Firestone Diamonds, listed on AIM, has released its final results for the year ended 30 June 2018 – representing the first full year of commercial production at its Liqhobong mine in Lesotho. According to the company the year was marked by an “exceptional operational performance” which saw a 128 % increase in diamonds recovered to 835 832 carats, an 18 % increase in grade to 22 cpht, a 93 % increase in ore tonnes treated to 3,8 Mt and a 5 % decrease in operating costs to US$11,62 per tonne treated.

Liqhobong delivers an exceptional performance

The Liqhobong mine in Lesotho (photo: Firestone Diamonds).

The largest diamond recovered during the year (in September 2017) was a 134-carat gem quality light yellow diamond while the most valuable diamond recovered, as measured by US dollar per carat, was a fancy pink diamond which realised a sale price of US$112 781 per carat.

Revenue increased by 125 % to US$62,2 million and the loss for the year decreased by 91 % to US$14,2 million.

The lower than expected frequency of valuable diamonds recovered and continued low prices for the ROM category diamonds during the early part of the year resulted in lower than expected average diamond values achieved at sale, prompting a revision to the mine plan. The result was a shorter nine-year mine plan, which could be supported by a lower average diamond value of US$75 per carat, whilst retaining the optionality of taking advantage of the longer 14-year life of mine should realised diamond values increase or should there be a sustained improvement in market conditions.

Liqhobong’s impeccable safety record was maintained throughout the 2018 financial year, reaching 6,2 million man hours worked without a single lost time injury at the end of the year.

Firestone notes that the processing plant includes a conventional 3-stage crushing circuit which is designed to crush kimberlite and to liberate diamonds. “We do our best to minimise diamond damage, however, the recovery process is inherently abrasive and damage does occur as in all recovery plants to a greater or lesser extent,” says Firestone.” During the year, there was an increase in diamond damage which is assessed on all +5 carat stones recovered, which resulted in a thorough investigation into all possible areas where damage might occur within the plant. Pleasingly, the minor modifications made subsequently to certain parts of the plant and recovery areas resulted in a decrease in diamond damage to well within acceptable industry standards by the year end.”

The year also saw Paul Bosma being appointed as CEO, effective as from 1 July 2018 following the departure of Stuart Brown, who led Firestone during the five-year period when it developed Liqhobong. Bosma, a geologist with 25 years’ experience in the mining industry (14 of them with De Beers), joined Firestone in 2014, later becoming GM of the mine and successfully managing the ramp-up to commercial production.

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