KR101205537B1 - Preparation method for magnesium compound using ferronickel slag - Google Patents

Abstract

The present invention relates to a method for producing a magnesium compound from ferronickel slag, characterized in that the solid phase portion is removed through a solid-liquid separation process of sedimentation or filtration in a solution in which ferronickel slag is added with an acid or an acid and an organic thickener. In addition to providing a method of effectively utilizing ferronickel slag, it is possible to achieve a reduction effect of magnesium-containing minerals such as dolomite, and also to use by-products of the magnesium compound manufacturing process as cement or mortar additives, mixed cement mixtures or concrete mixtures. To provide.

Description

Preparation method for magnesium compound using ferronickel slag

The present invention relates to a process for preparing magnesium compounds from ferronickel slag.

Ferronickel is an alloy of iron and nickel. The slag generated during smelting of this alloy is called ferronickel slag.

In Korea, ferronickel slag is generated as a by-product during the manufacturing process of ferronickel products (80% Fe, 80% Ni) of SNNC of Gwangyang, Jeonnam, and the chemical composition of ferronickel slag is shown in Table 1.

ingredient SiO ₂ Al ₂ O ₃ CaO MgO Fe ₂ O ₃ K ₂ O Na ₂ O SO ₃ LOI content 51.3 3.91 0.49 34.0 7.83 0.07 0.36 0.03 0.00

The main components of ferronickel slag are SiO ₂ and MgO, in addition to Fe ₂ O ₃ and Al ₂ O ₃ . In addition, it contains a small amount of Ni, Cl, SO ₃ and the like. The mineral phase of ferronickel slag is mainly composed of Fosterite (2MgO? SiO ₂ ) and Enstatite (MgO? SiO ₂ ).

Ferronickel slag is used as raw materials for roadbed and fertilizer because it does not contain heavy metal components related to soil pollution, and it is used as steelmaking agent because it does not contain copper unlike other nonferrous slag. It is also used as. However, the amount of recycling is still very small.

Ferronickel slag contains 34% by weight of MgO, which is higher than natural dolomite (20% by weight). Therefore, the extraction of magnesium from ferronickel slag, which is an industrial by-product, is more effective, and it may be accompanied by the advantage that natural resource saving and mine development are not required.However, a method for preparing magnesium compound from ferronickel slag that can be industrially used so far Is not being proposed.

It is an object of the present invention to provide a method for producing a magnesium compound from ferronickel slag.

The present invention provides a method for producing a magnesium compound from ferronickel slag, characterized in that the solid phase portion is removed through a solid-liquid separation process of sedimentation or filtration in a solution in which ferronickel slag is added together with an acid or an acid and an organic thickener.

In the method for producing a magnesium compound from the ferronickel slag of the present invention, after stirring the solution with the acid, the ferronickel slag is stirred for 3 to 24 hours, characterized in that the solid-liquid separation of the precipitate and the supernatant.

In the method for producing a magnesium compound from the ferronickel slag of the present invention, the ferronickel slag is characterized in that the solid solution is separated into a precipitate and a supernatant by stirring the solution containing the acid and the organic thickener immediately or less than 3 hours.

In the method for producing a magnesium compound from the ferronickel slag of the present invention, the hydrofluoric acid solution is further added to the liquid portion obtained through the solid-liquid separation.

In the method for producing a magnesium compound from the ferronickel slag of the present invention is characterized in that the hydrofluoric acid solution is further added to the liquid portion and then heated.

In the method for producing a magnesium compound from the ferronickel slag of the present invention, the ferronickel slag is characterized in that the addition of ammonia water to the solution or the liquid portion obtained through the solid-liquid separation of the acid or acid and the organic thickener together.

In the method for preparing a magnesium compound from the ferronickel slag of the present invention, a saturated ammonium oxalate solution or a saturated ammonium carbonate solution is added to a solution in which the ferronickel slag is added with an acid or an acid and an organic thickener together or the liquid portion obtained through the solid-liquid separation. It is characterized by further adding.

In the method for preparing a magnesium compound from the ferronickel slag of the present invention, the ferronickel slag is further added with one or more of ammonia water, saturated ammonium oxalate solution and saturated ammonium carbonate solution to the acid or acid and an organic thickener solution. It is characterized by removing the solid part through the solid-liquid separation process of sedimentation, filtration.

In the method for producing a magnesium compound from the ferronickel slag of the present invention, after further adding ammonia water, saturated ammonium oxalate solution or saturated ammonium carbonate solution to the liquid portion obtained through the solid-liquid separation, the solid-liquid separation process of sedimentation or filtration It is characterized by removing a solid part.

In the method for producing a magnesium compound from the ferronickel slag of the present invention is characterized in that the liquid portion obtained through the solid-liquid separation process is dried or calcined.

The present invention provides a method of using a solid part produced as a by-product in the solid-liquid separation process of the method for producing a magnesium compound from the ferronickel slag as a cement or mortar additive, a mixed cement mixture or a concrete mixture.

By providing a method for producing magnesium compound from ferronickel slag, it is possible to provide a method of effectively utilizing ferronickel slag, and at the same time to achieve a reduction effect of magnesium-containing minerals such as dolomite, and also by-products of magnesium compound manufacturing process It provides a method of using as a mortar additive, a mixture for mixing cement or a mixture for concrete.

Figure 1 shows the X-ray diffraction pattern of the product of Example 4 of the present invention.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are merely to illustrate the present invention, but the content of the present invention is not limited thereto.

First, the dissolution of ferronickel slag may use various acids such as hydrochloric acid, sulfuric acid, hydrofluoric acid, nitric acid, formic acid and acetic acid. The concentration of acid is preferably 0.1 to 5.0 M in terms of solubility of ferronickel slag, and the content of ferronickel slag is 10 to 200 parts by weight, preferably 20 to 80 parts by weight, based on 100 parts by weight of the acid solution.

Table 2 shows the ion concentration (% by weight) in the solution when 100 g of ferronickel slag was stirred at 600 rpm in a 0.5 M hydrochloric acid solution.

ingredient Na Mg K Ca Fe Al Si S for
year
city
liver 10 minutes - 0.34 - 0.01 0.08 0.01 0.35 30 minutes - 0.56 - 0.01 0.20 0.03 0.54 - 60 minutes - 0.59 - 0.01 0.21 0.03 0.49 - 90 minutes - 0.58 - - 0.13 0.01 0.34 120 minutes - 0.58 - - 0.07 0.006 0.18 -

To dissolve the ferronickel slag, the ferronickel slag is added to an acid or a mixed solution of an acid and an organic thickener and stirred for 30 minutes or more, preferably 40 to 120 minutes, more preferably 50 to 90 minutes. If the stirring time is shorter than the lower limit, magnesium ions may not be sufficiently dissolved in the solution or the concentration of ions other than magnesium ions may be high, resulting in high impurities in the final product. On the other hand, even if the stirring time is further increased, the dissolved amount of magnesium ions does not increase further. Agitation can be performed at 400-800 rpm.

As shown in Table 2, the acid contained not only magnesium ions but also various elements such as aluminum, iron, and silicon ions. In other words, it was confirmed that a pure magnesium compound could not be obtained by simply dissolving.

To increase the solubility of magnesium ions in ferronickel slag, the ionic concentration (% by weight) when fixing the dissolution conditions at 600 rpm for 30 minutes and changing only the temperature of the acid solution is shown in Table 3.

ingredient Na Mg K Ca Fe Al Si S On
Degree 30 ℃ - 0.56 - 0.01 0.20 0.03 0.54 - 50 ℃ - 0.58 - 0.01 0.21 0.02 0.55 - 70 ℃ - 0.60 - 0.01 0.21 0.03 0.51 - 90 ° C - 0.59 - 0.01 0.18 0.01 0.48 -

As the temperature increased, the elution of ions increased slightly, but there was no further change above 70 ° C. That is, although all can be eluted from room temperature to 100 degrees C or less, it was judged that it is the most favorable range from room temperature to 70 degreeC. Regardless of the type of acid, solubility no longer increased above 70 ° C.

On the other hand, the components of the residue after dissolution of the solution of Table 3 dissolved by stirring at 40 ° C., 600 rpm, 30 minutes with 0.5 M hydrochloric acid were analyzed and shown in Table 4.

ingredient SiO ₂ Al ₂ O ₃ CaO MgO Fe ₂ O ₃ K ₂ O Na ₂ O SO ₃ LOI content 53.3 3.96 0.27 31.3 8.36 0.10 0.27 0.11 0.00

The residue (or precipitate) after dissolution of Table 4 shows that the composition of the component is very similar to that of the initial starting ferronickel slag, which means that not only a certain component is dissolved but most components are dissolved. In particular, it was judged that dissolution of silicon ions was accompanied by dissolution of silicon alone and the separation of silicon constituents associated with magnesium as the silicon component bonded to magnesium was broken. Therefore, it is assumed that silicon may exist as a single ion, but many exist as magnesium-silicon bonds. Therefore, it is most effective to separate in consideration of the above state of existence.

In the present invention, a solid-liquid separation method such as sedimentation or filtration is used to remove the silicon component.

After dissolving the ferronickel slag by stirring in an acid solution for 3 to 24 hours, preferably 5 to 24 hours, more preferably 8 to 12 hours, and after filtering the solution, most of the silicon components are precipitated. Change to a residue.

When the ferronickel slag is dissolved in an acid solution in order to save the settling time, the organic thickener is mixed to increase the viscosity of the solution. The component can be removed. In the case of the inorganic thickener, the viscosity of the solution can be increased, but since the inorganic thickener itself acts as an impurity of the final magnesium compound to increase the impurity content, it is preferable to use an organic thickener. Thickeners can be used. The organic thickener is preferably added in an amount of 0.1 to 5% by weight, preferably 0.2 to 2% by weight, based on the acid solution.

This is because the silicon component in the solution alone or in combination with magnesium forms larger and heavier ionic materials. Pure magnesium ions, however, do not settle and are dispersed in solution and are present in the liquid phase, such as the supernatant or filtrate.

In addition, when the acid used for dissolving ferronickel slag is not hydrofluoric acid, when the hydrofluoric acid is added to the molar concentration of the silicon component of the liquid portion obtained through the solid-liquid separation process, the silicon remaining in the liquid portion is silicon fluoride Volatilized and removed. At this time, if the liquid phase is heated after the addition of fluoric acid, the gasification of silicon fluoride is further promoted.

In addition, ferro iron components contained in slag Nickel is added to aqueous ammonia _{(NH 4 OH) Fe (OH} ) sikimyeo changed to _2, and the resulting Fe (OH) ₂ is characterized in that settling. At this time, the addition amount of the ammonia water may be calculated and added according to the iron molar concentration of ferronickel slag analyzed in advance.

In addition, the calcium component contained in the ferronickel slag is precipitated using a saturated ammonium oxalate solution, where the calcium component is converted to calcium oxalate and precipitated. In addition, the solution may be precipitated using a saturated ammonium carbonate solution.

[Reaction Scheme]

_{^{Ca 2 + + (NH 4)}} 2 CO 3 → CaCO ₃ + 2NH ₄ ⁺

The removal of iron and the removal of calcium may be performed by removing ferronickel slag together with acid or acid and an organic thickener together in a solution to remove silicon, iron and calcium, all of which may be performed sequentially. It may be. However, it is more economical to run them all in the initial ferronickel slag acid solution.

When all the precipitates of the dissolved solution that has gone through the above process sinks to obtain a supernatant or filtered to obtain a filtrate to recover the liquid portion. When the recovered liquid portion is dried at 100 ° C., it may be obtained as a magnesium compound or magnesium hydrate, and when calcined at 100 ° C. or higher, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium oxide, or the like may be obtained.

Table 5 shows the results of chemical analysis of the material obtained through the above process. 100 g of ferronickel slag was added to 500 ml of each of acetic acid (Example 1), acetic acid (Example 2), nitric acid (Example 3), hydrochloric acid (Example 4) and sulfuric acid solution (Example 5) at 0.5 M. After stirring for 30 minutes at, the mixture was allowed to stand for 8 hours to obtain a supernatant and a precipitate. 6 ml of ammonia water and 50 ml of saturated ammonium oxalate solution were added to 400 ml of the supernatant obtained, and the mixture was stirred at 600 rpm for 30 minutes, followed by standing for 4 hours to obtain a supernatant and precipitate. 5 ml of 50% hydrofluoric acid is mixed with 400 ml of the supernatant and completely dried at 100 ° C. After drying, a Mg compound is obtained. Thereafter, the obtained powder was calcined at 500 ° C. to 600 ° C. for 30 minutes to prepare magnesium oxide (MgO).

ingredient SiO ₂ Al ₂ O ₃ CaO MgO Fe ₂ O ₃ SO ₃ Sum Example 1 0.39 0.39 5.47 93.55 0.98 0.59 101.37 Example 2 1.81 0.43 2.41 91.85 1.38 0.43 98.30 Example 3 0.19 0.39 3.60 93.30 3.60 0.55 101.62 Example 4 0.15 0.30 2.09 97.67 1.49 0.11 101.81 Example 5 0.16 0.33 3.43 94.75 1.64 0.12 100.43

X-ray diffraction pattern of the product of Example 4 is shown in FIG. As a result of Figure 1 it was confirmed that the product of Example 4 is magnesium oxide.

Regardless of the type of acid, the magnesium oxide components were all 90 wt% or more, and especially when hydrochloric acid was used, a high content of 97.67 wt% was confirmed.

It was confirmed the applicability of the precipitate (residue) obtained in the solid-liquid separation process of Example 4 of Table 5 as a cement or mortar additives, mixed cement mixtures or concrete mixtures.

The residue was dried and pulverized and 5% substitution was added to cement to give the compressive strength in Table 6 and the setting time in Table 7.

division 3 days 7 days 28 days Cement (OPC) 32 43 51 Cement substitute (5%) 33 42 53

When the residue obtained in the example of the present invention was added to the cement, it was confirmed that the compressive strength values of the same level were obtained for the 3 days, 7 days, and 28 days strength.

division First closing Cement (OPC) 215 minutes 6 hours 45 minutes Cement substitute (5%) 205 minutes 6 hours 50 minutes

Also, when the residue obtained in the examples of the present invention was added to cement, a level of condensation similar to that of OPC was derived.

In addition, the slag cement (based on the slag content of 45%), which is a kind of mixed cement, has the same strength value or higher than that of the slag cement even when the compressive strength value is measured by replacing 20% slag (20% residue + 25% slag). The values are shown (Table 8).

division 3 days 7 days 28 days Slag Cement (SC) 25 40 53 Slag replacement (20%) 29 43 58

Condensation tends to be slightly shorter in initial and final, resulting in shorter form removal time in civil applications (Table 9).

division First closing Slag Cement (SC) 235 minutes 7 hours 05 minutes Slag replacement (20%) 225 minutes 6 hours 55 minutes

Claims (11)

delete Magnesium compound is prepared from ferronickel slag, wherein the ferronickel slag is added to a solution containing an acid or an acid and an organic thickener, and then stirred for 3 to 24 hours to solidify the precipitate into a precipitate and a supernatant to remove a solid phase portion. Way.
The method of claim 2, wherein the ferronickel slag is solid-liquid separated from the precipitate and the supernatant by stirring the solution containing the acid and the organic thickener immediately or less than 3 hours. .
3. The method of claim 2, wherein the hydrofluoric acid solution is further added to the liquid portion obtained through solid-liquid separation.
The method of claim 4, wherein the magnesium compound is prepared from ferronickel slag, further comprising adding a hydrofluoric acid solution to the liquid portion and heating.
The method of claim 2, wherein ammonia water is further added to the liquid portion obtained through the solid-liquid separation to prepare a magnesium compound from ferronickel slag.
The ferronickel slag according to claim 2, further comprising adding a saturated ammonium oxalate solution or a saturated ammonium carbonate solution to an acid or a solution in which an acid and an organic thickener are added together or a liquid portion obtained through the solid-liquid separation. Process for preparing magnesium compound from nickel slag.
8. The ferronickel slag according to claim 6 or 7, wherein the ferronickel slag is added with an acid or an acid and an organic thickener together, and at least one of ammonia water, saturated ammonium oxalate solution and saturated ammonium carbonate solution is added, followed by sedimentation or filtration. Method of producing a magnesium compound from ferronickel slag characterized in that the solid phase portion is removed through a solid-liquid separation process of the.
According to claim 6 or 7, wherein the liquid portion obtained through the solid-liquid separation is further added to ammonia water, saturated ammonium oxalate solution or saturated ammonium carbonate solution, and then the solid phase portion is removed through the solid-liquid separation process of sedimentation or filtration. Method for producing a magnesium compound from ferronickel slag, characterized in that.
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