SU833545A1 - Method of producing paramagnetic liquid - Google Patents

Description

(54) METHOD FOR PRODUCING FERROMAGNETIC LIQUID

one

The invention relates to a technology for the production of ferromagnetic fluids used in ore flotation technology, in medical diagnostics, in metallographic studies in magnetic-liquid seals.

A method of producing ferromagnetic liquids is known, based on chemical precipitation of a highly dispersed magnet from aqueous solutions of ferrous and ferric salts, followed by washing the precipitate and peptizing it in a solution of oleic acid and kerosene l.

The disadvantages of this method are the long duration of the process and the small magnetization of the resulting product.

The closest to the proposed technical essence and the achieved result is the method of obtaining ferromagnetic fluid by precipitating highly dispersed magnetite from aqueous solutions of salts of divalent and ferric iron with an excess of aqueous solution of ammonia, washing the precipitate with distilled water to pH 10-12 and peptizing it in an oleic acid solution in organic

carrier fluid - kerosene when heated 2.

The disadvantage of this method is the low saturation magnetization of the resulting product.

The goal of the acquisition is the penetration of the ferro-magnetic saturation magnetization. liquids

The goal is achieved by the fact that, in the process involving the precipitation of agnetite from aqueous solutions of salts of vuh- and trivalent iron, an excess aqueous solution of ammonia and peptising the resulting precipitate in a solution of oleic acid in an organic carrier fluid, the magnetite: oleic precipitate is carried out at a weight ratio acid: carrier fluid equal to

(65-70): (10-15): (15-25).

When kerosene, silicone or mineral oils are used as a liquid carrier.

Claims (2)

These characteristics provide the best conditions for the dehydration and transfer of magnetite from an aqueous medium into an organic medium, and its stabilization in a carrier fluid, and obtaining in this way a concentrate of ferromagnetic liquid with a high saturation magnetization of 170–200 kA / m. The method is carried out as follows. The precipitate of highly dispersed magnetite, obtained by precipitation of salts of bivalent and trivalent iron, for example sulfates or chlorides, with an excess of aqueous ammonia solution, is washed several times with distilled water, and then peptized in a solution of oleic acid in a liquid with a specified weight ratio of components: magnetite, oleic acid and carrier fluid. A high concentration of ferric magnetic fluid is obtained, which is used directly or dispersed in the carrier fluid to the desired concentration. Kerosene, silicone oils, such as copolymer 3, copolymers of measure 5, and mineral oils of the type vereny, transformer type, are used as the carrier fluid. Example 1. A mixture of 1b% solutions of FeCIjMHzO and ResSC-, prepared from 100 and 200 g of the indicated compounds, with repeated stirring of a vlivhg in 750 ml of concentrated ammonia solution. The resulting black precipitate of magnetite in an amount of 110 g is washed with distilled water. After discharging the decantation of the free water, a solution of oleic acid in kerosene at the rate of 21 g of oleic acid in 33 g of kerosene is added to the mixture with stirring and low heat (40–50 ° C), providing the weight ratio of magnetite: oleic acid tag kerosene 67: 13:20 The result is a concentrate of ferromagnetic fluid in the form of a thick oily mass, easily separated from the aqueous phase. The resulting ferromagnetic fluid concentrate has a magnetization of 190 kA / m of saturation and, after centrifugation, is used directly or dispersed in a carrier fluid to the desired concentration. For example, dispersing it in 35 ml of kerosene provides a ferromagnetic fluid with a magnetization of 100 kA / m. Example 2. The magnetite, obtained as in example 1, is dispersed in 55 ml of a 35% gn solution of oleic acid in condenser oil, providing a weight ratio magnetite; oleic acid: oil 69:11:20. The formation of a highly magnetic concentrate with a magnetization of 170 kA / m is separated from the water. Dispersing the resulting concentrate in 15 ml of condenser oil gives a ferrofluid with a magnetization of 85 kA / m. The resulting ferromagnetic fluids are resistant to gravitational, centrifugal and magnetic forces, do not collapse when centrifuged for 1 hour with a separation factor of 8000, prolonged aging under normal conditions and in a non-uniform magnetic field with a gradient of 10 kA / mCH Invention formula 1. Method of producing ferromagnetic liquids, including the precipitation of magnetite from a solution of salts of bivalent and trivalent iron with an excess of an aqueous solution of ammonia and peptization of the resulting precipitate in a solution of oleic acid in organic matter carrier bone, characterized in that, in order to increase the saturation magnetization of the target product, peptization is carried out with a weight ratio of magnetite precipitate: oleic acid: carrier fluid equal to (65-70) :( 10-15) :( 15-25 ), 2. The method according to claim 1, about tl and h ayush and the fact that, as a carrier fluid use kerosene, silicone or mineral oils. Sources of information taken into account in the examination 1.Patent of France No. 2209989, cl. H 01 F 1/00, published. 1974. 2. USSR author's certificate number 568598, cl. Since 01 G 49/08, 1975.