الوجبة الخام المجانسة صومعة
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to1450 °C in a kiln, in a process known as calcination, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.