Water waste is often deemed an unwanted, but inevitable by-product of mining processes. Yet fashionable pump sealing expertise exists which can nearly get rid of this waste while conserving energy, bettering pump reliability and reaching long term operational financial savings.
Water is certainly one of the most important, and increasingly imperilled, assets on earth. That a lot is known and acknowledged by industries across the globe.
However, it’s also one of the most unnecessarily squandered resources in mining operations. And whereas the business has begun to embrace effectivity and sustainability-led advances corresponding to automation and renewable vitality, it remains steadfastly set in its methods when it comes to slurry pump know-how.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also generally recognized as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, together with poor reliability, lowered mean instances between failure (MTBF), intensive maintenance requirements and better operational prices.
These elements alone should give mine managers cause for a re-evaluation of the sealing strategies used on slurry pumps. However, any firm with a dedication to the International Standards Organisation ISO-14001 Standard for environmental management methods and ISO-50001 Standard for vitality management techniques ought to take observe of the excessive water waste and excessive power consumption that results from opting for these traditional sealing strategies.
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 one of the most wasteful aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential that packing is flushed with clear water to maintain it cool and lubricated, while each single slurry seals and expellers require a supply of cool, clear flush water to be injected into the method at high strain, sustaining a stable fluid film between the delicate seal faces to maintain them cool and lubricated, while forcing the damaging slurry away.
The flush water required in all three sealing approaches is supplied from an external source and injected into the process at a better pressure than the stuffing field stress, in line with the industry normal American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the method is sent to the tailings dam. This also has an impact on the water balance of the plant.
This approach constitutes a lack of clear water amounting to billions of gallons a year globally. One massive, standard slurry pump typically consumes 10 US gallons (37.eight litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water yearly – a surprising statistic by any measure.
At a time when global water provide is predicted to fall short of demand by some 40% by 20301 , removing pointless use of this useful useful resource ought to arguably be a central plank of any accountable sustainability programme. Yet excessive water use, and the upper power consumption it entails, stay embedded within the processes of many mining corporations. Worse still, it is honest to say that it’s usually accepted as simply ‘par for the course’ by reliability engineers and management alike.
But the very fact is that water waste on any scale is a completely pointless feature of slurry operations as it can be almost totally eradicated just by employing advanced double mechanical seals and fashionable water administration help methods.
Improve reliability The kind of seal chosen, the setting during which it operates, and crucially, the tank help system which provides the water to maximise seal life, mix to offer the answer to excessive water waste and vitality use.
Modern double mechanical seals have two units of faces, one sealing to the method fluid and one to environment, with a barrier space between the two. They are designed to meet the arduous requirements of heavy obligation slurry applications, with fortified metallic components which are extremely resistant to corrosion and erosion. Large ports and elevated radial clearances mean the lubrication which is vital to optimising seal life is maintained continually and persistently.
A pressurised barrier tank system is central to the environmental sustainability of this answer. It employs a thermosiphon process which supplies clean, cool water to the barrier space between the double seals at a pressure higher than the product pressure, ensuring a consistent, steady and clear fluid movie to keep the seal faces cool and lubricated.
As the mechanical seals generate heat, the new water in the barrier house rises to the tank and is radiated to the ambiance, allowing the cooler, denser water to sink back down to provide cool lubrication to the seal faces. เกจวัดแรงดันลม10bar , the flush water is continually recycled, flowing throughout the seal faces in a continuous loop and lowering leakage to the absolute 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 special pump systems, pressurised barrier tanks supply rankings up to 435 psi (30 bar), making them perfect for these functions. Self-topping and self-pressurising, they’re also almost maintenance-free.
Where no plant water provide is on the market for topping up the tank systems, or the availability has inadequate stress, fluid delivery units may be selected to produce the barrier fluid to seal faces. These have the added advantages of having the power to supply a water/glycol combination or oil to offer freeze safety in extraordinarily cold climates.
Wide-ranging benefits The benefits of upgrading to fashionable sealing options and help techniques 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 big dilution of product, resulting in significantly elevated filtration times and prices. The pump was sealed with a double mechanical seal designed to satisfy the arduous necessities of the process.
The supporting seal tank system decreased leakage and product dilution to just about zero. Return on investment was swift and the savings long-term. The benefits when it comes to water conservation have been equally longlasting and the company’s popularity enhanced.
The mining business should take care of a tricky and expensive challenge in phrases of maintaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is completely avoidable.
And when an organization can get rid of water waste simultaneously increasing reliability and lowering long term operational prices, the choice to improve to modern methods ought to absolutely be a moral imperative as properly as making sound business sense.
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