METHOD OF PRODUCING MAGNETIC FLUID Russian patent published in 2019 - IPC C01G49/08 H01F1/44 

FIELD: instrument engineering.

SUBSTANCE: invention can be used in instrument engineering. Proposed method comprises sedimentation of finely dispersed magnetite from water solutions of ferric and trivalent iron salts with excess of divalent iron with ammonium solution. After water washing magnetite deposit is divided into two equal parts. One part of the residue is mixed, heated and supplied with oleic acid in amount of 0.120–0.148 g/g of magnetite precipitate and kerosene as a carrier liquid. After stabilization and peptization of the magnetite deposit, the magnetic liquid is separated and mixed with the second part of the magnetite precipitate. Processes of mixing, heating, stabilization, peptization and separation of magnetic liquid are repeated.

EFFECT: invention allows reducing costs for reagents and energy carrier, simplifying technological process, reducing its duration with simultaneous reduction of viscosity of magnetic fluid in external magnetic field.

1 cl, 2 dwg, 1 tbl, 1 ex