Limestone Portland Cement

Crushed limestone is interground with clinker to produce cement, reducing the needs for clinker-making and calcination. The addition of up to 5% limestone has shown to have no negative impacts on the performance of Portland cement, while optimized limestone cement would improve the workability slightly.

Indian flag In India it was shown that the addition of alkali bicarbonate substantially reduces the potential for the alkali-aggregate reaction that takes place when alkali (NaOH) is formed in the cement. The potential expansion when using an alkali carbonate and bicarbonate in low porosity systems was measured using a highly reactive aggregate (crushed pyrex glass) according to the procedure outlined in A.S.T.M. C-227. The results demonstrated a reduced expansion of a low porosity mortar prepared with NaHCO3 when compared to an equivalent Na2CO3 system.

Development Status Products
Commercial

Limestone Portland CementCosts & Benefits

Parent Process: Blended Cement Alternatives
Energy Savings Potential

EU flag For a cement with 25 to 35% by mass limestone, thermal energy demand will decrease by 0.22 to 0.60 GJ/t-cement.  Electricity demand will also decrease by 12–23 kWh/t-cement

CO2 Emission Reduction Potential

EU flag For a cement with 25 to 35% by mass limestone, direct and indirect CO2 emission reductions can be 50 to 140 t CO2/t-cement and 6 to 16 kg CO2/t-cement. 

Costs

Capital costs for extra storage capacity for the other main constituents and the new cements as well as the technical equipment for handling and drying of these constituents may be € 8-12 million. 

Limestone Portland Cement Publications

Development of State of the Art Techniques in Cement Manufacturing: Trying to Look Ahead

The report represents the independent research efforts of the European Cement Research Academy (ECRA) to identify, describe and evaluate technologies which may contribute to increase energy efficiency and to reduce greenhouse gas emissions from global cement production today as well as in the medium and long-term future. 

Page Number: 

79-81