RU2000170C1 - Method for manufacture of mn-zn ferrite powder - Google Patents

Abstract

Usage: the invention can be used in the manufacture of powders by wet grinding of sintered defective products - production waste. SUMMARY OF THE INVENTION: upon wet grinding of sintered defective products of Mn-Zn ferrites of 2500 Nm C 2 grade, previously heat-treated by quenching in running water at a temperature of 1000 ° C, 0.05-0.3 may be added to the suspension. % polyacrylic acid. 1 tab.

Description

The invention relates to the technology of Mn-Zn ferrites and can be used in the manufacture of powders by wet grinding of sintered defective products - waste products.

A known method for producing ferrite powder by wet grinding in ball mills.

However, powders obtained by wet grinding of sintered defective Mn-Zn ferrite products have low activity, which makes it impossible to produce high-density products from them during subsequent sintering.

Closest to the proposed solution is a method of producing sintering active (Jerrite powder by wet grinding, comprising modifying the surface of the particles with meta-α-l hydroxide, which is part of the ferrite, in particular, applying Fe (OH) 3 in the amount of a - 0.1-1.5 mes %. Formed by this method on the surface

particles, a gel-like layer of hydroxide increases the activity of the powder during subsequent sintering. However, the modification of powders by wet grinding of sintered defective Mn-Zn ferrites by this method also does not allow obtaining high-density products during subsequent sintering.

The purpose of the invention is to increase the activity of Mn-Zn ferrite powder obtained by wet grinding of waste products.

The goal is achieved in that the surface modification of the powder particles is carried out during grinding by adding 0.05-0.3 May. % polyacrylic acid (PAA) by weight of the powder.

The introduction of PAA into an aqueous suspension of ferrite powder creates a slightly acidic medium, which accelerates the process of selective diffusion of divalent metal cations from spinel into the aqueous phase. The supersaturation of the aqueous medium with these cations causes them

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repeated deposition with the formation of a gel-like layer on the surface of the particles, increasing their sintering activity. At the same time, the removal of divalent cations from ferrite causes an increase in the content of Pb203 in the spinel lattice, which has a high sintering activity.

Example. The method was tested during wet grinding of sintered defective products of Mn-Zn ferrites of the 2500 NMS2 grade, previously heat-treated by quenching in running water from a temperature of 1000 ° C. The grinding was carried out in ball mills СМ6007А to a specific surface of 0.3-0.6 m2 / g. With wet grinding, PAK TK6-01-1260-81 was introduced into the sous. After grinding, the components of the binder were introduced into the suspension, wt.% By weight of the powder: polyvinyl alcohol 1.0; glycerol 0.15 and octanol 0.05. The resulting binder suspension was sprayed onto a granulation dryer to prepare a press powder. Sh12x20 products were pressed from press powders and calcined in a tunnel furnace with a given gas medium at 1300 ° C.

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Data on the density and electromagnetic parameters of the products after firing are shown in the table.

For comparison, the results are shown on a powder modified according to the prior art.

As the table shows, satisfactory density and electromagnetic parameters of the products are ensured when PAC is added to the suspension of at least 0.05 wt.%. Excessive addition of PAC (over 0.3 wt.%) Has an inhibitory effect on sintering processes, which reduces the density and level product parameters.

Using the proposed method allows to obtain Mn-Zn ferrites with the desired properties from powders obtained by wet grinding of sintered defective products,

Claims (1)

The claims A method of producing a powder of manganese-zinc ferrite, comprising modifying the surface of the particles, characterized in that the modification is carried out in the process of wet grinding by adding 0.05-0.3 wt.% By weight of the powder of polyacrylic acid.