What is cement?
Cement, generally speaking, is the name given to a powder substance that can harden independently when mixed with water.
Hydraulic cement, such as Portland cement used to make concrete, once mixed with it's initial water admixture, can harden regardless of if it is kept underwater.
Non-hydraulic cements, such as those used for certain types of plaster, must be kept dry after the initial mixing process, in order to harden. Cement is used to bind other materials together to form either mortar, plaster or concrete.
How is cement made?
Cement contains four elements;calcium, silicon, aluminium and
iron. These elements are found within the essential ingredients of cement, mainly limestone, with smaller amounts of sand and clay. The limestone is mined from a quarry, where large boulder size rocks are carved from the landscape and transported to a cement plant. There the limestone boulders are then hurled into a crusher that crunches them into very small pieces ready for blending. During the blending procedure, the sand and clay are added in the correct proportions and prepared for the next stage of the process. The resulting mixture is now ground into powder form. Next, the powder is fed into a rotating furnace for
sintering, where the raw materials are taken up to temperatures of 2700 degrees F until they become partially molten. They are left until they become red hot glassy cinders known as
clinker.Lastly, the clinker is cooled and ground into a fine powder and a small amount of gypsum is added. The finished product – Portland cement.
What factors influence cement prices?
Cement prices are determined by several factors including, but not limited to, demand, plant closures, oil and electricity prices. For example, recently cement prices saw a massive hike as China approved the building of two football stadiums.
Cement prices increased rapidly as other contractors emptied supplier shelves in preparation. China is now the worlds biggest producers of cement, followed by India.
