Ceramic particles for use in a solar power tower

Patent metadata

Field	Value
Publication number	US-10830497-B2
Application number	US-201816167317-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Dec 7, 2015
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

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 MnO, 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 sintered ceramic material comprises Mn 2 O 3 and Fe 2 O 3 , 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.

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

3. The ceramic particle of claim 1 , further comprising a spherical shape.

4. The ceramic particle of claim 3 , 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.

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

6. 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 MnO, 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 sintered ceramic material comprises Mn 2 O 3 and Fe 2 O 3 , wherein the mixture further comprises about 0.1 wt % to about 20 wt % FeO.

7. 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;
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 .

8. The method of claim 7 , 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.

9. The method of claim 7 , 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.

10. The method of claim 7 , wherein the slurry further comprises about 0.1 wt % to about 20 wt % iron oxide.

11. The method of claim 10 , wherein the sintering oxidizes a first portion of the iron oxide from FeO to Fe 2 O 3 .

12. The method of claim 11 , 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.

13. The method of claim 7 , 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.

14. The method of claim 13 , 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.

15. A method of manufacturing ceramic particles, comprising:
providing a slurry of ceramic raw material, a reactant and MnO, 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;
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, wherein the sintering oxidizes a first portion of the MnO to Mn 2 O 3 .

16. The method of claim 15 , wherein a second portion of the MnO is oxidized to Mn 2 O 3 upon being subjected to solar heat energy in a solar power tower.

17. A method of manufacturing ceramic particles, comprising:
providing a slurry of ceramic raw material, a reactant and MnO, wherein the slurry further comprises about 0.1 wt % to about 20 wt % iron 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, wherein the sintering oxidizes a first portion of the MnO to Mn 2 O 3 .

18. The method of claim 17 , wherein the sintering oxidizes a first portion of the iron oxide from FeO to Fe 2 O 3 .

19. The method of claim 18 , 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

Inventors

• Krause Claude
• Eldred Benjamin
• Canova Steve

Classifications

• C04B35/64

  Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) · CPC title

• C04B2235/77

  Density · CPC title

• C04B2235/3272

  Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite · CPC title

• C04B35/62886

  by wet chemical techniques · CPC title

• C04B35/62204

  using waste materials or refuse (clay-wares containing waste materials C04B33/132) · CPC title