Weir Minerals has recently showcased the operation of its GEHO positive displacement pumps at SIMEC Mining’s iron ore site in Whyalla, South Australia.
SIMEC Mining, which produces iron ore concentrate for the Whyalla steelworks, has been using GEHO positive displacement pumps to pump slurry over a distance of 67km from the plant to Whyalla, where it is then dewatered and converted to pellets for the steelmaking process.
The main purpose of the two GEHO pumps is to ensure the material stays suspended in the pipeline for the duration of the 67km journey to Whyalla.
“The GEHO pumps transport the slurry about 250 cubes an hour, 300 tonnes an hour into town,” said Chris Stanton, senior process engineer at SIMEC Mining. “They run every day, all day and are very powerful pumps. They have defined maintenance intervals that allow us to run each pump for the nominal amount of time without any risk of breakdown.”
The pumps are well maintained to perform year after year, which is made possible through the close partnership between Weir Minerals and SIMEC Mining.
“If the GEHO pumps didn’t operate properly then the pipeline would be at risk, and that would be a major issue as the pipeline is the lifeblood for both our operation and the entire township of Whyalla,” explained Anthony Sheely, concentrator operations coordinator at SIMEC Mining.
Going the distance
There are many challenges associated with pumping over long distances, which operators must be aware of, as Peter Thissen, global product manager for GEHO pumps at Weir Minerals, noted: “The biggest challenge of long distance pumping is generating slurry with a suitable particle size distribution for the application. Operators must concentrate the particle size distribution to make it a pumpable slurry whilst trying to minimise the amount of water used in the process.”
“We deal predominantly with high solids concentrations, which is becoming more important in both a water constrained and environmentally sensitive industry. Our depth of experience and knowledge together with the delivery of innovative designs has provided effective solutions to meet our customers’ needs around the world.”
When designing a long distance pipeline, a balance must be considered between the rate of flow, the concentration of the slurry and the size of the particles. For solids in slurry to remain in suspension, they must be moved by the liquid at a minimum speed.
Another challenge is the pipeline route, which must be the most economic method of transportation and suitable for the flow behaviour of the material.
“It’s much easier to build a pipeline on flat land as it stays horizontal and the operational condition for the materials is constant, as long as we can keep the particles in suspension,” continued Thissen. “However, if we have to cross rivers, mountains or valleys then the pipeline will be built on an angle and great consideration must be given to the design of the pipeline, transport velocities and starting and stopping the pipeline.”
Weir Minerals’ GEHO pumps have been designed to transport slurry over long distances, up to 550km and over 2,000 metres uphill.
“Our GEHO pumps are designed to handle high-density slurry with solids up to 85%,” said Thissen. “With extremely high availability, low energy consumption and operating costs they ensure uninterrupted, trouble-free operation.”
The diaphragm in the pump separates the abrasive slurry from the operating components, with the exception of the valves, protecting them from wear and prolonging the life of the pump. This results in significant savings for wear parts.
“As long as the make-up of the slurry doesn’t change and pumping conditions remain the same, our GEHO pumps will continue to operate indefinitely,” concluded Thissen. “Combined with long maintenance intervals and highly dedicated service engineers, they keep processing plants operating at peak performance while delivering a low total cost of ownership.”
To view the pumps in operation, go to our video page here.
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