Modern Mining May 2016

MODULAR PLANTS

either using our own GoldKacha concentrator or – for higher throughputs – Knelson con- centrators with jigs being used for the coarser mineral separations. Where gold dissolution is required, the flowsheet will incorporate our own highly efficient and revolutionary TriTank cyanidation system. Finally, we also offer the APT gold smelter, which is essentially an elec- tric furnace at small scale or diesel-fired at larger scale.” APT’s philosophy is to offer only mercury- free solutions. Indeed, it manufactures plants to specifically remediate mercury-contaminated areas, which can usually recover significant quantities of gold in the process. The company’s products are all manufac- tured in South Africa to APT’s designs and specifications by its in-house workshops or third-party fabricators and components are then pre-assembled and – where practical – tested locally before being despatched in containers to site. Says McFarlane: “Assembly on site – which is largely a ‘plug-and-play’ process – can either be undertaken by APT or by the customer with our assistance. Minimal civils are required – generally no more than a concrete screed and not even that with the small plants – and the plant can be in operation within days in some cases. In all, the whole process from initial order to commissioning normally requires no more than 14 to 20 weeks. “One recent 20 t/h gold plant we did was designed and fabricated in 14 weeks. It was then despatched to site and, once there, was in production in just four days. In another case, we took just six days to erect – and commission – an entire 40 t/h gravity tower.” He adds that every effort is made to ensure that maintenance demands are kept as low as possible. “In terms of componentry such as pumps and motors, we use recognised brands that are well supported and readily available and we also use standard bearings and shafts which can easily be sourced virtually anywhere in the world. We also have a minimalist design philosophy so that our plants are not encum- bered with unnecessary complexity or elaborate ‘bells and whistles’ that can fail and cause prob- lems, particularly out on remote sites.” While the APT range has been developed in- house, the company is an OEM for the Knelson concentrator range (now part of FLSmidth) in Southern Africa and the excellent Knelson products are incorporated in many of APT’s larger plants. APT prides itself on being highly inno- vative. One example of this is the recent addition of ‘GoldFix™’ to its offering. GoldFix

we provide processing solutions for just about everything else – gold and tin, of course, but also all the other precious and base metals, as well as diamonds and minerals such as ilmen- ite, tantalite and wolframite,” states McFarlane. A crucial part of the service that APT offers is an ability to do testwork on ores and, based on the results, devise a customised processing solution. “We don’t do the testwork ourselves,” says McFarlane. “Instead, we make use of our associate company, Peacocke & Simpson (P&S), based in Harare, Zimbabwe, which is known globally for its mineral testwork expertise and whose laboratory has ISO900: 2008 accredita- tion. P&S undertakes extractive metallurgical testing services using all the normal processes you would expect such as gravity concentra- tion, pulp or heap leaching and flotation, as well as some less common technologies – for example, pressure attrition leaching.” Elaborating on APT’s equipment line-up, McFarlane says that the plants provide ore processing solutions right through from initial crushing and screening to saleable product – usually bagged mineral concentrates or gold doré. “The flowsheet will typically include one of our RG scrubbers to disintegrate loose feeds and separate fines for gravity while the coarser rocks proceed to crushing and grinding,” he says. “Initial gravity recovery can be achieved

Small scale RG30 and GoldKacha for cassiterite recovery (cassiterite is the main tin ore).

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36  MODERN MINING  May 2016