Modern Mining July 2020

IRON ORE

Companies who thrive in the African mining industry are the ones that learn how to turn extremely difficult conditions into lucrative opportunities. This takes levels of insight, vast amounts of practical experience and perseverance, which are not easy to achieve. Modern Mining spoke to Franco Le Roux Mining, which has managed to find success in an application which would intimidate most mining contractors, to see what separates it from the rest. Turning difficult conditions into a lucrative opportunity

T he opportunity is a contract for remining of an old, untouched ROM stockpiles at a large iron ore mine. The contract was initially drawn up based on a few assumptions regarding the material properties, which were later proven to be quite far from reality. This could easily have spelled disaster for the project as it so often does, but some inspired thinking, along with the adaptability of Metso Lokotracks, helped Franco Le Roux Mining (FLRM) navigate these obstacles seamlessly. The assumption made regarding the material properties was that among the ROM stockpiles meant for remining, there would be an average of 37% natural fines (below -8 mm) that could be recovered and sent directly to the smelter. With this initial material description, the client specified a three-tier approach to the project: phase 1 would involve recovery of just the natural fines through the use of a mobile scalper; phase 2 would incor- porate a mobile jaw crusher to increase the fines generated for recovery by the mobile scalper; and phase 3 would add two mobile cone crushers as well as a mobile sizing screen to ensure all material would pass -8 mm.

The reality Shortly after implementation of phase one, it became clear that the working assumptions from which the job was speci- fied were just not the facts of the material properties. Instead of 37% natural fines on the product, the stockpiles were proving to contain between

17 – 22% of fines, about half of what was expected. Such a massive difference between the initial specification and reality would most often spell disaster for the viability of the contract due to the large tonnages which required crushing, but thanks to some foresight by the engineers who had already specified the process capabilities, a solution was already in the works, which meant that they would have to immediately skip to phase 3, a fully mobile three-stage crushing and screening plant to achieve the required tonnages of end-product. Pilot Crushtec to the rescue Fortunately, due to Pilot Crushtec International’s high

Below: The full complement of machinery required was deployed to site within a few weeks of the problem being identified on-site. Centre: A Metso Lokotrack LT200HP cone crusher supplied by Pilot Crushtec working on site.

16  MODERN MINING  July 2020