Method for producing high iron-content products from iron ore fines and biomass, and products thereof

Abstract

A process for obtaining a product of high iron content and high physical and metallurgical performance for use in reduction furnaces (blast furnaces, and direct reduction) and melting furnaces (smelters, melters, and electric furnaces), aiming at the sustainable production of iron and steel. The process includes mixing iron ore fines with biomass, binders, nanomaterials, additives, and catalysts, and performing subsequent steps of comminution, agglomeration, heat treatment, solid-solid separation, and coating.

1 . The process of obtaining high iron product from iron ore fines and biomass comprising the steps of:
 a. mixing iron ore fines, biomass, binders, nanomaterials, additives, and catalysts in an intensive mixer;   b. performing at least one step out of the group consisting of agglomeration and carbothermal reduction; and   c. performing at least one step out of the group consisting of solid-solid separation, carbothermal reduction, and agglomeration,   wherein the mixture obtained in step (a.) comprises at least 60 wt % iron ore fines, up to 30 wt % biomass; up to 15 wt % binders; up to 15 wt % nanomaterials; and up to 15 wt % chemical additives and catalysts,   wherein the granulometry of the iron ore fines is less than 10 mm, with d90 between 10 μm and 8 mm;   wherein the binders are selected from the group consisting of sodium silicate, pregelatinized cassava or corn starch, plant resins, polymers, geopolymers, among others; and   wherein the chemical additives may be based on C, Al, Ni, ferruginous kaolinite, or other material with high reduction potential, such as bauxite, alumina, polymers, and latex, among others, and may contain calcium and dolomite-based fluxants.   
     
     
         2 . The process of  claim 1 , further comprising:
 d. performing at least one step out of the group consisting of drying/curing and coating application.   
     
     
         3 . The process of  claim 1 , further comprising, after the mixing step, a comminution step is performed via pressing by means of roller press, roller crusher, or another comminution device. 
     
     
         4 . The process of  claim 1 , comprising the steps of:
 a. mixing iron ore fines, biomass, binders, nanomaterials, additives, and catalysts in an intensive mixer;   b. performing agglomeration via briquetting, pelletizing, or extrusion;   c. performing solid-solid separation via screening; and   d. performing drying/curing.   
     
     
         5 . The process of  claim 1 , comprising the steps of:
 a. mixing iron ore fines, biomass, binders, nanomaterials, additives, and catalysts in an intensive mixer;   b. performing agglomeration via briquetting, pelletizing, or extrusion;   c. performing carbothermal reduction; and   d. performing coating application.   
     
     
         6 . The process of  claim 5 , wherein, after the carbothermal reduction step, an additional agglomeration step is may be performed via briquetting, pelleting, or extrusion. 
     
     
         7 . The process of  claim 1 , comprising the steps of:
 a. mixing iron ore fines, biomass, binders, nanomaterials, additives, and catalysts in an intensive mixer;   b. performing carbothermal reduction;   c. performing agglomeration via briquetting, pelletizing, or extrusion; and   d. performing coating application.   
     
     
         8 . The process of  claim 7 , wherein, after the carbothermal reduction step, a solid-solid separation step is performed via magnetic separation or gravitic separation. 
     
     
         9 . The process of  claim 1 , comprising the steps of:
 a. mixing iron ore fines, biomass, binders, nanomaterials, additives, and catalysts in an intensive mixer;   b. performing carbothermal reduction; and   c. performing solid-solid separation by means of magnetic separation or gravitic separation.   
     
     
         10 . The process of  claim 7 , wherein, after the carbothermal reduction step, a disaggregation step may be performed. 
     
     
         11 . The process of  claim 1 , wherein the carbothermal reduction is performed in a microwave oven or conventional oven at temperatures in the range of 500° C. to 950° C. 
     
     
         12 . The process of  claim 1 , wherein the carbothermal reduction is performed in a microwave oven or conventional oven at temperatures in the range of 500° C. to 950° C. 
     
     
         13 . The process of  claim 2 , wherein the drying/curing is performed in a microwave oven, or conventional fuel-burning oven, at temperatures in the range of 240° C. to 400° C. 
     
     
         14 . The process according to  claim 1 , wherein the iron ore fines comprises at least 60% by weight of iron ore fines with particle size less than 10 mm, iron content (Fe Total ) of 30 to 68%, selected from the group consisting of sinter feed, pellet feed, and ultrafine iron ore tailings. 
     
     
         15 . The process according to  claim 1 , characterized wherein the biomass comprises up to 30% by weight of biomass that can come from eucalyptus trees, elephant grass, residues such as sugarcane bagasse, among others. 
     
     
         16 . The process according to  claim 1 , characterized wherein the biomass comprises up to 20% by weight of biomass that can come from eucalyptus trees, elephant grass, residues such as sugarcane bagasse, among others. 
     
     
         17 . The process of  claim 1 , wherein the biomass is used in pyrolyzed form. 
     
     
         18 . The process of  claim 1 , wherein the biomass has 20% to 80% fixed carbon. 
     
     
         19 . (canceled) 
     
     
         20 . The process of  claim 1 , wherein the catalysts comprise up to 15% by weight of catalysts selected from the group consisting of Ca, K, Na, Ni, Si, and W. 
     
     
         21 . The process of  claim 1 , wherein the nanomaterials comprise up to 15% by weight of nanomaterials selected from the group consisting of carbon nanotube, exfoliated graphite, functionalized micro-silicate, tubular nanosilica, tubular halloysite, carbon nanofiber, graphene, among others. 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . A high iron content agglomerated product obtained from iron ore and biomass fines produced from the process described in  claim 1 , having chemical, physical, and metallurgical qualities suitable for use in reduction furnaces and having a diameter of 8 to 150 mm, 6 to 20%, by weight carbon and 40 to 60% by weight total iron, being considered a self-reducing agglomerate. 
     
     
         25 . A high iron content agglomerated product obtained from iron ore and biomass fines produced from the process described in  claim 1 , having chemical, physical, and metallurgical qualities suitable for use in reduction and melting furnaces, having a diameter of 8 to 150 mm, total iron content above 60% by weight, carbon content below 5% by weight, abrasion resistance <25%, drum resistance >75%, impact/fall resistance >75%, compressive strength >150 daN, and metallization degree >50%. 
     
     
         26 . The agglomerated product according to  claim 25 , having 60 to 95% by weight total iron if the product is earmarked for use in a Blast Furnace. 
     
     
         27 . The agglomerated product according to  claim 25 , having above 85% by weight of metallic iron if the product is intended for use in an Electric Arc Furnace. 
     
     
         28 . A product of high iron content obtained from iron ore and biomass fines produced from the process described in  claim 1 , being in powder form and having chemical, physical, and metallurgical qualities suitable for use in Smelters and other melting furnaces, and having between 60% and 85% by weight of total iron.