Ceramic particles for use in a solar power tower

Patent metadata

Field	Value
Publication number	US-10107523-B2
Application number	US-201615370978-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Dec 7, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

Ceramic particles for use in a solar power tower and methods for making and using the ceramic particles are disclosed. The ceramic particle can include a sintered ceramic material formed from a mixture of a ceramic raw material and a darkening component comprising MnO as Mn2+. The ceramic particle can have a size from about 8 mesh to about 170 mesh and a density of less than 4 g/cc.

First claim

What is claimed is:

1. A ceramic particle for use in a solar power tower, comprising:
a sintered ceramic material formed from a mixture of a ceramic raw material and manganese oxide, the ceramic particle having a size from about 8 mesh to about 170 mesh and a bulk density of less than 3 g/cc, wherein the mixture comprises from about 1 ppmw to about 0.5 wt % manganese oxide.

2. The ceramic particle of claim 1 , wherein the ceramic raw material comprises from about 0.1 wt % to about 50 wt % silica and from about 30 wt % to about 99 wt % alumina.

3. The ceramic particle of claim 1 , wherein the mixture further comprises about 0.1 wt % to about 20 wt % FeO.

4. The ceramic particle of claim 1 , wherein the ceramic particle has a surface roughness of less than 5 μm.

5. The ceramic particle of claim 1 , wherein the manganese oxide is selected from the group consisting of MnO, Mn 2 O 3 , and MnO 2 and any mixture thereof.

6. The ceramic particle of claim 5 , wherein exposure of the ceramic particle to solar heat energy in the solar power tower reduces a Munsell Value of the ceramic particle by at least about 0.1.

7. A solar power tower comprising the ceramic particle of claim 1 .

8. A method of manufacturing ceramic particles, comprising:
preparing a slurry comprising water, a binder, a first portion of a ceramic raw material, and manganese oxide, wherein the slurry comprises from about 1 ppmw to about 0.5 wt % manganese oxide;
atomizing the slurry into droplets;
coating seeds comprising a second portion of the ceramic raw material with the droplets to form a plurality of green pellets; and
sintering the green pellets to provide a plurality of ceramic particles, wherein the sintering oxidizes a first portion of the manganese oxide from MnO to Mn 2 O 3 .

9. The method of claim 8 , wherein the ceramic raw material comprises from about 0.1 wt % to about 50 wt % silica and from about 30 wt % to about 99 wt % alumina.

10. The method of claim 8 , wherein a second portion of the manganese oxide is oxidized from MnO to Mn 2 O 3 upon being subjected to solar heat energy in a solar power tower.

11. The method of claim 8 , wherein the slurry further comprises about 0.1 wt % to about 20 wt % iron oxide.

12. The method of claim 11 , wherein the sintering oxidizes a first portion of the iron oxide from FeO to Fe 2 O 3 .

13. The method of claim 12 , wherein a second portion of the iron oxide is oxidized from FeO to Fe 2 O 3 upon being subjected to solar heat energy in a solar power tower.

14. The method of claim 8 , wherein the plurality of ceramic particles has a Munsell value of at least 6 prior to exposure to solar heat energy in a solar power tower.

15. The method of claim 14 , wherein the plurality of ceramic particles has a Munsell value of less than 6 after exposure to the solar heat energy in the solar power tower.

16. A method of manufacturing ceramic particles, comprising:
providing a slurry of ceramic raw material, a reactant and manganese oxide, wherein the mixture comprises from about 1 ppmw to about 0.5 wt % manganese oxide;
flowing the slurry through a nozzle in a gas while vibrating the slurry to form droplets;
receiving the droplets in a vessel containing a liquid having an upper surface, the liquid containing a coagulation agent;
reacting the reactant with the coagulation agent to cause coagulation of the reactant in the droplets;
transferring the droplets from the liquid;
drying the droplets to form green pellets;
sintering the green pellets in a selected temperature range to form a plurality of ceramic particles.

17. The method of claim 16 , wherein the ceramic raw material comprises from about 0.1 wt % to about 50 wt % silica and from about 30 wt % to about 99 wt % alumina.

18. The method of claim 16 , wherein a second portion of the manganese oxide is oxidized from MnO to Mn 2 O 3 upon being subjected to solar heat energy in a solar power tower.

19. The method of claim 16 , wherein the darkening component further comprises about 0.1 wt % to about 20 wt % iron oxide.

20. The method of claim 19 , wherein the sintering oxidizes a first portion of the iron oxide from FeO to Fe 2 O 3 .

21. The method of claim 20 , wherein a second portion of the iron oxide is oxidized from FeO to Fe 2 O 3 upon being subjected to solar heat energy in a solar power tower.

Assignees

• Carbo Ceramics Inc
• Carbo Ceramics Inc

Inventors

• Krause Claude
• Eldred Benjamin
• Canova Steve

Classifications

• C04B2235/3265

  Mn2O3 · CPC title

• F24S70/16 Primary

  made of ceramic; made of concrete; made of natural stone · CPC title

• C04B35/63

  using additives specially adapted for forming the products {, e.g.. binder binders} · CPC title

• F24S80/20

  Working fluids specially adapted for solar heat collectors · CPC title

• C04B2235/77

  Density · CPC title