Loading patent…
AssigneeThe J. E. Baker Company
InventorJames W. Stendera
Estimating the term…
Satisfactory bonding of refractory aggregate is obtained by providing the aggregate with at least 5.0% by weight of free CaO of minus 200 mesh (Tyler Standard Sieve) particle size, adding a small amount of a lithium compound to the aggregate and heating to a temperature of about 450.degree. C. The modulus of rupture at room temperature of a brick made from dead burnt dolomite aggregate containing a fine fraction providing the finely divided CaO and the lithium compound additive and fired to 450.degree. C. is well above 400 psi and may be substantially equivalent to that of a brick made of the same aggregate without the lithium compound additive and fired to 1200.degree. C. The invention comprises the method of increasing the low temperature bonding strength of refractory aggregates, the unfired mixtures of the refractory aggregate containing the requisite CaO and the lithium compound with or without temporary liquid or solid binding agents, and the fired products made therefrom.
A method for improving the low temperature bonding of refractory products comprising dry mixing a refractory aggregate comprising at least about 5% free CaO of less than 200 mesh size (Tyler Standard Sieve) with from about 0.1 to 5.0% by weight, based on the weight of the aggregate, of a finely divided solid lithium compound which does not decompose with evolution of water or other detrimental decomposition products upon heating, optionally adding a temporary non-aqueous binder to the mixture, emplacing, shaping and/or compacting the mixture and heating the emplaced, shaped and/or compacted mixture at a temperature in the range of from 400.degree. C. to 1200.degree. C.
An unfired refractory composition having low temperature bonding properties comprising a refractory aggregate containing at least about 5% by weight free CaO of less than 200 mesh (Tyler Standard sieve) particle size and having from about 0.1 to 5.0% by weight, based on the total weight of the aggregate, of a finely divided solid lithium compound which does not decompose with evolution of water or other detrimental decomposition products upon heating dry mixed therewith.
Dependencies are inferred from the claim text.