Heat resisting coating composition and method of applying it to the basic refractory surface of a furnace

Claim 1

A COATING COMPOSITION ADAPTED TO BE SPRAYED ONTO THE HOT BASIC REFRACTORY MATERIAL FORMING THE INNER SURFACE OF A HIGH TEMPERATURE FURNACE WHILE THE FURNACE IS IN OPERATION CONSISTING OF AN AQUEOUS SLURRY OF SPRAYABLE CONSISTENCY, AND SLURRY CONTAINING A BINDING AGENT, A SUSPENSION AGENT AND FINELY POWDERED REFRACTORY MATERIAL CONSISTING ESSENTIALLY OF CHROME ORE, UNCOMBINED MAGNESIA AND UNCOMBINED IRON OXIDE THE CHROME ORE CONSTITUTING THE MAJOR PORTION OF THE REFRACTORY MATERIAL, THE AMOUNT OF UNCOMBINED MAGNESIA IN THE REFRACTORY MATERIAL BEING AT LEAST 10 PARTS BY WEIGHT OVER AND ABOVE ANY MAGNESIA THAT MAY BE PRESENT IN THE CHROME ORE, AND THE AMOUNT OF UNCOMBINED ION OXIDE PRESENT IN THE REFRACTORY MATERIAL BEING SUCH AS TO PROVIDE AN EXCESS OF FROM 1 TO 6 PARTS BY WEIGHT OVER AND ABOVE THE AMOUNT REQUIRED TO FROM AN IRON-CHROME SPINEL WITH THE CHROME OXIDE PRESENT IN THE CHROME ORE, WHEREBY THE UNCOMBINED IRON OXIDE ACTS AS A FLUXING AGENT, UNDER THE HIGH TEMPERATURE OF THE FURNACE, FOR BOTH THE CHROME ORE AND THE UNCOMBINED MAGNESIA PRESENT IN SAID REFRACTORY MATERIAL WHEN SPRAYED ON SAID SURFACE, THE MAJOR PORTION OF THE CHROME ORE OF THE REFRACTORY MATERIAL BEING IN THE FORM OF CHROMITE, THE PARTICLE SIZE OF THE REFRACTORY MATERIAL BEING SUCH THAT 20% TO 40% WILL REMAIN ON A 100 MESH SCREEN, 40% TO 55% WILL REMAIN ON A 200 MESH SCREEN AND 45% TO 60% WILL PASS THROUGH A 200 MESH SCREEN.