in Rolla, Mo .
Written in English
At head of title: The University of Missouri. School of Mines and Metallurgy.
|Statement||by Paul G. Herold, Leonard Stearns and William J. Smothers.|
|Series||The University of Missouri. School of Mines and Metallurgy. Bulletin. March, 1942. Technical series,, v. 14, no. 4|
|Contributions||Stearns, Leonard, joint author., Smothers, William Joseph, 1919- joint author.|
|LC Classifications||TA1 .M75 vol. 14, no. 4|
|The Physical Object|
|Pagination||51 p. incl. tables, diagrs.|
|Number of Pages||51|
|LC Control Number||42037363|
This chapter emphasizes the properties of refractory, heat insulation, and carbon cathode materials during their application in the aluminium industry. Standard test method for true specific gravity of refractory materials by water immersion. Google Scholar. Standard test method for the permeability of refractories. Google Scholar. Author: Andrey Yurkov. Table 1 summarizes the properties of the principal refractories. Their usefulness in considering the best material for the job can be illustrated by reference to specific materials. Thus high alumina (85%) may have been suggested as a probable improvement over medium alumina for a particular application – say the combustion chamber of a blast-furnace stove operating at °C . The permeability to air flow of high-Al2O3 ultra-low-cement refractory castables has been quantified by Darcy's law according to U.S. ASTM C–96 and European PREth permeability methods. The surface heat loss can be computed with the help of a simple relation up to °C surface temperature. S = [10 + (Ts-Ta) / 20] x [Ts-Ta] Where, S = Surface heat loss in kcal/hr m2 Ts = Hot surface temperature in °C Insulation & refractories - revised (table format)
Permeability is a very important property of refractory materials. Some examples include, the key role of permeability to gases in the dewatering of refractory castables,, ; in oxygen pick-up using a submerged nozzle during the continuous casting of steel ; and in the corrosion of refractory linings by gases (Na 2 O, K 2 O,) or slag,.Corrosion could be described as a reactive . the recommended procedure for measuring Bulk Density of insulation bricks (containing >40 % true porosity) (ISO and ASTM C). Specific Gravity (or Real Density) and Total Porosity In order to measure Specific Gravity (SG) (or Real Density), a refractory should first be finely. Properties of Refractories. satyendra; Decem ; 1 Comment ; bulk density, Cold modulus of ruptute, Hot modulus of rupture, PCE, PLC, porosity, specific heat, Thermal conductivity, Thermal shock resistance,; Properties of Refractories. Refractories are those materials which have high melting points and have properties which make them suitable to act as heat resisting . Fig 3 Creep curves of refractories. Volume stability, expansion and shrinkage at high temperature – Permanent change in the dimension of a refractory due to contraction and expansion during service can take place due to. The changes in the allotropic forms which cause a change in specific gravity.
Lightweight refractories of low thermal conductivity find wider applications in low temperature heat treatment furnaces, for example in batch type furnaces where the low heat capacity of the refractory structure minimizes the heat stored during the intermittent heating and cooling cycles. Insulating refractories have very low thermal conductivity. In Smithells Metals Reference Book (Eighth Edition), Design of refractory linings. A refractory lining usually comprises a safety or backup layer behind the working lining in contact with the furnace contents. The whole body is encased in a metal shell. The temperature gradients in the system and the properties of all materials must be considered. The gas permeability of a refractory fireclay structure is ten or a hundred times greater than that of the refractory itself. Gas permeability of a refractory structure based on cement-grog mortar with thick joints is quite low. The same structure involves 15–20% less labor compared with a structure based on mortars with thin (1– mm) joints. The permeability of refractories is a governing factor in the deterioration of blast-furnace linings by liquids and gases. Permeability tests there fore were performed on 17 carbon, 11 mullite,