Pit & Quarry, October 2013

Red rock meets its match A California producer finds a cost effective way to process hard abrasive material T EDITED BY KEVIN YANIK hree men Working all day On a single job Thats typically the scenario that unfolds at Porterville Rock Recycle an aggregate producer based in Porterville Calif when a primary screen must be replaced Replacing screens is a labor intensive task but its one thats necessary for the operation to remain productive The less often the operation has to change out screens the better Still considering Porterville Rock recently began mining metabasalt a notoriously hard granite and red rock which owner Mitch Brown describes as harder and more abrasive than anything his business has processed in his time the operation was forced to replace screens more often than he preferred The upside of the red rock is its a high in demand material Brown says at least in California where Porterville Rock competes locally against four other producers Its such a good rock that it meets One of the main plants at Porterville Rock Recycle processes material The company recently began mining metabasalt a hard granite new California Department of Transportation regulations Brown says It goes into concrete products It goes into asphalt products and any road building material thats really its main use It meets the rock spec for railroads Its a great riprap source I havent found anything it wont work for right now The red rock has a downside though It beats the heck out of equipment including Porterville Rocks screens Considering this factor as well as the fact that Porterville Rock has 100 million tons of red rock remaining in its deposit at its Wilcox mine Brown sought solutions to extend the lifespan of his screens Looking for answers Initially Porterville Rock ran several screening tests to determine which screens would suit its red rock best The screens Browns crew installed originally in one screen box were a top deck wirecloth screen with a 2 in opening and 3 8 in double wire a middle deck wirecloth screen with urethane strips and both 1 1 8 in and 1 1 16 in openings and a bottom deck wire cloth screen with a square opening design that featured 1 2 in and 3 8 in openings The bottom deck screens were Unified Screening Crushing manufactured The original upper deck screens were no matches for Porterville Rocks red rock Brown says They lasted just three weeks The top and middle deck screens wore out much too soon and needed premature change out he says Once Brown realized he didnt have a usable system for the red rock one of his next moves was to phone Ray Sailer general manager of Unified Screening in California We listen to the people who come in and try new products all the time Brown says Its labor intensive when you have to start changing out screens and cone liners all the time When you start doing that you have to find longer lasting products to save on some of the labor Sailer visited the Wilcox site and observed the operation recommending a start on the middle deck with a diamond type 1 1 8 in opening and three gauge Tufflex wire For the bottom deck Sailer recommended keeping the square opening Unified screens According to Unified its SuperFlow screens sport a hybrid design that features a combination of Tufflex wire and polyurethane The combination is designed to deliver greater flexibility lon SCREENING The original upper deck screens were no match for Porterville Rocks red rock They lasted just three weeks 36 PIT QUARRY October 2013 www pitandquarry com