i-minerals inc. (TSX VENTURE:IMA) has received preliminary results from Ginn Minerals Technology, Inc. ("GMT") related to the processing of approximately 2,500 lbs of primary clay extracted from the Company's WBL Area deposit on the Helmer Bovill property.
This is the second round of metallurgical testing on the WBL primary clays in which GMT successfully separated the grit (potassium feldspar and quartz) fraction from the clay fraction. The clay fraction was then separated into a kaolin component and a halloysite component. The kaolin component was further processed into a metakaolin and has been submitted to a concrete laboratory for pozzolanic performance evaluation. Samples of the halloysite are being prepared for further testing, while a representative sample of the grit fraction has been sent to Minerals Research Lab in North Carolina ("MRL").
The primary clay was mixed at approximately 50% solids and then screened using a 325 mesh screen to remove the feldspathic sand fraction (grit). The remaining material was then hydrocycloned to remove additional fine grit still present in the clay fraction. The hydrocyclone overflow was then processed through additional hydrocyclones to make the halloysite/kaolinite separation.
As kaolinite and halloysite are chemically identical and have similar X-ray diffraction patterns, standard laboratory analysis can not quantify the portion of each mineral. Scanning Electronic Microscope ("SEM") photomicrographs are taken of the clay products to provide qualitative evidence pertaining to the level of success in separating the kaolinite and halloysite. Based upon these high magnification photographs, concentration of separate halloysite and kaolinite products was again achieved, with room for further optimization.
"We are pleased with the results from this last round of metallurgical testing," stated Gary Nelson, Manager of Metallurgical Operations for i-minerals. "We produced a concentrated halloysite product similar to our previous testing, and determined that additional process optimization is possible based on the comparative results for the two rounds of testing."
Processing of the 2,500 pounds has resulted in approximately 315 pounds of a calcined kaolin product and 330 pounds of a halloysite product. The kaolin was calcined by GMT (kaolin is heated to about 800o C for about 30 minutes and loses all water through dehydroxilization) with the resulting metakaolin being sent for pozzolon testing for use in high strength cement applications products.
The portion of the 2,500 pound sample that was retained on the 325 mesh screen is the grit fraction which has been sent to MRL to be processed into separate k-spar and quartz products. The quartz product will be analyzed for trace elements to determine if the quartz in the primary clay has lower initial levels of titanium and other trace elements than the initial quartz product from the granitoid rocks at Kelly's Basin. Lower levels of trace elements would be more conducive for the production of high purity quartz ("HPQ").
"The flow sheet employing the hydrocyclones has been employed in the deposits of Cornwall UK for quite some time and offers a relatively low cost, readily scalable technique for separating the valuable minerals that comprise our primary clay," commented Roger Kauffman, President and CEO of i-minerals. "We are anxious to receive the results from the next phases of testing such that we can better assess the value of the primary clays."