Kaiser Sand & Gravel, Pleasanton, Calif., processes sand and gravel in California’s Livermore Valley. Kaiser mines the sand and gravel from an open pit in an ancient alluvial plain. The material has a minimum of silts and clay and an 8-inch top size. After mining, a bulldozer moves the sand and gravel to a belt feeder that discharges onto a series of conveyor belts leading to a processing plant. Cone crushers then size-reduce the gravel as required. Sand and gravel are washed and moved through the plant across belt conveyors and through transfer points and chutes. The plant sizes the sand and gravel using rotating and vibrating screens. Finished sand and gravel are stored separately and then blended to specification, rewashed, and sold on demand. Front-end loaders or overhead bunkers dump the sand and gravel into customers’ trucks.
Rubber impact plates, sheeting combat abrasive wear during conveying
After trying to reduce wear using railroad rails and hardfaced steel bars for a chute and a transfer point, a sand and gravel company switches to rubber impact plates and flat sheeting.