Ironmaking feedstock

Abstract

The present invention relates to an ironmaking feedstock comprising a solid CaFe3O5 phase. The ironmaking feedstock may be produced by a process comprising reacting a combination of a calcium source and magnetite at elevated temperature under reducing conditions sufficient to produce the solid CaFe3O5 phase. The product may be in the form of agglomerates such as pellets, with a compressive strength such that the product is suitable for transportation.

1 . An ironmaking feedstock comprising a solid CaFe 3 O 5  phase. 
     
     
         2 . The ironmaking feedstock of  claim 1 , wherein the CaFe 3 O 5 , constitutes at least 10% by weight of all iron-containing components in the ironmaking feedstock as measured by quantitative phase analysis using the Rietveld method. 
     
     
         3 . The ironmaking feedstock of  claim 1 , in the form of agglomerates. 
     
     
         4 . The ironmaking feedstock of  claim 1 , in the form of pellets. 
     
     
         5 . The ironmaking feedstock of  claim 4  having a compressive strength of at least 14 MPa. 
     
     
         6 . The ironmaking feedstock of  claim 1 , wherein the CaFe 3 O 5  phase is the primary bonding phase. 
     
     
         7 . The ironmaking feedstock of  claim 1  having a reducibility index as measured in accordance with ISO 4695:2015 and ISO7215:2015, scaled down to a 6-7 gram sample size, of at least 10.0. 
     
     
         8 . The ironmaking feedstock of  claim 1 , comprising the product of a combination of a calcium source and magnetite that has been subjected to reductive conditions at elevated temperature sufficient to produce the solid CaFe 3 O 5  phase. 
     
     
         9 . A process for the production of an ironmaking feedstock, the process comprising reacting a combination of a calcium source and magnetite at elevated temperature under reducing conditions sufficient to produce a solid CaFe 3 O 5  phase. 
     
     
         10 . The process of  claim 9 , wherein the reaction conditions are sufficient to produce an ironmaking feedstock containing at least 10% CaFe 3 O 5  by weight with respect to all iron-containing components in the ironmaking feedstock as measured by quantitative phase analysis using the Rietveld method. 
     
     
         11 . The process of  claim 9 , wherein the elevated temperature is a temperature between about 500° C. and 1150° C. 
     
     
         12 . The process of  claim 9 , wherein the reducing conditions comprise at least one selected from the group consisting of a CO 2 /CO ratio of 1.0 or greater and a reduction potential of 9.8×10 −16  or less. 
     
     
         13 . The process of  claim 9 , wherein the molar ratio of calcium source to magnetite is between 0.1:1.0 and 1.2:1.0. 
     
     
         14 . The process of  claim 9 , wherein the reaction is conducted over a time period of between 20 minutes and 8 hours. 
     
     
         15 . The process of  claim 9 , comprising a pelletising step. 
     
     
         16 . The process of  claim 15 , wherein the pelletising step comprises pelletising the combination of the calcium source and the magnetite prior to conducting the reaction at elevated temperature under reducing conditions. 
     
     
         17 . The process of  claim 9 , further comprising processing an iron ore to yield a magnetite concentrate, and using the magnetite concentrate as the magnetite source for the reaction between the calcium source and the magnetite. 
     
     
         18 . The process of  claim 9 , wherein the calcium source is selected from the group consisting of calcium carbonate, calcium oxide, dolomite, gypsum and combinations thereof. 
     
     
         19 . The process of  claim 9 , further comprising producing iron from the ironmaking feedstock. 
     
     
         20 . A method of producing iron, comprising reducing the ironmaking feedstock of  claim 1  to form iron.