JPS5855646B2 - Jiseiri Yutaino Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a magnetic fluid using a ferromagnetic spinel compound generated by converting heavy metal ions in wastewater into ferrite and removing them from the system as a raw material.

Specifically, a substance that becomes ferrous ions by dissolution into wastewater containing heavy metal ions and an alkaline substance in an amount equal to or more than the total acid radicals are added, then an oxidizing agent is used to oxidize the resulting precipitate, and finally a strong A magnetic spinel compound is produced by incorporating and removing the heavy metal ions into the crystals of the spinel compound produced, and then mixing the spinel compound with a dispersant such as oleic acid and a dispersion medium such as kerosene. The present invention relates to a method for producing magnetic fluid.

Magnetic fluid is a recently developed liquid containing magnetic colloidal particles that exhibits interesting phenomena, and research into its application is progressing in various fields.

For example, a wide range of applications are being considered for applications in resource recovery and pollution prevention, such as the use of magnetic fluids to separate and recover non-magnetic metals and the recovery of oil floating on water surfaces.

However, the magnetic fluid itself is currently very expensive, and the field of application may be limited from an economical point of view.

The present invention enables the production of ferromagnetic spinel compound (magnetite and ferrite) particles produced from the treatment process of wastewater containing heavy metals in large quantities and at low cost from these fine particles, without simply discarding them as industrial waste, and for various applications. The purpose is to expand the possibilities of

To briefly explain about magnetic fluids, the liquid itself does not exhibit ferromagnetism, but it is made by combining ferromagnetic spinel-type compounds such as magnetite and ferrite with a particle size of about 100λ or less into hydrocarbons (such as molten oil). It is a colloidal solution suspended in silicone oil, fluorocarbon, etc.

Electrode clutch liquid has been known as something similar to this, but this is made by suspending micron-order iron particles in oil, and when placed in a magnetic field, the particles aggregate. Magnetic fluids have much smaller particles and exhibit superparamagnetic properties; when placed in a magnetic field, the liquid moves as if it were magnetic.

Therefore, ferromagnetic spinel type compound fine particles with a particle size of about several hundred λ are required as a raw material for the magnetic fluid.

On the other hand, water pollution has become a major problem in recent years, and in response to this problem, various technologies have been developed to specifically remove heavy metals from water, and one of these technologies is the heavy metal removal technology using the ferrite method, which has already been put into practical use.

To put it simply, this technology adds ferrous ions to industrial wastewater containing heavy metals, then adds an alkaline substance, and then blows in an oxidizing gas such as air to finally form iron oxides such as ferrite. This is a method of removing heavy metals from wastewater by incorporating them into the crystal lattice or adsorbing them.The ferrite particles produced by this process can be 0.01μ to 1μ depending on the reaction conditions, but in general They are fine particles with a particle size of several hundred holes, and are suitable for producing magnetic fluids.

That is, the present invention involves adding a dispersing agent such as oleic acid and a dispersing medium such as kerosene to a ferromagnetic spinel compound precipitate produced by incorporating heavy metal ions in wastewater by a wet oxidation ferrite method, thereby producing fine ferromagnetic spinel compound particles as a magnetic fluid. By recovering the ferromagnetic spinel compounds incorporating various heavy metals, we aim to reuse them as magnetic fluids with high utility value.

Details will be explained below using examples.

Example I Mn ion approximately 100091) In, Zn ion approximately 100
0.1 mol of ferrous chloride and 761 rll of 5N-NaOH were added to wastewater 11 containing approximately 70% of Nt ions, and air oxidation was performed at 70°C for 1 hour to obtain a ferromagnetic precipitate.

Mn, Zn, and Ni remaining in the solution obtained by filtering this precipitate
, Fe concentrations are 0.05, 0.02 and 0.02, respectively.
1, 0.07 ppII.

4 ml of oleic acid and 40 ml of kerosene were added to this precipitate and mixed for 2 hours using a mixer to obtain a dark brown magnetic fluid.

The saturation magnetic flux density Ms of this material was 130 Gauss.

Example 2 Cu ion about 10 Qppm, Ni ion about 40p
5N-
The mixture was neutralized by adding 41 ml of NaOH and oxidized at 40°C for 2 hours to obtain a black ferromagnetic precipitate.

Next, 3 ml of oleic acid and 25 ml of kerosene were added and the suspension was stirred and mixed to obtain a magnetic fluid.

Cu, Nls total Cr and F in the separated magnetic fluid
The residual concentrations of e are 0.05, 0.08, and 0.05, respectively.
08, 0.09 ppm.

The saturation magnetic flux density of the obtained magnetic fluid was 85 Gauss.

Claims (1)

[Claims] 1 Add a substance that becomes ferrous ions by dissolution into wastewater containing heavy metal ions and an alkaline substance in an amount equivalent to or more than the total acid radicals, and then oxidize the precipitate using an oxidizing agent to produce a ferromagnetic spinel-type compound. . A method for producing a magnetic fluid, which comprises incorporating and removing the heavy metal ions into the produced spinel compound crystals, and then mixing the spinel compound with a dispersant and a dispersion medium.