Magambazi Initial Mineral Resource Estimate
Category |
Estimated Quantities |
|
Tonnes (000s) |
Average grade (g/t gold) |
Contained gold(oz) |
Indicated |
15,186 |
1.48 |
721,300 |
Inferred |
6,683 |
1.36 |
292,400 |
A cut-off grade of 0.5 grams per tonne was selected as the resource base case, considering extraction by conventional surface mining and mineral processing methods. A summary of the estimated mineral resource for a range of cut-off grades was included, as follows:
|
Indicated |
Inferred |
Cut-off Grade
(g/t gold) |
Tonnes (000s) |
Average grade (g/t gold) |
Contained gold (ounces) |
Tonnes (000s) |
Average grade (g/t gold) |
Contained gold (ounces) |
0.3 |
19,685 |
1.23 |
777,500 |
9,256 |
1.09 |
324,500 |
0.4 |
17,218 |
1.36 |
750,300 |
7,831 |
1.23 |
308,800 |
0.5 |
15,186 |
1.48 |
721,300 |
6,683 |
1.36 |
292,400 |
0.6 |
13,392 |
1.6 |
689,900 |
5,593 |
1.52 |
273,400 |
0.7 |
11,884 |
1.72 |
658,700 |
4,791 |
1.67 |
256,800 |
1 |
8,593 |
2.07 |
570,600 |
3,058 |
2.14 |
210,700 |
The mineral resource estimate was prepared in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Standards on Mineral Resources and Mineral Reserves, adopted by CIM Council, as amended. The mineral resource estimate was prepared by independent qualified person, Mr. James N. Gray, P.Geo., of Advantage Geoservices Ltd. In support of this work, drilling data validation and historical context was provided by independent qualified persons Mr. Ian Farrelly, P.Geo. and Dr. Sandy Archibald, P.Geo. of Aurum Exploration Services. Mr. Gray, Mr. Farrelly and Dr. Archibald are each independent of Canaco and are Qualified Persons as defined by National Instrument 43-101. Each reviewed, validated and approved publication of the technical information contained in the May 15, 2012 news release.
Gold grades were estimated by inverse distance cubed interpolation within two grade domains. Low-grade and potentially mineralized domains were derived by ordinary kriging of a 0.2 gram per tonne indicator applied to five metre composite data. Composite grades were capped in the two domains at 2.5 and 15 grams per tonne respectively. The interpolation of indicators and of grade was carried out with a search oriented parallel to one of five interpreted structural trends. Rock densities were based on averages derived from more than 50,000 measurements. Resource classification was based on geometric parameters associated with sample location and drill density.
Measures were taken to validate that the mineral resource meets the condition of “reasonable prospects of economic extraction” as suggested under National Instrument 43-101. To this end, a pit shell was generated using a gold price of US$1,250 per ounce and an overall pit slope of 40° for the purpose of resource tabulation. Only blocks within the pit volume were included in the resource estimate. The cut-off grade of 0.5 grams per tonne was selected as the resource base case considering extraction by conventional surface mining and mineral processing methods.
Metallurgical Testing
In parallel with the initial mineral resource estimate, Canaco completed a comprehensive metallurgical test work program that concluded mineralization from the Magambazi area of the Handeni property may be processed using conventional gravity concentration and cyanide leaching to recover the contained gold. Gravity concentration installed in the grinding circuit is expected to recover approximately 70% of the gold in the plant feed into a gravity rougher concentrate representing approximately 2% of the mass feed.
A variety of tests were conducted on representative composite samples to determine the metallurgical response and its variability across the zones. An extensive sampling program was undertaken to generate composite samples that would be representative of the Magambazi mineralization as a whole and each zone in particular. Approximately 3,000 individual drill core intervals were selected as constituents for metallurgical test work composites, representing 2,325 metres of drill core. To maintain security and integrity of metallurgical samples, each drill core interval was kept segregated and shipped as an intact section of quartered core material to the metallurgical laboratory for processing.