Modern Mining May 2018

CRUSHING, SCREENING AND MILLING

test performance aligns with the expected parameters defined in the design. Having the design expertise in-house, which includes finite element analysis (FEA), Kwatani is able to seamlessly align and monitor the design and manufacturing processes to best effect. The FEA allows the structural and mechanical integrity of each custom design to be checked and proved on the test bench before it leaves the facility. As importantly, this test data can be applied during the commissioning process at the mine site to ensure that the machine is performing to specification – substantially reducing the mine’s risk of any commissioning delay. “This means that we can issue products in a perfect state, and test on the bench to check for any inconsistencies between our design parameters and our manufactured result,” says Schoepflin. “We then begin all these tests again once the machine is installed on site in a ‘cold’ condition and again under the load of real material.” She emphasises that Kwatani’s quality control processes are an integral part of the custom-engineered focus, as each machine has to be checked against its own specific design requirements. This, in turn, gives customers peace of mind that the machines supplied are both designed and manufactured with scien- tific accuracy to suit their on-mine duty. “It is also worth noting that the testing of large scalper screens is not a task that many OEMs are in a position to tackle, as it requires substantial facilities with sufficiently high lev- els of input power,” she adds. “Most companies can’t test this size of unit because they don’t have the requisite cranage capacity, electricity supply or specialised test facility.” Kwatani has developed the technical capa- bility to handle scale – both in terms of the contracts it wins and the dimensions of its cus- tom-engineered screens and feeders. However, says Schoepflin, this does not prevent it from tackling smaller projects and treating them all with the same level of meticulous attention. 

to Kenny Mayhew-Ridgers, Kwatani’s Chief Operating Officer. “We were able to cover all the bases for the customer, from design and fabrication to engi- neering and commissioning – all conducted within a strict framework of ISO quality stan- dards,” he says. “With our commitment to engineering for tonnage, we ensure that our machines are robust and built to last – while doing the duty expected by the customer with minimum downtime.” Kwatani’s 17 000 m 2 premises in Kempton Park near Johannesburg includes modern facil- ities for fabrication and assembly, as well as repair and testing facilities for vibrating equip- ment including exciter gearboxes and electrical motors. It has 160 tonnes of combined crane capacity and extensive warehousing. “To allow us to produce this number of machines over a relatively short period of time, we rely on a well-managed and highly efficient internal logistics system and supply chain,” says Schoepflin. “This is especially important when there are so many different machines in the order, each with its own specifications and requirements. In this case, we were dealing with over a dozen variations or machine types – adding to the complexity of the materials management process.” She also highlights the extensive test- ing process that each machine and exciter drive undergoes before being dispatched and commissioned. “Our test bench must be built up specifically for each type of machine, where they must run optimally for respective periods of about an hour before being passed and certificated,” she says. “As a company that specialises in custom engineering, our processes are set up to manage the production of a range of machine sizes in quick succession.” A vital aspect of the testing, says Mayhew- Ridgers, is that readings and measurements can be taken on the test bench – such as the stroke and acceleration – to ensure that the

Above: Kwatani’s fabrication workshop is in full production with the order for 44 screens. Approximately 200 tons of steel are currently on site; this photograph shows the pipe traverse for one of the screens. Above left: Various exciters on display and ready for shipment.

“As a company that specialises in custom engineering, our processes are set up to manage the production of a range of machine

sizes in quick succession.”

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May 2018  MODERN MINING  37