Resistor for refractory shaped bodies, and shaped bodies derived therefrom

Abstract

A resistor,which is solidified from a melt, is provided for a refractory shaped body, and includes a refractory mineral metal-oxide main component having elasticizers of a general formula A 2+ B 3+ 2 O 4 in an amount so that solubility of the main component for the elasticizer is exceeded with the elisticizers providing precipitation areas in the main component. The resistor is produced by a joint melting of the main component with oxides which form the elasticizers. A process is provided for the production of the resistor.

What is claimed is:  
     
         1 . A process for producing a refractory resistor, comprising: 
 mixing a refractory mineral metal-oxide main component and spinel-forming oxides with one another so that the main component and the spinel-forming oxides ate melted together;    adding a quantity of the spinel-forming oxides so that:    (1) solubility of the refractory mineral metal-oxide main component for these spinel-forming oxides is exceeded, and    (2) the spinel-forming oxides, during cooling of the melt, form spinel precipitations in the refractory mineral metal-oxide main component.    
     
     
         2 . The process as claimed in  claim 1 , wherein MgO and/or Al 2 O 3  and/or dolomite are used as the refractory mineral metal-oxide main component.  
     
     
         3 . The process as claimed in  claim 1 , wherein periclase is used as the refractory mineral metal-oxide main component.  
     
     
         4 . The process as claimed in  claim 1 , wherein oxides of elements Fe, Mg, Mn, Zn, Al, Cr are used as the spinel-forming minerals.  
     
     
         5 . The process as claimed in  claim 1 , wherein metal oxides which, in the resistor, form an MgO-saturated pleonastic spinel of a general formula(Fe, Mg)(Al) 2 O 3  are used as spinel-forming agents.  
     
     
         6 . The process as claimed in  claim 5 , wherein the metal oxides added is set so that the resistor contains 2 to 25% by mass of the spihel.  
     
     
         7 . The process as claimed in  claim 1 , wherein the refractory mineral metal-oxide main component is added so that the resistor contains 70 to 98% of the refractory mineral metal-oxide main component.  
     
     
         8 . The process as claimed in  claim 1 , wherein the resistor is melted from caustic magnesia, magnesium hydroxide or magnesite and iron compounds, or iron oxides including magnetite and alumina.  
     
     
         9 . The process as claimed in  claim 8 , wherein the caustic magnesia, the magnesium hydroxide or magnesite and the iron compounds, or the iron oxides including the magnetite and aluminum oxide as the alumina, are melted in an electric arc furnace at a temperature off 2500° C.  
     
     
         10 . The process as claimed in  claim 1 , wherein, after the melting process and the subsequent cooling, the melted product is prepared into fractions of 0 to 1 mm, 1 to 2 mm, 2 to 4 mm and meal.  
     
     
         11 . The process as claimed in  claim 10 , wherein a batch for production of solid shaped bodies is assembled according to a typical Fuller curve, so that a grain size corresponding to the Fuller curve is achieved by compiling the fractions and appropriate further additives.  
     
     
         12 . The process as claimed in  claim 11 , wherein the batch is mixed with further elasticizers including MgAl spinel, hercynite, zirconium oxide or further known elasticizers.  
     
     
         13 . The process as claimed in  claim 11 , wherein the batch is mixed with a required quantity of binder and is compressed under a specific pressure of at least>50 MPa, being 80 to 200 MPa, or between 100 to 150 MPa, to form shaped bodies.  
     
     
         14 . The process as claimed in  claim 11 , wherein the batch is mixed with lignin sulfonate.  
     
     
         15 . The process as claimed in  claim 11 , wherein a green shaped body is dried.  
     
     
         16 . The process as claimed in  claim 15 , wherein the dried shaped body is fired at>1000° C., being 1200 to 1750° C.