초록 ▼

Refractory foundry ladle liners made from castable magnesium oxide-based compositions are disclosed. The liner compositions include MgO-containing aggregate, Al2O3-containing aggregate, and an inorganic binder. The ladle liners are cast into shape, placed into ladle shells, and packed with sand. The

Refractory foundry ladle liners made from castable magnesium oxide-based compositions are disclosed. The liner compositions include MgO-containing aggregate, Al2O3-containing aggregate, and an inorganic binder. The ladle liners are cast into shape, placed into ladle shells, and packed with sand. The foundry ladle assemblies, including the pre-cast MgO-based ladle liners, are reusable for multiple foundry operations.

대표청구항 ▼

1. A pre-cast refractory ladle liner for use in a foundry ladle assembly comprising: at least 50 weight percent MgO aggregate based on the total weight of the liner;from 10 to 40 weight percent Al2O3 aggregate;from 1 to 30 weight percent inorganic binder; andfrom 1 to 20 weight percent of a non-oxid

1. A pre-cast refractory ladle liner for use in a foundry ladle assembly comprising: at least 50 weight percent MgO aggregate based on the total weight of the liner;from 10 to 40 weight percent Al2O3 aggregate;from 1 to 30 weight percent inorganic binder; andfrom 1 to 20 weight percent of a non-oxide ceramic additive. 2. The pre-cast refractory ladle liner of claim 1, wherein the MgO aggregate comprises from 60 to 90 weight percent of the liner. 3. The pre-cast refractory ladle liner of claim 1, wherein the MgO aggregate comprises from 65 to 85 weight percent of the liner. 4. The pre-cast refractory ladle liner of claim 1, wherein the MgO aggregate comprises at least 90 weight percent periclase. 5. The pre-cast refractory ladle liner of claim 4, wherein the MgO aggregate further comprises CaO and SiO2. 6. The pre-cast refractory ladle liner of claim 5, wherein the weight ratio of CaO:SiO2 is greater than 1:1. 7. The pre-cast refractory ladle liner of claim 1, wherein the Al2O3 aggregate comprises from 10 to 12 weight percent of the liner. 8. The pre-cast refractory ladle liner of claim 1, wherein the Al2O3 aggregate comprises at least 90 weight percent calcined alumina. 9. The pre-cast refractory ladle liner of claim 1, wherein the inorganic binder comprises calcium aluminate cement, hydratable alumina, colloidal silica, sodium silicate, potassium silicate, aluminum sulfate, magnesium sulfate, or a combination thereof. 10. The pre-cast refractory ladle liner of claim 1, wherein the inorganic binder comprises calcium aluminate cement. 11. The pre-cast refractory ladle liner of claim 1, wherein the inorganic binder comprises from 2 to 10 weight percent of the liner. 12. The pre-cast refractory ladle liner of claim 1, wherein the non-oxide ceramic additive comprises at least one carbide or nitride in an amount of from 1 to 10 weight percent of the liner. 13. The pre-cast refractory ladle liner of claim 1, further comprising from 0.05 to 2 weight percent of a polymeric dispersant additive. 14. A foundry ladle assembly comprising: a metal shell;a pre-cast refractory ladle liner inside the shell comprising: at least 50 weight percent MgO aggregate based on the total weight of the liner;from 10 to 40 weight percent Al2O3 aggregate;from 1 to 30 weight percent inorganic binder; andfrom 1 to 20 weight percent of a non-oxide ceramic additive; andsand at least partially filling a space between the shell and the pre-cast refractory ladle liner. 15. A method of making a pre-cast refractory ladle liner for use in a foundry ladle assembly, the method comprising: mixing MgO aggregate, Al2O3 aggregate, inorganic binder and non-oxide ceramic additive and water to produce a mixture, wherein the MgO aggregate comprises from 50 to 95 weight percent, the Al2O3 aggregate comprises from 2 to 40 weight percent, the inorganic binder comprises from 1 to 30 weight percent, and the non-oxide ceramic additive comprises from 1 to 20 percent based on the total dry weight of the mixture;introducing the mixture into a mold in a shape of a ladle liner;vibrating the mold during or after the step of introducing the mixture into the mold;allowing the mixture to set; andremoving the set mixture from the mold in the shape of the ladle liner. 16. The method of claim 15, further comprising placing the pre-cast ladle liner into a metal shell, and filling space between the shell and the pre-cast ladle liner with sand to produce the foundry ladle assembly. 17. The method of claim 15, wherein the Al2O3 aggregate comprises at least 10 weight percent based on the total dry weight of the mixture. 18. A pre-cast refractory ladle liner for use in a foundry ladle assembly comprising: at least 50 weight percent MgO aggregate based on the total weight of the liner;from 10 to 40 weight percent Al2O3 aggregate;from 1 to 30 weight percent inorganic binder; andgreater than 0.05 weight percent polymeric dispersant additive. 19. A foundry ladle assembly comprising: a metal shell;a pre-cast refractory ladle liner inside the shell comprising: at least 50 weight percent MgO aggregate based on the total weight of the liner;from 10 to 40 weight percent Al2O3 aggregate;from 1 to 30 weight percent inorganic binder; andgreater than 0.05 weight percent polymeric dispersant additive; andsand at least partially filling a space between the shell and the pre-cast refractory ladle liner. 20. A method of making a pre-cast refractory ladle liner for use in a foundry ladle assembly, the method comprising: mixing MgO aggregate, Al2O3 aggregate, inorganic binder, polymeric dispersant additive and water to produce a mixture, wherein the MgO aggregate comprises from 50 to 95 weight percent, the Al2O3 aggregate comprises from 2 to 40 weight percent, the inorganic binder comprises from 1 to 30 weight percent, and the polymeric dispersant additive comprises from 0.05 to 2 weight percent based on the total dry weight of the mixture;introducing the mixture into a mold in a shape of a ladle liner;vibrating the mold during or after the step of introducing the mixture into the mold;allowing the mixture to set; andremoving the set mixture from the mold in the shape of the ladle liner.