Froth pumping stays one of the complicated engineering challenges in mineral processing. Here, Weir Minerals provides recommendation for coping with the key challenges in this operation, the method to maximise pump availability and minimise maintenance 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 strategies are deployed without making allowances for the design of the mine’s froth pumping gear, it can outcome in the loss of useful minerals and profits.
Froth pumping stays one of the complicated engineering challenges in mineral processing. This is essentially due to the reality that air management issues in the hopper, sump and pump itself can sometimes lead to inefficient pumping, elevated upkeep and even misplaced product.
“We’ve started to note a sample among our clients who’re having trouble with their froth pumps,” stated Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By using more flocculants and other chemical substances designed to improve mineral restoration, they’re exacerbating current issues in circuit design and reducing the returns they’re looking for.”

Close ไดอะแฟรม of the froth’s makeup and physical qualities is commonly needed to resolve points. Ensuring operators’ froth dealing with equipment adheres to best design practices is an important first step in resolving issues.
Maintaining pressure The key problem in froth pumping is dealing 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 by way of the pump.
In addition to reducing the pump’s efficiency, the air build-up within the pump will cut back its flow and increase the slurry stage in the suction hopper. The elevated slurry level might push the pocket of air through the pump, causing surging and excessive vibration which can injury the pump bearings, impeller and shaft. “The greatest method to manage air in a froth pump is to invest in a froth pump with a steady air elimination system (CARS), which we now have in our Warman AHF, MF and LF pumps,” says Harvey.
This system permits air to maneuver from the pump’s impeller eye to an air assortment chamber in the again by way of a vent hole in the impeller. From the chamber, a move inducer removes the air from the pump by way of 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 it will give air trapped on the prime of the casing a method to escape the pump.”

Solving issues “A persistent drawback we see is when hoppers designed to satisfy the calls for of slurry pumping are used in a froth pumping application. Slurry hoppers require turbulence to stop the mineral content material from settling, while turbulence in a froth pump prevents the air from escaping and results in blockages,” mentioned Harvey.
Tanks designed for froth pumping promote continuous circular movement, the place solids and liquids are sent to the skin of the sump for additional transport while air centrifuges into the centre where it may be eliminated. This ‘whirlpool’ motion can be encouraged by introducing the slurry from the top of the tank at a tangential angle. Conical designs, rather than these with a flat or rounded flooring, further enhance the circulate of minerals and froth into the pump.
Smooth sailing To prevent blockages, the consumption pipe which links 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 travel back up the pipe where it might possibly escape from the sump, quite than build up into blockages.
“The shorter your intake pipe, the tougher it is for blockages to build up. However, along with a upkeep spool and isolation valve, it’s a good suggestion to go away enough area for a water injection port, which is helpful for flushing out any solids construct up,” mentioned Harvey.
“To make upkeep simpler, a dump valve can be included on the suction facet of the pump, between the pump and the isolation valve. This will enable customers to empty slurry from the pump and the discharge pipe system when stopping the pump for upkeep.”

pressure gauge octa are often categorized as both brittle, with giant air bubbles that break easily, or tenacious, where air varieties tight bubbles around minerals and is troublesome to separate. pressure gauge 10 bar being more tenacious than was accounted for is a frequent explanation for blockages as air can not effectively be removed.
“Two things are occurring out there at present. On one hand, mine operators are grinding the product much finer than earlier than to liberate more from the waste rock. They’re also using flocculants that produce a lot smaller bubbles which lock up the air much more than brittle froths,” said Harvey. “We’re working along with clients to find ways to manage these extra tenacious froths, by looking at their circuit design and dealing with areas the place the air may accumulate and block the system, paying particular attention to their pumps, pipes and sumps.
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