Less waste means more reliability

Water waste is often deemed an undesirable, but inevitable by-product of mining processes. Yet trendy pump sealing expertise exists which may virtually get rid of this waste whereas conserving power, improving pump reliability and achieving long run operational savings.
Water is probably one of the most important, and more and more imperilled, assets on earth. That a lot is understood and acknowledged by industries throughout the globe.
However, additionally it is one of the most unnecessarily squandered assets in mining operations. And while the trade has begun to embrace efficiency and sustainability-led advances similar to automation and renewable vitality, it remains steadfastly set in its methods when it comes to slurry pump expertise.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also generally recognized as ‘dynamic’ seals’) and single mechanical seals. All come with significant limitations, together with poor reliability, decreased imply instances between failure (MTBF), intensive maintenance necessities and higher operational prices.
These components alone should give mine managers trigger for a re-evaluation of the sealing strategies used on slurry pumps. However, any company with a dedication to the International Standards Organisation ISO-14001 Standard for environmental administration techniques and ISO-50001 Standard for energy management methods should take notice of the excessive water waste and excessive energy consumption that outcomes from opting for these conventional sealing strategies.
Inefficient sealing When used to seal the process pumps in a mine’s scrubber and floatation circuits, gland packing, single mechanical seals and expeller seals all demand one of the wasteful aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential 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, clean flush water to be injected into the method at excessive strain, maintaining a secure fluid movie between the delicate seal faces to keep them cool and lubricated, while forcing the damaging slurry away.
The flush water required in all three sealing approaches is provided from an exterior source and injected into the process at a higher strain than the stuffing field stress, according to the business commonplace American Petroleum Institute (API) Piping Plan 32. ไดอะแฟรม which doesn’t leak onto the ground or into the method is shipped to the tailings dam. This additionally has an effect on the water stability of the plant.
This strategy constitutes a lack of clean water amounting to billions of gallons a year globally. One massive, conventional slurry pump sometimes consumes 10 US gallons (37.8 litres) per minute, amounting to five.2 million US gallons (19.6 million litres) of water yearly – a shocking statistic by any measure.
At a time when world water supply is predicted to fall wanting demand by some 40% by 20301 , eradicating unnecessary use of this priceless useful resource should arguably be a central plank of any responsible sustainability programme. Yet excessive water use, and the higher energy consumption it entails, remain embedded in the processes of many mining companies. Worse nonetheless, it is truthful to say that it’s often accepted as merely ‘par for the course’ by reliability engineers and management alike.
But the fact is that water waste on any scale is a completely pointless feature of slurry operations as it may be nearly totally eliminated simply by employing superior double mechanical seals and modern water management support techniques.
Improve reliability The type of seal selected, the setting in which it operates, and crucially, the tank assist system which supplies the water to maximise seal life, mix to offer the answer to extreme water waste and energy use.
Modern double mechanical seals have two units of faces, one sealing to the process fluid and one to atmosphere, with a barrier house between the two. They are designed to fulfill the arduous requirements of heavy obligation slurry applications, with fortified metal components which are highly resistant to corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is significant to optimising seal life is maintained continually and persistently.
A pressurised barrier tank system is central to the environmental sustainability of this solution. It employs a thermosiphon process which provides clear, cool water to the barrier house between the double seals at a stress higher than the product stress, ensuring a constant, secure and clean fluid film to maintain the seal faces cool and lubricated.
As the mechanical seals generate heat, the recent water in the barrier space rises to the tank and is radiated to the ambiance, permitting the cooler, denser water to sink back down to provide cool lubrication to the seal faces. Most importantly, the flush water is consistently recycled, flowing across the seal faces in a continuous loop and lowering leakage to absolutely the minimal, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing multiple slurry pumps in a ‘series train’ with out the want to set up particular pump methods, pressurised barrier tanks supply ratings as a lot as 435 psi (30 bar), making them ideal for these functions. Self-topping and self-pressurising, they’re also virtually maintenance-free.
Where no plant water provide is out there for topping up the tank methods, or the supply has inadequate stress, fluid supply units can be selected to produce the barrier fluid to seal faces. These have the added benefits of being ready to supply a water/glycol combination or oil to supply freeze safety in extraordinarily chilly climates.
Wide-ranging advantages The benefits of upgrading to trendy sealing options and assist systems have been felt by a coal mine in Poland using a slurry pump to produce coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in big dilution of product, leading to significantly elevated filtration times and costs. The pump was sealed with a double mechanical seal designed to fulfill the arduous requirements of the process.
The supporting seal tank system decreased leakage and product dilution to virtually zero. Return on funding was swift and the financial savings long-term. The benefits by way of water conservation have been equally longlasting and the company’s popularity enhanced.
The mining business must deal with a tricky and costly challenge in terms of maintaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is totally avoidable.
And when an organization can eliminate water waste simultaneously growing reliability and reducing long term operational costs, the decision to upgrade to modern techniques should certainly be an ethical crucial in addition to making sound business sense.
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