Abstract: The invention is embodied in a workable binder which contains silica fume as the binding agent, and which uses alkali metal silicates, either hydrated or anhydrous or a combination thereof, as a hardening agent. The binder further includes a tempering or workability agent to facilitate handling. When mixed with aggregate, the binder can be used in a variety of refractory or construction applications to form a strong castable product having high strength without the use of calcareous components.

Abstract: Novel compositions are disclosed for the manufacture of gunning mixes and strong castable products for use as monolithic refractory and construction materials which may contain no lime bearing cements. Bonding is based on the setting reaction of fumed silica with an alkali metal silicate preferably a particulate sodium or potassium silicate that slowly dissolves in water such as an anhydrous sodium silicate of SiO.sub.2 :Na.sub.2 O molar ratio of 1:1 to 4:1; or an anhydrated potassium silicate having an SiO.sub.2 :K.sub.2 O molar ratio of 3:1, or a hydrated sodium silicate having an SiO.sub.2 :Na.sub.2 O molar ratio of 3:1. Setting and mechanical characteristics allow this class of castable and gun mixes to be placed more rapidly into service since the time required for curing is much less. Although initial set strengths are not as high as those of conventional castables, very high strengths can be made to occur shortly after setting by heating.

Abstract: A composition blending carbon with powdered chromium oxide in an alumina or aluminum silicate matrix, including silicon metal powder to inhibit carbon oxidation, is more advantageous in resisting molten iron and slags than refractories based on carbon or chrome additions not combined. The resultant refractory mixes are suitable for all conventional application methods.

Abstract: A composition blending carbon or graphite with powdered chromium oxide in a high alumina matrix, including silicon metal powder to inhibit carbon oxidation, is more advantageous in resisting molten iron and slags than refractories based on carbon or chrome additions not combined. The resultant refractory mixes are suitable for all conventional application methods.

Abstract: Refractory compositions containing alumina or aluminum silicate and a phosphate bonding agent can be improved by the addition of from 0.2 to 1.5 percent tetrasodium pyrophosphate (TSPP) in combination with bentonite. The TSPP minimizes the amount of bentonite required for good workability in aqueous formulations for ramming or hand applications, thereby miximizing density and minimizing water required for tempering, also extending the storage life of these refractories and maintaining a high percentage of initial workability over a period of several months.

Abstract: A plastic refractory lining composition which can be applied by hand or trowel to refractory or bare metal surfaces and is particularly resistant to slag and hot metal erosion and to metal skulling is comprised of a blend of high alumina or aluminum silicate coarse aggregates with a fine matrix of calcined alumina, carbon, and bentonite employing a phosphate binder and tetrasodium pyrophosphate for modification and stabilization of plasticity characteristics. Finely divided silicon metal can be included to impart oxidation resistance to the carbon. This refractory is sufficiently "sticky" for ease of building a lining.

Abstract: High alumina, phosphate containing refractory plastic composition suitable for placement by mechanical vibration using molding techniques are maximized in density and shelf life while requiring minimum water content for ease of placement through the combining of a relatively low content of bentonite with a small addition of tetrasodium pyrophosphate. The resulting compositions are easy to place by vibration with minimal tendency to slump on removal of forms.