METHOD OF PREPARING MAGNETIC LIQUID Russian patent published in 2011 - IPC H01F1/28 

FIELD: physics.

SUBSTANCE: method of preparing magnetic liquid involves mixing a chloride solution of a residue of galvanic sludge and spent etch solution in ratio Fe/Fe=3:2; preparing a suspension of magnetite via peptisation of the mixture of solutions by adding 40% sodium hydroxide, coating the surface of magnetite particles in the aqueous medium with an adsorbing layer of a stabilising substance, heating the suspension of magnetic particles on which a layer of stabilising substance is adsorbed, separation of said particles from the aqueous phase and mixing with an anhydrous carrier liquid.

EFFECT: low explosion hazard of production.

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