Aggregate Mining Operation Depends on Submersible Hard Metal Pumps to Transfer Abrasive Water

The state of Florida has witnessed unprecedented population growth over the past ten years growing by over 18% to 19 million full time residents. This growth is expected to continue as more baby boomers retire to the inviting warm weather and favourable taxation environment offered by the Sunshine State. By 2015, Floridians will number over 20 million.

With people come cars. There are currently over 15 million registered vehicles in Florida. That does not count the thousands of visitors and "snow birds" inhabiting the state part time. All of these vehicles and their occupants depend on a huge network (over 40,000 lane miles) of highways to get where they need to be. These roads demand constant care. A recent report showed over 20% of Florida's state-owned major roads had fallen out of good condition, meaning they will now be increasingly expensive to repair and maintain.

Florida will need to spend a minimum of $950 million annually for the next twenty years to get the current backlog of poor-condition major roads into a state of good repair and maintain all state-owned roads in good condition. This renewal depends on a reliable, sustainable supply of quality aggregate to build and maintain long-lasting, durable, and safe pavements.

Highway agencies plan and design projects to optimise the use of locally available aggregates. Using locally available aggregates reduces transportation costs and energy expended in moving these heavy bulk materials. It also reduces truck traffic and loadings on the existing highway system.

Thankfully, Florida has an excellent local supplier of quality aggregate. In Port Mayaca, Florida, on the east shore of Lake Okeechobee in south Florida, Lake Point Restoration, lies an aggregate mining operation fully capable of supplying much of the DOT's needs.

Lake Point Restoration owns an estimated 60 million tons of aggregate reserves in Port Mayaca where it produces three primary types of materials: Road Rock – Primary used in road construction, and is Lake Point's highest volume product. It is certified to the standards of the Florida Department of Transportation. Typically, Lake Point maintains an inventory of 40,000 to 75,000 tons; Coarse Aggregate Stone – The aggregate stones, in a range of sizes, are used in cement, asphalt, drainage, and embankments; Rip Rap – This material is used to create breakwaters on lakes, rivers, and ocean front harborages – in various sizes, usually between 6 inches and 36 inches. It is also used to protect shorelines against water erosion.

The Lake Point mining operation currently produces 1 million tons of material per year in its water intensive operations. The property is permitted to mine up to 20 feet below the controlled water table. The proven reserve estimated to contain over 60 million tons of aggregate reserves.

Operating at a location where the water table is only three to six feet below the surface, Lake Point was experiencing problems keeping rain and wash-down water from overflowing at one of the quarry's crushing and sizing locations. If this water isn't quickly evacuated it could lead to flooding of low lying quarry areas, delaying operations. Pumps must dependably remove this solids laden water to prevent lost production time. They turned to Holland Pump, a dewatering pump manufacturer in West Palm Beach, Florida, for a solution.

“We chose the LWA1500 because of its successful history in other applications,” says Kieley. “At Lake Point it is only used a few hours each day, especially during the summer, when it rains nearly every afternoon in this area. However, the water it pumps at the site is extremely abrasive, laden with fine limestone particulate.

The LWA Series, manufactured by BJM Pumps (USA) is a hard metal submersible slurry pump designed to outlast rubber lined units in sand and abrasive slurry service. It is fitted with a High Chrome Iron impeller and wear plate for maximum abrasion resistance. The integral hardened agitator mixes settled solids to prevent blockage and keep the operation humming. Other life cycle enhancing features include abrasion resistant double mechanical seal and robust motor enclosures. All of this solids pumping capability is built into a lightweight design for easy portability.

“We’d had experience with the LWA1500 because, in addition to sales, we have a rental fleet. And we’d found that some other manufacturers’ pumps, used in similar applications where the water was less abrasive, wore out much quicker than the BJM pump. So the LWA1500 was a natural choice for Lake Point. It’s a tough pump.