Process for the preparation of sulphur cement or a sulphur cement-aggregate composite

1. A process for the preparation of sulphur concrete, wherein the process comprises the following steps: (a) admixing at least an inorganic filler and/or aggregate and a polysulphide-containing organosilane, bis(3-triethoxysilylpropyl)tetrasulphide, and allowing the polysulphide-containing organosilane to react with the inorganic filler and/or aggregate; (b) admixing during or after step (a) elemental sulphur with the inorganic filler and/or aggregate at a temperature at which sulphur is liquid to obtain an admixture comprising molten sulphur and inorganic filler and/or aggregate; and (c) solidifying the admixture to obtain the sulphur concrete.

2. A process according to claim 1 , wherein step (a) is performed prior to step (b).

3. A process according to claim 2 , wherein the amount of organosilane admixed with the inorganic filler and/or aggregate is in the range of from 0.01 to 0.2 wt % based on the weight of inorganic filler and aggregate.

4. A process according to claim 3 , wherein the filler or aggregate has oxide or hydroxyl groups on its surface.

5. A process according to claim 4 , wherein the filler and/or aggregate is a silicate.

6. A process according to claim 5 , wherein the polysulphide-containing organosilane is dissolved in a solvent when admixed in step (a) with the inorganic filler and/or aggregate.

7. A process according to claim 6 , wherein the organosilane is dissolved in ethanol when admixed in step (a) with the inorganic filler and/or aggregate.

8. A process according to claim 2 , wherein the amount of organosilane admixed with the inorganic filler and/or aggregate is in the range of from 0.02 to 0.1 wt % based on the weight of inorganic filler and aggregate, and wherein the filler or aggregate has oxide or hydroxyl groups on its surface.

9. A process according to claim 1 , wherein the amount of organosilane admixed with the inorganic filler and/or aggregate is in the range of from 0.01 to 0.2 wt % based on the weight of inorganic filler and aggregate.

10. A process according to claim 9 , wherein the filler or aggregate has oxide or hydroxyl groups on its surface.

11. A process according to claim 10 , wherein the filler and/or aggregate is a silicate.

12. A process according to claim 11 , wherein the polysulphide-containing organosilane is dissolved in a solvent when admixed in step (a) with the inorganic filler and/or aggregate.

13. A process according to claim 12 , wherein the organosilane is dissolved in ethanol when admixed in step (a) with the inorganic filler and/or aggregate.

14. A process according to claim 1 , wherein the amount of organosilane admixed with the inorganic filler and/or aggregate is in the range of from 0.02 to 0.1 wt % based on the weight of inorganic filler and aggregate, and wherein the filler or aggregate has oxide or hydroxyl groups on its surface.

15. A process for the preparation of sulphur concrete, wherein the process comprises the following steps:

(a) admixing at least an inorganic filler and/or aggregate and a polysulphide-containing organosilane that is bis(3-triethoxysilylpropyl)tetrasulphide and allowing the polysulphide-containing organosilane to react with the inorganic filler and/or aggregate;

(b) admixing during or after step (a) elemental sulphur with the inorganic filler and/or aggregate at a temperature at which sulphur is liquid to obtain an admixture comprising molten sulphur and inorganic filler and/or aggregate; and

(c) solidifying the admixture to obtain the sulphur concrete.

16. A process comprising:

(a) admixing an inorganic ingredient with an organosilane that is bis(3-triethoxysilylpropyl)tetrasulphide, (TESPT) under conditions such that said organosilane is allowed to react with said inorganic ingredient to thereby form a first admixture;

(b) admixing elemental sulphur with said first admixture at a first temperature at which sulphur is liquid to obtain a second admixture comprising molten sulphur and said inorganic ingredient; and

(c) solidifying said second admixture by cooling said second admixture to a second temperature below the melting temperature of sulphur.

17. A process as recited in claim 16 , wherein the amount of organosilane admixed with said inorganic ingredient is in the range of from 0.01 to 0.2 wt % based on the weight of said inorganic ingredient.

18. A process as recited in claim 17 , wherein said admixing step (a) is conducted at a temperature in the range of from 120 to 150° C.

19. A process as recited in claim 18 , wherein said admixing step (b) is conducted at a temperature in the range of from 120 to 180° C.

20. A process as recited in claim 19 , wherein said inorganic ingredient is an inorganic filler or an inorganic aggregate or both.

21. A process as recited in claim 20 , wherein said inorganic ingredient has an oxide or an hydroxyl group on its surface.

22. A process as recited in claim 21 , wherein said organosilane is dissolved in a solvent when admixed with said inorganic ingredient.

23. A process as recited in claim 22 , wherein said solvent has a boiling temperature less than the temperature at which admixing step (a) is conducted in order to allow said solvent to evaporate during said admixing step (a).

24. A process comprising: mixing an inorganic ingredient, an organosilane bis(3-triethoxysilylpropyl)tetrasulphide, and sulphur at a first temperature at which said sulphur is liquid and under conditions such that said organosilane reacts with said inorganic material to form an admixture; and cooling said admixture to a second temperature below the melting temperature of sulphur to thereby solidify said admixture.

25. A process as recited in claim 24 , wherein the amount of organosilane mixed with said inorganic ingredient and said sulphur is in the range of from 0.02 to 0.1 wt % based on the weight of said inorganic ingredient.

26. A process as recited in claim 25 , wherein said first temperature is above 120° C.

27. A process as recited in claim 26 , wherein said inorganic ingredient is an inorganic filler or an inorganic aggregate or both.

28. A process as recited in claim 27 , wherein said inorganic ingredient has an oxide or an hydroxyl group on its surface.

29. A process as recited in claim 28 , wherein said organosilane is dissolved in a solvent when admixed with said inorganic ingredient.

30. A process as recited in claim 29 , wherein said solvent has a boiling temperature less than the temperature at which said mixing step is conducted in order to allow said solvent to evaporate during said mixing step.