Ferrosilicate proppant and granule composition

Abstract

There is provided a process for the thermal conversion of non-ferrous smelting slag to granular products having sufficient strength and other useful characteristics for use as proppant, gravel pack, roofing granules and abrasive blast materials. Non-ferrous smelting slag is treated with silica, alumina, calcia and magnesia and then heated for a period of time sufficient for reaction of the ingredients and homogenization prior to being made into granular products.

1 . A process for making a granular product, comprising: 
 mixing a non-ferrous metal smelting slag with one or more oxide additives to form a mixture, wherein the oxide additive is calcia, silica, alumina or magnesia;    melting the mixture at temperatures of 1150-1500° C.;    refining the melted mixture to achieve thermal and chemical homogeneities at temperatures of 1150-1500° C.; and    forming the refined mixture into substantially spherical particles or granules.    
     
     
         2 . The process of  claim 1  wherein the smelting slag is derived from smelting non-ferrous metals, wherein the non-ferrous metal is copper, lead, zinc or cadmium.  
     
     
         3 . The process of  claim 1  wherein the slag displays an amorphous microstructure or a polycrystalline microstructure.  
     
     
         4 . The process of  claim 1  wherein the melted mixture is atomized in air or air/steam, or water quenched.  
     
     
         5 . The process of  claim 1  wherein the melting is carried out at a temperature of about 1275° C.  
     
     
         6 . The process of  claim 1  wherein the melting is carried out at a temperature of about 1400° C.  
     
     
         7 . The process of  claim 1  wherein the melted mixture is refined with respect to chemical and thermal homogeneity at about 1315° C.  
     
     
         8 . The process of  claim 1  wherein the melted mixture is refined with respect to chemical and thermal homogeneity at about 1400° C.  
     
     
         9 . The process of  claim 1  wherein the oxide additives are industrial raw materials that contains iron oxide contaminant up to 10 wt %.  
     
     
         10 . The process of  claim 2  wherein the non-ferrous slag contains one or more typical contaminants, the contaminant being copper, lead, zinc, arsenic, antimony, cobalt, cadmium, chromium, manganese, nickel, fluorine, chlorine, germanium, sodium, tin, tellurium, potassium, barium, strontium, titanium, sulfur or zirconium.  
     
     
         11 . The process of  claim 2  wherein the slag may be added to the melting process as a dry granule or as a molten material as directly drawn from a smelting furnace.  
     
     
         12 . The process of  claim 1  wherein the melting is carried out in an electric melter where sulfur oxides are retained in the melt.  
     
     
         13 . The process of  claim 1  wherein the silica is an industrial grade silica sand or feldspathic sand.  
     
     
         14 . The process of  claim 1  wherein the calcia is industrial or agricultural grade limestone or dolomite.  
     
     
         15 . The process of  claim 1  wherein the magnesia are industrial or agricultural grade dolomite or magnesite.  
     
     
         16 . The process of  claim 1  wherein the alumina is industrial grade alumina or impure bauxite or impure industrial grade clays.  
     
     
         17 . The process of  claim 1  wherein the magnesia, calcia, silica and alumina are spent refractory from one or more industrial sources, wherein the industrial source is non-ferrous metal smelting, steelmaking or glassmaking.  
     
     
         18 . The process of  claim 1  wherein the granular product is a proppant material, a gravel pack granule, an abrasive blast material, or a roofing granule material,  
     
     
         19 . A composition comprising: 
 a non-ferrous metal smelting slag; and    one or more oxide additives, wherein the oxide additive is alumina, silica, magnesia or calcia.    
     
     
         20 . The composition of  claim 19  wherein the non-ferrous metal smelting slag and the one or more oxide additives form ferrosilicate.  
     
     
         21 . The composition of  claim 19  wherein the oxide additive further comprises iron oxide contaminant.  
     
     
         22 . The composition of  claim 21 , further comprising a reducing agent.  
     
     
         23 . The composition of  claim 22  wherein the reducing agent is carbon-based.  
     
     
         24 . The composition of  claim 23  wherein the alumina is an industrial grade alumina, impure bauxite or industrial grade clay, the calcia is industrial or agricultural grade limestone or dolomite, the magnesia is industrial or agricultural grade dolomite or magnesite, and the silica is industrial grade silica sand or feldspathic sand.