Weir’s solution for froth challenges

Froth pumping remains some of the complicated engineering challenges in mineral processing. Here, Weir Minerals presents advice for dealing with the important thing challenges on this operation, tips on how to maximise pump availability and minimise upkeep in operators’ flotation circuits.
To counteract declining ore grades, increasingly more mine operators are investing in techniques to increase 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 equipment, it can end result in the loss of useful minerals and profits.
Froth pumping stays one of the complex engineering challenges in mineral processing. This is essentially due to the fact that air management issues in the hopper, sump and pump itself can generally lead to inefficient pumping, increased upkeep and even lost product.
ที่วัดแรงดันน้ำ ’ve started to notice a sample amongst our customers who’re having hassle with their froth pumps,” stated Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By using more flocculants and other chemical compounds designed to enhance mineral restoration, they’re exacerbating existing problems in circuit design and lowering the returns they’re looking for.”
Close examination of the froth’s make-up and bodily qualities is usually needed to resolve points. Ensuring operators’ froth handling gear adheres to greatest design practices is a crucial first step in resolving issues.
Maintaining stress The key challenge in froth pumping is coping with air within the pump itself, because it tends to naturally centrifuge into the impeller’s eye, where it builds up into an “air lock” which impedes the movement of slurry through the pump.
In addition to lowering the pump’s efficiency, the air build-up within the pump will scale back its move and improve the slurry level in the suction hopper. The elevated slurry stage may push the pocket of air via the pump, causing surging and excessive vibration which might damage the pump bearings, impeller and shaft. “The finest method to handle air in a froth pump is to spend money on a froth pump with a steady air removal system (CARS), which we’ve 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 collection chamber in the again via a vent gap within the impeller. From the chamber, a flow inducer removes the air from the pump via a vent pipe. “It’s also necessary to place the pump’s discharge pipe on the high of the pump, or at a 45° angle as this will give air trapped on the prime of the casing a way to escape the pump.”
Solving problems “A persistent downside 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 prevent the mineral content from settling, whereas turbulence in a froth pump prevents the air from escaping and leads to blockages,” stated Harvey.
Tanks designed for froth pumping promote continuous circular movement, the place solids and liquids are despatched to the skin of the sump for additional transport whereas air centrifuges into the centre where it might be removed. This ‘whirlpool’ movement can be inspired by introducing the slurry from the top of the tank at a tangential angle. Conical designs, somewhat than these with a flat or rounded ground, further improve the move of minerals and froth into the pump.
Smooth sailing To stop blockages, the consumption pipe which links the tank to the pump ought to have a big diameter and slope downwards in path of the pump. ส่วนประกอบpressuregauge permits escaped air to separate and journey back up the pipe the place it could possibly escape from the sump, rather than building up into blockages.
“The shorter your consumption pipe, the more durable it’s for blockages to construct up. However, in addition to a upkeep spool and isolation valve, it’s a good suggestion to leave enough house for a water injection port, which is beneficial for flushing out any solids construct up,” stated 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 enable users to empty slurry from the pump and the discharge pipe system when stopping the pump for maintenance.”
Tenacious froths Froths are sometimes classified as either brittle, with large air bubbles that break easily, or tenacious, where air types tight bubbles round minerals and is difficult to separate. Froth being extra tenacious than was accounted for is a frequent reason for blockages as air can not effectively be eliminated.
“Two issues are occurring available within the market today. On one hand, mine operators are grinding the product a lot finer than before to liberate more from the waste rock. They’re additionally utilizing flocculants that produce much smaller bubbles which lock up the air a lot more than brittle froths,” mentioned Harvey. “We’re working together with customers to find methods to handle these more tenacious froths, by looking at their circuit design and dealing with areas where the air might accumulate and block the system, paying explicit consideration to their pumps, pipes and sumps.

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