VANCOUVER, BRITISH COLUMBIA--(Marketwire - June 26, 2012) - I-Minerals Inc. (TSX VENTURE:IMA)(PINKSHEETS:IMAHF) (the "Company") announces that further to the Company's press release of June 19, 2012 wherein the Company announced it had engaged DURTEC GmbH of Neubrandenburg, Germany ("DURTEC") to undertake a series of tests to determine if the basic characteristics of the halloysite produced from the Bovill Kaolin deposit can be improved through additional processing, I-Minerals has received the DURTEC report that clearly demonstrates trace levels of deleterious elements found in the halloysite can be materially reduced and the brightness of the halloysite product can be significantly improved.
DURTEC was provided with a basic halloysite product prepared by Ginn Mineral Technologies of Sandersville, Georgia using a standard wet separation technology. Key attributes of the basic halloysite product included:
- >90% less than 2 um (microns)
- free of crystalline silica
- low levels of deleterious heavy metals
- high aspect ratio (the ratio of the length of a tube to the diameter).
DURTEC, under the supervision of Dr. Joachim Schomburg, undertook two series of testing. The first tests were designed to improve the brightness of the halloysite by removing as much of the natural occurring iron content as possible. The iron, which average 1.2% across a small sample set, may have resulted in the halloysite product having a relatively low average GE Brightness of 70.8. The second testing objective was to remove as much of the other heavy metals as possible. Earlier work by DURTEC indicated I-Minerals' halloysite contained one of the lowest levels of initial trace elements as compared with five halloysite products tested and therefore had a preferential starting point in efforts to achieve a pure product. Several commonly used techniques for were tested including special chemical bleaching, calcination and magnetic separation with the following results:
Chemical Bleaching
A selective mixture of acid agents for bleaching resulted in brightness's up to 90% being achieved together with a strong reduction of heavy metal contents to below detection limits:
As | Pb | Cd | Hg |
<5 ppm | <20 ppm | <0.2ppm | <0.1ppm |
Scanning Electron Microscopy ("SEM") work indicated this technique had no impact on the halloysite crystal structure or the tube morphology.
Calcination
Calcination can be used for improvement of whiteness at different temperature steps:
Temperature step (heating rate 10K/min, 30 min held) |
L-value |
750°C | 73 |
1000°C | 83 |
1100°C | 84 |
1200°C | 82 |
The calcined halloysite nanotube ("HNT") material is expected to be similar to various Metakaolin products, often used in paper and rubber industry.
Magnetic Separation
Dry powder magnetic separation (field strength 18k Gauss) did not remove enough of the iron to materially improve the whiteness. Future test work will include wet High Gradient Magnetic Separator (HGMS) evaluations using Eriez equipment. The wet HGMS work is expected to provide better results.
This initial work clearly demonstrates the halloysite from the Bovill Kaolin deposits generally responds well to the various techniques utilized to improve the brightness and reduce the trace levels of heavy metals. These different processing techniques demonstrate that a range of HNT-products can be prepared from the Helmer-Bovill clay deposits that can be used in a range of different applications including ceramics, plastics and polymers, and life science applications including cosmetics and possibly pharmaceutical carriers. Multiple markets services by a diversified HNT product portfolio offer greater sales volumes and the more pure products offer opportunities in the high value life sciences markets.
"I have worked with halloysite from many of the known deposits around the world and the results from this latest round of testing add further support to my belief that I-Minerals' halloysite can be further processed to yield one of the best halloysite products available," stated Dr. Joachim Schomburg, President, DURTEC GmbH.
A. Lamar Long, CPG, is a qualified person ("QP") for I-Minerals inc. and has reviewed and approved the contents of this release.
"These results support our believe that the mineral products from the Bovill Kaolin deposit are high purity high value products," stated Thomas Conway, President and CEO of I-Minerals Inc. "Our earlier work has demonstrated we can produce a best in class K-spar product and high purity quartz products through standard flotation and now we believe we can produce one of the best halloysite products available based on aspect ratio, purity and other considerations."
I-Minerals Inc.
Thomas M. Conway, President & CEO
This News Release includes certain "forward looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995. Without limitation, statements regarding potential mineralization and resources, exploration results, and future plans and objectives of the Company are forward looking statements that involve various risks. Actual results could differ materially from those projected as a result of the following factors, among others: changes in the world wide price of mineral market conditions, risks inherent in mineral exploration, risk associated with development, construction and mining operations, the uncertainty of future profitability and uncertainty of access to additional capital.
NEITHER THE TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICES PROVIDER (AS THAT TERM IS DEFINED IN THE POLICIES OF THE TSX VENTURE EXCHANGE) ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS NEWS RELEASE.
Contact Information:
Barry Girling
877-303-6573 or 604-303-6573
604.684.0642 (FAX)
info@imineralsinc.com
www.imineralsinc.com
Encompass Communications Inc.
877-566-6592 or 604-630-0770
info@encompassinc.ca