Abstract A heating element is cast, extruded or formed from a composition comprising finely comminuted ferrous metal in a matrix essentially consisting of a base composition consisting essentially of tailings muds from lithium ore extraction, comprising a major percentage of silicon, lesser percentages of aluminum and calcium, and to which some alkali metals or lead may be added in order to ease working and depress the melting point. An electrically conductive composition of controlled resistance is prepared in which the ferrous particles contact each other so as to give the resultant element resistivity of 10 3 to 1,000 Ohm centimeters. The tailings mud is a by-product from ore extraction, which is particularly suitable for this purpose because of its fine state of comminution, and its workability.
A METHOD OF MAKING AN ELECTRICAL HEATING ELEMENT WHICH COMPRISES THE COMBINATION OF THE STEPS OF: PROVIDING A TAILINGS MUD COMPRISING BY WEIGHT ON A DRY BASIS 40 TO 70 PERCENT OF SILICA, 10 TO 20 PERCENT OF ALUMINA AND 10 TO 20 PERCENT OF CALCIA; AND MIXING SAID TAILINGS MUD WITH FROM 4 TO 30 PERCENT BY VOLUME OF PARTICLES SELECTED FROM IRON AND STEEL, FORMING SAID MIXTURE INTO A PHE-SELECTED SHAPE, FIRING SAID PHR-SELECTED SHAPE AT FROM ABOUT940*C. TO ABOUT 1,200*C. TO CAUSE SAID MIXTURE TO COALESCE, COOLING AND RESULTANT ARTICLE, ABRADING PORTIONS OF THE ARTICLE TO WHICH ELECTRODES ARE TO BE ATTACHED, AND ATTACHING ELECTRODES TO SAID ABRADED AREAS TO PROVIDE SAID ELECTRICAL HEATING ELEMENT.
Claim 2
Independent Claim
118 words
A METHOD OF MAKING AN ELECTRICAL HEATING ELEMENT WHICH COMPRISES THE COMBINATION OF THE STEPS OF: PROVIDING A TAILINGS MUD COMPRISING BY WEIGHT ON A DRY BASIS 40 TO 70 PERCENT OF SILICA, 10 TO 20 PERCENT OF ALUMINA AND 10 TO 20 PERCENT OF CALCIA; AND MIXING SAID TAILINGS MUD WITH FROM 4 TO 30 PERCENT BY VOLUME OF PARTICLES SELECTED FROM IRON AND STEEL, FORMING SAID MIXTURE INTO A PHE-SELECTED SHAPE, FIRING SAID PHR-SELECTED SHAPE AT FROM ABOUT940*C. TO ABOUT 1,200*C. TO CAUSE SAID MIXTURE TO COALESCE, COOLING AND RESULTANT ARTICLE, ABRADING PORTIONS OF THE ARTICLE TO WHICH ELECTRODES ARE TO BE ATTACHED, AND ATTACHING ELECTRODES TO SAID ABRADED AREAS TO PROVIDE SAID ELECTRICAL HEATING ELEMENT.
Claim 3
Dependent Claim
15 words
The electrical element of claim 1, said element having the form of a flat panel.