The raw materials will be ordered by a purchasing official based on the specifications derived from the refractory technologist. They will arrive at the refractory
plant in bulk in covered hopper railroad cars or trucks; as a liquid in railroad or
truck tankers; or on pallets of dry, bagged materials or drums. The bulk materials
generally are discharged into below-ground bins that supply various types of feeders, elevators, and belts for conveying to appropriate bulk storage silos or piles;
sometimes, the bulk materials are discharged onto concrete pads and handled by
front-end loaders. The pallets are stacked neatly in rows in the raw-material warehouses. All storage space must be clean and dry. Analyses certifying compliance
with specifications based on the required number of samples per batch must
accompany each shipment as set forth in advance between the quality assurance
departments of the purchaser and the raw material supplier. Initially, the refractory manufacturer’s quality-control personnel must sample and test each received
batch to verify the supplier’s data until confidence is built up between the two
parties and the supplier becomes certified. Tests may include various chemical
assays and bulk densities.