Pump manufacturer and supplier Verderflex says that peristaltic pumps in the mining environment have the ability to use less energy, require less space and reduce negative impacts on the environment.

Peristaltic pumps are based on the altering compression and relaxation of a hose or tube drawing the contents into the hose or tube. A rotating shoe or roller passes along the length of the hose or tube, which compresses the hose creating a seal between suction and discharge, thereby eliminating product slip.

When the hose or tube is restored, a strong vacuum is formed, which draws product into the pump. The pumped product does not come into contact with any moving parts and is contained within a heavy-duty hose or a precision extruded tube. The pumping action makes the pump suitable for accurate dosing applications.

Benefits

Hose pumps can circulate up to 80% solid content. Verderflex says that traditional centrifugal pump loses efficiency when the slurry reaches 30% solids. With this limitation, slurry pumps have significant process water demands: on a plant processing 75 t/h of ore at 65% solids, every time a hose pump replaces a process slurry pump, it saves over 1.1-million litres of water a year because of the slurry pump’s inefficiency. On the same duty, the hose pump requires less than 25% of the process water of a slurry pump.

Further, the company says that peristaltic pumps use less energy. On the same 75 t/h ore plant at full flow, a VF125 hose pump absorbs around 35 kW whereas a slurry pump needs over 70 kW, which results in a saving of over 50%. This directly translates into reduced electricity demand.

Power rationing is a concern for many established mines. On new developments, the infrastructure costs to import power can be considerable, and can even cause significant delays and generate considerable non-mining environmental opposition, says the company.

Peristaltic pumps also require less space, thereby decreasing overall plant size.

Pulp density is critical to plant performance, and an increased solid content can reduce the number of post-thickening filter stages, saving on the initial capital cost and reducing the footprint of mineral processing operation.

Verderflex also says that peristaltic pumps reduce a mine’s environmental impact.

Many mineral recovery processes use cyanide-based leaching techniques, particularly where gold is a key mineral. Cyanide has many adverse environmental consequences, including the pollution of land surrounding the plant, contamination of aquifers and decimation of life in water courses. Progressing cavity pumps have integral seals requiring regular replacement and representing a clear leakage risk. Peristaltic pumps are seal-less and, consequently, have a much lower contamination risk.

Further, the peristaltic pump has a gentle pumping action that reduces damage to fragile cell cultures in bio-oxidation reaction techniques.

The peristaltic pump uses a gentle pumping action, which reduces reagent usage and acid mine drainage waste treatment costs. A peristaltic pump’s gentle low shear pumping action maintains particle size reducing the use of flocculent and other process reagents.

“Conventional high-shear technologies, such as progressive cavity or screw pumps, significantly increase reagent use, increasing operating costs and raising post-processing costs owing to flotation reagent carryover,” says the company. Similarly, residual reagent can increase the waste remediation cost, or increase the environmental damage from tailings dams or its resultant groundwater pollution.

The company says that abrasion-resistant peristaltic pumps require lower maintenance costs.

Slurries are often acidic and highly abrasive. Consequentially, conventional slurry pumps use impellers made from increasingly expensive and non-standard materials with service lives that are measured in days.

Meanwhile, the company says that longer service intervals and easy on-site servicing reduce pump downtime.

In contrast, on a peristaltic pump, only the rubber hose is in contact with the pumped liquid and service life is measured in months, reducing pump downtime. As the hose can easily be changed on site, maintenance hours are similarly reduced.

Corrosion-resistant hoses eliminate costly special metal impellers. To pump highly acidic slurries, hoses are made from several standard elastomers, each proven in different mining environments, to withstand process chemicals and avoid the use of expensive exotic metal impellers.