Weir’s solution for froth challenges

Froth pumping stays one of the complicated engineering challenges in mineral processing. Here, Weir Minerals offers advice for coping with the necessary thing challenges in this operation, the means to maximise pump availability and minimise upkeep in operators’ flotation circuits.
To counteract declining ore grades, more and more mine operators are investing in techniques 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 equipment, it can lead to the loss of priceless minerals and earnings.
Froth pumping remains some of the complicated engineering challenges in mineral processing. This is largely because of the fact that air management issues within the hopper, sump and pump itself can generally result in inefficient pumping, elevated maintenance and even misplaced product.
“We’ve began to note a pattern among our customers who are having bother with their froth pumps,” stated Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By utilizing extra flocculants and other chemical compounds designed to improve mineral recovery, they’re exacerbating existing issues in circuit design and lowering the returns they’re on the lookout for.”
Close examination of the froth’s makeup and physical qualities is usually wanted to resolve issues. Ensuring operators’ froth dealing with tools adheres to greatest design practices is a crucial first step in resolving issues.
Maintaining ชนิดของpressuregauge in froth pumping is dealing with air within the pump itself, because 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 through the pump.
In addition to decreasing the pump’s efficiency, the air build-up in the pump will reduce its circulate and increase the slurry degree within the suction hopper. The elevated slurry stage could push the pocket of air by way of the pump, inflicting surging and excessive vibration which might harm the pump bearings, impeller and shaft. “The best approach to handle air in a froth pump is to invest in a froth pump with a steady air removal system (CARS), which we now have in our Warman AHF, MF and LF pumps,” says Harvey.
This system allows air to move from the pump’s impeller eye to an air collection chamber within the back through a vent gap within the impeller. From the chamber, a circulate inducer removes the air from the pump through a vent pipe. “It’s additionally essential to place the pump’s discharge pipe on the high of the pump, or at a 45° angle as this can give air trapped at the prime of the casing a way to escape the pump.”
Solving issues “A persistent drawback we see is when hoppers designed to fulfill the demands of slurry pumping are utilized in a froth pumping application. Slurry hoppers require turbulence to prevent the mineral content material from settling, while turbulence in a froth pump prevents the air from escaping and leads to blockages,” stated Harvey.
Tanks designed for froth pumping promote continuous circular motion, the place solids and liquids are sent to the surface of the sump for additional transport while air centrifuges into the centre the place it can be eliminated. This ‘whirlpool’ motion may be encouraged by introducing the slurry from the highest of the tank at a tangential angle. Conical designs, somewhat than these with a flat or rounded ground, further enhance the move of minerals and froth into the pump.
Smooth sailing To prevent blockages, the consumption pipe which hyperlinks the tank to the pump should have a large diameter and slope downwards in course of the pump. This design permits escaped air to separate and journey again up the pipe the place it could escape from the sump, quite than increase into blockages.
“The shorter your consumption pipe, the tougher it is for blockages to construct up. However, along with a upkeep spool and isolation valve, it’s a good suggestion to depart sufficient area for a water injection port, which is useful for flushing out any solids build up,” said Harvey.
“To make pressure gauge ราคา ถูก , a dump valve may be included on the suction side of the pump, between the pump and the isolation valve. This will allow customers to empty slurry from the pump and the discharge pipe system when stopping the pump for maintenance.”
Tenacious froths Froths are sometimes classified as both brittle, with large air bubbles that break simply, or tenacious, where air forms tight bubbles round minerals and is difficult to separate. Froth being extra tenacious than was accounted for is a frequent cause of blockages as air can’t effectively be eliminated.
“Two things are happening out there right now. On one hand, mine operators are grinding the product a lot finer than before to liberate more from the waste rock. They’re also utilizing flocculants that produce a lot smaller bubbles which lock up the air much more than brittle froths,” mentioned Harvey. “We’re working together with clients to seek out ways to handle these more tenacious froths, by looking at their circuit design and dealing with areas where the air may accumulate and block the system, paying specific consideration to their pumps, pipes and sumps.

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