JOHANNESBURG (miningweekly.com) – The processing of commissioning tailings negatively impacted on dual-listed Tharisa’s overall production and recoveries for the first quarter of the 2019 financial year.
During the quarter, ended December 31, platinum group metal (PGMs) production fell by 5.9% quarter-on-quarter to 33 600 oz and chrome concentrate output decreased by 10% quarter-on-quarter to 305 400 t, mainly as a result of reduced recoveries.
Tharisa attributed this to the reduced level of run-of-mine (RoM) material, which was supplemented with the reprocessing of 75 900 t of commissioning tailings to maintain plant throughput; however, this contributed to reduced recoveries during the first quarter of the year.
“Although we had planned for a slower first quarter in terms of mining production, we did not anticipate the full impact that blending tailings material would have on our overall recoveries,” CEO Phoevos Pouroulis said on Friday.
Tharisa subsequently revised its 2019 production guidance downwards owing to the quarter-on-quarter decrease in output during the first quarter of the year.
The company now expects to deliver between 150 000 oz and 160 000 oz of PGMs and between 1.4-million and 1.5-million tonnes of chrome concentrates during the 2019 financial year.
However, Tharisa plans to continue the implementation of its Vision 2020 projects during the year ahead and maintain its focus on optimising mining and processing performance, which will ensure that it delivers 200 000 oz of PGMs and two-million tonnes of chrome concentrates in 2020 from the Tharisa mine.
“We will revert back to processing fresh RoM material from mid-January and will achieve our targeted recoveries. We are addressing the operational performance of the mining division with particular reference to equipment availability and use through proactive maintenance and enhancing the capacity of our drill and blast operations,” he added.
Despite lower mined production volumes, the company’s grade control initiatives yielded positive results, with the PGM rougher feed grade improving by 7.4% for the quarter to 1.59 g/t and the Chromium(III) oxide RoM feed grade improving to 18.5% for the period under review.
Tharisa is focusing on improving its performance through the supplementation of three additional drill rigs on site as the efficiencies of the drill and blast operations are dealt with; the implementation of the necessary preventive maintenance systems to drive equipment availability and use increases; and the commissioning of a new Caterpillar 6050 excavator to increase waste removal capacity as part of the planned asset replacement programme.
Further, by the end of January, mining of the East pit will transition to 24-hour continuous operations, from the current 20-hour operation, to mirror the processing operations, thereby increasing capacity by some 15%.