JOHANNESBURG (miningweekly.com) – Mineral exploration, development and mining company African Minerals on Tuesday announced a hike in the direct shipping ore (DSO) resource of its Tonkolili iron-ore mine, in Sierra Leone.

The Aim-listed group reported a Joint Ore Reserve Committee-compliant mineral resource estimate of 142.1-million tonnes, grading 57% iron, up from the 2010 estimate of 126.5-million tonnes of DSO, grading 58.1% iron.

The updated resource comprised 99.6-million tonnes measured, 33.9-million tonnes indicated and 8.5-million tonnes inferred, with 2.9% silica, 6.6% alumina and 0.08% phosphorus.

“The increase in the Tonkolili DSO resource is a significant event. The increased life of the DSO resource, now with over 90% classified in the measured and indicated resource categories, will allow the company to produce a DSO product to 2020 and to take a longer-term view regarding the current operations,” African Minerals CEO Bernie Pryor said.

The production of DSO would be concurrent with African Mineral’s near-term expansion aims, which would see production capacity increase from 20-million tonnes a year to 25-million tonnes a year, while moving into an eight-million- to ten-million-tonne-a-year output of a higher-value saprolite hematite concentrate product after the establishment of the first saprolite concentrator in the first half of 2016.

“The company is currently assessing the metallurgical properties of the saprolite component of the mineral resource, which was reported in December 2010 at 1.1-billion tonnes, and intends to produce a formal mineral resource update regarding the saprolite component of the Tonkolili project shortly,” Pryor said.

The publication of the updated saprolite resource, incorporating the adjustments to the DSO resource, later this quarter, was the first step of the group’s expansion ambitions.