Typical Vertical Roller Mill (VRM) for GGBFS
The Orcem Vallejo Project will focus on production of ground granulated blast furnace slag, ("GGBFS"), as per ASTM C-989, as the principal finished product. The principal raw material will be unground GBFS (“granulate”), which will arrive at the VMT site by sea from Asia. Small amounts of gypsum (<5%) may also be mixed with the granulate during processing to optimize concrete performance. The gypsum is projected to come from existing mines in northern Nevada.
The actual production capacity of the Orcem facility will be a function of the product portfolio and product specifications; however, the current expectation is a capacity of 760,000 metric tons per year of GGBFS.
The granulate will be stored in open stockpiles in the designated storage areas. This material is naturally coarse and moist, between 6% and 12% moisture. It appears and handles like damp beach sand. The granulate will be transported from the waterfront to the stockpile by a series of covered belt conveyors. The final conveyor will discharge the granulate in the designated stockpile area.
All raw materials will be reclaimed from the stockpile areas with wheeled bucket loaders into hoppers which feed the processing plant. The plant production will typically be between 70 and 100 tons per hour.
The processing plant will consist primarily of a combined milling/drying process (using a Vertical Roller Mill, or "VRM", with an internal particle size classifier) and a product collection process (using a large bag filter unit to capture the finished product). All of this equipment will be contained within the Mill & Filter Building. The finished product collected in the main bag filter will be transported by enclosed conveyors to the product Storage Silos.
The finished product will be stored in three (3) large sealed finished product storage silos, each with a capacity of 4,000 tons.
The finished products will be delivered to customers, primarily concrete producers, by pneumatic dry bulk tank trailers. The tank trailers are sealed and are loaded via hatches on top of their tank trailers.