Name and Location
Tongo Dyke-1 diamond project, Sierra Leone.

Client
Stellar Diamonds.

Project Description
A scoping study completed on the project has confirmed the robust, positive economics of the project, justifying its advancement to the definitive feasibility study (DFS) stage.

The scoping study focused on an estimated 682 000 ct of the Dyke-1 resource to a depth of 300 m from surface over an initial 13-year life-of-mine (LoM). A decline access to provide early access to production ore is proposed, which will be followed by the sinking of a shaft to 300 m to gain access to ore on levels about 40 m apart.

Stellar’s directors have used the base case model produced by the study and increased the LoM to 17 years to achieve mining of about 1 051 000 ct of the existing inferred resource, which the company believes is achievable at Tongo.

Net Present Value/Internal Rate of Return
Not stated.

Value
The scoping study estimates the LoM capital requirement at $21.42-million, while the directors’ model estimates capital costs at $30.27-million.

Duration
Not stated.

Latest Developments
Stellar Diamonds has announced a 35% increase in the Joint Ore Reserves Committee- (Jorc-) compliant inferred resource for its 100%-owned Tongo kimberlite Dyke-1 project.

The project’s Jorc-compliant inferred resource now stands at 1.45-million carats, with bulk sampling results leading to a further 37% increase in the project’s average diamond grade to 165 carats per hundred tonnes (cpht).

“The combination of high grades and high diamond values make this kimberlite one of the highest-value kimberlites in the world in terms of in situ value of dollar per tonne,” says Stellar CE Karl Smithson.

The project’s in situ kimberlite value is estimated at between $239/t and $324/t, with an in situ resource value of between $214-million and $290-million.

Smithson notes that further resource potential exists from three parallel kimberlite dykes forming a part of the Tongo dyke swarm, including the 1-km-long Dyke-4, which has previously been bulk sampled and returned a diamond grade estimate of 110 cpht and an estimated average diamond value of $140/ct.

“Consistent with our focused strategy of accelerating our key kimberlite projects through the development pipeline and into production, as evidenced by the recent start of trial mining at our Guinean Baoulé project, a study into surface and underground mine development at Tongo is being finalised.

“In line with this, we are currently recalculating our financial model to reflect the resource upgrade and mine plan,” he says.

Key Contracts and Suppliers
Not stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Stellar Diamonds, tel +44 20 7010 7686 or fax +44 20 7010 7699.