When It Was Determined That The Increase Of Highly Reactive Volatilized Or Fume Silica To A Castable Would Dramatically Change The Physical Characteristics, A New Family Of Castables Resulted. These Dense Durable Refractory Castables, Based On The Use Of Low Calcium Aluminate Cement Content, Have Replaced Many Conventional Castables, Plastics, Ramming And Gunning Mixes And Are Used In Many Applications That Require High Refractoriness, Corrosion Resistance, And Abrasion Resistance. These Castables Maintain A Stable Composition With Low Porosity And Have High-Temperature Strength Ultimately The Low And Moderate Temperature Range. Today Practically Every Refractory Castable Manufacturer Has A Complete Line Of These Low Cement Castables, Ultra-Low Cement, And No Cement Castables. These Low Cement-Type Castables Discover Many Applications Through Industry Including The Steel, Iron And Steel Foundries, Aluminum Furnaces And Other Non-Ferrous Metals, Rotary Kilns, Incinerators And Also For Making Precast Shapes. The Energy Which Is Developed In These Castables Is Often Equal To Or Greater Than Fired Products.