Patent ID: 8033398

Claim:
A process for separating a value mineral from a non-value mineral by magnetic separation, comprising: intermixing a mineral substrate and a magnetic reagent to form a mixture; and applying a magnetic field to the mixture to thereby separate a value mineral from a non-value mineral in the mixture; wherein the magnetic reagent comprises a plurality of magnetite microparticles and a compound of the formula (I), R—(CONH—O—X) n (I) where the compound of the formula (I) has a molecular weight of about 2,000 or less; n is an integer in the range of 1 to 3; each X is individually selected from the group consisting of H, M and NR′ 4 ; M is a metal ion; R comprises from about 1 to about 50 carbons; and each R′ is individually selected from the group consisting of H, C 1 -C 10 alkyl, C 6 -C 10 aryl, and C 7 -C 10 aralkyl; where the plurality of magnetite microparticles have an average diameter of less than 50 microns; and where the plurality of magnetite microparticles and the compound of the formula (I) are present in the magnetic reagent in a weight ratio of magnetite microparticles: compound of the formula (I) in the range of about 10:1 to about 1:10.