Jul 10 2013
Focus Graphite Inc. is pleased to report that the final Phase II Locked Cycle Test (LCT) metallurgical results performed at SGS Canada Inc., in Lakefield, Ontario, continue to confirm an average concentrate grade of 96.4% C and a high average flake graphite recovery of 92.5% for its Lac Knife high-grade graphite deposit located near Fermont, Québec.
SGS Canada Inc. (“SGS”) has completed all six (6) Phase II locked cycle tests (LCTs) on composite core samples comprised of low-grade, semi-massive, and massive graphite mineralization with a head grade ranging between 6.0% C and 25.0% C.
Highlights of these test results are as follows:
- The carbon content of graphite concentrates produced from the six (6) composites averaged 96.4% C, including the finest graphite flake concentrate (-200 mesh) produced. This is a 4.4% increase over Phase I LCTs completed in mid-2012.
- The average graphite flake recovery for the overall deposit following the final Phase II LCT’s increased to 92.5% which confirms the previous four (4) tests and increases the recovery by 0.3% from the previous results.
- The proportion of large flakes (+80 mesh) recovered from the low grade, semi massive, and massive types of mineralization (total: six (6) graphite concentrate samples) ranges between 35% and 58%;
- The Phase II LCT program produced consistent results for all of the composite samples that were tested representing the mineralization types, which confirms the suitability of the proposed concentrator flow sheet to process these different types of mineralization within the Lac Knife deposit, namely the low-grade, semi-massive, and massive graphite mineralization;
- A series of comminution tests generally characterized the seven (7) composite samples (six (6) mineralization and one (1) waste host rock) that represent the deposit, to require a low consumption of energy per tonne processed (kWhr/t). Further testing will establish this more precisely which will be favourable for the crushing and grinding circuit design and operational costs per tonne;
- Detailed chemical analysis of the final concentrates did not identify any impurities that are normally considered deleterious.
- In addition, a LCT was completed on a composite sample of the deposit’s host rock grading 1% C. The concentrate grade obtained was also very good at 96%C with a flake graphite recovery of 94.5%. These results suggest that mining dilution would not impact the recovery nor the final concentrate grade and quality in a negative way;
* A locked cycle test is a repetitive batch flotation test conducted to assess concentrator flow sheet design. It is the preferred method for arriving at a metallurgical projection from laboratory testing. The final cycles of the test are designed to simulate a continuous, stable flotation circuit.
“These metallurgical test results were incorporated into the flow sheet design for the pilot plant tests that were completed in early May. The final pilot plant results are now pending and we hope to communicate this soon.” said Dr. Joseph Doninger, Director of Manufacturing and Technology for Focus Graphite.
The purpose of the pilot plant is to confirm the results obtained following the LCT test program and also to produce marketing samples of graphite flake for end user evaluations and generate graphite raw materials for second transformation testing. Pilot plant test results are pending.