Weir’s solution for froth challenges

เกจ์วัดแรงดันน้ำ pumping remains one of the advanced engineering challenges in mineral processing. Here, Weir Minerals presents advice for coping with the important thing challenges on 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 techniques to increase the minerals reclaimed from froth pumping. However, when these methods are deployed without making allowances for the design of the mine’s froth pumping tools, it may end up in the lack of valuable minerals and income.
Froth pumping remains one of the most complicated engineering challenges in mineral processing. This is largely as a outcome of the truth that air administration points within the hopper, sump and pump itself can typically 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,” mentioned Les Harvey, regional product supervisor for Slurry Pumps at Weir Minerals. “By utilizing extra flocculants and other chemical substances designed to improve mineral recovery, they’re exacerbating current issues in circuit design and decreasing the returns they’re on the lookout for.”
Close examination of the froth’s make-up and physical qualities is often needed to resolve issues. Ensuring operators’ froth dealing with gear adheres to greatest design practices is an important first step in resolving problems.
Maintaining pressure The key problem in froth pumping is coping 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 by way of the pump.
In addition to decreasing the pump’s effectivity, the air build-up within the pump will reduce its move and enhance the slurry level in the suction hopper. The increased slurry degree might push the pocket of air by way of the pump, causing surging and excessive vibration which may damage the pump bearings, impeller and shaft. “The finest approach to manage air in a froth pump is to invest in a froth pump with a continuous air removing system (CARS), which we 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 via a vent gap within the impeller. From the chamber, a circulate inducer removes the air from the pump by way of a vent pipe. “It’s also necessary to position the pump’s discharge pipe on the prime of the pump, or at a 45° angle as this will give air trapped on the high of the casing a way to escape the pump.”
Solving problems “A persistent problem we see is when hoppers designed to satisfy the calls for of slurry pumping are used in a froth pumping software. Slurry เพรสเชอร์เกจลม 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,” stated Harvey.
Tanks designed for froth pumping promote continuous round movement, where solids and liquids are despatched to the skin of the sump for further transport whereas air centrifuges into the centre the place it can be removed. This ‘whirlpool’ movement can 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 flow 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 big diameter and slope downwards towards the pump. This design permits escaped air to separate and journey back up the pipe where it can escape from the sump, quite than build up into blockages.
“The shorter your consumption pipe, the tougher it’s for blockages to build up. However, along with a upkeep spool and isolation valve, it’s a good suggestion to go away enough space 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 permit customers to drain slurry from the pump and the discharge pipe system when stopping the pump for maintenance.”
Tenacious froths Froths are sometimes categorised as either brittle, with large air bubbles that break simply, or tenacious, the place air varieties tight bubbles around minerals and is troublesome to separate. Froth being extra tenacious than was accounted for is a frequent reason for blockages as air can’t successfully be eliminated.
“Two issues 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 additionally utilizing flocculants that produce much smaller bubbles which lock up the air a lot more than brittle froths,” stated Harvey. “We’re working together with customers to search out methods to handle 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.

Leave a Comment