Weir’s resolution for froth challenges

Froth pumping stays one of the most complex engineering challenges in mineral processing. Here, Weir Minerals presents recommendation for dealing with the vital thing challenges in this operation, how to maximise pump availability and minimise upkeep in operators’ flotation circuits.
To counteract declining ore grades, more and more mine operators are investing in strategies to extend the minerals reclaimed from froth pumping. However, when these methods are deployed with out making allowances for the design of the mine’s froth pumping gear, it can lead to the loss of priceless minerals and profits.
ที่วัดแรงดัน pumping remains one of the most complicated engineering challenges in mineral processing. This is essentially because of the reality that air management points in the hopper, sump and pump itself can sometimes lead to inefficient pumping, increased upkeep and even misplaced product.
“We’ve began to notice a sample amongst our prospects who are having hassle with their froth pumps,” stated Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By using more flocculants and different chemicals designed to enhance mineral restoration, they’re exacerbating existing issues in circuit design and reducing the returns they’re in search of.”
Close examination of the froth’s make-up and physical qualities is usually needed to resolve issues. Ensuring operators’ froth handling equipment adheres to best design practices is a crucial first step in resolving issues.
Maintaining stress The key challenge in froth pumping is dealing with air within 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 via the pump.
In addition to reducing the pump’s effectivity, the air build-up within the pump will scale back its circulate and enhance the slurry level in the suction hopper. The elevated slurry degree might push the pocket of air through the pump, inflicting surging and extreme vibration which might injury the pump bearings, impeller and shaft. “The best approach to manage air in a froth pump is to put money into a froth pump with a steady air elimination 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 within the back through a vent gap within the impeller. From the chamber, a move inducer removes the air from the pump through a vent pipe. “It’s also important to position the pump’s discharge pipe at the high of the pump, or at a 45° angle as this can give air trapped on the top of the casing a approach to escape the pump.”
Solving issues “A persistent problem we see is when hoppers designed to satisfy the demands of slurry pumping are utilized in a froth pumping software. Slurry hoppers require turbulence to stop the mineral content from settling, while turbulence in a froth pump prevents the air from escaping and results in blockages,” said Harvey.
Tanks designed for froth pumping promote steady round motion, the place solids and liquids are sent to the skin of the sump for further transport while air centrifuges into the centre where it might be removed. This ‘whirlpool’ motion may be inspired by introducing the slurry from the top of the tank at a tangential angle. Conical designs, somewhat than those with a flat or rounded ground, further improve the flow of minerals and froth into the pump.
Smooth crusing To stop blockages, the consumption pipe which hyperlinks the tank to the pump ought to have a big diameter and slope downwards in the course of the pump. This design permits escaped air to separate and journey back up the pipe where it could escape from the sump, rather than building up into blockages.
“The shorter your intake pipe, the harder it’s for blockages to construct up. However, along with a upkeep spool and isolation valve, it’s a good idea to go away sufficient area for a water injection port, which is useful for flushing out any solids construct up,” said Harvey.
“To make maintenance easier, a dump valve can be included on the suction aspect of the pump, between the pump and the isolation valve. This will permit users to empty slurry from the pump and the discharge pipe system when stopping the pump for upkeep.”
Tenacious froths Froths are sometimes classified as both brittle, with large air bubbles that break easily, or tenacious, the place air types tight bubbles around minerals and is troublesome to separate. Froth being more tenacious than was accounted for is a frequent reason for blockages as air can’t successfully be removed.
“Two things are occurring in the market right now. On one hand, mine operators are grinding the product much finer than before to liberate extra 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 clients to find methods to handle these extra tenacious froths, by taking a glance at their circuit design and coping with areas the place the air may accumulate and block the system, paying explicit consideration to their pumps, pipes and sumps.

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