Safety, speed equate to dragline profitability
15 April 2008
In the operation of a dragline, cycle times and safety are what it's all about, especially when it comes to open pit extraction.
In White Springs, FL at the PCS Phosphate mine, a new Link-Belt LS-308HYLAB 5 dragline is being used to help process spoil for recycling and land restoration.
The crane strips away the overburden with a bucket that holds from 45 to 65 cubic yards of material. It scoops up the top 15 to 30 feet of earth and dumps it in spoil piles to the side of the mine pit. The dragline then digs out what is known as the matrix, which consists of equal parts of phosphate rock, clay and sand.
The matrix is dumped in a pit where high-pressure water guns create a slurry that is pumped to a beneficiation plant At the processing plant, the phosphate is separated from the sand and clay, and the clay slurry is pumped to a settling pond.
The sand is sent back to the mine site to be used in backfilling and reclamation. The phosphate is sent to the chemical processing plant where it is processed for use in fertilizer and other consumable and cosmetic products. Phosphogypsum, a byproduct of this process, is stored in large stacks near the chemical processing plant.
The PCS Phosphate mine's Link-Belt 308HYLAB5 dragline, a replacement of a previous LS-108 and LS-98, is a 110-ton capacity crawler mounted, lattice boom machine equipped with a 3 cubic yard Hendricks drag bucket.
Operator Jackie Robinson, a 33 year long company employee, said, “Operating the LS-308H II is a far cry from running a dozer. The new short throw hydraulic controls make it a far more sensitive machine. Finishing my second week on the 308, I have significantly picked up both my duty cycle times and the quantity of material that I have been able to excavate. This has come about by learning how to correctly position the drag bucket when entering the water to retrieve a full bucket.”