Physical process for the recovery of iron from magnetic cementitious spherical particles generated from metallurgical byproducts

Abstract

A physical process for recovering iron from magnetic cementitious spherical particles generated from metallurgical by-products such as slag from a basic oxygen converter (B.O.F.S) by applying a thermal process assisted by Ar—He plasma, which allows the microstructural and morphological transformation of these compounds based on iron, resulting in the generation of magnetic phases, among others. The separation process is based on the classification of the particles according to their new magnetic properties. Thus, when applying a magnetic field, the particles are separated into two fractions: a highly magnetic one and with low cementitious properties, and another fraction with high cementitious properties and almost no magnetic properties. The highly magnetic fraction is mixed with an aqueous medium to form an agglomerate and facilitate its transportation to be reefed to an iron melting process. The fraction with low magnetic properties has potential applications as a densifier in non-conventional cement and concrete.

1 . A physical process for recovering iron from magnetic cementitious spherical particles generated from metallurgical by-products, comprising the steps of:
 a) applying magnetic separation to said magnetic cementitious spherical particles to obtain a highly magnetic fraction and a highly cementitious fraction;   b) agglomerating said highly magnetic fraction obtained in a) with an aqueous medium to obtain a magnetic agglomerate; and   c) reinjecting said magnetic agglomerate to an iron melting process for the recovery of iron.   
     
     
         2 . The physical process for recovering iron of the  claim 1 , wherein in step a) said magnetic cementitious spherical particles are subject to at least one magnetic field which is able to classify particles in a highly magnetic fraction and in a highly cementitious fraction. 
     
     
         3 . The physical process for recovering iron of the  claim 2 , wherein said magnetic cementitious spherical particles have at least one magnetic phase, and said phase is optionally magnetite and/or maghemite. 
     
     
         4 . The physical process for recovering iron of the  claim 2 , wherein in step a) said magnetic cementitious spherical particles are subject to at least one magnetic field which is able to classify particles in a highly magnetic fraction and in a highly cementitious fraction. 
     
     
         5 . The physical process for recovering iron of the  claim 1 , wherein in step b) said highly magnetic fraction obtained in a) is homogeneously mixed with an aqueous medium, in a 1:4 ratio, aqueous medium to fraction, said aqueous medium is water; the mixture is maintained at rest for 24 to 48 hours to form a magnetic agglomerate. 
     
     
         6 . The physical process for recovering iron of the  claim 5 , wherein said aqueous medium is optionally added with silica nanoparticles from 0.1 to 1% w/w with a particle size between 1 and 20 nm. 
     
     
         7 . The physical process for recovering iron of the  claim 1 , wherein in step c) said magnetic agglomerate is obtained and in b) reinjected to an iron melting process. 
     
     
         8 . The physical process for recovering iron of the  claim 7 , wherein said iron melting process is optionally a blast furnace and basic oxygen converter.