The company’s pipeline of advanced alluvial and kimberlite exploration projects in the DRC includes its key Kwango River and Tshikapa initiatives.

Dr Mike de Wit

BRC-DiamondCore president
Dr Mike de Wit.

“Our intention here is to get the Kwango alluvial deposits up and running so that our DRC operations will be joining our South African side in contributing directly to the earnings bed,” BRC-DiamondCore president Mike de Wit tells Mining Review Africa. “It is too early to guarantee performance, but we certainly have good indications that the grades there are interesting."

The Kwango project lies along and to the east of the Kwango River between the towns of Tembo and Kasonga Lunda, in the Bandundu province of south western DRC.

The company has eight prospecting permits in the Kwango, but these have to be reduced by 50% in terms of DRC law. “We have identified the areas of interest, so should complete the process by the middle of the year. Obviously we will keep the areas that contain all the alluvial terraces, and drop the ground that is more distant from the river.

Mapping the gravel pit

Mapping the gravel pit
in the upstream section of
the Kwango River,close
to Tembo.

"We have prospected about a third of the alluvial terraces we have identified, and in that process we have identified about 12 million tonnes of gravel which have been confirmed as diamondiferous,” de Wit says. “The immediate next phase of our programme is to continue with exploration to expand on the 12 million tonnes but at the same time to start taking bulk samples out of the existing resource to establish a definite idea of grades and value of diamonds."

While BRC-DiamondCore has prospected eight targets to date, it had identified a total of 23, and there are another 15 to drill and pit. “It is therefore not unreasonable to assume that the current inferred resource of 12 million tonnes could be more than doubled in the course of time.”

Kwango river

The Kwango River flowing
over bedrock provides some
excellent trap-sites

In order to start bulk sampling at its Kwango River project, the company is well advanced with construction of a bulk sampling plant in South Africa. “It is about 90% complete, and the idea is to test and commission the plant at our Paardeberg East site in the Northern Cape,” de Wit says.

“We have one or two Congolese engineers assisting so that they can familiarise themselves with the operation of the plant, and that should take another two months. Then the plant will be containerised and shipped to the DRC. We are assessing the options, whether to send it by sea, or overland to Lubumbashi, to optimise the time it takes to get the plant to get to site.

“We hope to start the first stage of bulk sampling before the end of the year, and that will continue for at least 12 months, probably longer, as we are going to assess all the terraces stage by stage.

“Once we have proven the first terraces, we will look at bringing in a production plant, and hopefully start trial mining by late 2010,” de Wit says. “The progression from trial mining to mining is quick. Once you find your grades are holding and you are satisfied that your evaluation is accurate one would increase plant capacity and move into mining proper immediately.”

De Wit is understandably reluctant to predict production figures and values at such an early stage. “We certainly hope to see substantial additions to our earnings bed from the DRC. This is likely in terms of carats, although probably not in value. We believe that the stone size is probably smaller than those we produce in the Orange River, but we think we’ll produce a lot more carats, although at slightly lower value.”

Hydro-core Drill

Hydro-core drill being
prepared to start drilling on
the first Tshikapa target.

“We would be looking at anything in excess of 10 carats per 100 tonnes at a value of between US$100 and US$200 per carat, maybe up to US$250,” de Wit estimates. “We see this as a longer term project, and once we get our teeth into it I believe we will be successful in maintaining this operation for quite a few years.

“We have spent of the order of US$6 million (R46 million) in the Kwango to date, mainly on drilling and pitting, modelling and geophysics."

De Wit says that the period from now to trial mining will require approximately two years of operating costs. “If we do get into trial mining we will have to look at a bigger plant to start mining the areas of most interest, at the same time keeping the other plants working through the other terraces. We would be looking at least US$10 million (R76 million) to US$15 million (R114 million) to see us through this phase from now.” Again, the philosophy would be to build, test and commission the plants in South Africa and then ship them to the DRC.

He explains, however, that even during bulk sampling, it is unlikely the company would hold back on the sale of recovered diamonds, much like what’s happening at Silver Streams in South Africa, with diamonds from trial mining starting to make some money for the company.

Turning to kimberlite exploration in the DRC, BRCDiamondCore’s most advanced operation is the Tshikapa project, located in the southern part of the Kasai Occidental and Bandundu provinces in southern DRC.

“We have covered all the ground here with basic exploration greenfields techniques; stream sampling, follow-up sampling, airborne geophysics and detailed geophysics,” de Wit says.

“We have identified between 40 and 60 targets, and so far at least 10 of these are looking very prospective and could well be kimberlite-related primary sources. We now need to drill these, and I believe the next six months could be a very interesting time for us.

In order to tackle the new drilling phase quickly and efficiently, BRC-DiamondCore has commissioned its own drill rig in the DRC. “Our philosophy is that reliance on drilling contractors is not that good,” de Wit explains. “They find it more lucrative to work in countries like Zambia, so we decided to buy our own rig, and we can then drill as we see fit, and change our programme as the results dictate.

Drilling on high level

Drilling on a high level
terrace along the
Kwango River

“Speaking generally, it is a bit of a gamble, but one tries to minimise the risks. By doing your groundwork properly you can deduce which targets are likely to contain kimberlites, based on your stream sampling and geophysics. That certainly has given us an opportunity to prioritise certain targets, and to identify those that we believe are most likely to be linked to kimberlites. So it’s not just a hit-and-miss operation, it’s a very wellresearched and interpreted way of tackling the drilling phase.

De Wit says the various stages – evaluation, drilling, bulk sampling and a pre-feasibility study – could take the company close to the end of 2010 – which means almost three years. “Normally, once you’ve done the pre-feasibility that’s all the hard work, but by law in the DRC if you want to convert your prospecting right into a mining right you have to produce a feasibility study. With a promising pre-feasibility behind you, and that could take up to another year, you’re looking at three to four years before actual mining could take place,” de Wit says.

An operation of this nature would be expensive, but de Wit believes the combination of DiamondCore expertise in building and operating plants, and BRC’s experience in exploration, in-house expertise could confine expenditure to several million dollars, as opposed to a multi-million dollar operation.