Compositions and methods of use thereof in sandcasting
Compositions useful for foundry processes such as green sandcasting are discussed. The compositions may include ball clay, bentonite, and a carbonaceous material. The ball clay may include leonardite and/or causticized lignite, e.g., as a portion of the natural ball clay deposit. The composition may further include sand, such that the resulting mixture may be formed into a green sand mold for use in casting molded articles. Incorporation of ball clay materials in the compositions may help to improve the quality of the casted article.
1. A binder composition comprising:
ball clay;
bentonite; and
a carbonaceous material;
wherein the carbonaceous material comprises sea coal and/or leonardite.
2. The composition of claim 1 , wherein the ball clay further comprises causticized lignite.
3. The composition of claim 1 , wherein the ball clay has a loss on ignition (LOI) ranging from about 12% to about 50%.
4. The composition of claim 1 , wherein the ball clay comprises a first ball clay material having a loss on ignition (LOI) greater than about 9% and less than or equal to 12%, and a second ball clay material having an LOI greater than 12% and less than about 60%.
5. The composition of claim 1 , wherein the ball clay comprises from about 15% to about 35% alumina by weight with respect to the total weight of the ball clay.
6. The composition of claim 1 , wherein the ball clay comprises from about 30% to about 60% silica by weight with respect to the total weight of the ball clay.
7. The composition of claim 1 , wherein the ball clay comprises a first portion of leonardite or causticized lignite from a natural deposit of ball clay material, and wherein the carbonaceous material comprises a second portion of leonardite.
8. The composition of claim 1 , wherein the composition comprises from about 1% to about 70% bentonite by weight with respect to the total weight of the composition.
9. The composition of claim 1 , wherein the composition comprises from about 10% to about 40% ball clay by weight and from about 30% to about 60% bentonite by weight with respect to the total weight of the composition, and wherein the ball clay comprises from about 1% to about 10% of leonardite or causticized lignite.
10. A method of sand casting, the method comprising:
preparing a mixture by combining ball clay, bentonite, a carbonaceous material, and sand; and
preparing a mold by forming the mixture into a shape;
wherein the carbonaceous material comprises sea coal and/or leonardite.
11. The method of claim 10 , wherein the ball clay further comprises causticized lignite.
12. The method of claim 10 , wherein the ball clay, the bentonite, and the carbonaceous material comprise a binder composition, and preparing the mixture includes adding the binder composition to the sand.
13. The method of claim 12 , wherein the binder composition comprises from about 5% to about 20% by weight with respect to the total weight of the mixture.
14. The method of claim 10 , wherein the mixture comprises water providing for a moisture content ranging from about 1.5% to about 5.0% by weight with respect to the total weight of the mixture.
15. The method of claim 10 , wherein forming the mixture into the shape includes forming the mixture around a pattern, and removing the pattern to leave a cavity.
16. The method of claim 10 , wherein the mixture has a green compression strength ranging from about 10.0 N/cm 2 to about 15 N/cm 2 .
17. The method of claim 10 , wherein the mixture has a hot compression strength ranging from about 300 N/cm 2 to about 415 N/cm 2 at a temperature between 950° C. and 1100° C.
18. The method of claim 10 , further comprising:
introducing a metal or metal alloy into the mold to form a casted article; and
removing the casted article from the mold.