Casting elements and methods of making the same using low temperature solidification

Patent metadata

Field	Value
Publication number	US-12285797-B2
Application number	US-202017757950-A
Country	US
Kind code	B2
Filing date	Dec 24, 2020
Priority date	Dec 24, 2019
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

Foundry casting elements and methods of forming the same, the methods including: forming an aqueous slurry including an inorganic binder precursor, shaping the slurry using a pattern, curing the shaped slurry using a low temperature solidification process to form a casting element, and removing the pattern from the casting element.

First claim

What is claimed is:

1. A method of forming a foundry casting element, the method comprising:
forming an aqueous slurry comprising a solid inorganic binder material or a precursor thereof;
packing the slurry against a pattern to form a shaped slurry;
curing the shaped slurry at a temperature of less than 350° C. to form a casting element;
removing the pattern from the casting element,
wherein the solid inorganic binder material comprises at least one component selected from the group consisting of magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium carbonate hydrate, calcium oxide, calcium hydroxide, calcium carbonate, mono-calcium silicate, di-calcium silicate, tri-calcium silicate, calcium aluminate, calcium aluminosilicate, and a rare earth oxide,
wherein the curing comprises infiltrating the shaped slurry with CO 2 at a temperature ranging from about 15° C. to about 350° C. and at a pressure ranging from about 0.5 psig to about 5,000 psig, and
wherein the slurry optionally comprises an inert component selected from the group consisting of oxide sands, diamond, graphite, carbon black, graphene, graphene oxide, metal carbides, silicon carbide, boron carbide, tungsten carbide, niobium carbide, titanium boride, zirconium boride, zirconia, titania, alumina, olivine, diopside, garnet, spinel, quartz, cristobalite, tridymite, calcium carbonate and dolomite, wherein the inert component does not react with the binder material or the precursor thereof.

2. The method of claim 1 , wherein the curing occurs only after the slurry is shaped.

3. The method of claim 1 , wherein:
the at least one component is combined with one or more of clay, colloidal silica, and one or more elements selected from the group consisting of magnesium, aluminum, iron, zinc, zirconium, titanium, vanadium, yttrium, lithium, sodium, potassium, bismuth, cerium, strontium, calcium, barium, lanthanum, copper, and boron, wherein the one or more elements are in a form of oxide, hydroxide and/or hydrous oxide; and
the slurry further comprises H 3 PO 4 and a refractory sand.

4. The method of claim 1 , wherein:
the at least one component is combined with one or more of clay, colloidal silica, and one or more elements selected from the group consisting of magnesium, aluminum, iron, zinc, zirconium, titanium, vanadium, yttrium, lithium, sodium, potassium, bismuth, cerium, strontium, calcium, barium, lanthanum, copper, and boron, wherein the one or more elements are in a form of oxide, hydroxide and/or hydrous oxide.

5. A method of forming a foundry casting element, the method comprising: forming an aqueous first slurry comprising a refractory sand, colloidal silica and a binding polymer;
forming an aqueous second slurry comprising a solid inorganic binder material and a thermoreversible additive;
applying the first slurry to a pattern to form a first coating;
heating the second slurry to a temperature ranging from about 40° C. to about 250° C.;
dipping the pattern into the heated second slurry to form a second coating on the first coating;
gelating the second coating by allowing the second coating to cool to a temperature below about 40° C.; and
infiltrating the first coating and the second coating with CO 2 to cure the first coating and the second coating to form a casting element with two coating layers;
wherein the first slurry and/or second slurry optionally comprises an inert component selected from the group consisting of oxide sands, diamond, graphite, carbon black, graphene, graphene oxide, metal carbides, silicon carbide, boron carbide, tungsten carbide, niobium carbide, titanium boride, zirconium boride, zirconia, titania, alumina, olivine, diopside, garnet, spinel, quartz, cristobalite, tridymite, calcium carbonate and dolomite, wherein the inert component does not react with the binder material or the binding polymer.

6. The method of claim 5 , wherein the dipping and the gelating are performed at least twice to form a three-layer structure.

7. The method of claim 5 , wherein the refractory sand comprises a zircon sand;
wherein the method further comprises applying additional zircon sand to the first coating; and
the solid inorganic binder material comprises at least one component selected from the group consisting of magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide, mono-calcium silicate, di-calcium silicate, tri-calcium silicate, calcium aluminate, calcium aluminosilicate, and a rare earth oxide.

8. A method of forming a foundry casting element, the method comprising:
forming an aqueous slurry comprising a solid inorganic oxide material; and
infiltrating the slurry with CO 2 to at least partially convert the solid inorganic oxide material to a solid inorganic carbonate material and to form a refractory element for bricks, or castable, gunning, or ramming mixes;
wherein the foundry casting element optionally comprises an inert component selected from the group consisting of oxide sands, diamond, graphite, carbon black, graphene, graphene oxide, metal carbides, silicon carbide, boron carbide, tungsten carbide, niobium carbide, titanium boride, zirconium boride, zirconia, titania, alumina, olivine, diopside, garnet, spinel, quartz, cristobalite, tridymite, calcium carbonate and dolomite, wherein the inert component does not react with the inorganic oxide material,
wherein the CO 2 is infiltrated at a temperature ranging from about 15° C. to about 350° C. and at a pressure ranging from about 0.5 psig to about 5,000 psig.

9. The method of claim 8 , wherein the solid inorganic oxide material comprises CaSiO 3 , and the infiltrating the slurry with CO 2 at least partially converts the CaSiO 3 to a calcium carbonate in a sand mold foundry casting element.

10. The method of claim 8 , wherein:
the solid inorganic oxide material comprises MgO; and
infiltrating the shaped slurry with CO 2 partially converts the MgO to magnesium carbonate to form a refractory element for bricks, or castable, gunning or ramming mixes;
wherein the MgO particles are bonded to each other by magnesium carbonate particles, wherein the MgO particles are larger than the magnesium carbonate particles.

11. The method of claim 8 , wherein the slurry comprises the inert component and the resulting refractory element for bricks, or castable, gunning, or ramming mixes is admixed with the inert component.

12. The method of claim 8 , wherein the slurry comprises a silica sand, an olivine sand, a chromate sand, a zircon sand, a chamotte sand, aluminosilicate sand, or any combinations thereof.

Assignees

• Univ Rutgers

Inventors

• Riman Richard E
• Blinn Kevin

Classifications

• B22C1/18

  of inorganic agents {(B22C1/162 takes precedence)} · CPC title

• B22C9/123 Primary

  Gas-hardening · CPC title

• B22C9/061

  Materials which make up the mould · CPC title

• B22C9/04

  Use of lost patterns · CPC title

• B22C3/00

  Selection of compositions for coating the surfaces of moulds, cores, or patterns · CPC title