Preparation of hydroxysodalite
The invention is directed to a process and method for forming synthetic hydroxysodalite from nepheline and feldspar and/or nepheline syenite. A caustic material such as a solution of sodium hydroxide is combined with the nepheline and feldspar and/or nepheline syenite to form the synthetic hydroxysodalite.
1. A method for forming synthetic hydroxysodalite from nepheline comprising the steps of:
a) providing a source of nepheline and feldspar;
b) providing a solution of caustic material;
c) combining together the source of nepheline and feldspar and solution caustic material to form a reaction mixture; and,
d) separating synthetic hydroxysodalite from said reaction mixture after a period of time.
2. The method as defined in claim 1 , wherein said source of nepheline and feldspar includes nepheline syenite.
3. The method as defined in claim 2 , wherein said source of nepheline and felspar includes at least about 90 weight percent nepheline syenite.
4. The method as defined in claim 2 , wherein said solution of caustic material includes sodium hydroxide.
5. The method as defined in claim 4 , wherein a weight ratio of solid caustic material to nepheline is at least about 2:1.
6. The method as defined in claim 5 , including the step of heating reaction mixture to a temperature of at least about 90° C.
7. The method as defined in claim 6 , wherein said period of time is at least about one hour.
8. The method as defined in claim 1 , wherein said solution of caustic material includes sodium hydroxide.
9. The method as defined in claim 8 , wherein said solution of caustic material includes at least about 40 weight percent sodium hydroxide.
10. The method as defined in claim 1 , wherein a weight ratio of solid caustic material to nepheline is at least about 2:1.
11. The method as defined in claim 10 , wherein a weight ratio of solid caustic material to nepheline is at least about 4:1.
12. The method as defined in claim 1 , including the step of heating reaction mixture to a temperature of at least about 90° C.
13. The method as defined in claim 12 , including the step of heating reaction mixture to a temperature of about 110-140° C.
14. The method as defined in claim 1 , wherein said period of time is at least about one hour.
15. The method as defined in claim 14 , wherein said period of time is at least about twelve hours.
16. The method as defined in claim 1 , wherein said step of separating synthetic hydroxysodalite from said reaction mixture includes a vacuum filtration process.
17. The method as defined in claim 1 , including the step of washing said synthetic hydroxysodalite after said separation step.
18. The method as defined in claim 17 , wherein said step of washing includes the application of deionized water on said synthetic hydroxysodalite.
19. The method as defined in claim 17 , including the step of drying said synthetic hydroxysodalite after said washing step.
20. The method as defined in claim 19 , wherein said step of drying includes the use of heated air.
21. The method as defined in claim 1 , including the step of classifying said synthetic hydroxysodalite to obtain a desired particle size distribution of said synthetic hydroxysodalite.
22. The method as defined in claim 1 , including the step of adding an aluminum source to said reaction mixture.
23. A method for forming synthetic hydroxysodalite from nepheline comprising the steps of:
a) providing a source of nepheline syenite having an average particle size of about 2-20 μm
b) providing a 40-60 weight percent solution of sodium hydroxide;
c) combining together the source of nepheline syenite and solution of sodium hydroxide to form a reaction mixture, a weight ratio of solid sodium hydroxide to nepheline syenite is 4-10:1;
d) heating said reaction mixture at about 100-130° C. for about 8-72 hours until a conversion percentage of nepheline syenite to synthetic hydroxysodalite of least about 60% is achieved;
e) separating said synthetic hydroxysodalite from said reaction mixture; and,
f) washing and drying said separated synthetic hydroxysodalite.
24. The method as defined in claim 23 , wherein said step of separating synthetic hydroxysodalite from said reaction mixture includes a vacuum filtration process.
25. The method as defined in claim 23 , wherein said step of washing includes the application of deionized water on said synthetic hydroxysodalite.
26. The method as defined in claim 23 , wherein said step of drying includes the use of heated air.
27. The method as defined in claim 23 , including the step of classifying said synthetic hydroxysodalite to obtain a desired particle size distribution of said synthetic hydroxysodalite.
28. The method as defined in claim 23 , including the step of adding aluminum hydroxide to said reaction mixture.