Process for producing geopolymers
View Patent ↗A process for producing a geopolymer includes combusting at least one of oil shale and mineral residues originating from a production of oil using the oil shale so as to produce a combustion product. The combustion product is ground. An alkaline activator is added to the combustion product to form a geopolymer mixture. Water is added to the geopolymer mixture. The geopolymer mixture is adjusted so as to obtain a mol ratio of Si:Al of 2 to 5, a mol ratio of K:Al of 0.6 to 0.7, a mol ratio of Si:K of 3 to 10, a mol ratio of Ca:Al of 0.1 to 0.4, and a mol ratio of Si:CA of 4.9 to 41. The geopolymer mixture is hardened.
1. A process for producing a geopolymer, comprising:
combusting at least one of oil shale and mineral residues so as to produce a combustion product, the at least one oil shale and mineral residues originating from a production of oil using the oil shale;
grinding the combustion product;
adding an alkaline activator to the combustion product to form a geopolymer mixture;
adding water to the geopolymer mixture;
adjusting the geopolymer mixture so as to obtain a mol ratio of Si:Al of 2 to 5, a mol ratio of K:Al of 0.6 to 0.7, a mol ratio of Si:K of 3 to 10, a mol ratio of Ca:Al of 0.1 to 0.4, and a mol ratio of Si:CA of 4.9 to 41; and
hardening the geopolymer mixture.
2. The process according to claim 1 , wherein the oil shale has a Ca content of at least 10% (w/w).
3. The process according to claim 1 , further comprising grinding the oil shale to a mean grain size of <10 mm prior to the combusting.
4. The process according to claim 1 , further comprising grinding the oil shale to a mean grain size of <5 mm prior to the combusting.
5. The process according to claim 1 , wherein the combusting is performed at 850 to 1000° C.
6. The process according to claim 1 , wherein the combusting is performed at 900 to 950° C.
7. The process according to claim 1 , further comprising cooling the combustion product after the combusting.
8. The process according to claim 1 , wherein the at least one binder is added to the ground combustion products.
9. The process according to claim 8 , wherein the at least one binder includes at least one of fly ash and calcined clay.
10. The process according to claim 1 , wherein the alkaline activator includes at least one of sodium hydroxide solution, potassium hydroxide solution, sodium waterglass solution and potassium waterglass solution.
11. The process according to claim 1 , wherein the hardening is performed in less than 24 hours.
12. The process according to claim 1 , wherein the hardening is performed in less than 6 hours.
13. A geopolymer having a mol ratio of Si:Al of 2 to 5, a mol ratio of K:Al of 0.6 to 0.7, a mol ratio of Si:K of 3 to 10, a mol ratio of Ca:Al of 0.1 to 0.4, and a mol ratio of Si:CA of 4.9 to 41, the geopolymer being produced by a process comprising:
combusting at least one of oil shale and mineral residues so as to produce a combustion product, the at least one oil shale and mineral residues originating from a production of oil using the oil shale;
grinding the combustion product;
adding an alkaline activator to the combustion product so as to form a geopolymer mixture;
adding water to the geopolymer mixture; and
hardening the geopolymer mixture.