Insulating product for the refractory industry, corresponding insulating materials and products, and uses

Abstract

An insulating product for the refractory industry or an insulating material as intermediate for production of such a product, and a corresponding insulating material/insulating product are provided. Likewise the use of a matrix encapsulation process in the production of an insulating product for the refractory industry and a corresponding insulating product and/or an insulating material as intermediate for production of such a product are provided.

We claim: 
     
         1 . An insulating product for the refractory industry or insulating material as intermediate for production of such a product, comprising a number of refractory composite particles, wherein these composite particles comprise
 particles of one or more refractory substances and   nanoparticulate silicon dioxide that functions as binder or binder component for said particles of the refractory substances and   
       wherein the composite particles present in the product or intermediate are characterized by
 (A) thermal stability at a temperature of 1600° C. or higher, determined by the sintering test, and/or 
 (B) a thermal conductivity value at room temperature (20° C.) γR of ≤0.26 W/m*K. 
 
     
     
         2 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 1 , wherein the product or intermediate is producible by a process, having the following steps:
 (a) producing composite particles having a grain size of less than 5 mm, determined by sieving, in a matrix encapsulation process having the following steps:
 (a1) producing droplets of a suspension composed of at least the following starting materials:
 as dispersed phases 
 (i) one or more refractory substances selected from the group consisting of refractory solids and precursors of refractory solids, 
 (ii) additionally one or more density-reducing substances selected from the group consisting of lightweight fillers having a respective bulk density in the range from 10 to 350 g/L and pyrolyzable fillers, 
 and as continuous phase 
 (iv) a solidifiable liquid, 
 
 (a2) solidifying the solidifiable liquid, such that the droplets harden to give hardened droplets and the refractory substance(s) and the density-reducing substance(s) are encapsulated in the solidifying continuous phase, 
 (a3) treating the hardened droplets so as to result in said composite particles, the treating comprising a thermal treatment, 
   
       wherein step (a1), producing droplets of a suspension, further comprises as starting material as dispersed phase:
 (iii) colloidal silicon dioxide in addition to constituents (i) and (ii); and/or 
 wherein the process comprises as an additional step: 
 (b) mixing the composite particles produced in step (a3) with a binder comprising a binder component selected from the group consisting of
 alumina cements, 
 calcium aluminate cements, 
 monoaluminum phosphate or solution of monoaluminum phosphate, 
 monomagnesium phosphate or solution of monomagnesium phosphate, 
 phosphoric acid, 
 inorganic phosphate, 
 boron compounds, preferably boron oxide, 
 magnesium sulfate or solution of magnesium sulfate, 
 silica sol, 
 sols of aluminum oxide, 
 plastic clays, 
 hydratable aluminum oxide binder, 
 ethyl silicate and 
 aluminum sulfate. 
 
 
     
     
         3 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 1 , wherein the composite particles present in the product or intermediate are characterized by
 (B) a thermal conductivity value at room temperature (20° C.) γR of ≤0.07 W/m*K.   
     
     
         4 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 1 , wherein the composite particles present in the product or intermediate are characterized by
 (C) a grain strength ≥1.5 N/mm 2 , determined to EN 13055-1, Annex A, Method 1, at a grain size in the range of 0.25-0.5 mm, and/or   (D) a bulk density ≤750 g/L, and/or   (E) a grain size of not more than 5 mm, determined by sieving, and/or   (F) a water absorption capacity, determined via water absorption according to Enslin, of ≤4.5 mL/g.   
     
     
         5 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 4 , wherein the composite particles present in the product or intermediate are characterized by
 (C) a grain strength ≥3.0 N/mm 2 , determined to EN 13055-1, Annex A, Method 1, at a grain size in the range of 0.25-0.5 mm, and/or   (D) a bulk density ≤350 g/L, and/or   (E) a grain size of not more than 1 mm, determined by sieving, and/or   (F) a water absorption capacity, determined via water absorption according to Enslin, of ≤2.0 mL/g.   
     
     
         6 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 1 , comprising the curing product of a binder component selected from the group consisting of:
 alumina cements,   calcium aluminate cements,   monoaluminum phosphate or solution of monoaluminum phosphate,   monomagnesium phosphate or solution of monomagnesium phosphate,   phosphoric acid,   inorganic phosphate,   boron compounds,   magnesium sulfate or solution of magnesium sulfate,   silica sol,   sols of aluminum oxide,   plastic clays,   hydratable aluminum oxide binder,   ethyl silicate and   aluminum sulfate   
       and/or
 additionally comprising one or more substances selected from the group consisting of:
 fireclay, lightweight fireclay, corundum, hollow spherical corundum, sintered corundum, fused corundum, sintered mullite, fused mullite, aluminum oxide (alumina), andalusite, kyanite, sillimanite, cordierite, clays, wollastonite, zirconium mullite, zirconium corundum, spheres of fly ash and vermiculite. 
 
 
     
     
         7 . The insulating product for the refractory industry or the insulating material as intermediate for production of such a product as claimed in  claim 1 , wherein the insulating product or insulating material as intermediate is selected from the group consisting of shaped and unshaped refractory and highly refractory products. 
     
     
         8 . The insulating product for the refractory industry or the insulating material as intermediate for production of such a product as claimed in  claim 1 , wherein the insulating product or insulating material as intermediate is selected from the group consisting of
 high-alumina bricks,   fireclay bricks,   refractory concretes,   repair compounds,   leveling compounds,   mortars and adhesives,   crucibles,   ladle linings,   casting launders,   stopper compounds,   immersion nozzles,   slide gates,   feed nozzles for metallurgy,   pouring compounds, and   furnace linings.   
     
     
         9 . An insulating product for the refractory industry or insulating material as intermediate for production of such a product, comprising
 a number of refractory composite particles, where said refractory composite particles comprise particles of one or more refractory substances; and   the curing product of a binder component selected from the group consisting of:
 alumina cements, 
 calcium aluminate cements, 
 monoaluminum phosphate or solution of monoaluminum phosphate, 
 monomagnesium phosphate or solution of monomagnesium phosphate, 
 phosphoric acid, 
 inorganic phosphate, 
 boron compounds, 
 magnesium sulfate or solution of magnesium sulfate, 
 silica sol, 
 sols of aluminum oxide, 
 plastic clays, 
 hydratable aluminum oxide binder, 
 ethyl silicate and 
 aluminum sulfate, 
   
       wherein the refractory composite particles present in the product or intermediate are characterized by
 (A) thermal stability at a temperature of 1600° C. or higher, determined by the sintering test, and/or 
 (B) a thermal conductivity value at room temperature (20° C.) γR of ≤0.26 W/m*K. 
 
     
     
         10 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 9 , wherein the refractory composite particles present in the product or intermediate additionally comprise nanoparticulate silicon dioxide that functions as binder or binder component for said particles of the refractory substances. 
     
     
         11 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 9 , wherein the composite particles present in the product or intermediate are characterized by
 (B) a thermal conductivity value at room temperature (20° C.) γR of ≤0.07 W/m*K.   
     
     
         12 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 9 , wherein the refractory composite particles present in the product or intermediate comprise:
 (C) a grain strength ≥1.5 N/mm 2 , determined to EN 13055-1, Annex A, Method 1, at a grain size in the range of 0.25-0.5 mm, and/or   (D) a bulk density ≤750 g/L, and/or   (E) a grain size of not more than 5.0 mm, determined by sieving, and/or   (F) a water absorption capacity, determined via water absorption according to Enslin, of ≤4.5 mL/g.   
     
     
         13 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 12 , wherein the composite particles present in the product or intermediate are characterized by
 (C) a grain strength ≥2.0 N/mm 2 , determined to EN 13055-1, Annex A, Method 1, at a grain size in the range of 0.25-0.5 mm, and/or   (D) a bulk density ≤500 g/L, and/or   (E) a grain size of not more than 2.0 mm, determined by sieving, and/or   (F) a water absorption capacity, determined via water absorption according to Enslin, of ≤3.5 mL/g.   
     
     
         14 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 13 , wherein the composite particles present in the product or intermediate are characterized by
 (C) a grain strength ≥3.0 N/mm 2 , determined to EN 13055-1, Annex A, Method 1, at a grain size in the range of 0.25-0.5 mm, and/or   (D) a bulk density ≤350 g/L, and/or   (E) a grain size of not more than 1.0 mm, determined by sieving, and/or   (F) a water absorption capacity, determined via water absorption according to Enslin, of ≤2.0 mL/g.   
     
     
         15 . The insulating product for the refractory industry or insulating material as intermediate for production of such a product as claimed in  claim 9 , additionally comprising one or more substances selected from the group consisting of fireclay, lightweight fireclay, corundum, hollow spherical corundum, sintered corundum, fused corundum, sintered mullite, fused mullite, aluminum oxide (alumina), andalusite, kyanite, sillimanite, cordierite, clays, wollastonite, zirconium mullite, zirconium corundum, spheres of fly ash and vermiculite. 
     
     
         16 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 9 , wherein the refractory composite particles present in the product or intermediate comprise one or more density-reducing substances selected from the group consisting of lightweight fillers having a respective bulk density in the range from 10 to 350 g/L and pyrolyzable fillers. 
     
     
         17 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 16 , wherein the pyrolyzable fillers include at least one filler selected from the group consisting of polymer beads and styrofoam beads. 
     
     
         18 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 9 , wherein the refractory substances include at least one substance selected from the group consisting of:
 oxides, nitrides and carbides, each comprising one or more elements from the group consisting of Si, Al, Zr, Ti, Mg and Ca, and   mixed oxides, mixed carbides and mixed nitrides, each comprising one or more elements from the group consisting of Si, Al, Zr, Ti, Mg and Ca.   
     
     
         19 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 9 , wherein the refractory substances include at least one substance selected from the group consisting of:
 aluminum oxide,   zirconium oxide,   titanium dioxide,   silicon dioxide,   magnesium oxide,   calcium oxide,   calcium silicate,   sheet silicates,   aluminum silicates,   magnesium aluminum silicate,   silicon carbide, and   boron nitride.   
     
     
         20 . The insulating product for the refractory industry or insulating material as intermediate for production of a product as claimed in  claim 9 , wherein the product or intermediate is produced by a process comprising:
 (a) producing composite particles having a grain size of less than 5 mm, determined by sieving, in a matrix encapsulation process having the following steps:
 (a1) producing droplets of a suspension composed of at least the following starting materials:
 as dispersed phases 
 (i) one or more refractory substances selected from the group consisting of refractory solids and precursors of refractory solids, 
 (ii) additionally one or more density-reducing substances selected from the group consisting of lightweight fillers having a respective bulk density in the range from 10 to 350 g/L and pyrolyzable fillers, 
 and as continuous phase 
 (iv) a solidifiable liquid, 
 
 (a2) solidifying the solidifiable liquid, such that the droplets harden to give hardened droplets and the refractory substance(s) and the density-reducing substance(s) are encapsulated in the solidifying continuous phase, 
 (a3) treating the hardened droplets so as to result in said composite particles, the treating comprising a thermal treatment, 
   (b) mixing the composite particles produced in step (a3) with a binder comprising a binder component selected from the group consisting of
 alumina cements, 
 calcium aluminate cements, 
 monoaluminum phosphate or solution of monoaluminum phosphate, 
 monomagnesium phosphate or solution of monomagnesium phosphate, 
 phosphoric acid, 
 inorganic phosphate, 
 boron compounds, 
 magnesium sulfate or solution of magnesium sulfate, 
 silica sol, 
 sols of aluminum oxide, 
 plastic clays, 
 hydratable aluminum oxide binder, 
 ethyl silicate and 
 aluminum sulfate, 
   and optionally, in step (b) or in a further step after step (a), mixing with one or more further substances to produce a curable refractory composition, and optionally curing the curable refractory composition.