal property is the
Nokomis Deposit located within the rapidly emerging Duluth Complex mining camp
in northeastern Minnesota. The Duluth Complex hosts one of the world's largest
undeveloped repositories of copper, nickel and PGMs, including the world's
third largest accumulation of nickel sulphides, and one of the world's largest
accumulations of polymetallic copper and platinum group metals.
This document may contain forward-looking statements (including
"forward-looking statements" within the meaning of the US Private Securities
Litigation Reform Act of 1995) relating to Duluth's operations or to the
environment in which it operates. Such statements are based on operations,
estimates, forecasts and projections. They are not guarantees of future
performance and involve risks and uncertainties that are difficult to predict
and may be beyond Duluth's control. A number of important factors could cause
actual outcomes and results to differ materially from those expressed in
forward-looking statements, including those set forth in other public filings.
In addition, such statements relate to the date on which they are made.
Consequently, undue reliance should not be placed on such forward-looking
statements. Duluth disclaims any intention or obligation to update or revise
any forward-looking statements, whether as a result of new information, future
events or otherwise, save and except as may be required by applicable
securities laws.
SOURCE Duluth Metals Limited
Mara Strazdins, Director of Corporate Communications, at
mstrazdins@duluthmetals.com or at (416) 369-1500 or Henry Sandri, President
and CEO, at hsandri@duluthmetals.com; Minnesota corporate office: telephone
(651) 389-9990; Web Page: www.duluthmetals.com
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