Pumping slurries with a peristaltic pump
Verder Peristaltic Pumps offer several advantages for mines to pump their slurries.
Some of the advantages include less water, power, space, damage chemicals and downtime.
According to the company, the hose pumps can circulate slurry SGs of 1.6 to 1.8 or up to 80% solid content.
The traditional centrifugal pump loses efficiency when the slurry SG reaches 1.3 or 30% solids.
With this limitation, slurry pumps have significant process water demands : on a plant processing 75 tonnes of ore per hour, and at 65% solids, every time a hose pump replaces a process slurry pump, it saves over 1,100 Million litres of water annually 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.
Verder has been supplying pumps to the mining sector in South Africa for the past 15 years and is a brand synonymous with quality and durability.
On the same 75 ore tonnes per hour plant, on thickener underflow duty at full flow, a VF125 hose pump absorbs around 35 kW whereas a slurry pump needs over 70kW : a saving of over 50%.
This directly translates into reduced electrical requirements. 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.
There is also a significant economic case – in the above example, the hose pump reduced annual operating power demand by over 210 MWh.
With a variety of peristaltic pumps that are specifically designed to be used in mining.
Peristaltic pumps increase downline efficiency and reduce overall plant size. As pulp density is critical to optimum plant performance, 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.
In addition, Peristaltic Pumps reduce mining’s environmental impact because many of its recovery processes use Cyanide based leaching techniques especially where Gold is a key mineral.
Cyanide has many adverse environmental consequences including polluting the land surrounding the plant, contaminating aquifers and decimating life in water courses.
The traditional dosing solution, 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.
The Peristaltic Pumps also have a gentle pumping action, ideal for Bio-oxidation Techniques and minimises damage to fragile cell cultures in bio-oxidation reaction techniques.
One such requirement is the Biox (R) process that uses a live culture to free gold from sulphide ores, reducing Cyanide usage and improving process yields.
On the other hand Peristaltic Pump’s gentle pumping action reduces reagent usage and acid mine drainage waste treatment costs.
A peristaltic pump’s gentle low shear pumping action maintains particle size minimising the use of flocculent and other process reagents.
Conventional high shear technologies such as progressive cavity or screw pump significantly increase reagent usage increasing operating costs and raising post processing costs due to flotation reagent carryover.
Similarly, residual reagent can increase the waste remediation cost or increase the environmental damage from tailings dams or their resultant groundwater pollution.
In addition, abrasion resistant peristaltic pumps lower maintenance costs, as slurries are often acidic and or highly abrasive.
Consequentially, conventional slurry pumps use impellers made from increasingly expensive and non standard materials with service lives that are measured in days.
The longer service intervals and easy in-situ servicing reduce pump downtime. In contrast, on a peristaltic pump, only the rubber hose is in contact with the pumped liquid and as the ultimate rubber lined pump, service life is measured in months, reducing pump downtime and as the hose can easily be changed in situ, maintenance hours are similarly reduced.
Meanwhile its corrosion resistant hoses eliminate costly special metal impellers
To pump highly acidic slurries, hoses are made from several standard elastomers, each proven in the mining environment to withstand process chemicals and avoiding the use of expensive exotic metal impellers.
By using a Verder Peristaltic pump it significantly reduces production cost and downtime, providing in a more cost effective process.
The Verder Group comprises Verder Liquids Division and are present in 24 countries worldwide.