De Beers - Victor Mine
Exploration
Diamond Exploration
Diamond exploration activities by De Beers in Canada started in the early 1960s. However, it was not until the 1980s that a permanent presence was incorporated with the establishment of De Beers Canada Exploration Inc. (previously known as Monopros Limited), a wholly owned subsidiary of De Beers. De Beers Canada Inc. is now a fully integrated exploration and mining company.
De Beers Canada carries out exploration activities throughout Canada and has made more than 230 kimberlite discoveries, over half of which carry diamonds. On average only one in every 200 kimberlites discovered contains a sufficient number and value of diamonds to become a mine.
De Beers has injected a substantial investment into Canada in recent years. Exploration programs are currently focused in northern Ontario in the vicinity of the Victor Mine, which has 15 other diamond-bearing kimberlites previously identified by De Beers in 1987-88.
Extensive use is made of the De Beers dedicated laboratories in South Africa where microdiamond recoveries, age dating of kimberlites and trace element mineral chemistry studies are undertaken and can be compared by in-house consultants against comparable data from De Beers' own producing mines.
Exploration Stages
Early Exploration
Prospective exploration targets are identified by conducting desktop studies. Early exploration usually consists of reconnaissance work in the identified target areas. Soil samples are excavated or stream samples are collected by hand. Where the ground is unsuitable for hand sampling, airborne geophysical surveys are used to identify features that could indicate the presence of kimberlites – the host rock for diamonds. This type of work causes little or no environmental impact.
Follow-up Exploration
This stage examines areas of interest identified during reconnaissance and uses many of the same techniques (sampling, surveys, etc.). At this stage, the work is concentrated in relatively small areas, usually 10% of the original work area.
Geophysics plays an important role in this stage of exploration. Sites of potential interest identified during the airborne magnetic surveys are investigated either on the ground by geophysicists or using a helicopter-borne magnetic or electromagnetic system which flies small pattern surveys over blocks of land. Ground geological mapping is also likely to be used during this stage of work.
Target Delineation and Evaluation
Most diamond projects are particularly sensitive to grade (carats per tonne) and revenue (dollars per carat). Therefore, these are the first parameters to be determined during the evaluation process.
To reach this stage is rare, as kimberlites are hard to find, and many do not contain diamonds. At this stage, any anomalies, or irregularities, which could suggest the presence of kimberlites are examined in one of three ways.
Core Drilling:
To test these anomalies and discover what caused them, a small diameter core hole is drilled. If the material is kimberlitic, the rock sample is analyzed for the presence of microscopic diamonds (diamonds smaller than 0.5mm in at least two dimensions).
Mini Bulk Sampling:
Where such diamonds are found in appreciable quantities, a mini-bulk sample (of several tonnes) is then taken, usually by drilling, to test the kimberlite and obtain a better first estimate of the diamond grade. If the results from the mini-bulk sampling are promising, then a full evaluation programme is undertaken, using bulk samples.
Bulk Sampling:
Bulk sampling usually involves trench or pit excavation as well as large diameter drilling to extract bulk samples. Before the work begins, an environmental baseline study is undertaken. The application of geochemical methods adds value in this process by providing information at an early stage on the diamond-bearing potential of a kimberlite.
If the exploration stages confirm the presence of ore bodies with the potential to become mines, they are further tested. This constrains the size of the ore body, its shape below the surface to a depth of at least 200m (600 feet), and provides additional bulk samples used to determine both the diamond grade (the weight of diamonds per tonne of kimberlite) and value per carat for the diamonds.
Gahcho Kué
Since 1995 exploration, environmental studies and other work has been underway leading up to the development of the proposed Gahcho Kué diamond mine.
Located at Kennady Lake, approximately 280 km northeast of Yellowknife and 80 km southeast of our Snap Lake Mine in the Northwest Territories, the Gahcho Kué Project is a joint venture between De Beers Canada Inc. (51%) and Mountain Province Diamonds Inc. (49%).
Exploration has determined that three kimberlite deposits currently have potential to be mined: 5034, Hearne and Tuzo.
De Beers, as the operator, is committed to building this new mine to high safety standards and with deep respect for the land.
Victor Extension
Victor is one of 16 diamond-bearing kimberlite pipes in the immediate vicinity of the Victor Mine site and is currently producing some of the most remarkable rough diamonds in the world. All of the previously identified pipes in the cluster are within a 25km radius of the Victor site.
Since the opening of the Victor Mine in July 2008, De Beers Canada exploration efforts have been focused around extending the resource reserves at the Victor Mine. This work is often carried out in the winter months when moving around the target areas is easier for the team. Programs involve a variety of assessment techniques including core sampling, large diameter drilling and bulk samples. Current analysis indicates these satellite pipes are all smaller than the current Victor pipe, which has 27 million tonnes of ore and a forecast 12-year life-of-mine.
As more information is gathered about each pipe, priorities are developed regarding the economic potential of each target. Current programs are completing assessments on some of the more promising targets, but much work remains to determine if these pipes will become economic and extend the life of the Victor Mine.
To support the extension program, the Victor Mine has undertaken a Cost Optimization initiative at the mine to lower the day-to-day operating cost of the mine, enhancing the economics of these potential resources.
If the resources prove out, it would extend the life of mine and continue to provide substantial economic benefit for the surrounding communities.
Source: https://www.canada.debeersgroup.com/Exploration/
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