Cement clinker is a solid material produced in the manufacture of Portland cement as an intermediary product. It is produced by sintering (fusing together without melting to the point of liquefaction) limestone and aluminosilicate materials such as clay during the cement kiln stage. Clinker is a nodular material which is used as the binder in cement products. Cement is a binding agent that sets and hardens to adhere to building units such as stones, bricks, tiles etc. The primary use of clinker is to manufacture cement.