WO2009060405A1

WO2009060405A1 - Cement compositions

Info

Publication number: WO2009060405A1
Application number: PCT/IB2008/054641
Authority: WO
Inventors: Thomas Douglas Brindle
Original assignee: Umkomaas Lignin (Proprietary) Limited T/A Lignotech Sa
Priority date: 2007-11-06
Filing date: 2008-11-06
Publication date: 2009-05-14

Abstract

The present invention is directed to a hydraulic cement composition exhibiting enhanced early (i.e. 1, 3, 7 days) and later 28 day and 56 day compressive strength properties after mixing and allowing the cement composition to set. The enhancement is achieved through the use of an additive composition comprising a combination of amine hydrochloride/s and a dispersant, preferably lignosulphonate/s.

Description

CEMENT COMPOSITIONS

FIELD OF THE INVENTION

This invention relates to improving the strength properties and water requirement of Portland cement as well as blended cement compositions. More specifically it relates to a hydraulic cement composition such as Portland cement to which is added an additive, which may be interground with the cement clinker to improve physical properties such as strength development. Furthermore, the additive may be intermixed with the powdered cement or cement blend prior to or in conjunction with the addition of water and which improves the strength and reduces the water requirement of the hydrated cement and compositions made from the said cement, such as Portland cement concrete.

BACKGROUND OF THE INVENTION

The demand for cement in the developing countries, coupled with environmental pressures to reduce carbon emissions globally, has led to the unprecedented use of fillers such as limestone and clinker substitutes such as granulated blast furnace slag, natural or artificial pozzolan, pulverised fuel ash and the like. The term "filler" refers to an inert material which contributes no strength gain characteristics to hydraulic cement, whereas a "clinker substitute" refers to material which contributes to long-term strength development.

The manufacture of clinker entails the sintering of a mixture of calcium carbonate (limestone) aluminium silicate (clay or shale) silicon dioxide (sand) and miscellaneous iron oxides. This sintering process relies on the use of coal, oil, gas or other fuels to provide sufficient heat to fuse the components into hardened nodules referred to as clinker. From an environmental perspective the use of either fillers and or clinker substitutes reduces the carbon emissions by a reduction in the total clinker production for a given off-take of hydraulic cement. Alternatively, the clinker production can be extended by the use of fillers and clinker substitutes to produce additional hydraulic cement for a given production rate of clinker.

The principal phases which constitute more than 90% of Portland cement are tricalcium silicate - (3CaO.SiO₂), C₃S, dicalcium silicate - (2CaO.SiO₂), C₂S, tricalcium aluminate - (3CaO. AI₂O₃₎ and tetracalcium aluminoferrite - (4CaCAI₂O₃-Fe₂O₃) or C₄AF. Variations in the proportions of these phases produce different types of cement. In addition to these major phases, several other compounds contribute to the hydration process, of which gypsum (CaSO₄.2H₂O in the pure natural form) is important. Portland cement clinker is prepared by igniting a mixture of raw materials composed mainly of calcium carbonate and suitable aluminium silicates known as calcareous and argillaceous materials (or other equivalent mixtures) respectively. The preferred method of burning the homogenous mixture of the constituents is referred to as the dry process whereby the raw mix is milled in the dry state and added to the kiln where the mixture is fired at 1250-1500⁰C. This is then cooled at a rate sufficient to preserve the chemical compounds or phases in a state of frozen equilibrium as partly glassy and partly crystalline material, referred to as clinker. The actual burning technology is not within the scope of this discussion but affects the chemistry of the clinker dramatically.

Chemical analysis of the clinker determines the quantity of the elements (calcium, silicon, aluminium, iron and so forth) in a Portland cement but the amounts of compounds or phases cannot be determined.

R.H. Bogue proposed a method by which these phases (or potential compositions) could be calculated and this empirical formula is still in use.

TABLE 1

Comparison between different cement manufacturers

TABLE 2

Comparison of main potential compounds or phases

As can be seen from Tables 1 and 2, the chemistry of the ciinker for the same cement type can differ from plant to plant dependent on the available raw materials and burning conditions.

The clinker is then milled together with calculated amounts of gypsum to produce Portland cement. The fineness or specific surface area determines the setting and strength gain characteristics of the finished product.

Of these compounds, the C₃S attains the greater part of its strength in 7 days with rapidly reducing strength gain thereafter. C₂S contributes little strength development up to 28 days but continues to steadily gain strength over long periods. The C₃A might produce some strength at 1 day but is also known to decrease the later strengths.

It probably makes no contribution to the cementing action other than accounting for the initial set. The C₄AF accounts for little, if any cementing action.

If the main compounds as outlined above are considered, the effect that these components have on the hydration process is briefly as follows:

2(3CaO.SiO₂₎ + 6H₂O = 3CaO.2SiO₂.3H2O + 3Ca (OH)₂

2(2CaO.SiO₂₎ + 4 H₂O = 3CaO.2SiO2.3H2O + Ca (OH)₂

3CaO-AI₂O₃ + 12 H₂O + 2Ca (OH) ₂ = 3CaO. AI₂O₃. Ca (OH)₂.12H₂O

3CaO-AI₂O₃ + 10 H₂O + 2CaSO₄.2H₂O = 3CaO. AI₂O₃. CaSO₄.12H₂O 4CaO-AI₂O₃-Fe₂O₃ + 10 H₂O + 2Ca(OH)₂ = 63CaO. AI₂O₃ Fe₂O₃. 12H₂O

As the hydration reaction takes place at a solid-liquid interface and produces further solids of variable composition (either amorphous or, if crystalline adopts more than one morphology), it is difficult to prove hydration experimentally.

When water is added to the cement, several reactions occur almost immediately as the sulphate and free lime dissolves. Surface skins of hydrated minerals form on the other constituents and proceeds to systematically break or rupture and hydration products grow away from the surfaces into the interstitial spaces between grains. Crystals of calcium hydroxide are deposited and consequently the spaces are filled with hydration products, which result in stiffening and subsequent strength development. Both C₃S and C₂S can exist in more than one form, only α- C₃S and β- C₂S have the correct structure to react with water forming a strong hydrated mass. Impure forms present in cement are often referred to as alite and belite respectively. This calcium silicate hydrate occurs in at least 4 forms, as fibres, a reticular network, small equant grains and tobermorite gel. The two calcium silicates react to produce calcium hydroxide and silicate hydrate called tobermorite gel (3CaO.2SiO₂.3H₂O. or C-S-H.)

Tricalcium aluminate or C₃A has the fastest rate of reaction with water. It has a large influence on the rate of heat release and hardening rate, and is largely responsible for "flash" or "quick set" in the cement water phase. It consumes large amounts of water upon hydration and therefore impacts on workability and slump retention.

The C₃A reacts immediately with water to form calcium aluminate hydrate if there is insufficient sulphate in solution. This is referred to as flash set or permanent stiffening. Too much sulphate in solution may precipitate out as gypsum causing false set, which is temporary.

C₃A hydrates in the presence of sulphate to form ettringite at a controlled rate. Ettringite forms around the C₃A grains and limits access to water.

The amount of sulphate ion in the cement, as well as the form of calcium sulphate occurring, determines the amount of sulphate present in the solution. Gypsum is added to the clinker during comminution to slow down the rate of hydration of the C₃A. A thin skin of ettringite forms on the surface of the C₃A immediately and thickens as the C₃A reacts from beneath.

As the unit cell of ettringite is much larger than that of the original C₃A, the pressure developed causes the ettringite skin to eventually burst, thereby allowing sulphate in solution to come into contact with unreacted C₃A. This skin reforms and the cycle is repeated until all the sulphate in solution is consumed, whereupon the C₃A can react faster and directly The transformation of ettringite into needle-like crystals of monosulphate occurs which leads to loss of workability and to setting of the paste or concrete. This rapid reaction has a minimal contribution to strength development as a mass of very tiny unstructured crystals are formed. As the aluminate hydrates also tend to coat the Alite or C₃S, excess may retard and inhibit the onset of strength giving C₃S.

The C₄AF is generally the least reactive of the major components but can inhibit the development of strength, particularly at later ages. As clinker particles fracture during milling of cement, particles or grains of the silicate phases are partially or fully coated by the C₄AF, which, as part of the interstitial phase in cement is not as hard as the silicate phase and fractures more readily.

SUMMARY OF THE INVENTION

A first aspect of the invention relates to an additive composition for use in preparing a hydraulic cement composition, the additive composition comprising amine hydrohalide/s.

Preferably, the additive composition comprises a combination of amine hydrohalide/s and a dispersant such as naphthalene sulphonate formaldehyde, melamine sulphonate formaldehyde, carboxylic acid/s, polycarboxylic phosphonates, polycarboxylic ethoxylates or lignosulphonate/s, preferably lignosulphonate/s.

The amine hydrohalide/s and dispersant may be present at a ratio (by weight) of 1 :66 to 1 :5, preferably 1 :32 to 1 :7, most preferably 1 :32 to 1 :16 amine hydrohalide to dispersant. The amine hydrohalide may be hydrobromide or hydrochloride, preferably hydrochloride.

The additive may be a liquid composition or a solid composition.

A liquid additive composition typically contains 1.5-20%, preferably 3-12%, most preferably 3-6% by weight amine hydrohalide active ingredient.

A liquid additive composition typically contains 30-60%, preferably 40-50%, most preferably 43-48% by weight dispersant solids.

A solid additive composition typically contains 1.5-18%, preferably 3-12%, most preferably 3-6% by weight amine hydrohalide active ingredient.

A solid additive composition typically contains 98.5-82%, preferably 97-88% by weight, most preferably 97-94% by weight dispersant solids.

The amine hydrochloride may be a triethanolamine, a monoethanolamine, a diethanolamine or mixtures of mono-di-triethanolamine hydrochloride.

The amine hydrochloride is preferably a Triethanolamine hydrochloride (also known as 2,2', 2" - Nitrilotriethanol hydrochloride) or Tris (2-hydroxyethyl) amine hydrochloride.

The lignosulphonate/s is/are typically from metallic salts such as calcium, sodium, magnesium and the like.

The lignosulphonate may be in a solution produced from hardwood, softwood and straw.

The lignosulphonate solution may result from spent sulphite liquor treatment such as sulphonation, sulphoalkylation, sugar fermentation, precipitation, membrane filtration, oxidation, carboxylation and desulphonation.

The lignosulphonate solution preferably has a low sugar content, typically 0.5-2%, preferably 0.5-1% m/m sugar. A second aspect of the invention relates to a method of producing an additive composition described above, the method including the steps of: preparing a 25-45%, preferably 30%, active ingredient m/m amine hydrohalide solution by reaction of amine with hydrohalous acid which reaction causes an exotherm; and adding the amine hydrohalide solution to a lignosulphonate solution (typically having a lignosulphonate solids content of 30-60% by weight) immediately after the exotherm.

A third aspect of the invention relates to a method of preparing a hydraulic cement composition comprising a mixture of Portland cement, wherein amine hydrohalide/s is/are added during the method of preparing the hydraulic cement composition.

The amine hydrohalide may be hydrobromide or hydrochloride, preferably hydrochloride.

Preferably, the amine hydrohalide is added with a dispersant such as naphthalene sulphonate formaldehyde, melamine sulphonate formaldehyde, carboxylic acid/s, polycarboxylic phosphonates, polycarboxylic ethoxylates or lignosulphonate/s, most preferably a calcium, sodium and/or magnesium lignosulphonate/s.

The dispersant and amine hydrohalide/s may be added prior to or in conjunction with the addition of water during the method of preparing the hydraulic cement composition.

The dispersant and amine hydrohalide is preferably added during grinding of the cement in which case the dispersant an amine hydrohalide further acts to reduce the water requirement for a given flow ability, as well as acting as a milling aid.

The amine hydrohalide is typically added in an amount of 0.001 to 0.05%, preferably 0.005 to 0.05%, most preferably 0.01 to 0.05% by weight, based on the total cementitious content.

The calcium, sodium and/or magnesium lignosulphonate/s are typically added in an amount of 0.05 to 0.2 %, preferably 0.75 to 0.2%, most preferably 0.1 to 0.2%, based on the total cementitious content. The calcium, sodium and/or magnesium lignosulphonate and an amine hydrochloride is preferably contained in an additive composition described above.

The liquid additive composition is typically added in an amount of 0.05% to 0.5%, preferably 0.1% to 0.4%, more preferably 0.1% to 0.3%, typically 0.2% by weight of said cement composition, based on the total cementitious content.

The cement composition may be prepared from a clinker additionally containing a clinker substitute with or without additional limestone filler.

A fourth aspect of the invention relates to a hydraulic cement composition comprising a mixture of Portland cement containing an amine hydrohalide as described above and preferably a dispersant as described above, in the amounts described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a graph showing adiabatic calorimetry for the cement hydration processes of a control and commercial cement compositions in comparison with cement compositions containing an additive composition according to the present invention; and

Figure 2 is a graph showing hydration adiabatic calorimetry for the cement hydration processes of a control and cement compositions containing different amounts of additive composition according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a hydraulic cement composition exhibiting enhanced early (i.e. 1 , 3, 7 days) and later 28 day and 56 day compressive strength properties after mixing and allowing the cement composition to set.

The water requirement of the hydraulic cement composition should be equal to or improved over the equivalent mass of conventional Portland cement used for comparative studies. These attributes are imparted by incorporating a water reducing, strength-enhancing additive into a suitable hydraulic Portland cement or cement composition. Furthermore setting times are not extended and may be reduced, dependent on application rate of the additive.

According to the invention, the early strength gain, later strength-enhancing additive is a combination of amine hydrochloride such as Triethanolamine hydrochloride (also known as 2,2',2"-Nitrilotriethanol hydrochloride) or Tris (2-hydroxyethyl) amine hydrochloride with a molecular formula as in Formula 1 with metallic salts of lignosulphonate extracted from both hard and soft wood timber species. Other suitable hydrochlorides are monoethanolamine, diethanolamine or mixtures of mono- di-triethanolamine hydrochloride.

Formula 1

Molecular Formula (HOCH₂CH₂)₃N ^■ HCI

OH

HCI

/^•' N

HO OH

The combination extends to include all ultra filtrated and vanillin based products extracted from both hard and soft woods.

The graph in Figure 1 shows adiabatic calorimetry for the cement hydration processes of:

A - Cement composition containing: 100% Triethanolamine Hydrochloride solution

(30% active) at 0.4% Im/m

B - Cement composition containing liquid additive composition of the invention: 50%

Triethanolamine Hydrochloride solution (30 % active) plus 50% Calcium lignosulphonate solution (50% lignosulphonate solids content) at 0.4% Im/m

C - Cement composition containing: prior art additive comprising Triethanolamine

Chloride and Calcium Chloride at 0.4% Im/m

D - Control cement composition

E - Cement composition containing: prior art additive comprising Triethanolamine

Chloride and Calcium Chloride at 0.4% Im/m. With reference to the Graph in Figure 1 , the Triethanolamine Hydrochloride (A) displays a unique heat release signature when added to the hydraulic cement as a stand-alone product and is easily identifiable by the secondary peak, which occurs after 2-4 days. The inclusion of the Triethanolamine Hydrochloride in a lignosulphonate base depicts essentially the same heat release signature albeit on a different time scale (B). The secondary peak is not present in the cement control composition (D), nor the cement compositions containing prior art Chloride additives (C and E).

Typically the amine hydrochloride is produced in situ by reaction of amine with hydrochloric acid as a 25-45% active ingredient composition. The amine is massed into a vessel with a mechanical agitator. Water equal to the mass of the amine is added and thoroughly stirred or agitated. An exotherm, or heat release is generated by the reaction between the amine and hydrochloric acid and continues until the resultant mixture achieves a neutral state of 6.5-7.5, at which point, the amine halide has been formed. The amine hydrochloride is added to a lignosulphonate or other dispersant solution (30-50% by weight solids content) in an amount of 5-60% m/m solution immediately after the exotherm.

The resultant composition can be further reacted at high temperature, cooled and packaged as a ready-to-use liquid or spray dried product.

The resultant product is typically added to the hydraulic cement as a liquid during the inter-grinding or milling process.

The complexity of the ratios between the hydrochloride and lignosulphonate solids becomes apparent when addition rates are increased without increases in the hydrochloride content. In the Graph in Figure 2, which shows hydration adiabatic calorimetry for the cement hydration processes of:

A - Cement composition containing liquid additive composition of the invention: 20%

Triethanolamine Hydrochloride solution (30% active) plus 80% Calcium lignosulphonate (50% by weight lignosulphonate solids) at 0.1% Is/m

B - Cement composition containing liquid additive composition of the invention: 20%

Triethanolamine Hydrochloride solution (30% active) plus 80% Calcium lignosulphonate (50% by weight lignosulphonate solids) at 0.075% Is/m C - Cement composition containing liquid additive composition of the invention: 20% Triethanolamine Hydrochloride solution (30% active) plus 80% Calcium lignosulphonate (50% by weight lignosulphonate solids) at 0.05% Is/m D - Control cement composition.

This graph depicts the extension of setting times as the dosage increases. However, the silica hydration peaks rise as the addition rate is increased. It is apparent that the ratio of the hydrochloride to lignosulphonate solids needs to be adjusted for different effects in the cement blends.

It is generally accepted that the addition of accelerating chemical additives to cement and cement compositions can either enhance compressive strength gain characteristics at early ages or at a later stage. It is extremely rare that the strength enhancement effect can be manifested at all ages. The use of lignosulphonates retards the setting time of hydraulic cements due to residual sugars such as xylose, pentose, sucrose and so forth. In addition, the addition of lignosulphonates and various other dispersants such as naphthalene sulphonate formaldehyde tends to affect the rate of dissolution in the water phase, of sulphate from the gypsum or calcium sulphate. If insufficient sulphate is present in the solution, the C₃A forms at a rapid and uncontrolled rate, which has an impact on the formation of the silicate hydrates and leads to retardation at early ages.

The later strength development is generally enhanced by the use of retarding admixtures. Ideally, the inclusion of an additive, which allows rapid dissolution of sulphate in solution and prevents the reduction of calcium ions during the formation of ettringite, would negate the initial retardation effect of the dispersant /water reducing agent.

To this end, the dispersant or water reducer may be added to either blended or interground hydraulic cements to improve the flow of the mortar or concrete when water is added. It is well known that additions of filler or clinker substitutes such as granulated blast furnace slag or pulverised fly ash or combinations thereof increases the water requirement of the hydraulic cement for a given water cement ratio. Use of lignosulphonates during inter-grinding or intermixing of cementitious materials would allow for the inclusion of increased proportions of clinker substitutes without raising the water requirement. The use of the accelerators such as calcium and sodium chlorides, nitrates, nitrites, thiocyanates and the like known to the art are generally ineffective at low addition rates and in many cases are limited to specific concentrations. Many such accelerators are incompatible with lignosulphonates in solution.

The invention addresses this objective without sacrificing early strength development and extending setting times by using a combination of lignosuiphonate, typically calcium, sodium and/or magnesium lignosuiphonate and an amine hydrochloride. Experiments indicate a reduction in setting times with enhanced early strength gain, even at increased additions of clinker substitutes. An additional benefit is an increase in strengths at 28 days. Furthermore, the hydrochloride is non-corrosive.

The invention will now be described with reference to the following non-limiting Examples:

EXAMPLE 1

Addition rates of 0.1-0.25% additive liquid m/m of Portland cement results in a reduction of the standard consistency or water reduction of the interground hydraulic cement. The liquid additive is a blend of a 40% (by weight) solids solution of a hardwood low sugar content calcium/sodium lignosuiphonate mixture with an 8% m/m solution of triethanolamine hydrochloride (30% active ingredient). See Table 1 below for comparative mortar tests where the liquid additive described above is referred to as DP234A.

Table 1

Physical properties of mortar produced with OPC Table 1 depicts the results of increasing the addition rate of the liquid additive for ordinary Portland cement. The standard consistency reduces with increased application rate and the initial setting time decreases quite dramatically. The final set does not follow this trend. Initial compressive strengths are not dramatically affected but increase substantially at higher addition rates. Both 7 and 28-day compressive strengths show considerable gains for all addition rates.

The application of the liquid additive to mortar prepared from the same ordinary Portland cement blend with 50% m/m milled blast furnace slag is presented in Table 2 below where the additive the additive described above is referred to as DP243A.

Table 2 Physical properties of mortar produced with OPC/ milled, granulated slag blend.

The addition of the liquid additive was based on the total cementitious cement content and in effect, was doubled dosed, as the milled slag is basically inert at early ages. This is clearly indicated by the reduction in 1-day compressive strengths. Logically, setting times were extended. Percentage standard consistency reduced in line with the OPC as per Table 1. Once again the 7-day compressive strengths improved with substantial gains at 28 days.

EXAMPLE 2

Example 2 depicts addition rates of 0.1-0.2% liquid additive m/m of Portland cement. The liquid additive is a blend of a 36% (by weight) m/m solids solution of a hardwood calcium/sodium lignosulphonate mixture with a 16% m/m solution of triethanolamine hydrochloride (30% active ingredient.) See Table 3 below for comparative mortar tests. In Tables 3 the additive described above is referred to as DP-435B.

Table 3

Physical properties of mortar produced with OPC

Increasing the triethanolamine hydrochloride and decreasing the lignosulphonate components resulted in improved 1-day compressive strengths for all addition rates with 0.15% m/m of cement contributing an increase of 18%. The 7-day compressive strengths were marginally improved whilst higher addition rates of 0.15 and 0.2% m/m with cement improved the 28-day results by 10.9 and 26% respectively. Initial setting times were not significantly affected.

The same exercise was repeated with a 50:50 blend of OPC with milled blast furnace cement and the results are depicted in Table 4 where the liquid additive described above is referred to as DP-435B. Table 4

Physical properties of mortar produced with OPC/ milled, blastfurnace slag blend.

The same comment is applicable as per Table 2, whereby double addition rates were effectively applied. Standard consistency percentage was affected by the reduction in lignosulphonate solids. The 1-day compressive strengths were reduced by the addition of the liquid additive and only the 0.2% addition rate achieved comparable strength to that of the control sample. The 7-day compressive strengths were above the control sample whilst the 28 results were surprisingly unimpressive for addition rates below 0.2%. At an addition rate of 0.2% m/m of cement, the 28-day compressive strength produced an increase of 50% over the control sample. Setting times were increased with higher addition rates of the liquid additive.

EXAMPLE 3

Addition rates of 0.1-0.15% liquid m/m of Portland cement blend with 50% m/m milled slag results in a reduction of the standard consistency or water reduction of the interground hydraulic cement. The liquid additive is a blend of a 40% solids solution of a hardwood calcium lignosulphonate mixture with an 8% m/m solution of triethanolamine hydrochloride (30% active ingredient). The particular cement blend differs chemically from the blend used in Tables 1-4. See Table 5 for comparative mortar tests. In Table 5 the additive described above is referred to as DP-244. Table 5

Physical properties of mortar produced with an OPC/ milled, blast furnace slag blend.

Standard consistency reduction is typically lower than other cement blends, due to the particle distribution of the milled slag and cement clinker. The 1-day compressive strengths are basically equal to the control sample although initial and final setting times are slightly extended. The 0.1% m/m addition of the liquid additive achieved a moderate increase of 10% at 7 days with a 15% increase at 28 days over the control sample. The addition of 0.15% m/m did not improve performance but rather reduced the effect of the liquid additive.

Claims

1. An additive composition for use in preparing a hydraulic cement composition, the additive composition comprising amine hydrohalide/s.

2. The additive composition as claimed in claim 1 , comprising a combination of amine hydrohalide/s and a dispersant.

3. The additive composition as claimed in claim 2, wherein the dispersant is naphthalene sulphonate formaldehyde, melamine sulphonate formaldehyde, carboxylic acid/s, polycarboxylic phosphonates, polycarboxylic ethoxylates or lignosulphonate/s.

4. The additive composition as claimed in claim 3, wherein the dispersant is lignosulphonate/s.

5. The additive composition as claimed in any one of claims 2 - 4, wherein the amine hydrohalide/s and dispersant are present at a ratio (by weight) of 1:66 to 1 :5 amine hydrohalide to dispersant.

6. The additive composition as claimed in claim 5, wherein the amine hydrohalide/s and dispersant are present at a ratio (by weight) of 1:32 to 1:7 amine hydrohalide to dispersant.

7. The additive composition as claimed in claim 6, wherein the amine hydrohalide/s and dispersant are present at a ratio (by weight) of 1:32 to 1:16 amine hydrohalide to dispersant.

8. The additive composition as claimed in any one of the preceding claims, wherein the amine hydrohalide is hydrobromide or hydrochloride.

9. The additive composition as claimed in claim 8, wherein the amine hydrohalide is amine hydrochloride.

10. A liquid additive composition as claimed in any one of the preceding claims, containing 1.5-20% by weight amine hydrohalide active ingredient.

11. A liquid additive composition as claimed in claim 10, containing 3-12% by weight amine hydrohalide active ingredient.

12. A liquid additive composition as claimed in claim 11, containing 3-6% by weight amine hydrohalide active ingredient.

13. A liquid additive composition as claimed in any one of claims 2-12, containing 30-60% by weight dispersant solids.

14. A liquid additive composition as claimed in claim 13, containing 40-50% by weight dispersant solids.

15. A liquid additive composition as claimed in claim 14, containing 43-48% by weight dispersant solids.

16. A solid additive composition as claimed in any one of claims 1 - 9, containing 1.5-18% by weight amine hydrohalide active ingredient.

17. A solid additive composition as claimed in claim 16, containing 3-12% by weight amine hydrohalide active ingredient.

18. A solid additive composition as claimed in claim 17, containing 3-6% by weight amine hydrohalide active ingredient.

19. A solid additive composition as claimed in claim 16, containing 98.5-82% by weight lignosulphonate solids.

20. A solid additive composition as claimed in claim 17, containing 97-88% by weight lignosulphonate solids.

21. A solid additive composition as claimed in claim 18, containing 97-94% by weight lignosulphonate solids.

22. An additive composition as claimed in any one of claims 9 - 21 , wherein the amine hydrochloride is a triethanolamine, a monoethanolamine, a diethanolamine or mixtures of mono-di-triethanolamine hydrochloride.

23. An additive composition as claimed in any one of claims 9 - 21 , wherein the amine hydrochloride is Triethanolamine hydrochloride (also known as 2,2', 2" - Nitrilotriethanol hydrochloride) orTris (2-hydroxyethyl) amine hydrochloride.

24. An additive composition as claimed in any one of claims 4 -23, wherein the lignosulphonate/s is/are typically from metallic salts.

25. An additive composition as claimed in claim 24, wherein the lignosulphonate/s is/are typically from metallic salts of calcium, sodium, or magnesium.

26. An additive composition as claimed in claim 25, wherein the lignosulphonateis derived from a solution produced from hardwood, softwood and straw.

27. An additive composition as claimed in claim 26, wherein the lignosulphonate solution results from spent sulphite liquor treatment.

28. An additive composition as claimed in claim 27, wherein the spent sulphite liquor treatment is sulphonation, sulphoalkylation, sugar fermentation, precipitation, membrane filtration, oxidation, carboxylation or desulphonation.

29. An additive composition as claimed in any one of claims 26 - 28, wherein the lignosulphonate solution has a low sugar content of 0.5-2% m/m sugar.

30. An additive composition as claimed in claim 29, wherein the lignosulphonate solution has a low sugar content of 0.5-1% m/m sugar.

31. A method of producing an additive composition as defined in any one of claims 4 - 30, the method including the steps of: preparing a 25-45% active ingredient m/m amine hydrohalide solution by reaction of amine with hydrohalous acid which reaction causes an exotherm; and adding the amine hydrohalide solution to a lignosulphonate solution immediately after the exotherm.

32. A method of preparing a hydraulic cement composition comprising a mixture of Portland cement, wherein amine hydrohalide/s is/are added during the method of preparing the hydraulic cement composition.

33. The method as claimed in claim 32, wherein the amine hydrohalide is hydrobromide or hydrochloride.

34. The method as claimed in claim 33, wherein the amine hydrohalide is amine hydrochloride.

35. The method as claimed in any one of claims 32 - 34, wherein the amine hydrohalide is added with a dispersant.

36. The method as claimed in claim 35, wherein the dispersant is naphthalene sulphonate formaldehyde, melamine sulphonate formaldehyde, carboxylic acid/s, polycarboxylic phosphonates, polycarboxylic ethoxylates or lignosulphonate/s.

37. The method as claimed in claim 36, wherein the dispersant is lignosulphonate/s.

38. The method as claimed in claim 37, wherein the dispersant is calcium, sodium and/or magnesium lignosulphonate/s.

39. The method as claimed in any one of claims 32 - 38, wherein the dispersant and amine hydrohalide/s are added prior to or in conjunction with the addition of water during the method of preparing the hydraulic cement composition.

40. The method as claimed in any one of claims 32 - 38, wherein the dispersant and amine hydrohalide are added during grinding of the cement in which case the dispersant and amine hydrohalide further acts to reduce the water requirement for a given flow ability, as well as acting as a milling aid.

41. The method as claimed in any one of claims 32 — 40, wherein the amine hydrohalide is added in an amount of 0.001 to 0.05% by weight, based on the total cementitious content.

42. The method as claimed in claim 41 , wherein the amine hydrohalide is added in an amount of 0.005 to 0.05% by weight, based on the total cementitious content.

43. The method as claimed in claims 42, wherein the amine hydrohalide is added in an amount of 0.01 to 0.05% by weight, based on the total cementitious content.

44. The method as claimed in any one of claims 32 - 43, wherein the dispersant is added in an amount of 0.05 to 0.2% by weight based on the total cementitious content.

45. The method as claimed in claim 44, wherein the dispersant is added in an amount of 0.75 to 0.2% by weight based on the total cementitious content.

46. The method as claimed in claim 45, wherein the dispersant is added in an amount of 0.1 to 0.2% by weight based on the total cementitious content.

47. The method as claimed in any one of claims 32 - 46, wherein the dispersant and amine hydrohalide are added in a composition as defined in any one of claims 2 - 30.

48. The method as claimed in claim 47, wherein the dispersant is a liquid additive composition as defined in any one of claims 10 - 15, wherein the liquid additive composition is added in an amount of 0.05% to 0.5% by weight of said cement composition, based on the total cementitious content.

49. The method as claimed in claim 48, wherein the liquid additive composition is added in an amount of 0.1% to 0.4% by weight of said cement composition, based on the total cementitious content.

50. The method as claimed in claim 49, wherein liquid additive composition is added in an amount of 0.1% to 0.3% by weight of said cement composition, based on the total cementitious content.

51. The method as claimed in claim 50, wherein liquid additive composition is added in an amount of 0.2% by weight of said cement composition, based on the total cementitious content.

52. The method as claimed in any one of claims 32 - 51 , wherein the cement composition is prepared from a clinker additionally containing a clinker substitute with or without additional limestone filler.

53. A hydraulic cement composition comprising a mixture of Portland cement containing an amine hydrohalide.

54. A hydraulic cement composition as claimed in claim 53, further comprising lignosulphonate/s.