Binder compositions and processes of preparing iron ore pellets

Abstract

Binder compositions for agglomerating iron ore fines are provided, the compositions comprising: (a) about 30 to about 80% by weight one or more types of anionic or nonionic acrylamide-containing polymer; (b) about 10 to about 35% by weight one or more types of inorganic or organic monomeric electrolyte; and (c) about 10 to about 35% one or more types of finely ground wood fiber. A process for preparing iron ore pellets with the binder compositions is also provided, the process comprising: (i) adding a binder composition to particulate iron ore to form a mixture; and (ii) forming the mixture into pellets.

We claim: 
     
         1 . A binder composition for agglomerating iron ore fines comprising:
 (a) about 30 to about 80% by weight one or more types of anionic or nonionic acrylamide-containing polymer;   (b) about 10 to about 35% by weight one or more types of inorganic or organic monomeric electrolyte; and   (c) about 10 to about 35% one or more types of finely ground wood fiber.   
     
     
         2 . The composition of  claim 1 , wherein the one or more types of finely ground wood fibers consists of fibers wherein about 95% of the fibers are less than 150 μm in length and about 80% of the fibers are more than 10 μm in length. 
     
     
         3 . The composition of  claim 1 , wherein the one or more types of finely ground wood fibers consists of fibers wherein about 95% of the fibers are less than 150 μm in length and about 80% of the fibers are more than 50 μm in length. 
     
     
         4 . The composition of  claim 1 , wherein the one or more inorganic or organic monomeric electrolyte is an inorganic water soluble salts of carboxylic, dicarboxylic, and tricarboxylic acids. 
     
     
         5 . The composition of  claim 1 , wherein the one or more inorganic or organic monomeric electrolyte comprises sodium carbonate, sodium bicarbonate, sodium citrate, sodium hydroxide, sodium oxalate, sodium tartrate, sodium benzoate, sodium stearate, sodium silicate, and the corresponding ammonium, potassium, calcium or magnesium salts of the preceding salts, calcium oxide, and mixtures thereof 
     
     
         6 . The composition of  claim 1 , wherein the one or more types of inorganic or organic monomeric electrolyte comprises sodium carbonate. 
     
     
         7 . The composition of  claim 1 , wherein the one or more types of inorganic or organic monomeric electrolyte comprises sodium citrate. 
     
     
         8 . The composition of  claim 1 , wherein the one or more types of inorganic or organic monomeric electrolyte comprises sodium carbonate and sodium citrate. 
     
     
         9 . The composition of  claim 1 , wherein the one or more types of anionic or nonionic acrylamide-containing polymer is an anionic polymer. 
     
     
         10 . The composition of  claim 1 , wherein the one or more types of anionic or nonionic acrylamide-containing polymer is a nonionic polymer. 
     
     
         11 . The composition of  claim 1 , wherein the one or more types of anionic or nonionic acrylamide-containing polymer is polyacrylamide. 
     
     
         12 . A process for preparing iron ore pellets comprising:
 (i) adding a binder composition to particulate iron ore to form a mixture; and   (ii) forming the mixture into pellets;   wherein the binder composition comprises:   (a) about 30 to about 80% by weight one or more types of anionic or nonionic acrylamide-containing polymer;   (b) about 10 to about 35% by weight one or more types of inorganic or organic monomeric electrolyte; and   (c) about 10 to about 35% one or more types of finely ground wood fiber.   
     
     
         13 . The process of  claim 12 , wherein the pellet comprises about 0.03 to about 0.06% binder per kilogram of iron ore fines. 
     
     
         14 . The process of  claim 12 , wherein the processes further the step of mixing the mixture after the addition of the binder composition. 
     
     
         15 . The process of  claim 12 , wherein the process further comprises the step of adding water. 
     
     
         16 . The process of  claim 12 , wherein the step of forming of the mixture into pellets comprises balling on a disc or balling in a drum. 
     
     
         17 . The process of  claim 12 , wherein the process further comprises drying and firing the pellets.