Alternative Raw MaterialsTechnologies & Measures
|Technology or Measure||Energy Savings Potential||CO2 Emission Reduction Potential Based on Literature||Costs||Development Status|
|Use of EAF slag - CemStar®|
As the calcination energy demand is estimated to be 1.9 GJ/t-clinker, substituting 10% of clinker with steel slag will reduce energy consumption by 0.19 GJ/t-clinker.
Replacing 10% of clinker by steel slag can reduce CO2 emissions by approximately 11%
Equipment costs are mainly for material handling and vary between US $200,000 and $500,000 per installation. Total investments are approximately double the equipment costs. CemStar® charges a royalty fee.
|Fly Ash as Raw Material||Carbon content of the fly ash can help reduce fossil fuel usage (in the order of hundreds to thousands of kJ/kg-fly ash)|
Costs for a 2000 ton-silo and input facillities is reported to be between US $2.7 to 3.2 million [1US$=¥110].
For India, installation costs for a similar plant were reported to be $0.6 - 0.8 million.
|Calcareous Oil Shale as Alternative Raw Material|
Energy consumption can be reduced by around 0.7 GJ/t portland cement.
Some oil shale deposits may be partially decarbonated and their use would lead to reduced CO2 emissions from the calcination process. The amount of this reduction will depend on the extent that the oil shale is decarbonated and the amount of limestone replaced by the oil shale in the raw meal.
Assuming that 8 percent of the raw meal is replaced with oil shale, an investment of US $1per annual ton of cement capacity would be required for installation of a feed system, and operating costs would increase by US $0.08/t cement (assuming that the source of the shale is close to the facility).
|Use of Slag as Raw Material|
With slag use of 10 kg/t-clinker, energy consumption can be reduced by 17 kJ/t-clinker (APP, 2009). Substituting 15% of conventional raw materials by granulated steel slag is estimated to reduce thermal energy consumption by 0.1 to 0.4 GJ/t-clinker, and increase electricity consumption between 0 to 2 kWh/t-clinker (CSI/ECRA, 2009).
CO2 reduction are estimated at between 0 to 117 kg CO2/t-clinker (CSI/ECRA, 2009)
Investment and operational costs are estimated to be between € 0 to 6 million, and € 0 to 4.2/t-clinker, respectively (CSI/RECRA, 2009)
|Carbide Slag as Raw Material|
In a Chinese project, 184 thousand tons of CO2 reduction was forseen with the use of 315 thousand t/y of carbide slag and thereby substituting 432 thousand t/y of limestone.
Total investments for utilizing 315 thousand t/y carbide slag was approximatly RMB 29.4 million (US $4.3 million [with 1RMB=US $0.146])