We source our limestone, pozzolans and clay primarily from ALQC and IQAC. We also source raw materials, including limestone, clay, pozzolans and gypsum, from third parties both in the Philippines and from abroad. These raw materials are delivered from the quarry to our crushing facilities on trucks that we lease from third parties. The crushed raw materials are then delivered by belt-conveyor to our production facilities, where we manufacture cement through a closely controlled chemical process. In this process the limestone and clay are first pre-homogenized, a process that consists of combining different types of limestone and clay. The resulting mix is typically dried, and then prepared for the kiln. In the kiln, the raw materials are processed at a very high temperature to produce clinker. Clinker is the intermediate product used in the manufacturing of cement.
There are two primary processes used to manufacture clinker: the dry process and the wet process. Our plants use the dry process, which is more energy efficient. In the wet process, the raw materials are mixed with water to form slurry, which is fed into a kiln. Fuel costs are greater in the wet process than in the dry process because the water that is added to the raw materials to form slurry must be evaporated during the clinker manufacturing process.
The clinker is then cooled down, mixed with gypsum and fed in specified proportions into a cement grinding mill where they are ground into an extremely fine powder and mixed with grinding aids including admixtures (which control properties of the concrete including plasticity, pumpability, freeze-thaw resistance, strength and setting time) and other cement additives, which we produce or source from third parties, to produce finished cement.