JPS62138331A - Preparation of iron oxide for raw material of ferrite from iron ore - Google Patents

Abstract

PURPOSE:To obtain the titled iron oxide having low content of impurities useful as a raw material for general ferrite from hematite type iron ore by pulverizing the hematite type iron ore contg. small amt. of impurities comprising gangue components and removing the gangue components by washing with water. CONSTITUTION:Hematite type iron ore 1 contg. >=67% T.Fe and contg. small amt. of above described impurities is fed along with water to a crusher 2 to crush by the wer process to 1-20mum mean particle size. Then, the treated ore is fed to an adjusting tank 3 where the concn. of the ore slurry is adjusted by adding water and a surface active agent. Further, the adjusted slurry is fed to a surface flow classifier 6. At thiss stage, the water washing effect is improved by using an ultrasonic device 5 installed in the course. Impurities are washed off in the classifier 6, and concentrate 7 is obtd. from the bottom. The concentrate 7 is dried further and pulverized to obtain the target iron oxide as the raw material for ferrite.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing iron oxide, which is free of impurities and can be used as a high-quality ferrite raw material, using hematite iron ore as a raw material.

(Prior art) Well-known high-quality iron ore has traditionally been used as a ferrite raw material after being finely pulverized, but it is generally used as a ferrite raw material because it contains many impurities, so it is used as a raw material for lower grade ferrite or as an extender. It is difficult to use large quantities as a raw material for general ferrite.

(Problems to be Solved by the Invention) The purpose of the present invention is to solve the above problems and provide a method for producing fine iron oxide with few impurities, which can be used as a general ferrite raw material, from hematite iron ore. This is what I am trying to do.

(Means for Solving the Problems) The above-mentioned object of the present invention is to solve the problem by
2o3e MgO* CaOe This is achieved by finely pulverizing hematite iron ore containing few impurities such as MnO as a raw material and removing the gangue portion by washing with water.

The present invention will be explained in more detail below.

The present inventors selected hematite-based iron ore (hereinafter simply referred to as iron ore), which has few impurities and is relatively easy to obtain, for the purpose of producing iron oxide as a raw material for ferrite. Various studies were conducted on methods for removing impurities. As a result, EPMA analysis revealed that the distribution of impurities was as follows: 1) There were many impurities on the surface of the ore, and 2) There were localized areas that were considered to be impurity-rich gangue.

As it became clear that impurities in iron ore were unevenly distributed, we decided to reduce the particle size until it was possible to separate the gangue by crushing, and to apply all suitable ore beneficiation techniques. Confidence was obtained that it is possible to remove fine particles.

As a result of examining the existence form of gangue in more detail, it was found as an analogy that clay (equivalent to gangue) with many impurities is attached to ore with few impurities. This analogy
Therefore, we investigated a method of washing the gangue with water and experimentally confirmed that it was possible to remove impurities and that it was relatively easy to do.

In other words, as can be seen from the examples below, iron ore has an average particle size l
It has been discovered that it is possible to reduce the amount of impurities in iron ore to below A by combining grinding on the order of ~20 μm and washing with water.

From the distribution of the gangue and experimentally, crushing is performed when the average particle size is 1 to 1.
The best efficiency is obtained when the thickness is on the order of 20 μm.

If the size is larger than this, impurities inside the grains will not be removed, resulting in a drop in purity, and the method of classifying and removing large grains later is different from the method of fully adjusting the grain size before washing with water, but the process is different in principle. are the same) If the ore is small, washing with water and recovering the concentrate is difficult and inefficient.

Of course, in order to increase the efficiency of removing impurities by washing with water, it is sufficient to efficiently separate ore and impurities in water and perform separate recovery operations. For this purpose, sufficient stirring in water (wet grinding operation is also effective), and for thorough dispersion in water, addition of a surfactant and irradiation with ultrasonic waves were effective.

In addition, in practice, pulverization (pulverization to an average particle size of 1 to 20 μm) can be easily carried out by using, for example, a sol mill, and washing with water can be carried out, for example, by dispersing the ore in water using a stirrer in a tank. Then, the concentrate is removed using a cyclone or the like (hereinafter, the ore with few impurities after washing with water is referred to as the concentrate).
Retrieving it is relatively easy. Ultrasonic irradiation,
A surfactant can also be easily added during this process.

FIG. 1 is a diagram showing an example of a flow sheet of the present invention.

Iron ore 1 is supplied together with water to a crusher 2 and wet-pulverized. Water and surfactant are then added in adjustment tank 3 to adjust the ore slurry concentration. This adjusted slurry is sent to a surface flow classifier 6 by a bonder 4, and an ultrasonic device 5 is installed in this path to improve the ultrasonic washing effect.

In the surface flow classifier 6, impurities are washed away and a concentrate 7 can be obtained from the lower part. This is then dried and pulverized to produce a product. The pulverization system may be a known pulverizer (for example, a sol mill) or a combination of a pulverizer and a classifier and an appropriate system, and a wet pulverization system without drying is also possible. Here, the pulverizer 2 was wet-type, but dry-type pulverization is also possible, and it is also possible to omit a slurry adjustment tank, add a surfactant, and omit the ultrasonic device, or change the position. In addition, a wet classifier such as a wet cyclone can be used to recover the concentrate, but the method is not limited thereto.

The present invention will be explained based on examples.

Examples Iron ore of the brand listed below was crushed in a sol mill, washed with water, and the raw ore was mixed with 810□, At203. and MnO were analyzed to measure the impurity removal effect.

Grave 1 Grinding: Average particle size 11μm Slurry concentration: 10ch Separation: Wet cyclone Concentrate yield 95ch Concentrate...Yield 87% shop 2 Grinding: average particle size 5 μm - concentrate m, ■.

17 μm - Concentrate V, M Ultrasonic cleaning double-layer wave number 29 kHz Surfactant di-nonionic 1% Addition - Concentrate ■, ■, without addition Concentrate ■, ■ Separation dual surface flow classifier (Note) Example Components of iron ore (brand name MBR-PF produced in Brazil) used in Extremely useful.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the implementation flow of the present invention.

Claims (3)

[Claims] (1) A method for producing iron oxide for ferrite raw material from iron ore, which comprises pulverizing hematite-based iron ore containing 67% or more of T and Fe and having low impurities to an average particle size of 1 to 20 μm, and then washing with water. (2) The method for producing iron oxide for ferrite raw material from iron ore according to claim 1, in which one or both of a surfactant and ultrasonic waves is used during the water washing. (3) A method for producing iron oxide for ferrite raw material, which comprises finely pulverizing iron ore with few impurities obtained by the method according to claim 1 or 2 to an average particle size of about 1 μm.