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Froth pumping remains one of the most complex engineering challenges in mineral processing. Here, pressure gauge offers advice for coping with the key challenges in this operation, how to maximise pump availability and minimise upkeep in operators’ flotation circuits.
To counteract declining ไดอะแฟรม , increasingly 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 equipment, it can outcome in the lack of priceless minerals and income.
Froth pumping remains one of the complex engineering challenges in mineral processing. This is basically due to the truth that air administration points in the hopper, sump and pump itself can generally result in inefficient pumping, elevated maintenance and even misplaced product.
“We’ve began to notice a pattern among our prospects who are having trouble with their froth pumps,” stated Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By using more flocculants and different chemical substances designed to enhance mineral recovery, they’re exacerbating existing problems in circuit design and decreasing the returns they’re in search of.”

Close digital pressure gauge of the froth’s makeup and bodily qualities is usually wanted to resolve issues. Ensuring operators’ froth dealing with equipment adheres to greatest design practices is an important first step in resolving problems.
Maintaining strain The key challenge in froth pumping is dealing with air in 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 motion of slurry through the pump.
In addition to lowering the pump’s efficiency, the air build-up in the pump will scale back its move and enhance the slurry level in the suction hopper. The increased slurry degree could push the pocket of air through the pump, causing surging and extreme vibration which can harm the pump bearings, impeller and shaft. “The greatest way to handle air in a froth pump is to put cash into a froth pump with a steady air removing system (CARS), which we 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 by way of a vent gap in the impeller. From the chamber, a flow inducer removes the air from the pump via a vent pipe. “It’s also important to place the pump’s discharge pipe at the high of the pump, or at a 45° angle as it will give air trapped at the high of the casing a approach to escape the pump.”

Solving issues “A persistent downside we see is when hoppers designed to fulfill the calls for of slurry pumping are utilized in a froth pumping application. Slurry hoppers require turbulence to stop the mineral content material from settling, whereas turbulence in a froth pump prevents the air from escaping and results in blockages,” stated Harvey.
Tanks designed for froth pumping promote continuous round motion, the place solids and liquids are sent to the skin of the sump for further transport while air centrifuges into the centre the place it can be eliminated. This ‘whirlpool’ movement may be inspired by introducing the slurry from the highest of the tank at a tangential angle. Conical designs, rather than those with a flat or rounded floor, additional improve the move of minerals and froth into the pump.
Smooth crusing To prevent blockages, the consumption pipe which hyperlinks the tank to the pump should have a large diameter and slope downwards in the direction of the pump. This design allows escaped air to separate and travel back up the pipe the place it could escape from the sump, somewhat than building up into blockages.
“The shorter your consumption pipe, the more durable it is for blockages to build up. However, along with a maintenance spool and isolation valve, it’s a good suggestion to go away sufficient space for a water injection port, which is useful for flushing out any solids construct up,” stated Harvey.
“To make upkeep easier, a dump valve may be included on the suction aspect of the pump, between the pump and the isolation valve. This will enable customers to drain slurry from the pump and the discharge pipe system when stopping the pump for upkeep.”

Tenacious froths Froths are sometimes categorised as both brittle, with massive air bubbles that break easily, or tenacious, where air forms 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 cannot successfully be removed.
“Two things are occurring in the market right now. On one hand, mine operators are grinding the product a lot finer than earlier than to liberate more from the waste rock. They’re additionally using flocculants that produce much smaller bubbles which lock up the air a lot more than brittle froths,” mentioned Harvey. “We’re working together with prospects to find ways to handle these more tenacious froths, by taking a look at their circuit design and dealing with areas where the air could accumulate and block the system, paying particular consideration to their pumps, pipes and sumps.
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