| 摘要 |
<p>Properties of a green sand for casting composed of siliceous sand, bentonite and water can be improved by utilizing surface activating characteristics of a waste liquor from the pulp manufacturing process. When a pulp cooking waste liquor having a pH of 9 to 13 or a concentrate or powder thereof is incorporated into this green sand, the green strength, the flowability and the packing property are remarkably improved. The used green sand mold has a good disintegrating property and the handling of the return sand is performed very easily, and the temperature control of the return sand can be remarkably facilitated. Further, when this green sand composition is used, occurrence of such defects as buckles, scabs, sand marks and cuts is effectively prevented. When an aluminum ion or transition metal ion is incorporated together with the pulp cooking waste liquor, the foregoing effects are further enhanced.</p> |
