Method for upgrading iron ore utilizing multiple magnetic separators
AssigneeIron Dynamics, Inc.
InventorLarry J. Lehtinen
Life of this patent
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Abstract
The present invention relates to upgrading iron ore to decrease the amount of nonferrous materials therein, and to thereby increase the iron content thereof. More particularly, the invention relates to a process utilizing magnetic fields to separate a significant amount of non-magnetic material, such as silica or pyrolusite, from valuable iron oxide in an iron ore or iron ore concentrate. The invention therefore finds advantageous use to provide an improved source of iron oxides for high purity uses such as, for example, direct reduction processes and heavy media coal beneficiation processes.
Claims71
A method for upgrading iron ore, comprising:
- providing a substantially dry feed stream including a weakly magnetic particulate ore, a strongly magnetic particulate ore and one or more particulate nonmagnetic contaminants;
- passing the ore through a first magnetic field having a field strength of from about 500 to about 2000 gauss to thereby separate the ore into a first magnetic fraction and a first nonmagnetic fraction;
- and
- passing the first nonmagnetic fraction through a second magnetic field having a field strength of from about 4000 to about 30,000 gauss to thereby separate the first nonmagnetic fraction into a second magnetic fraction and a second nonmagnetic fraction.
A method for upgrading iron ore, comprising:
- providing a substantially dry feed stream including a weakly magnetic particulate ore, a strongly magnetic particulate ore and one or more particulate nonmagnetic contaminants;
- subjecting the feed stream to a size separation at a size split of from about 10 to about 150 mesh, thereby providing a first oversize fraction and a first undersize fraction;
- passing the first undersize fraction through a first magnetic field having a field strength of from about 500 to about 2000 gauss to thereby separate the ore into a first magnetic fraction and a first nonmagnetic fraction;
- and
- passing the first nonmagnetic fraction through a second magnetic field having a field strength of from about 4000 to about 30,000 gauss to thereby separate the first nonmagnetic fraction into a second magnetic fraction and a second nonmagnetic fraction.
A method for upgrading iron ore, comprising:
- providing a substantially dry feed stream including a weakly magnetic particulate ore, a strongly magnetic particulate ore and one or more particulate nonmagnetic contaminants;
- passing the ore through a first magnetic field having a field strength of from about 500 to about 2000 gauss to thereby separate the ore into a first magnetic fraction and a first nonmagnetic fraction;
- subjecting the first nonmagnetic fraction to a size separation at a size split of from about 10 to about 150 mesh, thereby providing an oversize fraction and an undersize fraction;
- and
- passing the undersize fraction through a second magnetic field having a field strength of from about 4000 to about 30,000 gauss to thereby separate the undersize fraction into a second magnetic fraction and a second nonmagnetic fraction.
Dependencies are inferred from the claim text.