b.Ingredients for cement production

The major ingredients for the production of cement include clay, limestone, marl, chalk, and others, noteworthy quantities of which are endlessly quarried to service the demand for cement. Substitute materials have been sourced to substitute for traditional natural ingredients. The cement sector at present uses huge quantities of power station fly ash, blast furnace slag, natural pozzolana, limestone, and silica fume, mainly to substitute for natural raw materials in the production process of blended cement such as pozzolana fly ash and granular ground bluest farness. The use of these alternative materials has significant economic benefits and positive environmental advantages. The needs to quarry primary raw materials are reduced, energy consumption in cement production is cut, and overall reductions in emission of dust, CO2 and acid gases are attained. In some applications, the performance of concrete can be enhanced when these alternative materials complement Portland cement clinker.

#### c.Energy/power

Cement production is one of the energy-intensive processes. The specific thermal energy-demanding of a cement kiln varies between 3,000 and 7,500 million joules for a ton of clinker, depending on the basic process design of the plant. The explicit electrical energy-demanding typically ranges between 90 and 130 kWh and 60–130 Kg of fuel oil per ton of cement." The industry of cement was expected to produce 4.7 million tons per year to meet the demand in 2015, 27 million tons per year. However, the industry achieved an output of only 11.17 million tons of it in the year 2009/2010″. This result suggests the need to increase the production and supply capacity of cement to meet the need of the fast-growing construction industry.
