Preparation for producing refractory materials
View Patent ↗Preparation for producing refractory materials, characterized in that it comprises one or more particulate, refractory components and one or more binders, where—the particulate, refractory component has a mean particle diameter of >0.3 m and—the binder is selected from among—from 0.05 to 50% by weight of a very finely particulate binder having a mean particle diameter of from 10 nm to 0.3 m selected from the group consisting of aluminum oxide, titanium dioxide, zirconium dioxide and/or mixed oxides of the abovementioned oxides, —from 0 to 20% by weight of an inorganic binder, from 0 to 20% by weight of a hydraulically setting binder, —from 0 to 15% by weight of an organic, silicon-free binder—and the preparation additionally contains from 0 to 35% by weight of water, where—the proportion of the particulate, refractory component is equal to 100 and the percentages of the further materials in the preparation are based on the particulate component.
1. A preparation for producing refractory materials, comprising:
one or more particulate, refractory components;
at least one binder; and
3 to 15% by weight of water;
wherein
the particulate, refractory component has a mean particle diameter of greater than 0.3 μm and
the at least one binder comprises:
from 0.05 to 50% by weight of a very fine particulate binder having a mean particle diameter of from 10 nm to 0.3 μm, selected from the group consisting of a pyrogenic aluminum oxide, a pyrogenic titanium dioxide, a pyrogenic zirconium dioxide and mixed oxides thereof,
from 0 to 20% by weight of an inorganic binder,
from 0 to 20% by weight of a hydraulically setting binder, and
from 0 to 15% by weight of an organic, silicon-free binder,
where the proportion of the particulate, refractory component is equal to 100 and the percentages of the additional materials in the preparation are based on the particulate component.
2. The preparation according to claim 1 , wherein the sum of said particulate component and said very fine particulate binders is at least 70% by weight, based on the total amount of the preparation.
3. The preparation according to claim 1 , wherein the very fine particulate binder is selected from the group consisting of a pyrogenic aluminum oxide, a pyrogenic titanium dioxide and a pyrogenic zirconium dioxide.
4. The preparation according to claim 1 , wherein the very fine particulate binder has a mean particle diameter of from 40 to 300 nm.
5. The preparation according to claim 1 , wherein the particulate, refractory component is one or more compounds selected from the group consisting of aluminium oxide, magnesium oxide, magnesium aluminate, zirconium dioxide, calcium oxide, silicon dioxide, magnesium silicate, calcium silicate, zirconium silicate, mullite, calcium aluminate, silicon carbide, silicon nitride, SiAlON, aluminium nitride, aluminium oxynitride and chromium oxide.
6. The preparation according to claim 1 , wherein the proportion of inorganic binders in the preparation is from 0 to 5% by weight.
7. The preparation according to claim 1 , wherein the proportion of hydraulically setting binders in the preparation is from 0 to 5% by weight.
8. The preparation according to claim 1 , wherein the proportion of organic, silicon-free binders in the preparation is from 0 to 5% by weight.
9. The preparation according to claim 1 , comprising:
from 0.1 to 4% by weight of pyrogenic aluminium oxide having a mean particle diameter of from 40 to 300 nm, and
from 3 to 15% by weight of water
wherein the preparation is free of inorganic, hydraulically setting and organic, silicon-free binders.
10. A process for preparing the preparation according to claim 1 , wherein the particulate, refractory component and the very fine particulate binder are mixed, in the presence of water, and optionally, in the presence of inorganic, hydraulically setting and/or organic, silicon-free binders.
11. The process according to claim 10 , wherein the very fine particulate binder is added in the form of an aqueous dispersion.
12. The process according to claim 11 , wherein the aqueous dispersion contains additives for adjusting the pH and for increasing the zeta potential.
13. The process according to claim 11 , wherein the aqueous dispersion has a content of very fine particulate binder of at least 15% by weight.
14. A process for producing a green body, comprising:
consolidating the preparation according to claim 1 at temperatures of from 10 to 50° C. and subsequently at temperatures of from greater than 50° C. to 200° C. by drying and by the addition of a coagulating agent.
15. The process according to claim 14 , wherein a proportion of coagulating agent is from 0.05 to 5% by weight, based on the preparation.
16. The process according to claim 14 , wherein the coagulating agent is magnesium oxide.
17. A green body obtained by the process according to claim 14 .
18. A process for producing shaped and unshaped refractory bodies, wherein the green body according to claim 17 is treated at temperatures of from greater than 200° C. to 2000° C.
19. A process for producing shaped and unshaped refractory bodies, comprising:
consolidating the preparation according to claim 1 at temperatures of from 10 to 50° C. and subsequently at temperatures of from greater than 50° C. to 200° C. by drying and by the addition of a coagulating agent and
treating the consolidated body at temperatures of from greater than 200° C. to 2000° C.