Compositions comprising oxidized materials for sand casting and methods of preparation and use thereof

Abstract

Compositions useful for green sandcasting are discussed, as well as methods of preparing and using such compositions. Binder compositions may comprise a carbonaceous material, an inorganic binding agent, and a high aspect ratio silicate, wherein at least one of the carbonaceous material or the inorganic material in the binder composition may be oxidized. For example, the inorganic binding agent may be oxidized with a ratio of ferrous iron (Fe2+) to ferric iron (Fe3+) less than 1.2. or less than 1. Green sand prepared from such binder compositions may exhibit a reduction in emissions during sandcasting.

1 . A binder composition comprising:
 a carbonaceous material;   an inorganic binding agent; and   a high aspect ratio silicate;   wherein at least one of the carbonaceous material or the inorganic binding agent is oxidized.   
     
     
         2 . A binder composition according to  claim 1 , wherein:
 the inorganic binding agent is an oxidized inorganic binding agent; and   the inorganic binding agent has a ratio of Fe 2+  to Fe 3+  less than 1.2.   
     
     
         3 . A binder composition according to  claim 1 , wherein:
 the carbonaceous material is an oxidized carbonaceous material is prepared by treatment with an oxidation agent.   
     
     
         4 . The binder composition of  claim 3 , wherein the oxidation agent comprises soda ash, hydrogen peroxide, ozone, or a combination thereof. 
     
     
         5 . The binder composition of  claim 1 , wherein a ratio of Fe 2+ /Fe 3+  of the inorganic binding agent is less than 1. 
     
     
         6 . The binder composition of  claim 1 , wherein the inorganic binding agent comprises sodium bentonite, calcium bentonite, or a mixture thereof. 
     
     
         7 . The binder composition of  claim 1 , wherein the composition comprises from about 70% by weight to about 90% by weight of the inorganic binding agent. 
     
     
         8 . The binder composition of  claim 1 , wherein the carbonaceous material comprises oxidized coal (optionally oxidized lignite coal, oxidized bituminous coal, or oxidized sea coal), oxidized lignite, oxidized leonardite, oxidized graphite, oxidized anthracite, oxidized cellulose, or a combination thereof. 
     
     
         9 . The binder composition of  claim 1 , wherein the composition comprises from about 0.1° A by weight to about 20.0% by weight of the carbonaceous material. 
     
     
         10 . (canceled) 
     
     
         11 . The binder composition of  claim 1 , wherein the high aspect ratio silicate comprises mica or talc. 
     
     
         12 . The binder composition of  claim 1 , wherein the binder composition comprises from about 0.1% A by weight to about 5.0% by weight of the high aspect ratio silicate. 
     
     
         13 . The binder composition of  claim 1 , wherein the high aspect ratio silicate comprises muscovite, paragonite, lepidolite, phlogopite, biotite, or a combination thereof. 
     
     
         14 . A green sand composition comprising the binder composition of  claim 1  and an aggregate. 
     
     
         15 . The green sand composition of  claim 14 , wherein the aggregate comprises silica sand, zircon sand, an aluminosilicate, or a mixture thereof. 
     
     
         16 . A method of preparing a foundry composition, the method comprising preparing a binder composition by:
 oxidizing a carbonaceous material; and   combining the oxidized carbonaceous material with an inorganic binding agent.   
     
     
         17 . The method of  claim 16 , wherein oxidizing the carbonaceous material includes treating the carbonaceous material with an oxidation agent. 
     
     
         18 . The method of  claim 17 , wherein the oxidation agent comprises soda ash, hydrogen peroxide, ozone, or a combination thereof. 
     
     
         19 . The method of  claim 18 , further comprising combining the oxidized carbonaceous material with a high aspect ratio silicate before, after, or at the same time as combining the oxidized carbonaceous material with the inorganic binding agent. 
     
     
         20 . The method of  claim 16 , wherein a ratio of Fe 2+  to Fe 3+  of the inorganic binding agent is less than 1.2. 
     
     
         21 . The method of  claim 20 , further comprising adding an aggregate and water to the binder composition to form a green sand composition, optionally wherein the green sand composition has a green compression strength ranging from about 21.5 N/m 2  to about 30.5 N/m 2  and a green shear strength ranging from about 2.5 N/m 2  to about 3.7 N/m 2 . 
     
     
         22 - 26 . (canceled)