JPS61201672A - Manufacture of inorganic polycomponent antiabrasive material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a manufacturing method 1 for an inorganic multi-component wear-resistant material, in particular, by using metal smelting slag, an inorganic multi-component material that is inexpensive and of stable quality. The present invention relates to a method for producing a component-based wear-resistant material.

(Prior art and problems) Examples of wear-resistant materials based on inorganic oxides include corundum (α-A(?203), chromite (Cr203),
) etc. are well known, and Fi! Awarded as an abrasive material for rWI. However, such wear-resistant materials made of a single inorganic oxide are not widely used as wear-resistant materials for structures because the cost of extracting and producing a single compound is high and their impact resistance is low. do not have.

Tokuko Sho 3B- as a wear-resistant material for low-cost structures.
Materials made by melting and casting natural igneous rocks, such as basalt wood, as described in No. 21886, are well known. Basalt wood is a wear-resistant material made of inorganic multi-component oxides that is low in production cost and is made by melting raw materials mainly consisting of natural basic igneous rocks and pouring them into molds. be.

The natural basalt used in the manufacture of basalt wood is generally S
In addition to iO245-50%, AQ203, iron oxide, Mg
Basalt phenocrysts, which are composed of various oxides such as O and CaO, are often darkish and dense, and include plagioclase peridotite,
It is composed of pyroxene, magnetite, etc., and the base stone, plagioclase, is shaped like an elongated rectangular column and has a so-called basaltic structure with an indeterminate orientation. The Mohs hardness of basalt is about 5 to 7, but in order to make basalt wood made from naturally occurring basalt effective as a wear-resistant material, it is necessary to use especially high-hardness pyroxenes (Mohs hardness 6 to 7). As the content increases, the crystal grain size increases! [Refinement is necessary. For this purpose, a crystal nucleation promoting substance such as magnetite or titanite is added, and fine crystals are uniformly dispersed by heat treatment after melting.

As the main raw material for conventional basalt wood is naturally occurring basalt, there are constraints on the supply of raw materials, and in terms of weight, the cost of transporting the raw materials from the raw material source to the manufacturing factory cannot be ignored. Ta.

On the other hand, in the metal smelting industry, a large amount of smelting slag rich in inorganic oxides is generated in various total smelting processes. Currently, this smelting slag is used as a substitute for crushed stone for road subgrades, and is recycled again during the smelting process to recover residual valuable metals. However, it is hoped that it will be used for more effective purposes in the future.

(Means for solving the problem) Since the raw material for metal smelting is a natural ore containing metals, the stony part of the slag that remains after the metal elements are separated and extracted is essentially a general rock constituent. and R4u. In addition, in order to promote the separation of non-metallic substances during the metal smelting process, an appropriate solvent is added to lower the melting point of the slag, so the produced slag has good fluidity similar to natural basalt. are doing.

The present inventors focused on such characteristics of metal smelting slag,
It has been discovered that by melting this after adjusting the appropriate components and further heat-treating it to finely disperse the hard mineral phase, an inorganic multi-component oxide useful as a wear-resistant material can be produced at a low cost.

Here, the present invention adds additives to one or more types of fully smelted slag, and the composition of the resulting mixture is: SiO2: 50-55%, A12203: 3-1
5%, CaO: 3-15%, MgO: 3-15%
, alkali metal oxide = 5% or less, iron content: 8 to 12%, underground inevitable impurities (both are weight %), and after melting this mixture, the temperature is 1000 to 1200 ° C. This is a method for producing an inorganic multi-component wear-resistant material, which is characterized by performing a heat treatment for 3 to 20 minutes.

(Function) The present invention will be explained in more detail below. In the following description, percentages are by weight unless otherwise specified.

First, the reason why the components of the raw material mixture are limited within the above range in the method of the present invention will be explained.

SiO2, AQ20i, CaO, MgO: When manufacturing a wear-resistant material from metal smelting slag, a finely dispersed high-hardness mineral phase must be formed inside the smelted material. That is, it is important to form a mineral phase as hard as possible by utilizing the main components constituting the slag.

From this point of view, the present inventors studied the composition of various slags, the phase diagram of the slag component system, and the hardness of each crystallized phase, and obtained the following findings.

Table 1 shows typical compositions of blast furnace slag, converter slag, silicomanganese slag, and nickel slag, which are typical metal smelting slags.

From Table 1, it can be seen that the main chemical components constituting various smelting slags can be considered to be five types of metal oxides: CaO, SiO2, A2203, MgO, and iron oxide.

In the production of wear-resistant materials, the mixture of various metal oxides used as raw materials is once melted to obtain a uniform composition, so the crystallization phase and melting point in the chemical equilibrium state of the mixed oxide system were investigated from an equilibrium phase diagram. . Regarding the main slag components mentioned above, for example, CaO-AC! 203 SiO2 ternary system, CaO-MgO-AQ 203 (15%)-Si
The phase diagram of the four-component system of O2 and the three-component system of CaO-iron oxide-SiO2 is published in the literature [e.g., for the Japan Iron and Steel Institute, "Steel Handbook" 3rd edition, Volume 1 (published June 1981)]. It is shown. Among the crystalline mineral phases that appear in these phase diagrams, the minerals found in the region of low melting temperature (e.g., melting temperature 1300°C or less) that are easy to melt are listed as follows (Mohs in parentheses). Hardness) Nitrichimite (7,0)
, pseudobolastonite (5,0), anorsite (6
~6.5), melilite (5-6), pyroxine (6-7), forsterite (7,0), hematite (5-6), guicalcium silicate (5), rankinite (5,5) and Calcium ferrite (
5).

Among these mineral phases, it is advantageous to select a crystalline structure phase with as high hardness as possible for the purpose of producing wear-resistant materials. It is conceivable to adjust the component range to such a level that mainly generates forsterite (2Mg0 .SiO2) or forsterite (2Mg0 .SiO2).

Focusing on these three types of mineral phases and examining the above-mentioned known phase diagram, we find that CaOAQ203SiO, which does not contain MgO
In the ternary system of 2 and CaO-iron oxide-SiO2, although a tridymite crystallization region exists in the phase diagram, 13
The region in which tridymite can be crystallized from a melt melted at a temperature of 00° C. or lower is extremely narrow.

In order to manufacture wear-resistant materials, it is necessary to strictly control the composition of raw material components within this range, but this composition control is industrially difficult when considering the compositional fluctuations of various smelting slags.

On the other hand, CaO-MgO-AQ containing MgO
In the four-component system of 203-5iO2, the melting region below 1300° C. is wide, and a considerable portion of this region is occupied by highly hard mineral phases such as pyroxine, tridymite, and forsterite. Therefore, it has been found that with this four-component system, the desired crystallization of a high-hardness crystalline mineral phase can be easily achieved in a low melting point region even if there are some compositional fluctuations in the raw material slag.

Based on the above knowledge, in the present invention, SiO2, A220
3. Contain four components, MgO and CaO, as essential components in the raw material mixture. The ratio of these four components in the raw material mixture takes into account the component range in the region where the high-hardness mineral phase crystallizes in the melting point region of 1300°C or less in the four-component system phase diagram described above and the presence of other components in the raw material mixture. Then, SiO2: 50-55%, A (220373-15%
, CaO: 3 to 15%, and MgO: 3 to 15%. If it is outside this range, it will be difficult to crystallize the desired mineral phase, and a product with wear resistance will not be obtained.

Preferred ratios of the above four components in the raw material mixture are: SiO2: 50-55%, AC7203: 10-1
5%, CaO: 10-15%, MgO: 10-1
5%.

Iron content: Iron content is often contained in small amounts in smelting slag, mainly as iron oxide. Iron content promotes crystal nucleation in the melt, and it itself produces iron oxide as the initial product during solidification. In this sense, the presence of a small amount of iron of around 10% was found to be rather desirable for the production of wear-resistant materials. Therefore, in the present invention, iron is contained in the raw material mixture in an amount within the range of 8 to 12%.

Alkali metal oxides: Alkali metal oxides such as Ni2O and Na2O are often present in small amounts in smelting slag, so they are components that are often inevitably mixed into raw materials. It has been found that the incorporation of a small amount of alkali metal oxide of 5% or less has the advantage of lowering the melting temperature of the wear-resistant material and improving workability. Therefore, in the present invention, inclusion of alkali metal oxides in an amount of 5% or less is acceptable.

Depending on the type of slag used, other metal oxides such as Ti02 and MnO may be mixed into the raw material mixture as unavoidable impurities, as shown in Table 1. If the total amount of these is about 10% or less, there will be no substantial adverse effect on the method of the present invention.

According to the method of the present invention, SiO2, K1 in the raw material mixture
It is necessary to adjust the amounts of each component of No. 203, CaO, MgO, iron and alkali metal oxide within the ranges mentioned above. For example, when manufacturing wear-resistant materials using raw materials mainly consisting of blast furnace slag or converter slag, the first
As is clear from the composition shown in the table, SiO2 is present in the raw material.
Since there is a shortage of and MgO components and an excess of CaO components, additives containing a large amount of -go and SiO2 or other smelting slag are added to compensate for the insufficient components, and the amounts of each of the above components can be adjusted according to the present invention. Adjust within the specified range. The types and typical compositions of inexpensive additives that can be used for the purpose of component adjustment are shown in Table 2 below.

As can be seen from Table 2, for example, in the case of raw materials mainly consisting of blast furnace slag or converter slag, components containing large amounts of MgO and/or SiO2, such as sea sand, serpentine, peridotite, schnite, and Other smelting slags such as nickel slag and silicomanganese slag are used by blending one or more of the above-mentioned nickel slags in appropriate amounts to adjust the composition to within the range specified by the present invention. In this case, the ingredients are similarly adjusted by appropriately blending additives to compensate for the missing ingredients compared to the ingredient composition range according to the present invention.

The raw material mixture whose components have been adjusted as described above is heated and melted to bring the mixture into a chemical equilibrium state, and then cooled to crystallize a mineral phase with high hardness.The raw material mixture used in the present invention has a low melting point. In general, the ingredients are adjusted to be 130
It melts at a temperature of 0°C or lower, preferably 1250°C or lower. It is desirable to maintain the temperature at the melting temperature for at least 1 minute, preferably 3 minutes or more, to ensure that an equilibrium state is obtained. Melting can be carried out using any heating furnace, such as an electric furnace or a high-frequency induction heating furnace, in an atmospheric atmosphere. Can be done below.

In order to produce a good wear-resistant material from an inorganic multi-component oxide according to the present invention, it is important to finely disperse crystallized highly hard mineral phase crystals.

However, simply melting and cooling the raw material mixture
According to the present invention, since the crystallized mineral phase does not become fine,
Heat treatment is performed during the cooling process after melting to finely disperse crystal grains.

The conditions for such heat treatment are such that the behavior of crystal nucleus generation and crystal growth from the melt is determined by the chemical potential (degree of supersaturation, degree of supercooling).
Since the optimum conditions can be theoretically predicted for a simple system, theory cannot provide sufficient knowledge for a complex system such as the inorganic multi-component system used in the present invention. Therefore, the present inventors conducted the following experiment in order to determine the optimal heat treatment conditions.

Iron content 8.9%, SiO2 50.0%, Ca08.5%
, Al2O3 14.6%, Mg011.1%, K2O3
, 46% was charged into an alumina port, heated in an electric furnace and held at a temperature of 1250°C for 10 minutes until the mixture was completely melted. After cooling to a heat treatment temperature of , heat treatment was performed at this heat treatment temperature while changing the holding time, and then air cooling was performed.

After polishing the obtained sample slab, it was observed under a microscope with a magnification of 400 times, and the number of crystal grains existing within a 25 μm x 25 μm area was counted. The attached drawing shows a graph of the relationship between heat treatment temperature and time and the number of crystal grains crystallized.

From the attached drawings, 1000~1200℃, especially 1100~
It can be seen that the number of crystal grains crystallized increases in the heat treatment temperature range of 1150°C. This is thought to be because if the heat treatment temperature is too low, the slag melt becomes vitrified due to a rapid cooling treatment, resulting in a decrease in the number of crystal grains. On the other hand, if the heat treatment temperature is too high, the degree of supersaturation will be low, the crystal growth rate will be high, and the crystal grains will become coarse, so fine dispersion of the crystal grains cannot be achieved. For this reason, the heat treatment temperature is set at 1000 to 1200°C in the method of the present invention.
was within the range of Preferably, the heat treatment is between 1100 and 11
It is carried out at a temperature within the range of 50°C.

If the heat treatment time is too short, the crystals become glassy and brittle, while if the heat treatment time is too long, the crystal grains become coarse, both of which are unfavorable for developing wear resistance. In the method, the heat treatment time was within the range of 3 to 20 minutes. However, since the specific optimum heat treatment time varies depending on the casting size and the heat treatment temperature, it is desirable to determine the appropriate heat treatment conditions by experiment within the scope of the present invention.

After this heat treatment is completed, the mixture is cooled to room temperature, but in order to prevent crystal grain growth and coarsening during this cooling, it is preferable to avoid extreme slow cooling.

The wear-resistant material thus obtained has a highly hard mineral phase finely dispersed and crystallized, and exhibits performance comparable to commercially available basalt materials.

Next, the present invention will be explained in more detail with reference to Examples.

(Example) Metal smelting slag with the composition shown in Table 1 is used as the main raw material, and additives with the composition shown in Table 2 are added so that the component composition of the mixture is within the range specified by the present invention. A raw material mixture was obtained by blending as follows. 20g of this raw material mixture was charged into an alumina boat, placed in an electric furnace and heated to 1250℃ for 10 minutes.
After holding for a minute, the mixture completely melted. Next, it was cooled to 1100° C. in a furnace, heat-treated by holding it at 1100° C. for 10 minutes, and then rapidly cooled to room temperature by air cooling to obtain a test slab. The micro Vickers hardness of each of the obtained test slabs was measured under a load of 200 g. Third
The table shows the blending ratio of the raw materials used, the component composition of the raw material mixture, and the micro-Vickers hardness of the product.

From the results in Table 3, 1S: Sayo, SS: Sea sand, the wear-resistant material produced by the method of the present invention has a hardness comparable to that of commercially available basalt materials.
It can be seen that it has excellent performance as a wear-resistant material.

(Effects of the invention) As is clear from the above explanation, according to the method of the present invention,
The supply of raw materials does not need to depend on natural basalt from a specific production area, and can be easily supplied from smelters or steelworks distributed throughout the country. Allocation to the production of consumable materials is extremely effective from the perspective of thermal energy and transportation costs. In addition, in addition to the main raw material ore, a wide variety of auxiliary raw materials, including solvent materials, are used in smelting and extraction of metals, which is the main purpose of smelters and steel plants, regardless of whether they are natural products or recovered byproducts. When manufacturing wear-resistant materials from raw materials mainly composed of by-product slag, advantageous production of wear-resistant materials is also possible in that it is extremely easy to obtain additive components for adjusting the component composition and crystal phase.

Therefore, there are no constraints on the supply of raw materials that are associated with the production of basalt wood from conventional raw materials mainly consisting of natural basalt. Furthermore, it is possible to select a relatively wide range of slag rings and compounding ranges, and by effectively using smelting slag, it is possible to produce wear-resistant materials of good and stable quality at low cost, making it an effective technology for the effective use of by-products. Extremely valuable.

[Brief explanation of drawings]

The accompanying drawing is a graph showing the relationship between the heat treatment temperature and time of an inorganic multicomponent mixture and the number of crystal grains crystallized. Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent Attorney Akira Hirose - 1000110) +2Q. ! Hunger “JL Agriculture”

Claims (1)

[Claims] The composition of the mixture obtained by adding additives to one or more metal refining slags is: SiO_2: 50 to 55%, Al_2O_3: 3 to 15%.
%, CaO: 3 to 15%, MgO: 3 to 15%, alkali metal oxides: 5% or less, iron: 8 to 12%, and other unavoidable impurities (all of the above are weight %). , after melting this mixture, to a temperature of 1000-1200 ° C.
A method for producing an inorganic multicomponent wear-resistant material, the method comprising performing heat treatment for 20 minutes.