Scoping study in-hand

Based on the positive results of a scoping study by AGRA Simons, Diamond Fields International (DFI-T) plans to proceed to a full feasibility study for its wholly owned Marshall Fork feature, near Luderitz, Namibia. It is one of four diamond-bearing features found in the company’s marine concessions, which cover 660 sq. km. along the coast of the southern African nation.

The scoping study follows an independent resource estimate completed by MDRI, a division of AGRA Simons, which showed that the Marshall Fork feature contains an indicated resource of 364,900 carats and an inferred resource of 549,700 carats, for a total of 914,600 carats over an area measuring 1 million sq. metres.

The study was based on proposed mining technology developed by Seacore, a British marine drilling and civil engineering company. It is described as a horizontal mining system using an articulated, slewing mining arm and pump assembly attached at the base of a rigid, heave-compensated slurry pipe.

The system is capable of excavating more than 4,000 cubic metres per day. This material would deliver the diamondiferous gravel to a nominal 100-tonne-per-day, dense-media separation plant aboard a support vessel. The company says the proposed mining system is based on proven technology components. The suitability of the system will be tested during the full feasibility study.

AGRA Simons estimates that capital and operating costs for a sea diamond-mining operation would be US$39 million over a 2-year period. Net revenue for the “base case” indicated resource estimate is US$52.1 million, which would result in an initial production rate of more than 250,000 carats per year.

This estimate is based on an average sale price of US$150 per carat for the more than 95% gem-quality diamonds typically extracted from the concession. Last year, more than 10,000 carats of diamonds were sold for US$160 per carat. The Namibian government collects a 10% royalty on all diamonds prior to export for sale.

Net revenue increases to US$86 million for the base case plus 50% of the inferred resources, and US$119 million for the base case plus 100% of the inferred resource. Recovery of the inferred resources would not incur an increase in capital costs.

Diamond Fields estimates that its marine concessions contain resources (in all categories) of more than 2 million carats.