Ceramic foundry media and related methods

Patent metadata

Field	Value
Publication number	US-12031089-B2
Application number	US-202117329292-A
Country	US
Kind code	B2
Filing date	May 25, 2021
Priority date	Jul 31, 2014
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

Ceramic foundry media is provided. The ceramic foundry media have a size of about 80 mesh to about 10 mesh, an average largest pore size of less than about 20 microns, and a surface roughness of less than about 4 microns. The ceramic foundry media are formed by drip casting. A slurry of finely divided particles is flowed through nozzles and formed into droplets under the influence of vibration. Uniform sized, smooth surface, spherical green particles are formed. The green particles are dried and sintered to form the foundry media.

First claim

What is claimed is:

1. A method, comprising:
providing a slurry of ceramic raw material, the slurry comprising a polysaccharide, a dispersant, and a pH-adjusting agent, wherein the slurry has a solids content from about 25 wt % to about 75 wt %; wherein the slurry has a viscosity of less than 150 cP and a pH of about 9 to about 10.5;
flowing the slurry through a nozzle while vibrating the slurry to form droplets in a surrounding gas to form droplets having a substantially spherical shape, wherein the slurry of ceramic raw material flows through the nozzle at a rate of about 1 to about 15 kg/(mm 2 ×hr);
gelling the droplets upon contact with a liquid to provide gelled droplets, wherein the liquid comprises a coagulation agent;
transferring the gelled droplets from the liquid;
drying the gelled droplets to form green pellets;
sintering the green pellets in a selected temperature range to form sintered pellets;
introducing the sintered pellets to a mixing vessel, the mixing vessel comprising a chemical treatment agent solution; and
introducing microwave energy to the mixing vessel comprising the sintered pellets and the chemical treatment agent solution.

2. The method of claim 1 , wherein the polysaccharide is an alginate.

3. The method of claim 1 , wherein the coagulation agent is calcium chloride.

4. The method of claim 1 , wherein the reactant and the coagulation agent react to form a semi-solid surface on the droplets.

5. The method of claim 1 , wherein the slurry is vibrated as it flows from the nozzle by vibrating the nozzle.

6. The method of claim 1 , wherein the ceramic raw material is selected from the group consisting of bauxite, kaolin, alumina, and mixtures thereof.

7. The method of claim 1 , wherein the gas is air.

8. The method of claim 1 , wherein the sintered pellets have an average largest pore size of less than about 20 microns.

9. The method of claim 1 , wherein the sintered pellets have an average roughness of less than about 2 microns.

10. The method of claim 1 , wherein the sintered pellets are formed without subjecting the droplets to a sol-gel reaction.

11. The method of claim 1 , wherein the green pellets are sintered at a temperature in the range from about 1400° C. to about 1650° C.

12. The method of claim 1 , wherein sintering the green pellets comprises introducing the green pellets to a gas-fired rotary kiln.

13. The method of claim 1 , wherein sintering the green pellets comprises introducing the green pellets to a microwave furnace.

14. The method of claim 1 , wherein the dispersant comprises about 0.05% to about 0.45% by weight of the slurry based on the dry weight of the ceramic raw material.

15. The method of claim 1 , wherein the dispersant is selected from the group consisting of sodium polyacrylate, ammonium polyacrylate, ammonium polymethacrylate, tetra sodium pyrophosphate, tetra potassium pyrophosphate, polyphosphate, ammonium polyphosphate, ammonium citrate, ferric ammonium citrate, ammonium polymethacrylate, and combinations thereof.

16. The method of claim 1 , wherein the pH-adjusting agent is selected from the group consisting of ammonia, sodium carbonate, and combinations thereof.

17. The method of claim 1 , wherein the chemical treatment agent solution comprises a chemical treatment agent and a carrier.

18. The method of claim 17 , wherein the chemical treatment agent solution comprises about 5 wt % to about 65 wt % of the chemical treatment agent.

19. The method of claim 17 , wherein the chemical treatment agent solution comprises about 35 wt % to about 85 wt % carrier.

20. The method of claim 1 , wherein the microwave energy is provided by a first microwave generator and a second microwave generator.

Assignees

• Carbo Ceramics Inc

Inventors

• Howe Steven C
• Cannan Chad
• Roper Todd

Classifications

• C09K2208/32

  Anticorrosion additives · CPC title

• C09K2208/22

  Hydrates inhibition by using well treatment fluids containing inhibitors of hydrate formers · CPC title

• C09K2208/20

  Hydrogen sulfide elimination · CPC title

• C09K2208/12

  Swell inhibition, i.e. using additives to drilling or well treatment fluids for inhibiting clay or shale swelling or disintegrating · CPC title

• C09K2208/10

  Nanoparticle-containing well treatment fluids · CPC title