JPS6025386B2 - Production method of β-spodumene products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an improved method for manufacturing 8-spodumene products with low coefficients of thermal expansion.

Generally speaking, betalite becomes a solid solution of B-spodumene when heated to a temperature of 670q0 or higher, but Si02, which is not solidified, remains in the state of Q-quartz.

This Q-quartz transforms into 81-quartz at a temperature of 57,300°C, but at this time it undergoes transformation expansion, which causes micro-cracks in the product due to heat cycles and eventually destroys the Q-quartz.
-The presence of quartz is unfavorable. Conventional B-spodumene (
Molecular formula Lj20, AI203, 4S based on theoretical composition
j02) The products are Aoi Rouseki and Betalite (molecular formula Li20, AI203, $i02 based on theoretical composition) and Li2C.
It was obtained by firing a mixture with 03, but
The Li2C03 is expensive, the strength of the obtained product is low, and when molding is performed, the lithium ion of Li2C03 is eluted into the water added during molding, which causes secondary aggregation. It has the disadvantage that it cannot be molded and the composition changes, making it impossible to obtain the desired product.

The inventors of the present invention have developed a method to solve the above-mentioned drawbacks. The present invention provides a method for producing an 8-spodumene product, which is characterized by mixing 1.5 to 3.5% of 8-spodumene products in terms of oxide and firing the mixture.

Absorbing Q-quartz contained in the betalite raw material and Q-quartz produced by the decomposition of betalite as a compound,
8- Mg○, Ca○ to completely solidify the spodumene
By adding 1.5 to 3.5% of TiO2 and firing, it is possible to obtain a B-spodumene that is non-water-absorbent, dense, has a low expansion coefficient, and is strong.

In addition to Mg0, Ca0, and Ti02, any compound that changes into these during firing is included in the technical scope of the present invention. For example, M&03, Mg(OH)2, Mg(N02)2, C
aC03, Ca(OH)2, etc.

The base material obtained by the above process can be molded by mud casting, extrusion molding, die press molding, etc. depending on the product with complex shape, thick wall, or thin wall.
This is done by rubber press molding, injection molding, etc.

Next, explanation will be given by focusing on examples.

Example 1 Chemical composition li204.1%, AI20316.62%,
Na200.62%, Si0277.13%, K200
．． 47%, Ca00.01%, Fe2030.04%,
Mg00.10 1g mountain sso. 78% total 99.93
% of naturally produced betalite (hereinafter abbreviated as petalite) was dry-pulverized and most of it was reduced to 10r or less.

This and the average particle size of Magnesia, Calsha, and Titania are 10
One needle type of Buddha powder in the composition ratio shown in Table 1 (Sample M.1
~M. 13) was mixed by wet pulverization in a ball mill for 2 hours, and the resulting slurry was coated with carboxymethyl cellulose code (C,
M, C) 0.5% were mixed to adjust the moisture content to 32%. Using this clay material, a plate with a width of 12 yen, a length of 4, and a thickness of 5 yen was manufactured by casting, and samples for water absorption, X-ray diffraction, transverse rupture strength, and thermal expansion measurements are attached in Table 1. It was cut into the dimensions shown in , and heated in an electric furnace at a rate of about 150° C./hr, and then held at a predetermined temperature for about 3 minutes and fired.

For comparison, Li2C039. $ parts by weight,
After adding 13.7 parts by weight of AI203 and pulverizing in the same manner, the slurry number was adjusted in the same manner and casting molding was performed, but lithium ions were eluted from Lj2C03 and secondary agglomeration occurred and molding could not be performed.

Various properties of the fired products of the examples were measured using the measuring apparatus and method shown in the appendix of Table 1, and are shown in Table 1.

Based on these values, sample No. 1 with Betalite alone was roughly considered. 1 and Betalite 99.5% and Magnesia 0.5
A sample vessel with a composition of %. In No. 2, Si02 is not exposed to water and remains as Q-quartz, and undergoes transformation expansion at the Q→8 transition. This state is shown in Figure 1, and the dotted line curve in the figure is for sample No. 1, and the solid curve indicates sample No. 5 is shown. As you will see, No. No. 1 has an inflection point between 500 and 600 oo and also has a large expansion coefficient.
．． 5 has no refraction point. Next is the sample snake. 2 and M. 3 betalite 99.5-99.0% and magnesha 0.5-1.
The composition with 0% added has a water absorption rate of 7 to 10% and a transverse rupture strength of 250 to 350 k9/ground, which is so weak that it cannot be used as a product. Sample M. 4~No. Beta light Satoshi in the present invention of 7.
For compositions containing 2-96.7% magnesia and 1.8-3.3% magnesia, water absorption is 0%, X-ray diffraction shows all 3-spodumenes, transverse rupture strength 750-800k9/2, thermal expansion coefficient is good at 1.2×10-6 between 20 and 800 qo.

Sample ship. 8, No. 9 Betalight 96.0, 95.0
% plus 4.0% and 5.0% magnesia, the firing temperature range becomes narrower, making it difficult to obtain a dense body, and Q-quartz remains. Sample rudder. 10. Earth. 11 is beta light 98.0 ~
This invention has a composition of 96.7% and 2.0 to 3.3% of Calcia, so there is virtually no water absorption, and X-ray diffraction shows that it is all 8-spodumene, and the transverse rupture strength is 750 to 800k9.
/ The thermal expansion coefficient is 1.1× between 20 and 50,000.
It is 10-6, which is good.

Sample ship. 12, No. 13 is beta light 98.0~96
．． The present invention has a composition of 7% and 2.0 to 3.3% titania, so it has virtually no water absorption, and in X-ray analysis, it is all 8-spodumene and has a transverse rupture strength of 750 to 800 k.
g/enemy, thermal expansion coefficient is 1.9× between 20 and 50,000
10-6, which is good.

``Railboat de]'' Sakurato S Word of intent ``N) x g8 Umachi Kantaku x Shiranu Kagi Pig H carp boat delicious rut jie g groove thin taste flea yang 轡埠细In the composition of the present invention, the characteristic values except for the coefficient of thermal expansion were almost the same.

The coefficient of thermal expansion is within the measurement temperature range (
For 20 to 500 qo), the value is 1.1 x 10-6/℃, but for 20 to 800 qo, the value is 1.5 x 10-6, and the value for the composition with magnesia added is greater than 1.2 x 10-6. It shows. Also, the composition including titania is 20-80
In the temperature range of 00C, it is 2.0×10-6, and the coefficient of thermal expansion increases in the order of magnesia, calcia, and titania. In order to reconfirm these characteristic values, sample 5 (Betalite 98.0% Magnesia 2.0%) in Table 1 and the sample ship were used. 10 (Petalite 98.0% Karsha 2.0%)
and sample location. 12 (Betalite 98.0% Titanya 2.
When various properties other than those listed in Table 1 of 0%) were measured, the following values were obtained. Young's modulus, 5.0×1 and k9/, respectively,
Compressive strength, 2400-2500k9/earth, thermal conductivity (2
5qo) 0.003 &a evening/skin-sec/°C, and thermal shock resistance of 600 to 650°C, all of which were excellent.

The device name and dimensions used for the above measurements and the sample dimensions were a universal testing machine manufactured by Shinko Tsushin Kogyo with a three-point bending method, a span of 2 mm, and a sample size of 30 x 5 x 1 in terms of Young's modulus.
The pressure resistance was determined using a universal testing machine also manufactured by Shinko Tsushin Kogyo using the sample water method on the 5 x 5 x 5 side. Thermal conductivity was measured using a laser flash method with a thermal constant measuring device manufactured by Miki Engineering, and a sample size of 90 x 1.2 was used. Thermal shock resistance was measured using a Hasselmann type universal testing machine manufactured by Shinko Tsushin Kogyo. After holding the sample at a specified temperature for 15 minutes, it was dropped into water and the bending strength of the sample was measured. The limit temperature difference was determined without causing strength deterioration. show. 30×
A sample of 5 x 10 ribs was used.

In addition, in the Zenigurumi test, a cylinder with an outer diameter of 3, an inner diameter of 24, and a length of 8 is placed in the center of a mold with an inner diameter of 5 and a height of 80. The results of examining crack cracks after cooling were found to be good in all cases, and the lungs shown in Table 1 used for comparison. 1. Rudder. 2, N
o. All samples of the same quality as No. 3 had cracks. Example
2 Prepared using the same raw materials and the same weight ratio as in Example 1,
The two were wet mixed in a ball mill and dried to form a powder.

Add 5% paraffin to the powder and press the mold to 1000
It was molded to the same dimensions as the measurement sample of Example 1 at a pressure of k9/ground. After drying, baking was performed using an electric furnace at a predetermined temperature raised to about 150 qo/Hr and held at a predetermined temperature for about 30 minutes. Various properties of the fired products were measured for each sample using the same equipment and method as in Example 1, and are shown in Table 2. Table 2 shows No. 1 samples from among the samples listed in Table 1 of Example 1. All entries were written in the same manner except for 1, 2, 8, and 9.

The firing temperature range in Table 2 and the values of water absorption, X-ray diffraction, and coefficient of thermal expansion are almost the same as those in Table 1 of Example 1, except for the transverse rupture strength of each sample in Table 1. The measured value is improved by about 20 to 30 k9/ground.

In addition, the present invention absorbs Q-quartz in betalite as a compound and completely solidifies into 8-spodumene, resulting in a product that does not undergo transformation expansion, has no water absorption, has a delicate low expansion coefficient, and is resistant to heat cycles. In addition, lithium ions do not elute into the water added during the molding process to include Li2C03 and cause secondary aggregation, and the desired product with no change in composition can be obtained.

The 8-spodumene of the present invention having the above-mentioned materials and hakama properties can be used for mirror-fitting, thin-walled products, complex-shaped products, etc.
It can be manufactured using extrusion, molds, rubber presses, or injection molding, so it can be used for parts for heat exchangers, equipment for rapid heating and cooling, parts for heating equipment, catalyst carriers, and the inside of automobile engines because of their low heat conductivity. It is expected that it will be used as a heat insulating material component.

[Brief explanation of the drawing]

Figure 1 shows sample M. 1 and a ship. The solid line is the thermal expansion curve with M.5. 5. The dotted line is a ship. 1 is shown. Figure 1

Claims (1)

[Claims] 1 Molding a powder consisting of 98.5 to 96.5% of petalite and 1.5 to 3.5% of an oxide of Mg, Ca or Ti, or a compound that becomes the oxide during firing, in terms of oxide,
A method for producing a β-spodium product characterized by baking.