JP7224995B2 - Slag analysis method - Google Patents

Description

The present invention relates to a method for analyzing slag, and in particular, slag suitable for analyzing physical properties such as the concentration and particle size distribution (particle diameter, number) of mat grains present in slag when specific gravity is separated into mat and slag. It relates to the analysis method of.

Non-ferrous metal smelting is carried out by a method of melting raw materials to separate them into matte and slag by specific gravity, and concentrating the target metals in the matte. In copper smelting, which is an example of non-ferrous metal smelting, copper concentrate, which is the raw material, is blown into a flash furnace together with oxygen-enriched air. Matte and slag consisting of iron oxide, silicic acid, etc. are produced. Matte and slag are separated by using the difference in specific gravity, then the matte is put into a converter to produce blister copper, and the slag is rapidly cooled with pressurized water to produce granulated slag.

It is known that the above method of producing matte and slag results in the target metal being mixed into the slag. The loss caused by the contamination of the target metal in the slag is called "slag loss". Slag loss includes chemical dissolution loss, in which the target metal dissolves in slag to cause loss, and suspension loss due to matte particles that are physically mixed in and suspended in slag. In order to increase the recovery rate of the target metal, it is desirable to minimize the suspension loss caused by the matte particles suspended in the slag.

The properties of slag are observed to evaluate the slag loss when it is separated into matte and slag by specific gravity. For example, Non-Patent Documents 1 and 2 describe measuring the phase state of slag using an electron probe microanalyzer (EMPA) and performing quantitative microanalysis of solid solutions such as spinels contained in slag. It is

Evgueni Jak et al., “Integrated Experimental Phase Experimental Phase Equilibria and Thermodynamic Modeling Studies For Copper Pyrometallurgy”, Copper 2016, pp.1316-1331 Hector M. Henao et al., “Investigation of Liquidus Temperartures and Phase Equilibria of Copper Smelting Slags in the FeO-Fe2O3-SiO2-CaO-MgO-Al2O3 System at PO210-8atm”, Metallurgical and Materials Transactions B, Volume 41B, August 2010, pp.767-779

However, both of Non-Patent Documents 1 and 2 still have room for examination as methods for analyzing slag loss. For example, the method of analyzing slag loss using EMPA as described in Non-Patent Documents 1 and 2 is based on microscopic observation of slag, so mat grains of various particle sizes are especially suspended. There are cases where it cannot be said that the pull-up loss that is used is properly evaluated. In addition, it is not possible to analyze the particle size distribution of the suspended mat grains from a macroscopic point of view.

In view of the above problems, the present disclosure provides a slag analysis method capable of analyzing suspended mat grains present in slag by a simpler method.

In order to solve the above-described problems, the present inventors have made extensive studies and found that it is useful to observe slag with a digital microscope.

In one aspect, the slag analysis method according to the embodiment of the present invention completed based on the above knowledge is a slag analysis method for analyzing suspended mat grains present in the slag using a digital microscope.

In one embodiment of the slag analysis method of the present invention, the particle size distribution of suspended mat particles is analyzed.

In one embodiment of the slag analysis method of the present invention, the hanging mat loss is analyzed from the particle size distribution of the hanging mat grains.

In one embodiment of the slag analysis method according to the embodiment of the present invention, the slag to be analyzed is embedded in resin to prepare an analysis sample, the brightness of the digital microscope is adjusted, and the suspension mat in the observation field By highlighting the phase, adjusting the brightness of the digital microscope to highlight the slag phase in the observation field, and measuring the areas of the highlighted suspended mat phase and slag phase. A method of analyzing slag, comprising analyzing at least one of concentration, particle size and particle size distribution of suspended mat grains present in an analytical sample.

In one embodiment of the slag analysis method of the present invention, the slag is granulated slag.

In one embodiment of the slag analysis method of the present invention, the suspended matte grains contain copper.

ADVANTAGE OF THE INVENTION According to this invention, the analysis method of the slag which can analyze the density|concentration of the mat grain which exists in slag by a simpler method can be provided.

FIG. 4 is a diagram representing the gravity separation of slag and matte in a furnace with slag and matte. FIG. 5 is an explanatory diagram showing an example of extracting a slag phase within an observation field; FIG. 10 is an explanatory diagram showing an example of extracting a suspended mat phase within an observation field; It is the whole sample observation photograph by a microscope. It is a slag phase partial extraction image. It is a suspended mat phase partial extraction image. Photographs of detected suspended mat grains and the minimum grain size of each grain. FIG. 4 is a distribution map of suspended mat particles.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The slag analysis method according to the embodiment of the present invention can be used, for example, for concentration analysis of slag generated from a furnace that melts raw materials to produce slag and matte.

In the present invention, the "furnace for producing slag and matte" includes, for example, a flash smelting furnace when copper ore is used, but of course includes various melting furnaces other than flash smelting furnaces. be. In the following, an example of extracting granulated slag obtained by granulating slag obtained by melting copper ore into a flash furnace and analyzing the copper component in the granulated slag will be explained. Embodiments The present invention is not limited to copper ore, and can be applied to various materials, and is of course not limited to the following examples.

FIG. 1 shows the positional relationship between molten matte and molten slag separated by specific gravity in a flash smelting furnace. In the lowermost layer, there is a liquid phase mat (bulk mat 1) in which the target metal is concentrated, and above the bulk mat 1 there is a liquid phase slag (bulk slag 3). A liquid phase intermediate layer 2 is formed between the bulk mat 1 and the bulk slag 3 .

As shown in FIG. 1, the bulk slag 3 and the intermediate layer 2 have spinels 10 solid phase precipitated in a liquid phase slag 13 and suspended mat grains 11 dispersed therein. The slag analysis method according to the present embodiment uses a digital microscope to directly analyze the suspended mat grains 11 dispersed in the liquid phase slag 13, thereby analyzing the concentration of the target metal.

Conventionally, the bulk slag 3 was microscopically observed using EMPA as disclosed in Patent Documents 1 and 2, and the concentration of the suspended mat grains 11 in the bulk slag 3 was estimated therefrom. On the other hand, in this embodiment, the suspended mat grains 11 of the target metal dispersed in the liquid phase slag 13 of the bulk slag 3 are directly quantified using a digital microscope. By subtracting this from the chemical analysis value of the bulk slag 3, the chemically dissolved metal amount (concentration) dissolved in the bulk slag 3 is estimated.

Examples of the digital microscope according to the present embodiment include microscope CHX-6000 manufactured by Keyence Corporation. Measurement using a digital microscope is easy to obtain results easily and quickly, and is particularly suitable for analysis of suspended mat phases and suspended mat particles. In addition, since analysis from a macroscopic point of view is possible compared to the case of using EMPA or the like, it is possible to analyze not only the concentration of the suspended mat grains 11 but also the physical properties such as the particle size and quantity of the suspended mat grains. becomes possible.

On the other hand, in the conventional methods as described in Patent Documents 1 and 2, by measuring the amount of the target metal chemically dissolved in the liquid phase slag 13, the difference between the chemical analysis value of the bulk slag 3 and the amount of the suspended mat grains 11 is determined. Since it is a method of calculating the concentration, the accuracy of the amount of chemically dissolved target metal is good. However, since it is a microscopic observation, it cannot be applied to detailed analysis of the suspended mat grains 11 that exist dispersedly in the bulk slag 3 and affect the substantial slag loss, and the analysis requires a high level of skill. was

Specifically, as an analysis method according to the present embodiment, first, a slag to be analyzed is embedded in a resin to prepare an analysis sample. The slag is not particularly limited as long as it produces the suspended mat grains 11. For example, water granulated slag obtained by granulating slag obtained by putting copper ore into a flash smelting furnace and melting it may be used. can be done.

As shown in the schematic diagram of FIG. 2, the cross section of the analysis sample obtained by embedding in the resin is observed with a digital microscope. Specifically, in observation with a digital microscope, the brightness of the suspended mat phase containing the suspended mat grains 11 and the slag phase (10+13) containing the liquid phase slag 13 and the spinel 10 are adjusted to be different. Since the liquid phase slag 13 and the spinel 10 are close in brightness, as shown in FIG.

Furthermore, the slag phases 10 + 13 in the observation field are highlighted on the monitor attached to the digital microscope, and the area of the slag phases 10 + 13 (the sum of the areas of the liquid phase slag 13 and the spinel 10 in FIG. 1) is calculated using analysis software. calculate.

Next, the slag phase containing the suspended mat grains 11 in the bulk slag 3 within the observation field is highlighted. Then, the area of the suspended mat grains 11 in the highlighted slag phase is calculated using analysis software, and the concentration of the target metal dispersed in the bulk slag 3 (=suspended slag loss) is calculated.

As a method for calculating the suspended slag loss, for example, the following formula can be used.
Suspended slag loss = (Area of suspended mat grain) x (Matte density 4.7) x Mat quality (% Cu) / [{(Bulk slag area) x (Bulk slag density 3.0)} + {Area of suspended mat grain 11 x Mat density 4.7}]

Examples of the present invention are presented below along with comparative examples, which are provided for a better understanding of the invention and its advantages and are not intended to be limiting of the invention.

Twelve granulated slag samples were prepared by granulating slag obtained by melting copper ore in a flash smelting furnace, and suspended mat grains in the granulated slag were observed with a digital microscope. . A microscope CHX-6000 manufactured by Keyence Corporation was used as a digital microscope. First, a slag sample was embedded in resin and a cross section was taken out by polishing. Next, the entire sample was observed with a digital microscope. The slag phase portion (that is, the portion containing the liquid phase slag portion and the spinel) and the suspended mat phase portion were distinguished by setting the brightness, and the grain size, number, and area of each phase were measured by image extraction.

FIG. 4 shows a photograph of the entire sample observed with a microscope, FIG. 5 shows an extracted image of the slag phase part, and FIG. 6 shows an extracted image of the suspended mat phase part. From the suspended mat phase partial extraction image of FIG. 6, suspended mat particles were detected as shown in FIG. 7, and the minimum particle size of the particles was measured. Table 1 shows the results of the total number of particles measured. The total number of particles was 210 and D50 was 13.9 μm. Particle distribution is shown in FIG. The amount of copper in the suspended mat grains calculated from the grain distribution was 0.19% by weight.

DESCRIPTION OF SYMBOLS 1... Bulk mat 2... Intermediate layer 3... Bulk slag 10... Spinel 11... Suspended mat particle 13... Liquid phase slag

Claims (4)

Preparing an analysis sample by embedding slag to be analyzed with resin;
adjusting the brightness of the digital microscope to highlight the suspended matte phase in the field of view;
before or after highlighting the suspended matte phase, adjusting the brightness of the digital microscope to highlight the slag phase in the observation field;
analyzing the concentration, particle size and/or particle size distribution of suspended mat grains present in said analytical sample by measuring the highlighted areas of said suspended mat phase and said slag phase. analysis method. 2. The slag analysis method according to claim 1, wherein the suspension mat loss is analyzed from the particle size distribution of the suspension mat grains. The slag analysis method according to claim 1 or 2, wherein the slag is granulated slag. The method for analyzing slag according to any one of claims 1 to 3, wherein the suspended mat grains contain copper.

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