| Description |
vi, 67 leaves : illustrations, photographs ; 29 cm |
| Summary |
"The crystallization process in a zirconia-alumina- silica melt of high viscosity was studied, A system was used of the same composition found in commercial electrocast glass tank refractories. Artificial nucleation was tried in an attempt to control the process of crystallization; the method involved the addition of suitable "seeding" material. It was found that introduction of nucleation agents consisting of the major component oxides of the system had noted effect upon the course of crystallization. Preferred orientation normally found in unseeded electrocast refractories was diminished with the addition of zirconia grains and amplified with particles of tabular alumina. Results obtained point to two different courses to be followed in further investigations depending upon the users of electrocast refractories. Melts seeded with zirconia produced blocks in which partial or complete elimination of an undesirable shrinkage cavity was attained. The term block is used for fusion cast test blocks having dimensions of 12" x 12" x 6" These blocks had an increased porosity, but maintained their structural soundness. Tabular alumina was used as a nucleating agent resulting in a block of very dense structure with a large central shrinkage cavity"--Abstract, leaf vi. |
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