Froth pumping stays one of the complicated engineering challenges in mineral processing. Here, เครื่องมือที่ใช้วัดความดันโลหิต provides recommendation for coping with the key challenges on this operation, tips on how to maximise pump availability and minimise maintenance in operators’ flotation circuits.
To counteract declining ore grades, increasingly mine operators are investing in methods to extend the minerals reclaimed from froth pumping. However, when these methods are deployed without making allowances for the design of the mine’s froth pumping tools, it can lead to the loss of valuable minerals and profits.
Froth pumping stays some of the advanced engineering challenges in mineral processing. This is basically due to the reality that air administration issues within the hopper, sump and pump itself can generally lead to inefficient pumping, elevated maintenance and even misplaced product.
“We’ve began to notice a pattern among our customers who’re having trouble with their froth pumps,” said Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By utilizing extra flocculants and different chemical compounds designed to improve mineral restoration, they’re exacerbating existing problems in circuit design and reducing the returns they’re in search of.”
Close examination of the froth’s make-up and physical qualities is often wanted to resolve issues. Ensuring operators’ froth handling equipment adheres to finest design practices is a crucial first step in resolving issues.
Maintaining stress The key challenge in froth pumping is coping with air in the pump itself, as it tends to naturally centrifuge into the impeller’s eye, the place it builds up into an “air lock” which impedes the motion of slurry by way of the pump.
In addition to decreasing the pump’s effectivity, the air build-up within the pump will reduce its move and improve the slurry degree in the suction hopper. The elevated slurry degree could push the pocket of air via the pump, causing surging and extreme vibration which might injury the pump bearings, impeller and shaft. “The finest way to manage air in a froth pump is to invest in a froth pump with a continuous air removal system (CARS), which we have in our Warman AHF, MF and LF pumps,” says Harvey.
This system allows air to maneuver from the pump’s impeller eye to an air assortment chamber in the back via a vent hole in the impeller. From the chamber, a move inducer removes the air from the pump via a vent pipe. “It’s additionally essential to place the pump’s discharge pipe on the prime of the pump, or at a 45° angle as this will give air trapped on the high of the casing a method to escape the pump.”
Solving problems “A persistent problem we see is when hoppers designed to satisfy the calls for of slurry pumping are utilized in a froth pumping application. Slurry hoppers require turbulence to forestall the mineral content material from settling, whereas turbulence in a froth pump prevents the air from escaping and leads to blockages,” said Harvey.
Tanks designed for froth pumping promote continuous circular movement, where solids and liquids are despatched to the outside of the sump for further transport whereas air centrifuges into the centre the place it may be removed. This ‘whirlpool’ movement may be inspired by introducing the slurry from the top of the tank at a tangential angle. Conical designs, rather than those with a flat or rounded flooring, further improve the circulate of minerals and froth into the pump.
Smooth crusing To prevent blockages, the intake pipe which links the tank to the pump should have a big diameter and slope downwards in path of the pump. This design permits escaped air to separate and travel back up the pipe where it can escape from the sump, rather than building up into blockages.
“The shorter your intake pipe, the tougher it’s for blockages to construct up. However, in addition to a upkeep spool and isolation valve, it’s a good idea to go away sufficient house for a water injection port, which is helpful for flushing out any solids construct up,” mentioned Harvey.
“To make upkeep easier, a dump valve could be included on the suction side of the pump, between the pump and the isolation valve. This will allow customers to drain slurry from the pump and the discharge pipe system when stopping the pump for maintenance.”
Tenacious froths Froths are often categorised as either brittle, with large air bubbles that break easily, or tenacious, where air types tight bubbles round minerals and is tough to separate. Froth being more tenacious than was accounted for is a frequent explanation for blockages as air can’t successfully be removed.
“Two issues are happening available within the market right now. On one hand, mine operators are grinding the product much finer than before to liberate more from the waste rock. They’re also using flocculants that produce much smaller bubbles which lock up the air much more than brittle froths,” stated Harvey. “We’re working along with prospects to find ways to manage these extra tenacious froths, by taking a look at their circuit design and dealing with areas where the air could accumulate and block the system, paying specific attention to their pumps, pipes and sumps.
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