Customized Cement Additives to Deliver Maximum Benefit

1 September 2011 Customized Cement Additives to Deliver Maximum Benefit2 2011W. R. Grace & Cement Additives Briefly Role in CO2 Reduction Facilitate Alternative Raw Materials & Fuels Traditional Influence of Additives Customised Approach3 2011W. R. Grace & Co. Why use an additive? Cement can be made without using chemical Additives They are not (usually) needed So why do some plants use them? How to discover a profitable way to exploit the application of a chemical additive? Create economic value from the benefits that an additive can create that exceeds their cost Requires knowledge of Cement plant, Cement , market requirements, costs, flexibilities/constraints, etc Requires knowledge of Cement additive capabilities, applications, formulations, costs, etc Requires a rigorous evaluation procedureWhy Cement Additives ?

2 2011W. R. Grace & 2011W. R. Grace & Additives DevelopmentChemical compounds for use in the production of Cement to increase the output and efficiency of the grinding process and improve the performance and quality of the finished Cement , with the objective to reduce overall manufacturing amine acetate grinding aids patented1970 TDA Quality Improver series introduced for blended cement1990 CBA Quality Improvers developed and patented2003 ESE non-chloride early strength enhancers introduced2004 SYNCHRO chromium-reducing Additives introduced 5 2011W. R. Grace & of Cement Additives Increase in Cement mill output,with associated reduction in Cement mill system kWh/tonne, reduction in mill run hours and reduction in Cement grinding costs.

3 Increase production capacity to meet salesvolume. Improving Cement flowability(reduce pack-set) to shorten loading/unloading operations and reduce distribution costs. Improve Cement performance, to meet customer needs, satisfy Standards, meet/exceed competition and improve market position. Improve Cement performance to allow clinker chemistry changesor to lower raw material/fuel costsfrom use of alternative materials. Improve Cement performance to increase use of cementitiousmaterials( non Portland Cement clinker). Improve Cement performance to use cementitiousmaterials to reduce the clinker factorto lower compositional costs, to increase Cement volume per unit of clinker, to reduce environmental impact ( CO2).

4 Improve Cement performance to permit higher class of Cement or new Cement typeor to meet new market needs. 6 Avg of CO2is produced/each tonne of Cement producedLess CO2 Less FuelLess ClinkerMore SCM sMill OutputCement Additives Role in CO2 ReductionMore Alternative FuelsProductivity & Cement volume/tonne of clinker7 2011W. R. Grace & Co. Clinker replacement in Cement is an opportunity Consider 5% increase in filler in the Cement slag, fly ash, pozzolan, limestone, etc Will reduce * CO2/t Cement = For a 1mtpa Cement plant = 42,500t CO2 At CO2 value of $15/t = $ or $ Cement This is in addition to usual process cost reduction CO2value depends on level with reference to NAP and ability to sell/buy allocationsEU Emissions Trading SchemeCement Additives Role in CO2 Reduction8 Version Power 2,100kWElectricity $/kWhNoneESEA ncillaries 500kWR&M $/tAdditive Cost/t 01500 Total 2,600kWClinker 20$/tDosage g/t 0500 Clinker tonnes 750.

5 000 SCM 6$/tSCM % 2530CO2 0$/tt/hr 6066 Clinker CO2 Factor 862kg/tkWh/t cost Cost/t cost/t cost/t Cost/t Saving/t Saving $ 248,377% Return 31% Cement Volume 11,071,4291,153,846 Increase 082,4181 Assumes 5% gypsumExample 1 - Good clinker/SCM cost differentialPozzolanic Cement Good Differential costNet Saving, $ Additives Role in CO2 Reduction9 Version Power 2,100kWElectricity $/kWhNoneESEA ncillaries 500kWR&M $/tAdditive Cost/t 01500 Total 2,600kWClinker 15$/tDosage g/t 0500 Clinker tonnes 750,000 SCM 10$/tSCM % 2530CO2 0$/tt/hr 6066 Clinker CO2 Factor 862kg/tkWh/t cost Cost/t cost/t cost/t Cost/t Saving/t Saving $ -233,766% Return -29% Cement Volume 11,071,4291,153,846 Increase 082,4181 Assumes 5% gypsumExample 2 - Lower clinker/SCM cost differentialPozzolanic Cement Lower Differential costNet Cost, $ Additives Role in CO2 Reduction10 Version Power 2,100kWElectricity $/kWhNoneESEA ncillaries 500kWR&M $/tAdditive Cost/t 01500 Total 2,600kWClinker 15$/tDosage g/t 0500 Clinker tonnes 750.

6 000 SCM 10$/tSCM % 2530CO2 15$/tt/hr 6066 Clinker CO2 Factor 862kg/tkWh/t cost Cost/t cost/t cost/t Cost/t Saving/t Saving $ 416,705% Return 52% Cement Volume 11,071,4291,153,846 Increase 082,4181 Assumes 5% gypsumExample 3 - Low cost differential, CO2 includedPozzolanic Cement Lower Differential costCO2 ValueNet Saving, $ Additives Role in CO2 Reduction11 2011W. R. Grace & Co. Selection of alternative raw materials and fuels needs careful consideration of the potential impact on: Environmental Emissions Process Operation Cement Heath & Safety Cement Performance Overall EconomicsUtilizing Alternative Fuels and raw Materials14 2011W.

7 R. Grace & Co. Limitations are often imposed on alternative material usage due to Environmental and/or Health and Safety reasons. However, the full impact on Cement performance has notbeen studied for alltrace elements and as noted by Taylor becomes complex in combinations of multiple trace elements in the same Cement . However the role of many minor elements has been studied sufficiently to predict certain potential effects, for example concerning Setting Time Early Strength Late StrengthEffects on Cement Performance15 2011W. R. Grace & Alternative Solution What is needed is a solution to quality issues that does not simply require an increase in Cement fineness and thus a loss in mill throughput, promotes Maximum plant utilization and facilitates the use of available alternative fuels and materials.

8 One clear alternative is the use of chemical additive technology in the finished grinding step. Many of the detrimental impacts on clinker mineralogy can be mitigated in the finished grinding phase through the application of chemical 2011W. R. Grace & Co. For instance, Cement Additives known as Quality Improvers have been formulated to address specific quality issues and are in regular WW use. Early and Late Strength Enhancement CBA, TDA, Extend Set Times Shorten Set Times Reduce Water Demand Reduce Cr (IV) -SynchroAn Alternative Solution17 2011W. R. Grace & Co. Reduce coating and Reduce Packset Increase Mill Output, by 5 -30% Narrower Cement PSD (Grinding performance) Increase 28-day strength, 5-15% or say 2 -10 MPa Increase 2-day strength, 10-30% or say 2 -10 MPa Reduce setting time, 10-40 minutes (initial set) Extend setting time, 10-40 minutes (initial set) Reduce water demand (concrete), by 2 -5% Cement Additives CapabilitiesProcessQualityProcessing AdditivesPerformance Additives18 One of the key modern challenges is to accommodate an increased use of supplementary materials and demand for high-performance, versatile and robust Additives (strengths enhancers, water reducers.)

9 Is increasing year by has developed a proprietary methodto screen for additive components and optimize the formulation for a given, individual process involves:1) modern statistical methods for multi-component screening and optimization; 2) improvements in the sampling and handling of Cement samples and preparation of mortar Additives19 2011W. R. Grace & Co. Traditional Approach -understand needs for the additive Select generic additive able to influence Cement performance in a common way In part dependent on Cement type, but mostly on additive chemistry . Customisation aims to match the Cement variables to the Cement additive variables Huge number of permutations, needs screening and statistical approach.

10 Requires numerous physical tests But still needs to be robust to be not so specific so that only suits a unique set of variable, cannot deal within source variability But test methods also involve standard deviation, so need to reduce the testing noise Result is higher performing additive Part from optimised dosage and combination of chemicals Part from matching to Cement characteristicsWhy Customised Additives ?20 There are many variables in a Cement / additive system, which interact simultaneously:For a given set of Cement performances(strengths, setting, rheology,..) customisationaims to match Cement variables to additive variablesVariables and VariabilityCement chemistry and physical differences influenced by materials and process:Silicates, LSF or C3S:C2 SAluminate, reactivity, alkali modifiedFerrite, A.