Customized Cement Additives to Deliver Maximum Benefit

September 2011 Introduction

 Cement Additives Briefly

 Role in CO2 Reduction

 Facilitate Alternative Raw Materials & Fuels

 Traditional Influence of Additives

 Customised Approach

. 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 procedure

3 © 2011W. R. Grace & Co. Cement Additives – Development Chemical 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 costs.

1967 1970 1990 2003 2004 HEA2® amine TDA® Quality CBA® Quality ESE® non- SYNCHRO® acetate grinding Improver series Improvers chloride early chromium- aids patented introduced for developed and strength reducing blended cement patented enhancers additives introduced introduced

. 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. . Increase production capacity to meet sales volume. . 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 changes or to lower raw material/fuel costs from use of alternative materials. . Improve cement performance to increase use of cementitious materials (i.e. non Portland cement clinker). . Improve cement performance to use cementitious materials to reduce the clinker factor to lower compositional costs, to increase cement

volume per unit of clinker, to reduce environmental impact (e.g. CO2). . Improve cement performance to permit higher class of cement or new cement type or to meet new market needs.

Avg 0.7t of CO2 is produced/each tonne of cement produced

Less Fuel Mill Output Less CO2

Less Clinker

More Alternative Fuels Productivity & Cement volume/ More SCM’s tonne of clinker 6 Cement Additives Role in CO2 Reduction EU Emissions Trading Scheme

• Clinker replacement in cement is an opportunity • Consider 5% increase in filler in the cement • e.g. slag, fly ash, pozzolan, limestone, etc

• Will reduce 0.05 * 0.85t CO2/t cement = 0.0425t

• For a 1mtpa cement plant = 42,500t CO2 • At CO2 value of $15/t = $0.638mm or $0.638/t cement • This is in addition to usual process cost reduction

• CO2 value depends on level with reference to NAP and ability to sell/buy allocations

Example 1 - Good clinker/SCM cost differential Pozzolanic Cement

Version 4.2

Reference Mill Power 2,100 kW Electricity 0.06 $/kWh None ESE Ancillaries 500 kW R&M 0.5 $/t Additive Cost/t 0 1500 Total 2,600 kW Clinker 20 $/t Dosage g/t 0 500 Clinker tonnes 750,000 SCM 6 $/t SCM % 25 30 CO2 0 $/t t/hr 60 66 Clinker CO2 Factor 862 kg/t kWh/t 43.3 39.4 kWh/t cost 2.60 2.36 R&M Cost/t 0.50 0.45 Composition cost/t 1 15.50 14.80 1 ® CO2 cost/t 0.00 0.00 Sum 18.60 17.62 Saving/t 0.98

Additive Cost/t 0.00 0.75 Net Saving/t 0.23 Annual Saving $ 248,377 % Return 31% Cement Volume 1 1,071,429 1,153,846 Increase 0 82,418

Good Differential cost 1 Assumes 5% gypsum

Net Saving, $0.23/t 8 Cement Additives Role in CO2 Reduction

Example 2 - Lower clinker/SCM cost differential Pozzolanic Cement

Version 4.2

Reference Mill Power 2,100 kW Electricity 0.06 $/kWh None ESE Ancillaries 500 kW R&M 0.5 $/t Additive Cost/t 0 1500 Total 2,600 kW Clinker 15 $/t Dosage g/t 0 500 Clinker tonnes 750,000 SCM 10 $/t SCM % 25 30 CO2 0 $/t t/hr 60 66 Clinker CO2 Factor 862 kg/t kWh/t 43.3 39.4 kWh/t cost 2.60 2.36 R&M Cost/t 0.50 0.45 Composition cost/t 1 13.00 12.75 1 ® CO2 cost/t 0.00 0.00 Sum 16.10 15.57 Saving/t 0.53

Additive Cost/t 0.00 0.75 Net Saving/t -0.22 Annual Saving $ -233,766 % Return -29% Cement Volume 1 1,071,429 1,153,846 Increase 0 82,418

Lower Differential cost 1 Assumes 5% gypsum

Net Cost, $0.22/t 9 Cement Additives Role in CO2 Reduction

Example 3 - Low cost differential, CO2 included Pozzolanic Cement

Version 4.2

Reference Mill Power 2,100 kW Electricity 0.05 $/kWh None ESE Ancillaries 500 kW R&M 0.5 $/t Additive Cost/t 0 1500 Total 2,600 kW Clinker 15 $/t Dosage g/t 0 500 Clinker tonnes 750,000 SCM 10 $/t SCM % 25 30 CO2 15 $/t t/hr 60 66 Clinker CO2 Factor 862 kg/t kWh/t 43.3 39.4 kWh/t cost 2.17 1.97 R&M Cost/t 0.50 0.45 Composition cost/t 1 13.00 12.75 1 ® CO2 cost/t 9.05 8.40 Sum 24.72 23.58 Saving/t 1.14

Additive Cost/t 0.00 0.75 Net Saving/t 0.39 Annual Saving $ 416,705 % Return 52% Cement Volume 1 1,071,429 1,153,846 Increase 0 82,418

Lower Differential cost 1 Assumes 5% gypsum

CO2 Value Net Saving, $0.39/t 10 Utilizing Alternative Fuels and raw Materials

 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 Economics

 However, the full impact on cement performance has not been studied for all trace 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 Strength 14 © 2011W. R. Grace & Co. An 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.

 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 additives.

 Early and Late Strength Enhancement – CBA, TDA, ESE…

 Extend Set Times – RDA…

 Shorten Set Times – TDA…

 Reduce Water Demand – TDA…

 Reduce Cr (IV) - Synchro

Cement Additives – Capabilities

Performance Additives Processing Additives Process  Reduce coating and Reduce Packset

 Increase Mill Output, by 5 - 30%

 Narrower cement PSD (Grinding performance)

Quality  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%

17 © 2011W. R. Grace & Co. Customised Additives One of the key modern challenges is to accommodate an increased use of supplementary materials and fuels. The demand for high-performance, versatile and robust additives (strengths enhancers, water reducers,…) is increasing year by year. Grace has developed a proprietary method to screen for additive components and optimize the formulation for a given, individual cement. The 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 specimens.

18 Why Customised Additives?  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. Requires numerous physical tests

 But still needs to be “robust” to be not so specific so that only suits a unique set of variable, i.e. 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

19  Part from matching to cement characteristics © 2011W. R. Grace & Co. Variables and Variability There are many variables in a cement / additive system, which interact simultaneously: Cement chemistry and physical Additive chemical components are not differences influenced by materials and the same, do not have the same effect, process: and their availability and cost varies Silicates, LSF or C3S:C2S regionally: Aluminate, reactivity, alkali modified Glycols (~5) Ferrite, A:F ratio Alkanolamines (~10) Alkalis, Total and water soluble Na/Ca chlorides Huge Sulfate, Clinker and Cement Inorganic salts (Si-, Al-, N-, …) number Forms of Sulfate, Gypsum Source Organic salts (C, O, S, N) of permu- Fineness, Blaine, Residues, PSD Carboxylic acids tations! Surface Properties, Carbonation, Pre- Na/K hydroxide hydration, LOI Oligo/Poly-Saccharides Free Lime Lignosulphonates Clinker Crystallography, Thermal History PCE’s Cement Composition, Slag, Fly Ash, Surfactants (natural and synthetic) Pozzolan, Limestone Chelating agents Minor Components, MgO, Cl, F, P2O5 Biocides

For a given set of cement performances (strengths, setting, rheology,…) customisation aims to “match” cement variables to additive variables

20 The Statistical Method By the use of a Design Of Experiment it is possible to achieve the best statistical confidence on results, with the minimum number of tests. The basis of the statistical methods is well known and quite many statistical packages can be used (MiniTab, eChip,...). Over 3000 mortar tests were run in Grace labs since early 2000’s in order to define and refine the proprietary customized method. The key to the technology is not just to find a statistical method but to make it work in a multi variable and relatively noisy application such as cement strength testing and prediction. The “Signal to Noise Ratio” is a key parameter when running this type of tests. Very high quality lab equipments, and results- oriented technicians are required. May be combined with mechanistic studies (in progress).

21 Variables and Variability For any given parameter (strengths in this example) the variability in the measurement process plays a key role, and has to be reduced at minimum: Cement 1: StDev reduced by more than 50%

Cement 2: Not only the variability Variability of “blocks” (day, was reduced, but higher strength operator) is at minimum average values were found

22 The Statistical method The process consists of: 1 – Definition of technical and commercial needs 2 – Design of the Experiment 3 – …do the mortar/concrete test… 4 – …do it again… 5 – …and again… 6 – Analysis of the experimental results 7 – Use of models to predict optimum performance Vs cost 8 – Validation of model and predictions 9 – Field trial No predicted results are ever disclosed – only actual tests. The added values are: Find process settings or formulation which gives “best tradeoff” optimum for all performance metrics & cost; Explore sensitivities, understand interactions and non-linearities; “Robust” formulations (don’t only suit a unique set of variables). 23 Customised Additives The resulting additive is typically more complex and at higher raw material cost than a traditional QI, and the amount of testing required much larger (depending on the number of variables). However the performance in terms of strength enhancement can be substantial, as the following example shows...

24 Customized Case Study

ppm 1d MPa 2d MPa 28d MPa 1d% 2d% 1&2d%av 28d%

Blank 7,4 14,3 32,5

Target 11,0 20,0 37,0 149% 140% 144% 114% "Traditional" CBA 1104 350 8,6 17,2 35,6 116% 120% 118% 110% Additives CBC 1276 1000 9,0 17,7 35,5 122% 124% 123% 109%

ESE 223 350 9,6 17,4 34,8 130% 122% 126% 107%

TDA 7039 2000 9,6 17,4 34,6 130% 122% 126% 106% Early Strengths XR 607 5000 10,3 18,9 35,6 139% 132% 136% 110% XR Additives XR 525 4000 11,3 19,6 34,5 153% 137% 145% 106% All Ages XR XR 630 5000 11,6 20,6 37,4 157% 144% 150% 115% Additives XR 632 3000 11,0 20,2 37,0 149% 141% 145% 114% Target met

Formulated additves, EN196-1 mortar strengths, Gauge water addition, Actual strengths

25 Customised Additives Through this innovative process it is possible to: Evaluate new chemicals and synergies; Design tailor-made additives for specific cements. This intensive, resources-demanding testing is applied when a solid business justification exist, to: Achieve performances unachievable by traditional additives; or Achieve same performances with a lower incidence. The key challenge is usually represented by the need to combine two opposite needs: Robust chemical formulation able to resist in changing clinker/SCM/environmental conditions; Sharp selection of dosages and chemicals to get maximum benefit at minimum cost. Success rate has been encouraging so far – but there’s no guarantee of success before starting the long testing!

26 Customised Cement Additives Evaluation Opportunity Additive Target Value Created Product Plant Trial Agreement Assessment Selection Grinding System Energy Costs Industrial Test Supply Process Cement & Material costs Screen Customer Plant Conditions Cement Market Production Customise Shared Results Service & Performance Performance Market Value Support Market Dosage Cost

Defining Targets Value Product Proving Closing

What are the Customised Solution, Continual Assessment Targets of a Meeting Targets, And Improvement Chemical Additive? Creating Net Economic Benefit

Where can a Understand Mutual Assessment Chemical Additive the Total Value Mutual Agreement Create Benefits?

Input: Plant Data: Mill system, cement type, raw materials and energy costs, etc.

Company: Grace Cement Type: PC2 Mill Power (kW): 2,100 Currency USD Version2.3 Plant: Demo Annual Tonnage: 500,000 Ancillaries (kW): 450 21.4% 12 Sep 2010 Run Date: 03 December 2010 Total (kW): 2,550 Clinker ($/t): 25.00 1 MPa = 6 kg cement/m3 rule Quality vs. Value Gypsum ($/t): 18.00 Benefit = % of rule Box GRACE Cement Additive SCM 1 ($/t): 12.00 Slag 1 MPa = 0 kg cement/m3 SCM 2 ($/t): 7.00 Fly Ash Concrete 300 kg cement/m3 Not in Use Value Assessment Cement Margin ($): Volume Cement Price $/tonne Cement Margin ($): 10.00 Filler 1 MPa = 0.00 $/tonne Relationships Box CO2 Impact 1 MPa = 17 18 m2/kg (28 & 2 days) Electricity ($/kWh): 0.050 1% SCM 1 = 0.25 0.19 MPa (mortar 28 & 2 days) In Use • Grace tools R&M Cost ($/t): 0.60 1% SCM 2 = 0.6 0.45 MPa (mortar 28 & 2 days) Clinker Factor 862 CO2 kg/t Mortar, EN196 or ASTM: EN196 1% SCM 1 = -2 m2/kg (at constant kWh/t) ETS Value 15 $/t CO2 Mortar/Concrete Ratio: 1.25 1% SCM 2 = 2 m2/kg (at constant kWh/t) • Grace technology 1. Control 2. Test 3. Test 4. Control 5. Test 6. Test SSA Adjustable Strength Adjusted Strength Corrected Filler Adjustable

Model Input Model • Simulation Model Additive None TDA 730 TDA 730 None TDA 730 TDA 730 Additive Cost ($/t) 0 450 450 0 450 450 Additive Dosage (g/t) 0 1,500 1,500 0 1,500 1,500 • Industry Mill Output (Tonnes/hour) 60.0 66.0 86.6 60.0 86.6 65.2 Run Hours 8,333 7,576 5,771 8,333 5,771 7,668 SSA (m2/kg) 380 385 326 380 326 386 benchmarks 45-micron residue (%) 7 5 9 7 9 5 PSD RRN Guide 0.96 1.00 1.00 0.96 1.00 1.00 Mortar 2 days (MPa) 22.0 25.5 22.2 22.0 22.2 22.9 • Rules of Thumb Mortar 28 days (MPa) 52.0 55.5 52.0 52.0 52.0 52.0 Concrete 28 days (MPa) 41.6 44.4 41.6 41.6 41.6 41.6 Concrete Slump (mm) 75 75 75 75 75 75 • GCP benchmarks Slump corrected 28d (MPa) 41.6 44.4 41.6 41.6 41.6 41.6

% Slag 7 7 7 7 7 12 • Best practice % Fly Ash 8 8 8 8 8 12 % Gypsum 5 5 5 5 5 5 • Trials BENEFITS Output Gain 10.0% 44.4% 0.0% 44.4% 8.7% Potential increase in volume (from t/hr) 50,000 222,015 0 222,015 43,354 Strength Increase (Concrete) 6.7% 0.0% 0.0% 0.0% 0.0% • People Reduction in Run hours 758 2,562 0 2,562 665 Potential increase in volume (from SCM) 0 0 0 0 63,380 $/year $/t $/year $/t $/year $/t $/year $/t $/year $/t experience Potential Increased Contribution Margin 0 0 0 0 633,803 SAVINGS Total -213,636 -0.43 81,460 0.16 0 0.00 81,460 0.16 1,038,064 2.08 kWh/t 96,591 0.19 326,712 0.65 0 0.00 326,712 0.65 84,777 0.17 R&M 27,273 0.05 92,248 0.18 0 0.00 92,248 0.18 23,937 0.05 Additive -337,500 -0.68 -337,500 -0.68 0 0.00 -337,500 -0.68 -337,500 -0.68 SCM 685,000 1.37 CO2 581,850 1.16 Quality Not Included

Output: Customized application with Value assessment 28 © 2010 W. R. Grace & Co. Summary  Cement Additives can play a significant role in the modern cement manufacturing plant to reduce costs and enhance profit.

 Their use is covered by International and National cement standards.

 There is ~80 years of historic use

 Provide economic benefits from:

 Higher t/hr, lower kWh/t, lower R&M costs, higher quality, increased clinker substitution, lower distribution costs….

 Can help to reduce CO2 per tonne of cement and Facilitate use of alternative materials and fuels

 Customization is able to bring maximum benefit

29 Thank You Obrigado

September 2011