Water waste is often deemed an unwanted, however inevitable by-product of mining processes. Yet modern pump sealing expertise exists which can just about eliminate this waste whereas conserving power, enhancing pump reliability and reaching long run operational financial savings.
Water is amongst the most important, and increasingly imperilled, assets on earth. That a lot is known and acknowledged by industries throughout the globe.
However, it is also one of the unnecessarily squandered sources in mining operations. And whereas the industry has begun to embrace effectivity and sustainability-led advances similar to automation and renewable vitality, it stays steadfastly set in its ways when it comes to slurry pump expertise.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also generally known as ‘dynamic’ seals’) and single mechanical seals. All include vital limitations, including poor reliability, reduced imply instances between failure (MTBF), intensive upkeep requirements and higher operational prices.
These factors alone should 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 techniques and ISO-50001 Standard for energy administration methods ought to pay consideration to the excessive water waste and high power consumption that results 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 one of the most wasteful aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clear water to maintain it cool and lubricated, whereas both single slurry seals and expellers require a supply of cool, clean flush water to be injected into the process at excessive stress, maintaining a stable 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 exterior supply and injected into the process at a higher stress than the stuffing field strain, consistent with the business standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is distributed to the tailings dam. This also has an impact on the water balance of the plant.
This method constitutes a loss of clean water amounting to billions of gallons a year globally. One giant, standard slurry pump sometimes consumes 10 US gallons (37.eight litres) per minute, amounting to five.2 million US gallons (19.6 million litres) of water every year – a shocking statistic by any measure.
At a time when international water supply is predicted to fall short of demand by some 40% by 20301 , eradicating unnecessary use of this priceless 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 in the processes of many mining companies. Worse still, it’s fair to say that it is typically 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 very pointless function of slurry operations as it can be virtually totally eliminated simply by employing advanced double mechanical seals and trendy water administration help systems.
Improve reliability The sort of seal selected, the surroundings during which it operates, and crucially, the tank support system which provides the water to maximise seal life, mix to offer the answer to extreme water waste and vitality use.
Modern double mechanical seals have two units of faces, one sealing to the process fluid and one to environment, with a barrier space between the two. They are designed to fulfill the arduous necessities of heavy obligation slurry functions, with fortified metal elements which are extremely proof against corrosion and erosion. Large ports and elevated radial clearances imply the lubrication which is important to optimising seal life is maintained constantly and consistently.
A pressurised barrier tank system is central to the environmental sustainability of this answer. It employs a thermosiphon process which provides clean, cool water to the barrier area between the double seals at a stress higher than the product strain, guaranteeing a constant, stable and clean fluid film to maintain the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water within the barrier house rises to the tank and is radiated to the atmosphere, allowing the cooler, denser water to sink again down to offer cool lubrication to the seal faces. Most importantly, the flush water is continually recycled, flowing across the seal faces in a steady loop and lowering leakage to the absolute minimal, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing multiple slurry pumps in a ‘series train’ without the want to set up special pump techniques, pressurised barrier tanks provide rankings as a lot as 435 psi (30 bar), making them ideal for these applications. Self-topping and self-pressurising, they’re also nearly maintenance-free.
Where no plant water supply is on the market for topping up the tank techniques, or the supply has insufficient pressure, fluid delivery models could be selected to produce the barrier fluid to seal faces. These have the added benefits of with the ability to supply a water/glycol combination or oil to provide freeze protection in extremely chilly climates.
Wide-ranging advantages The benefits of upgrading to fashionable sealing options and assist systems were 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, resulting in greatly elevated filtration times and prices. The pump was sealed with a double mechanical seal designed to fulfill the arduous requirements of the process.
The supporting seal tank system reduced leakage and product dilution to just about zero. Return on funding was swift and the savings long-term. The benefits in phrases of water conservation have been equally longlasting and the company’s reputation enhanced.
differential pressure gauge ราคา mining business should cope with a troublesome and costly problem when it comes to sustaining rotating equipment. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is completely avoidable.
And when an organization can eliminate water waste concurrently increasing reliability and lowering long term operational costs, the decision to improve to trendy techniques ought to certainly be an ethical crucial in addition to making sound enterprise sense.