JPS5846466B2 - Artificial stone and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a technology for utilizing slag from the steel industry, and relates to an artificial stone (decorative cloth such as imitation jewelry or marble) that is opalescent and opaque and can be colored as desired, using slag as the main raw material. , and its manufacturing method.

The amount of slag discharged as a by-product of the steel industry is extremely large, and various improvement technologies have been proposed against the backdrop of the contemporary demand for resource conservation.

The present invention was made as part of these efforts, and aims to provide high-quality artificial stone obtained using waste slag as the main raw material, and a method for manufacturing such artificial stone at low cost and rationally. .

As a method for manufacturing artificial stone from waste slag, for example, Japanese Patent Application Laid-Open Nos. 151-713-1982 and 4521-1987 are known, but the present invention proposes an artificial stone and a method for manufacturing the same that are different from these. The present invention discloses an artificial stone that specifies the fractional composition, particularly the metal fluoride content, that constitutes the artificial stone, and increases the crystallization rate of the metal fluoride to provide an artificial stone with excellent decorative functions. In order to obtain stone, an appropriate amount of metal fluoride is mixed with the blast furnace slag (this is done by reheating it after melting, shaping, and solidification), which effectively crystallizes the metal fluoride. exists.

The present inventors have been conducting various research for some time based on the idea that it is possible to provide artificial stone using blast furnace slag as a raw material. and how to appropriately set physical conditions such as melting conditions and cooling conditions;
How to improve the quality of artificial stone from the aspect of component composition, ■Above■
We have conducted repeated experiments on a method of combining (1) and (2) to improve the quality of artificial stone from both the component composition and physical manufacturing conditions.

In the process, the inventors confirmed that as long as blast furnace slag is used alone as a raw material, there is a limit to the quality of the artificial stone that can be obtained, no matter how the physical conditions for manufacturing are adjusted. ,
In order to obtain high-quality artificial stone, it was decided that the optimal composition of artificial stone should be clarified.

Based on this judgment, the present inventors prepared artificial stones with different compositions by blending various oxides and ores with blast furnace slag, and compared their quality.

As a result, O, a type of metal fluoride, is an essential component.
It was confirmed that those containing 3 to 40 (weight % or less) of aF2 exhibited superior quality compared to artificial stones with compositions outside these ranges.

In other words, in order to obtain high-quality artificial stone, the conventional method of using blast furnace slag as a raw material is insufficient, so it is necessary to mix an appropriate amount of Oa F 2 according to the composition of the blast furnace slag and adjust the composition appropriately. There is a need to.

In particular, since CaF 2 is hardly contained in blast furnace slag, it is essential to actively mix it into the blast furnace slag.

In other words, Oa F 2 exhibits a special function of emulsifying the artificial stone, and is a base for giving it a brighter color compared to the conventional artificial stone that only recrystallizes the matrix, which tends to be dark in color. (milky white) can be molded.

In addition, CaF2 has the effect of lowering the melting point of the raw material, and along with this, ■ Special heat resistance is not required for melting furnaces and melting crucibles, and commercially available products can be used. ■ Sudden temperatures during the casting process You can also enjoy the following effects: the drop is alleviated, you have more time to work, and the cost of the heat source during melting is reduced.

Although it is of course possible to use pure CaF2, the most common ones, taking into consideration industrial properties, are barbarian and quartzite.

In addition, as a coloring agent to be added as necessary, 0oC)
Examples include coloring metal oxides such as CrxOs and CrxOs.

By the way, as a method of adjusting the color tone of artificial stone, a method of adjusting the crystallization rate is known as shown in Japanese Patent Laid-Open Nos. 51-15178.

Therefore, the present inventors experimentally confirmed the influence of the crystallization rate on the artificial stone having the above-mentioned preferable component composition.

As a result, for components other than Oa F 2 among the artificial stone constituents, almost no correlation was observed between crystallization rate and quality.

However, the crystallization rate of CaF2 seems to have a significant effect on the emulsification of the entire artificial stone, and in order to achieve emulsification, the crystallization rate of CaF2 must be at least 5.
% or more.

From the above results, in the present invention, blast furnace slag is used as the main raw material, and appropriate amounts of S i 02 , Oa O, and V, O3 are blended as necessary to obtain a suitable component composition, and the crystallization rate of Ca F 2 is set to 5%. It is essential to do the above, and thereby high-quality artificial stone can be obtained.

Next, the process of manufacturing the above-mentioned artificial stone will be explained with reference to FIG.

The steps indicated by solid lines in the figure are specific examples of the method of the present invention, and are hereinafter referred to as "steps of the present invention."

Further, the process indicated by the broken line is a normal process that is permissible for obtaining the artificial stone of the present invention, and is hereinafter referred to as "normal process".

First, in the ■ process, the blast furnace slag is colored, and in the [F] process, the brutality is colored.

Here, slow-cooled solidified slag should be used as the blast furnace slag; use of quenched slag is not preferable because the artificial stone will turn black.

In addition, highly transparent colors such as white, green, and purple are used as appropriate for barbarism.

Next, both raw materials are crushed into 1 mmφ by an appropriate crusher in step 2.
Dry crushing is carried out to a level below 0.

After that, the blast furnace slag is heat-treated (roasted) in the air (in an oxidizing atmosphere) at a temperature of 500°C or more and below the melting point in step 2, if necessary.
do.

In the [F] step, raw materials are mixed, and at this time, other oxides (S102.CaO2, 'u
203) or a coloring material (CoO2Or203, etc.) may be appropriately blended.

If you use only the raw material and do not add a coloring agent, you will end up with a milky white artificial stone.

In step [F], melting is carried out at a temperature approximately 150 to 250°C higher than the melting point of the formulation (usually 1300 to 1450°C).

Since the melting point of the formulation is lowered by the blending of the barbarian, this temperature may be relatively lower than that of the case without the barbarian.

The melting atmosphere should be appropriately determined depending on the type of colorant to be blended; for example, when Co and Cr4t are used, the melting is performed in an oxidizing atmosphere, and when Se and Cd are used, the melting is performed in a reducing atmosphere.

Next, 0 process of molding and solidification is performed. In this step, a simple dropping method or a casting method is adopted depending on the shape of the desired artificial stone.

That is, the former method uses a molded plate (
For example, the molten material is dropped onto a SUS plate (SUS plate) and shaped into a hemispherical shape by the surface tension of the molten material itself.

In the latter method, a graphite or steel mold of a predetermined shape is preheated to 500 to 800°C, and the molten material is poured into the mold and solidified.

Thereafter, in the step [F], the preheating temperature is maintained for a predetermined period of time to homogenize and remove internal strains generated during cooling and solidification.

The temperature and time for keeping warm may be determined as appropriate depending on the shape and size of the molded product.

Next, in the "process of the present invention", reheating treatment of step (2) is performed.

This process is extremely effective, especially when the amount of OaF2 blended is small.
2 to promote crystallization of Ca F 2 to a predetermined crystallization rate (
5% or more) to make the artificial stone milky and opaque.

Specifically, this is carried out by reheating at 550 to 800°C for 10 minutes or more.

However, the crystallization of Cr a F 2 progresses slightly even in the slow cooling process (■) described below, so if the amount of CaF 2 blended is large, even if the crystallization rate of the total Oa F 2 is low, the artificial stone as a whole will not reach the specified Oa F 2. 2 crystallization ratio may be ensured.

Therefore, when preparing a large amount of OaF 2 , the artificial stone of the present invention can be obtained by employing the "normal process" in which step (1) is omitted, and by appropriately selecting the conditions of the slow cooling step (2) described later.

However, in any case, the crystallization rate of CaF2 can be increased by performing the reheating treatment described in (2), so if the "process of the present invention" is adopted, a higher quality artificial stone can be obtained.

Finally, by performing slow cooling in step (2), the artificial stone of the present invention can be obtained.

This step is to prevent the molded product from cracking due to thermal strain generated during cooling, and is usually carried out at a temperature of 10° C./min or less, although it depends on the shape and size of the molded product.

In particular, the cooling rate between 500°C and 100°C is 10°C.
When the temperature exceeds ℃/min, cracking becomes noticeable.

The artificial stone obtained as a result of the above has a specific gravity of about 28, which is comparable to the specific gravity of marble, 2.5 to 2.9, and a hardness of 200.
~500 Hv, 4-5 Mohs, comparable to opal's 4-6 Mohs.

Further, the crystallization rate of C a F 2 is 5 to 20%, and it is a milky opaque substance with a glossy surface, and is of high quality as an artificial jewelry or a decorative stone.

Next, a part of the experimental progress until the present invention was completed will be described.

(Relationship between the blending ratio of CaF2 and emulsification) Using the blast furnace slag of Himotori shown in Table 1, the barbarity of Himotori shown in Table 2, and 5iO2 (reagent: 99.9% or more) as raw materials, each component Artificial stones were manufactured with different blending ratios.

However, the production was carried out according to the "normal process", roasting conditions for blast furnace slag: 1000℃ x 5 hours, melting conditions: 1400℃, molding and solidification: dropping on SUS plate, heat retention conditions: 550℃ x
30 minutes, slow cooling conditions: 10° C./min or less.

The results are shown in Figure 2. In FIG. 2, the blended amount of blast furnace slag is 50 parts by weight even in the case of slag.

As is clear from the results in Figure 2, there is not much correlation between the amount of Si02 added, which contributes to the vitrification of artificial stone, and emulsification, and the degree of emulsification is significantly affected by the amount of Si02 added. As shown in Figure O, at about 25 parts by weight, it becomes semi-turbid, and when it is added at 30 parts by weight or more, it becomes completely cloudy.

Therefore, in order to obtain the artificial stone of the present invention by the above-mentioned "normal process", 25 parts by weight or more of barbarian should be blended into the total raw materials.

(CaF2 compounding ratio and its crystallization rate) The CaF2 compounding rate and crystallization rate of CaF2 of the artificial stone obtained in the "normal process" and the addition of reheating treatment at 800°C for 90 minutes were the same as above. Similarly (“process of the present invention”)
The relationship between the Ca F 2 blending ratio and the Ca F 2 crystallization rate of the obtained artificial stone was observed, and the results shown in FIG. 3 were obtained.

Incidentally, the crystallization rate of Ca F 2 was measured by X-ray diffraction method.

As is clear from the results shown in Figure 3, ``In the normal process, a large amount of brute force must be added to ensure the predetermined CaF2 crystallization rate, but when the ``process of the present invention'' is adopted, it is relatively High CaF even when only a small amount of barbaric acid is added
2 crystallization rates can be obtained.

[Relationship between reheating treatment conditions, CaF2 crystallization rate, and surface gloss] The two types of raw material formulations shown in Table 3 were adopted, and the artificial material was treated in the same manner as above, except that the recrystallization treatment conditions were variously changed. Stone was manufactured, and the relationship between reheating treatment conditions, surface gloss, and Ca F 2 crystallization rate was investigated.

The results are shown in Table 4 (relationship with surface gloss) and Figure 4 (0aF
2 Relationship with crystallization rate).

As is clear from the results in Table 4, in order to impart excellent gloss to the artificial stone, it is desirable that the reheat treatment temperature be lower than 800°C, more preferably 700°C or lower.

As far as this experiment is concerned, no difference was observed between sample layer 1 and /162.

Furthermore, as is clear from the results shown in Figure 4 (heat retention time is 90 minutes even after collapse), the higher the amount of CaF2 mixed, the higher the crystallization rate of CaF2, and the higher the reheating temperature, the lower the crystallization rate. It gets expensive.

In addition, the blending ratio of barbarian (CaF2) was 30 parts by weight (sample AI
), the predetermined CaF2 crystallization rate (5% or more) can be secured regardless of the presence or absence of reheating treatment, but Oa
When the blending ratio of F 2 is less than about 25 parts by weight (sample layer 2), recrystallization treatment is essential, and if this is omitted, a predetermined Ca F 2 crystallization rate cannot be secured.

As is clear from this result, the reheating treatment characterized by the "process of the present invention" is particularly important when the blending ratio of Ca F 2 is reduced.

The present invention is roughly configured as described above, and specifies the fractional composition of a molten raw material mainly consisting of blast furnace slag, and in particular, specifies the fractional composition of a molten raw material mainly consisting of blast furnace slag.
2 and the recrystallization rate is set to a predetermined value or higher (this makes it possible to provide high-quality artificial stone.

Furthermore, by performing reheating treatment during the manufacturing process, high-quality artificial stone can be produced even when the amount of CaF2, which is an auxiliary raw material, is reduced.This book contributes to the technology of utilizing blast furnace slag. The significance of this invention is extremely significant.

Next, examples of the present invention will be shown.

Example: Blast furnace slag and barbage having the compositions shown in Tables 1 and 2 were used, and S102 was used as an auxiliary raw material, and OaO and Cr were used as colorants.
203 (all three are experimental reagents with 99.9% or more)
Three kinds of raw materials were prepared according to Table 5.

This was treated according to the "process of the present invention" shown in FIG. 1 to obtain artificial stone.

The specific conditions are as follows. Melting process: 1300℃
, Oxidizing atmosphere Molding process: Dropped onto a SUS plate preheated to 500-600°C Heat retention process: 500°C x 30 minutes Reheating treatment: 600°C x 1 hour Slow cooling process: Cooled to 100°C or less at 5°C/min The obtained artificial stone had the properties and physical properties shown in Table 6 below, and was of extremely high quality as a decorative rough stone.

[Brief explanation of drawings]

Figure 1 is a flow sheet illustrating the manufacturing method of the present invention;
The figure shows the relationship between the combination ratio of barbarism and emulsification, and Figure 3 is O
FIG. 4 is a graph showing the relationship between the blending ratio of a F 2 and the crystallization rate, and FIG. 4 is a graph showing the relationship between the reheat treatment temperature and the crystallization rate of Ca F 2.

Claims (1)

[Claims] 1. An artificial stone whose main raw material is blast furnace slag, which includes CaF2:
An artificial stone containing 5 to 40% by weight of Oa F 2 and crystallized in an amount of 5% by weight or more. 2 Melt the raw material made by adding metal fluoride to blast furnace slag,
A method for producing an artificial stone, which comprises forming and solidifying the metal fluoride and then subjecting it to a reheating treatment to crystallize the metal fluoride.