Search results
Results From The WOW.Com Content Network
Cement clinker is a solid material produced in the manufacture of portland cement as an intermediary product. Clinker occurs as lumps or nodules, usually 3 millimetres (0.12 in) to 25 millimetres (0.98 in) in diameter.
Clinker is a generic name given to waste from industrial processes, particularly those that involve smelting metals, welding, burning fossil fuels and use of a blacksmith's forge, which commonly causes a large buildup of clinker around the tuyere.
Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, (3 CaO·SiO 2, and 2 CaO·SiO 2), the remainder consisting of aluminium- and iron-containing clinker phases and other compounds.
Portland cement clinker was first made (in 1825) in a modified form of the traditional static lime kiln. [2] [3] [4] The basic, egg-cup shaped lime kiln was provided with a conical or beehive shaped extension to increase draught and thus obtain the higher temperature needed to make cement clinker.
Clinker bricks are partially-vitrified bricks used in the construction of buildings. Clinker bricks are produced when wet clay bricks are exposed to excessive heat during the firing process , sintering the surface of the brick and forming a shiny, dark-colored coating.
One reason why the carbon emissions are so high is because cement has to be heated to very high temperatures in order for clinker to form. A major culprit of this is alite (Ca 3 SiO 5), a mineral in concrete that cures within hours of pouring and is therefore responsible for much of its initial strength. However, alite also has to be heated to ...
With off-white clinker coal firing can be used which has many advantages for costs and output. It is important to finely grind the coal and have a burner which gives a very short bright flame (high velocity low primary air) so that the excess oxygen can be kept low close to zero with maybe 0.1% CO.
Alite is more reactive because of its higher Ca content, and the presence of an oxide ion in the lattice. During clinker grinding, first step of partial dissolution of C 3 S involves hydration of superficial oxide ions and leads to a hydroxylated C 3 S surface. [5] 3Ca + 2 + SiO 4− 4 + O 2− + H 2 O → 3Ca 2+ + SiO 4− 4 + 2OH −