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

Client
Stellar Diamonds.

Project Description
The Dyke-1 project has a Joint Ore Reserves Committee-compliant inferred resource of 1.074-million carats at 120 carats per hundred tonnes (cpht), with the resource remaining open at depth.

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.

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
Initial sample processing at Stellar Diamonds’ Tongo dyke kimberlite project have confirmed the resource’s continued high-grade nature, with grades expected to increase further as more diamonds are recovered following reprocessing.

Initial processing yielded 151 ct from 141 t of kimberlite for a grade of 107 cpht. This is expected to increase, in line with the 120 cpht level established in previous results, in future.

“The quality of diamonds observed in these bulk sample results at Tongo is outstanding, with an estimated 86% being classified as gem quality, with many white diamonds exhibiting fine crystal shapes,” says Stellar CE Karl Smithson.

Bulk sampling at the project is ongoing with 772 t collected to date, as part of the Dyke-1 mining DFS, with the objective being to recover a minimum 1 000 ct parcel for diamond grade and value confirmation.

Extraction and processing of the kimberlite bulk sample will form part of the DFS for underground mining at Tongo, which is on track for delivery in the second half of 2014. 

Once the DFS is completed a production decision will be taken at Tongo.

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.