Granulation of refractory oxides and the properties of the granules produced

Abstract

In the construction of the core, the following must be taken into account: a downward taper of roughly 1-10% caused by the shrinkage of the ingot as it cools; the possibility of collapsing across a section if the core is squeezed when the ingot crystallizes; the possibility of independent movement relative to the immobile crucible when selecting the optimum level of installation of the core; and the use of screens to protect the pipes bringing water to the core since these pass through the zone of radiation from the melt.We melted shaped blocks under laboratory conditions in high-frequency equipment one of which had a power of 60 kW and a frequency of 5.28 MHz while the other had a rating of 120 kW at 1.76 MHz. In the first equipment we obtained rectangular mullite, corundum, and baddeleyite-corundum blocks of maximum section 200 • 220 mm and also pipe-shaped blocks and arched muffles of corundum with a maximum section of 220 • 250 mm and a wall thickness of 20 mm (Fig. 5). In the second equipment we melted blocks of magnesial spinel, forsterite, and mullite with a maximum section of 300 • 300 mm and length up to 1600 ram.In order to prevent descruction by thermoelastic stresses, the blanks were heat treated or cooled slowly. CONCLUSIONSIt is shown that the use of induction melting of oxide materials in a cold crucible makes it possible to achieve a high-productivity process for melting into blocks or with discharge for the production of fused material for industrial refractories and also to provide fused blanks for lining blocks and arched muffles.

Feasibility and prospects for the use of digital technologies in the audit of a testing laboratory

“…Authors in [3] observe the methodological approach for conducting RA of QMS when checking compliance with the requirements of the standards governing the functioning of the organization QMS; they give recommendations for drawing up an audit plan. The key issues of the work [4] are the organization of RA and the need for special training of expert auditors to conduct inspections of the production state and production management systems.…”

Production and use of ?-alumina

“…Comparison of the corundum chamotte and spheres of GKOI alumina with similar articles obtained from GK [4] suggests that the alumina in the u-form produced at PAZ can be used to obtain good-quality articles and dense briquet of high purity. Open porosity, % Water absorption, %…”