Ceramic particles for use in a solar power tower

Patent metadata

Field	Value
Publication number	US-11768013-B2
Application number	US-202017092506-A
Country	US
Kind code	B2
Filing date	Nov 9, 2020
Priority date	Dec 7, 2015
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

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 raw material and MnO. The sintered ceramic material can include about 0.01 wt % to about 10 wt % MnO, about 0.1 wt % to about 20 wt % Fe 2 O 3 , and about 0.01 wt % to about 10 wt % Mn 2 O 3 . The ceramic particle can have a size from about 8 mesh to about 170 mesh.

First claim

What is claimed is:

1. A ceramic particle for use in a solar power tower, comprising:
a ceramic material formed from a mixture comprising a raw material and MnO, wherein the raw material comprises kaolin or bauxite or a mixture thereof, and wherein the ceramic material further comprises:
about 0.01 wt % to about 10 wt % MnO,
about 0.1 wt % to about 20 wt % Fe 2 O 3 , and
about 0.01 wt % to about 10 wt % Mn 2 O 3 ; and
wherein the ceramic particle has a size of about 8 mesh to about 170 mesh.

2. The ceramic particle of claim 1 , wherein the mixture further comprises about 0.01 wt % to about 20 wt % FeO.

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

4. The ceramic particle of claim 1 , wherein the ceramic particle has a density of at least about 1.5 g/cc.

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

6. The ceramic particle of claim 1 , wherein the ceramic particle has a spherical shape.

7. 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.

8. The ceramic particle of claim 1 , wherein the mixture is formed into green pellets that are calcined to provide the ceramic material.

9. The ceramic particle of claim 1 , wherein the mixture is formed into green pellets that are dried and then sintered to provide the ceramic material.

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

11. A method of manufacturing ceramic particles for use in a solar power tower, comprising:
introducing a raw material and manganese oxide to a mixer, the raw material comprising about 0.1 wt % to about 50 wt % silica and about 30 wt % to about 99 wt % alumina;
stirring the raw material and manganese oxide to form a dry homogeneous particulate mixture having an average particle size of less than about 15 microns;
introducing water to the mixer to contact the dry homogeneous particulate mixture;
stirring the dry homogeneous particulate mixture with the water to cause formation of green pellets;
removing the green pellets from the mixer;
drying the green pellets to provide dried pellets; and
sintering the dried 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 .

12. The method of claim 11 , wherein the raw material comprises alumina, kaolin, or bauxite or mixtures thereof.

13. The method of claim 11 , further comprising subjecting the ceramic particles to solar heat energy in the solar power tower to oxidize a second portion of the manganese oxide from MnO to Mn 2 O 3 .

14. The method of claim 11 , 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. The method of claim 11 , wherein sintering comprises subjecting the dried pellets to a temperature between about 1,250° C. to about 1,550° C. for about 4 minutes to about 20 minutes.

17. A method of manufacturing ceramic particles for use in a solar power tower, comprising:
introducing a raw material and manganese oxide to a mixer;
introducing about 0.01 wt % to about 20 wt % FeO to the mixer;
stirring the raw material, manganese oxide, and FeO to form a dry homogeneous particulate mixture having an average particle size of less than about 15 microns;
introducing water to the mixer to contact the dry homogeneous particulate mixture;
stirring the dry homogeneous particulate mixture with the water to cause formation of green pellets;
removing the green pellets from the mixer;
drying the green pellets to provide dried pellets; and
sintering the dried 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 .

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 subjecting the ceramic particles to solar heat energy in a solar power tower.

Assignees

• Carbo Ceramics Inc

Inventors

• Krause Claude
• Eldred Benjamin
• Canova Steve

Classifications

• F24S70/16 Primary

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

• C04B33/04

  Clay; Kaolin · CPC title

• C04B35/1115

  Minute sintered entities, e.g. sintered abrasive grains or shaped particles such as platelets (abrasives C09K3/14) · CPC title

• C04B35/14

  based on silica · CPC title

• C04B35/18

  rich in aluminium oxide · CPC title