KR101899693B1 - Method for recovering valuable resources from slag and fine slag for efficiently recovering valuable resources - Google Patents

Abstract

The present invention relates to a method for efficiently recovering valuable resources from slag and a fine slag for efficiently recovering valuable resources.
The method for recovering oil resources according to the present invention comprises the steps of: preparing molten slag; Spraying high-pressure water into the molten slag to obtain a fine amorphous slag; Adding the fine amorphous slag to an acid solution to obtain a leached solution in which lean resources are leached out of the slag; And separating the leach solution from solid leach residue.

Description

METHOD FOR RECOVERING VALUABLE RESOURCES FROM SLUG AND FINE SLAG FOR EFFICIENTLY RECOVERING VALUABLE RESOURCES FOR EFFICIENT RECOVERY OF FUEL RESOURCES,

The present invention relates to a method for efficiently recovering valuable resources from slag and a fine slag for efficiently recovering valuable resources.

In metal smelting and the like, slag is formed on the molten metal to control the reaction and prevent the metal from being oxidized from the atmosphere. In addition, the slag may contain components derived from the ore.

Slag is a mixture of various minerals. Of the elements constituting the minerals contained in the slag, some useful oil resources are included if they can be separated and recovered from the slag.

However, these oil resources are not easily separated because they are included as constituent parts of minerals, and wet or dry extraction methods have been suggested for oil resource recovery.

That is, Korean Patent Registration No. 10-1191743 discloses a method of leaching magnesium from ferronickel slag. According to the above document, the ferronickel slag is crushed and pyrolyzed and then leached out as a leaching solvent and filtered to obtain ferronickel The process of leaching magnesium from the slag is disclosed.

However, this process requires crushing and pulverizing processes, which may cause environmental problems due to dust generation due to dried slag, and may increase production costs.

According to one aspect of the present invention, there is provided a novel method for efficiently recovering valuable resources contained in slag without having to go through an additional crushing process, and a fine slag for efficiently recovering valuable resources.

The object of the present invention is not limited to the above description. Those skilled in the art will appreciate that there is no difficulty in understanding the additional task of the present invention from the overall description of the present invention.

The method for recovering oil resources according to the present invention comprises the steps of: preparing molten slag; Spraying high-pressure water into the molten slag to obtain a fine amorphous slag; Adding the fine amorphous slag to an acid solution to obtain a leached solution in which lean resources are leached out of the slag; And separating the leach solution from solid leach residue.

According to still another aspect of the present invention, the fine slag has a particle size of 200 탆 or less and contains amorphous material therein.

As described above, according to the present invention, the slag condition of the slag can be appropriately controlled so that the slag can be changed to a condition suitable for the extraction of oil resources, so that the recovery rate of oil resources can be increased without additional crushing have.

1 is a process flow diagram illustrating an exemplary method for implementing the present invention;
2 is a graph showing the particle size distribution of the slag of the present invention produced according to the present invention,
3 is a flow chart showing the process of Comparative Example 1, and
4 is a graph showing the particle size distribution of the slag produced according to Comparative Example 1. Fig.

The present inventors have conducted intensive studies to solve the problem that a crushing operation was inevitable in order to widen the surface area of slag in the conventional wet process for recovering oil resources. As a result of studying depth, when the slag is cooled, And that some or all of the mineral phases in the slag are present in an amorphous form and are advantageous for leaching into the acid, leading to the present invention.

Hereinafter, the present invention will be described in detail.

The overall manufacturing process of the present invention is shown in Fig.

The slag to be used in the present invention includes crude oil resources, and the type of the slag is not particularly limited as long as the oil resource is a component capable of dissolving (leaching) into an acid. As an example, ferronickel slag contains a large amount of oil resources such as Mg, and Mg extracted from the ferronickel slag can be supplied as a magnesium oxide source which is a slag forming agent for steel making.

The ferronickel production process is roughly divided into a raw material treatment process for treating the raw material in a state suitable for reduction, a preliminary reduction process for reducing a part of the raw material, an electric furnace process for producing a ferronickel melt by melting and reducing the preliminarily reduced raw material A refining process for removing impurities from the ferronickel molten metal, and a casting process for obtaining a final ferronickel mass or a cast steel. According to one embodiment of the present invention, the present invention can be applied to a ferronickel electric furnace slag generated in an electric furnace for producing ferronickel.

A representative composition of the ferronickel electric furnace slag is shown in Table 1 below.

ingredient SiO2 MgO Fe2O3 Al2O3 Cr2O3 CaO Content (% by weight) 48 ~ 54 27 to 36 4 to 13 1-3 1-2 0.1 to 1.5

The remainder not shown in the table is impurities. As can be seen from the above Table 1, it can be seen that the content of MgO (Mg component converted to oxide) in the ferroelectric electric furnace slag is 25 wt% or more and is contained in an amount suitable for Mg recovery.

However, the present invention is not limited to the above-described slag, and any slag having a Mg component (that is, MgO) of 25% or more when converted to oxide may be applied to the present invention.

As described above, the slag containing a large amount of oil resources is separated from the molten metal and is temporarily accommodated in the slag port or the like in the melted state, or is discharged from the furnace without being accommodated and cooled. It is possible to divide the raw skeleton slag obtained by excluding the slag according to the cooling method and cooling it as it is, and the wastewater slag which has the cooling rate increased by spraying the water when excluding it.

Any slag obtained in any way can not be used for the process of leaching and the like because its grain size is large, and it is necessary to undergo a crushing process. In other words, the reaction that oil resources leach out from the acid occurs through the surface. The larger the unit weight or the unit volume evacuation surface area, the more the reaction is promoted. However, it takes time to perform this shredding process, and energy consumption also increases. That is, in the crushing process, the slag must be crushed through a crushing device such as a ball mill, and energy is consumed for drying the crushed slag as well as energy for operating the equipment, which is costly disadvantage. Therefore, it is preferable that the above-described crushing process is omitted as much as possible.

In the present invention, a process of spraying high-pressure water to the molten slag discharged to eliminate the crushing process is adopted. The inventors of the present invention have found that when the pressure of the high-pressure water is set to a certain level or more, the average particle size of the slag is 200 탆 or less, preferably 100 탆 or less, The amorphous crystal structure is formed not in a stoichiometric ratio, and thus it is possible to leach valuable resources such as Mg easily into the acid without undergoing additional crushing process.

That is, in the case of general crystalline minerals, since each component element exists in a stable state, even if it is exposed to an acid, it is not easy to leach out. However, since the amorphous compound is chemically unstable, it can be easily leached to an acid. Accordingly, the present invention aims at utilizing slag as amorphous fine slag by high-pressure water injection, and utilizing it for recovering valuable resources.

At this time, the pressure of the high-pressure water is preferably 1 kgf / cm ² or more. If the pressure of the high-pressure water is insufficient, the slag can not sufficiently be atomized, and it is difficult to obtain an amorphous slag. Therefore, the pressure of the high-pressure water is preferably 1 kgf / cm ² or more. The higher the pressure is, the more the above effect can be obtained. However, since the energy cost due to the high pressure may increase at too high a pressure, it is practically preferable to control the pressure to 4 kgf / cm ² or less. A more preferable range of the high-pressure water pressure is 2 to 3 kgf / cm ² .

Even if the discharge pressure of the high-pressure water is the same, it is advantageous to spray at a close distance as much as possible because the amount of impact transmitted to the slag and the amount of cooling of the slag may vary according to the spray distance. It is preferable that the distance is 0.5 to 3 m or less. Too close may cause equipment damage due to molten slag.

According to one embodiment of the present invention, the slag that is atomized by the high-pressure water injection can be recovered separately from the water by the filter. At this time, only the slag having an appropriate particle size can be separated and recovered as necessary.

The amorphous fine slag obtained by the above-described high-pressure water injection process is then added to the acid solution. The addition to the acid solution is for recovering oil resources such as Mg contained in the slag, and it is generally preferable to use a strong acid with a pH of 2 or less, and hydrochloric acid or sulfuric acid can be used. It is more preferable to use hydrochloric acid.

The fine slag may be formulated at a ratio of 300 to 400 g per liter of the acid solution. If the amount of slag is too small, the concentration of leached oil resources is low, and the process of concentration and the like may be costly and the consumption of acid may be large. Conversely, when the amount of slag is too large, It can not leach and remain in the slag.

As a result of the above-mentioned process, the leached liquid in which the oil-rich resources are leached is obtained. According to one embodiment of the present invention, the leach solution obtained by the above process may contain at least 2.5% of oil resources (on an element basis). When the content of oil resources is less than 2.5% by weight, the economical efficiency is insufficient. The higher the content of oil resources, the more advantageous it is. However, since the leaching takes a long time to increase the content, the upper limit is preferably 10% %.

Thereafter, the operation of separating the leachate from the solid phase may be followed. As can be seen in Table 1, the slag prior to the normal aging contains a large amount of SiO2, but this SiO2 component is a component that does not leach out to the acid and contains SiO2 in the solid phase. According to the results of elemental analysis, the Si contained in the SiO 2 is contained in an amount of about 24% by weight or more. When extracted separately, a good raw material of water glass can be obtained.

Thus, in one embodiment of the present invention, the method may further comprise the further step of separating Si from the separated solid phase (also called leaching residue). That is, since Si in SiO 2 does not leach out to the acid, it easily leaches out into the NaOH solution. Therefore, the process of leaching Si in the solid phase by adding the solid phase to the NaOH solution can be followed.

At this time, it is advantageous that the pH of the NaOH solution is 11 or more to obtain sufficient leaching effect. The higher the pH, the better the leaching. However, considering the use environment and the like, usually the pH is lower than 13, so the upper limit can be set at 13.

As still further aspects of the present invention, the present invention provides a slag for efficiently recovering said valuable resources according to one embodiment. When the slag is added to an acid without grinding, the slag is easy to be leached and can easily provide a leach solution and residues for recovering valuable resources, and is a fine slag having a particle size of 200 μm or less and containing amorphous. Preferably, the particle size of the fine slag of the present invention may be 100 탆 or less.

Hereinafter, the present invention will be described more specifically by way of examples. It should be noted, however, that the following examples are intended to illustrate and specify the present invention and not to limit the scope of the present invention. And the scope of the present invention is determined by the matters described in the claims and the matters reasonably deduced therefrom.

(Example)

Honor

The molten slag discharged from an electric furnace for melting ore for the production of ferronickel is accommodated in a slag pot and a high pressure water having a pressure of 2.5 kgf / cm2 is injected into the slag to be excluded while excluding slag from the slag pot The slag was atomized. During high-pressure water injection, the tip of the injection nozzle was spaced 1.5 m from the slag. The particulate slag was separated from the water by a filter, and the result of analyzing the particle size of the obtained particulate slag is shown in FIG. In the figure, 36.66 탆 indicates the particle size of the particles corresponding to the lower 50% of the total particles. As shown in the drawing, the particle size of the fine slag was distributed between 0.5 and 350 μm, and 50% of the total particles had a particle size of 35.66 μm or less.

Table 2 shows the results of analyzing the components of the fine slag.

ingredient SiO2 MgO Fe2O3 Al2O3 Cr2O3 CaO Content (% by weight) 50.8 29.7 12.5 2.3 1.1 1.2

The fine slag was added to a 35% hydrochloric acid aqueous solution having a pH of less than 2 at a ratio of 300 g per liter of the aqueous solution. To accelerate the reaction, the aqueous solution was stirred for 2 hours while allowing the oil resources such as Mg in the slag to leach into the acid , And an extract was obtained.

Then, the leached liquid was separated from solid leach residues using GFC (glass fiber filter).

Comparative Example

Through the procedure shown in FIG. 3, an oil-leaved liquid containing oil resources was obtained. That is, in the same manner as in the case of the above-described example, the slag melted from the electric furnace was produced by a conventional method of producing slag water, and recovered. The average particle size of the recovered slag was approximately 2 mm. The results of analyzing the components of the slag recovered in Table 3 are shown.

ingredient SiO2 MgO Fe2O3 Al2O3 Cr2O3 CaO Content (% by weight) 51.4 31.0 13.1 1.8 1.2 0.3

As can be seen in Table 3, the components of the recovered slag were not significantly different from those of the slag recovered through the inventive method described in Table 2. [ The recovered slag was dried and selected to have a maximum particle size of 2 mm or less.

 Followed by crushing the selected slag using a ball mill. FIG. 4 shows the result of analyzing the particle size of the crushed slag. In the figure, 19.49 mu m means the particle size of the particles corresponding to the lower 50% of the total particles. As can be seen in the figure, about 50% of the slag had a particle size of 19.49 μm or less.

The recovered slag was subjected to acid leaching in the same manner as in the case of the present invention, and then the solid phase and the leachate were separated.

Inventive example Of slag  Statistical analysis

The fine slag (obtained before addition to the acid) obtained by the inventive method was sampled and subjected to X-ray diffraction analysis. In the case of the crystalline slag, a peak was formed at a constant position as a result of the X-ray diffraction analysis, but the slag obtained by the above-mentioned example of the present invention had no distinct peak and was detected at various angles (2?). That is, it was found that the fine slag obtained by the inventive example exhibited irregular peak intensity of the diffraction line and varied width, which means that the slag was amorphized as a typical diffraction line pattern of an amorphous crystal structure.

Honor  And Comparative example  compare

Table 4 shows the results of analysis of the components of the leach solution of the invention and each of the comparative examples. Each component represents its content in element units, and the remaining components correspond to elements such as water as a solvent or oxygen bonded to the element.

ingredient Si Mg Fe Ca Cr Al Honor 0.003 4.56 One 0.17 0.14 0.20 Comparative Example <0.001 5.86 2.5 0.02 0.19 0.08

From the results shown in Table 4, the inventive example shows no significant difference in the elution amount of Mg, although the 50% particle size was 34.96 占 퐉 which was much larger than the comparative example in which the slag was crushed.

These results are interpreted as a result of the amorphization of the mineral phases contained in the slag together with the slag atomization by the high pressure water spraying of the present invention. It was possible to make the slag finer at the same time and to amorphize the slag by high-pressure water spraying, and it was possible to make it equal to the comparative example in which the elution amount of Mg, which is a crude oil resource, was broken even though no additional crushing operation was performed.

However, if the unfractured slag is used as it is, the particle size of the slag is so large that the specific surface area required for the reaction is absolutely insufficient, and the effect of accelerating the leaching due to the amorphization can not be obtained. .

In order to examine whether the solid phase separated from the leachate can be utilized in the production of the water glass, component analysis of the solid leach residue was carried out, and the results are shown in Table 5. As with the analysis results in Table 4, the remaining components mean the content of elements such as oxygen or the like that are bound to water or each element as a solvent.

ingredient Si Mg Fe Ca Cr Al Honor 30.80 5.71 2.18 0.35 0.08 0.09 Comparative Example 1 29.15 3.32 2.45 0.34 0.09 0.18

As can be seen from Table 2 and Table 5, in the present invention, Mg was contained in the slag before leaching, whereas Mg was largely leached out by leaching, and the Si content in the solid phase was the maximum content And thereafter it was found to be advantageous for leaching a basic solution such as NaOH. The Si thus leached by the basic solution is used as a raw material for water glass. This tendency was almost the same as the comparative example in which the slag was dried and crushed, which means that the method of the present invention is simple and has the same effect as the conventional method.

However, when the conventional water-based slag is leached, there is no significant change in the slag component, and a large amount of Mg or Fe is contained in the leaching residues of the solid phase, which may adversely affect Si extraction.

Accordingly, it has been confirmed that it is an effective method to obtain a high-pressure-water milled slag as in the present invention and use it directly in the acid leaching process, thereby improving the overall process efficiency and obtaining a high extraction effect.

Claims (10)

Preparing molten slag;
Jetting high-pressure water to the molten slag at a pressure of 1 kgf / cm 2 or more to obtain a fine amorphous slag;
Adding the fine amorphous slag to an acid solution to obtain a leached solution in which lean resources are leached out of the slag; And
Separating the leach solution and solid leach residue
To efficiently recover the valuable resources from the slag.
The method according to claim 1, wherein the fine grain amorphous slag has an average grain size of 200 μm or less.
The method according to claim 2, wherein the finely divided amorphous slag has an average particle size of 100 μm or less.
delete The method of claim 1, further comprising separating Si further from the solid leach residue.
The method according to any one of claims 1 to 3, wherein the molten slag efficiently recovers oil resources from slag, which is an electric furnace slag generated in the smelting of ferronickel.
The method according to any one of claims 1 to 3 and 5, wherein the acid solution is recovered efficiently from slag having a pH of 2 or less.
A micrograin slag having a particle size of 200 mu m or less and efficiently recovering oil-rich resources including amorphous materials therein.
The fine slag according to claim 8, wherein the granulated slag has a particle size of 100 μm or less.
The fine slag according to claim 8 or 9, wherein the slag is an electric furnace slag generated during the smelting of ferronickel.

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