Less waste means extra reliability

Water waste is usually deemed an undesirable, however inevitable by-product of mining processes. Yet modern pump sealing know-how exists which may just about get rid of this waste while conserving energy, enhancing pump reliability and attaining long run operational savings.
Water is probably considered one of the most significant, and more and more imperilled, sources on earth. That much is understood and acknowledged by industries throughout the globe.
However, it is also one of the most unnecessarily squandered sources in mining operations. And while the industry has begun to embrace effectivity and sustainability-led advances corresponding to automation and renewable energy, it stays steadfastly set in its methods in phrases of slurry pump know-how.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also known as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, together with poor reliability, decreased mean occasions between failure (MTBF), intensive upkeep necessities and better operational costs.
These elements alone ought to give mine managers cause for a re-evaluation of the sealing methods used on slurry pumps. However, any company with a commitment to the International Standards Organisation ISO-14001 Standard for environmental management systems and ISO-50001 Standard for vitality administration systems should take observe of the extreme water waste and excessive power consumption that outcomes from choosing these traditional sealing methods.
Inefficient sealing When used to seal the method pumps in a mine’s scrubber and floatation circuits, gland packing, single mechanical seals and expeller seals all demand some of the wasteful aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clean water to maintain it cool and lubricated, whereas each single slurry seals and expellers require a provide of cool, clear flush water to be injected into the method at high pressure, sustaining a steady fluid movie between the delicate seal faces to maintain them cool and lubricated, whereas forcing the damaging slurry away.
The flush water required in all three sealing approaches is equipped from an external supply and injected into the method at a better stress than the stuffing box pressure, consistent with the business commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is shipped to the tailings dam. This also has an effect on the water steadiness of the plant.
This method constitutes a lack of clean water amounting to billions of gallons a 12 months globally. One giant, typical slurry pump usually consumes 10 US gallons (37.eight litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water every year – a surprising statistic by any measure.
At a time when international water supply is predicted to fall wanting demand by some 40% by 20301 , eradicating pointless use of this useful useful resource ought to arguably be a central plank of any accountable sustainability programme. Yet extreme water use, and the higher energy consumption it entails, stay embedded within the processes of many mining firms. Worse nonetheless, it’s truthful to say that it is often accepted as simply ‘par for the course’ by reliability engineers and administration alike.
But the very fact is that water waste on any scale is a totally pointless feature of slurry operations as it can be nearly totally eliminated simply by employing advanced double mechanical seals and modern water management assist techniques.
Improve Up-sell of seal chosen, the surroundings during which it operates, and crucially, the tank help system which supplies the water to maximise seal life, mix to offer the solution to extreme water waste and energy use.
Modern double mechanical seals have two units of faces, one sealing to the method fluid and one to ambiance, with a barrier house between the 2. They are designed to fulfill the arduous requirements of heavy responsibility slurry applications, with fortified steel elements which are highly resistant to corrosion and erosion. Large ports and increased radial clearances mean the lubrication which is significant to optimising seal life is maintained continuously and constantly.
A pressurised barrier tank system is central to the environmental sustainability of this solution. It employs a thermosiphon process which provides clean, cool water to the barrier space between the double seals at a strain larger than the product pressure, ensuring a consistent, stable and clean fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate heat, the new water in the barrier space rises to the tank and is radiated to the environment, allowing the cooler, denser water to sink back down to offer cool lubrication to the seal faces. Most importantly, the flush water is consistently recycled, flowing throughout the seal faces in a continuous loop and lowering leakage to absolutely the minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a number of slurry pumps in a ‘series train’ with out the necessity to set up particular pump systems, pressurised barrier tanks supply scores as a lot as 435 psi (30 bar), making them perfect for these purposes. Self-topping and self-pressurising, they are also almost maintenance-free.
Where no plant water supply is available for topping up the tank methods, or the availability has inadequate strain, fluid delivery items may be selected to supply the barrier fluid to seal faces. These have the added benefits of having the power to supply a water/glycol combination or oil to provide freeze protection in extraordinarily chilly climates.
Wide-ranging benefits The benefits of upgrading to trendy sealing solutions and help methods had been felt by a coal mine in Poland using a slurry pump to provide coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in huge dilution of product, resulting in greatly elevated filtration instances and costs. The pump was sealed with a double mechanical seal designed to meet the arduous requirements of the process.
The supporting seal tank system decreased leakage and product dilution to nearly zero. Return on investment was swift and the savings long-term. The benefits in phrases of water conservation have been equally longlasting and the company’s status enhanced.
The mining business must take care of a tough and expensive challenge when it comes to sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is totally avoidable.
And when an organization can eliminate water waste at the identical time as growing reliability and decreasing long term operational prices, the choice to upgrade to trendy systems should absolutely be an ethical imperative as well as making sound business sense.
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