Aluminum silicate, metal ion adsorbent, and method for producing same

Patent metadata

Field	Value
Publication number	US-9782749-B2
Application number	US-201114004581-A
Country	US
Kind code	B2
Filing date	Dec 7, 2011
Priority date	Mar 11, 2011
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

The aluminum silicate of the invention has: an element ratio of Si and Al, represented by Si/Al, of from 0.3 to 1.0 by molar ratio; a peak at approximately 3 ppm in a 27 Al-NMR spectrum; peak A at approximately −78 ppm and peak B at approximately −85 ppm in a 29 Si-NMR spectrum; and a peak at approximately 2θ=26.9° and a peak at approximately 2θ=40.3° in a powder X-ray diffraction spectrum. The aluminum silicate has an area ratio of peak B with respect to peak A of from 2.0 to 9.0, or does not include a tubular substance having a length of 50 nm or more as observed in a transmission electron microscope (TEM) photograph of the aluminum silicate taken at a magnification of 100,000. The aluminum silicate is produced by a method comprising: subjecting a reaction product of a silicate ion solution and an aluminum ion solution to desalting and solid separation; subjecting a resultant to a thermal treatment in an aqueous medium in the presence of an acid under concentration conditions in an aqueous medium such that a silicon atom concentration is 100 mmol/L or more and an aluminum atom concentration is 100 mmol/L or more; and subjecting a resultant to further desalting and solid separation.

First claim

The invention claimed is:

1. An aluminum silicate, having:
an element ratio of Si and Al, represented by Si/Al, of from 0.3 to 1.0 by molar ratio;
a peak at approximately 3 pmm in a 27 Al-NMR spectrum;
a peak at approximately −78 ppm and a peak at approximately −85 ppm in a 29 Si-NMR spectrum;
peaks at approximately 2θ=26.9°, 18.8°, 20.3°, 27.8°, 40.3°, 40.6° and 53.3° in a powder X-ray diffraction spectrum in which a CuKα ray is used as an X-ray source; and
an area ratio of peak A and peak B, represented by peak B/peak A, of from 2.0 to 9.0, wherein peak A is at approximately −78 ppm and peak B is at approximately −85 ppm, in a 29 Si-NMR spectrum.

2. The aluminum silicate according to claim 1 , wherein the aluminum silicate does not comprise a tubular substance having a length of 50 nm or more as observed in a transmission electron microscope (TEM) photograph of the aluminum silicate taken at a magnification of 100,000.

3. The aluminum silicate according to claim 1 , wherein the aluminum silicate has a BET specific surface area of 250 m 2 /g or more, a total pore volume of 0.1 cm 3 /g or more, and an average pore diameter of 1.5 nm or more.

4. A method of producing the aluminum silicate according to claim 1 , the method comprising:
(a) a process of obtaining a reaction product by mixing a solution that includes silicate ions and solution that includes aluminum ions;
(b) a process subjecting the reaction product to desalting and solid separation;
(c) a process of subjecting a resultant of the solid separation in process (b) to a thermal treatment in an aqueous medium in the present of an acid, under concentration conditions such that a silicon atom concentration is 100 mmol/L or more and an aluminum atom concentration is 100 mmol/L or more; and
(d) a process of subjecting a resultant of the thermal treatment in process (c) to desalting and solid separation.

5. The method of producing the aluminum silicate according to claim 4 , wherein the resultant of the solid separation in process (b) has an electric conductivity of 4.0 S/m or less when the resultant is dispersed in water such that a concentration of the resultant is 60 g/L.

6. The method of producing the aluminum silicate according to claim 4 , wherein the thermal treatment in process (c) is performed with a pH of from 3 to less than 7, at a temperature of from 80° C. to 160° C. and for time of within 96 hours.

7. The method for producing the aluminum silicate according to claim 4 , wherein in process (a), the solution that includes silicate ions has a silicon atom concentration of 100 mmol/L or more, the solution that includes aluminum ions has an aluminum atom concentration of 100 mmol/L, and the mixing is performed such that an element ration of the aluminum with to silicon, represented by Si/Al, is from 0.3 to 1.0 by molar ratio.

8. The method of producing the aluminum silicate according to claim 4 , wherein process (b) comprises a process of obtaining a dispersion by dispersing the reaction product in an aqueous medium and a process of performing solid separation with a pH of the dispersion adjusted to from 5 to 7.

9. An aluminum silicate, having:
an element ratio of Si and Al, represented by Si/Al, of from 0.3 to 1.0 by molar ratio;
a peak at approximately 3 pmm in a 27 Al-NMR spectrum;
a peak at approximately −78 ppm and a peak at approximately −85 ppm in a 29 Si-NMR spectrum; and
peaks at approximately 2θ=26.9, 18.8°, 20.3°, 27.8°, 40.3°, 40.6° and 53.3° in a powder X-ray diffraction spectrum in which a CuKα ray is used as an X-ray source,
the aluminum silicate not comprising a tubular substance having a length of 50 nm or more as observed in a transmission electron microscope (TEM) photograph of the aluminum silicate taken at a magnification of 100,000.

10. The aluminum silicate according to claim 9 , wherein aluminum silicate has a BET specific surface area of 250 m 2 /g or more, a total pore volume of 0.1 cm 3 /g or more, and an average pore diameter of 1.5 nm or more.

11. A metal ion adsorbent, comprising an aluminum silicate having:
an element ratio of Si and Al, represented by Si/Al, of from 0.3 to 1.0 by molar ratio;
a peak at approximately 3 pmm in a 27 Al-NMR spectrum;
a peak at approximately −78 ppm and a peak at approximately −85 ppm in a 29 Si-NMR spectrum;
an area ratio of peak A and peak B, represented by peak B/peak A, of from 2.0 to 9.0, wherein peak A is at approximately −78 ppm and peak B is at approximately −85 ppm, in a 29 Si-NMR spectrum; and
peaks at approximately 2θ=26.9°, 18.8°, 20.3°, 27.8°, 40.3°, 40.6° and 53.3° in a powder X-ray diffraction spectrum in which a CuKα ray is used as an X-ray source.

12. The metal ion adsorbent according to claim 11 , wherein the aluminum silicate does not comprise a tubular substance having a length of 50 nm or more as observed in a transmission electron microscope (TEM) photograph of the aluminum silicate taken at a magnification of 100,000.

13. The metal ion adsorbent according to claim 11 , wherein the aluminum silicate has a BET specific surface area of 250 m 2 /g or more, a total pore volume of 0.1 cm 3 /g or more, and an average pore diameter of 1.5 nm or more.

14. A method of producing the metal ion adsorbent according to claim 11 , the comprising:
(a) a process of obtaining a reaction product by mixing a solution that includes silicate ions and solution that includes aluminum ions;
(b) a process subjecting the reaction product to desalting and solid separation;
(c) a process of subjecting a resultant of the solid separation in process (b) to a thermal treatment in an aqueous medium in the present of an acid; and
(d) a process of subjecting a resultant of the thermal treatment in process (c) to desalting and solid separation.

15. The method of producing the aluminum silicate according to claim 14 , wherein the treatment in process (c) is performed under concentration conditions in the aqueous medium such that a silicon atom concentration is 100 mmol/L or more and an aluminum atom concentration is 100 mmol/L or more.

16. The method of producing the metal ion adsorbent according to claim 14 , wherein the resultant of the solid separation in process (b) has an electric conductivity of 4.0 S/m or less when the resultant is dispersed in water such that a concentration of the resultant is 60 g/L.

17. The method of producing the metal ion adsorbent according to claim 14 , wherein the thermal treatment in process (c) is performed with a pH of from 3 to less than 7, at a temperature of 80° C. to 160° C. and for a time of within 96 hours.

18. The method of producing the metal ion adsorbent according to claim 14 , wherein in process (a), the solution that includes silicate ions has a silicon atom concentration of 100 mmol/L or more, the solution that includes aluminum ions has an aluminum atom concentration of 100 mmol/L, and the mixing is performed such that an element ration of the aluminum with to silicon, represented by Si/Al, is from 0.3 to 1.0 by molar ratio.

19. The method of producing the metal ion adsorbent according to claim 14 , wherein process (b) comprises a process of obtaining a dispersion by dispersing the reaction product in an aqueous medium and a process of performing solid separation with a pH of the dispersion adjusted to from 5 to 7.

Assignees

• Mikuni Hiroki
• Kawai Kiyoshi
• Hitachi Chemical Co Ltd

Inventors

• Mikuni Hiroki
• Kawai Kiyoshi

Classifications

• C01P2006/16

  Pore diameter · CPC title

• B01J20/28061

  being in the range 100-500 m2/g · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• B01J20/28078

  Pore diameter · CPC title

• C01P2006/12

  Surface area · CPC title