Tag Archives: Willem Slabbert

Multotec provides Guinea bauxite verification with sampling equipment

Multotec Process Equipment’s high-precision sampling equipment has found a home in Guinea, with bauxite producers in the West African country using the South Africa-based company’s tools to verify the quality of mined material before it is shipped overseas.

The company has recently provided two tariff sampling plants to a major bauxite producer in the country, including what is possibly one of the largest hammer samplers in the world, it said.

One of the plants is located at the bauxite mining operation itself, while the other is at the export facility where the high-grade bauxite is loaded onto ships.

According to Willem Slabbert, Sampling and Magnetics Specialist at Multotec Process Equipment, the samplers serve a vital role in representatively measuring the quality of the material mined and then exported, as well as its physical characteristics.

“At the mine, the sampling plant gives the mining company and their third-party mining contractor a scientific basis on which to check compliance with their contractual requirements,” Slabbert says.

“Similarly, the plant at the export facility assures the end customer of the quality of bauxite they are purchasing.”

The solution designed for this specific application includes hammer samplers, double-roll crushers, rotating plate dividers, feeder conveyors and barcoded carousels to link the sampling plant’s hourly performance to the indexed samples produced, Multotec explained. There is also protection equipment – a moisture analyser, overbelt magnet and metal detector – and inter-sampling plant conveyors.

“The plants were designed as a holistic solution, to deliver measurements in line with the international standard ISO8685 – ensuring that both sides of a contractual agreement can feel confident in the results,” Slabbert says. “They are also fully automatic and PLC-controlled for maximum efficiency.”

He highlighted that the sampling and materials handling solution was based on extensive test work carried out at Multotec’s facilities in Spartan, near Johannesburg. Crusher tests were also conducted on the specific bauxite, which comprised a substrate material with very hard embedded nodules.

“We identified custom-designed, heavy-duty, double-roll crushers as the optimal solution to deal with the extreme hardness of the nodules in the material,” Slabbert says. “The abrasiveness and stickiness of the Guinean bauxite also required low-friction liners to be designed into each plant.”

Multotec also has a West Africa branch in Ghana to supporting its installations. This branch also sources local components for customers.

Multotec Process Equipment has experience in sampling bauxite in Guinea, says Slabbert, with a sampling plant installed two decades ago for another bauxite producer.

Multotec on the front line of West Africa mineral sampling scene

Multotec Process Equipment says the growth and diversification of West Africa’s mining sector is making the precision of mineral sampling a “vital priority”.

For over two decades, Multotec has been active in the West Africa market, with its samplers at over 30 sites in countries including Ghana, Liberia, Burkina Faso, Guinea, Sierra Leone, Mali and Guinea-Bissau. A range of commodity sectors use the equipment for both slurry and dry sampling applications, among them gold, bauxite, iron ore and heavy minerals.

Multotec has also presented representative sampling training courses explaining the practical aspects of implementing the Theory of Sampling (TOS).

Willem Slabbert, Process Manager at Multotec Process Equipment, said: “In bulk minerals like bauxite – where our sampling plants have been in operation with a major West African producer for 17 years – the sampling protocol and ‘correctness’ of equipment design is key to ensuring bottom-line success.”

He highlighted the importance of reproducible and accurate sampling – cumulatively termed representative – at the interface between the mine and port, and on the ship-loading conveyor to the client.

The sampling, which must comply with ISO standards and best practice as prescribed by the TOS, confirms the mine is supplying product to the end-customer’s contractual specification. “Any imperfection in the sampling process can lead to unnecessary contractual disputes and potential financial losses for the mine or client,” Slabbert says.

Multotec supplies wet slurry samplers to several gold mines in West Africa, who rely on good gold accounting and reconciliation at their processing plants. The equipment is popular among large gold producers as well as the smaller entrants, according to the company.

“With a comprehensive range of Two-In-One, primary and ancillary samplers, we are able to tailor each installation to the customer’s specific application,” Slabbert says. “This means accommodating variables like throughput rates and slurry densities, including accounting for grade variability from various mine sources feeding a single processing plant, in many of the West African deposits.”

For brownfield projects, Multotec can design solutions to suit and fit the structural constraints of the customer’s existing infrastructure.

Local service support is available from Multotec’s Ghana branch as well as regional agents and service providers operating in other countries. This ensures a point of contact as first line of support and, drawing on its expertise across a range of disciplines, Multotec can put specialists, engineers, design draughtsmen and millwrights to work on projects throughout the West African territories.