JPS60103072A - Manufacture of ceramic 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 The present invention relates to a method for producing a ceramic material, and more particularly to a method for producing a ceramic material. This invention relates to a method for producing a ceramic material with excellent formability, using 8-component phosphorus fertilizer as the main raw material.

Both calcined phosphorus fertilizer and dissolved phosphorus fertilizer are widely used industrially as phosphoric acid or lime fertilizers. Calcined phosphorus fertilizer Ca3 (PO4)2 and CaNaPO4
However, among these, magnesia heavy phosphorus fertilizer etc.
70 and Si○2 components were dissolved in IM. On the other hand, molten metal is made of glass whose main component is Ca0-MgO-P2O3-F, and phosphate ions exist as a single ion.

Hitherto, calcined phosphorus fertilizers and melted phosphorus fertilizers have been industrially produced and used mainly as fertilizers, but no attempt has been made to utilize them for ceramics' FA benefits.

An object of the present invention is to provide a method for producing a ceramic material having stable quality and good formability using calcined phosphorous fertilizer or melted phosphorous fertilizer as a raw material.

The present inventors have discovered that both calcined phosphorous fertilizer and melted phosphorous fertilizer can be produced industrially in large quantities and under stable quality control.
Focusing on the fact that fjJ can be obtained at low cost, research was conducted on using it as a raw material for ceramic materials. the result,
The main crystal structure of calcined phosphorus fertilizer or fused phosphorus fertilizer is Avatai 1
The crystal has a relatively soft scale-like shape with a Mohs hardness of about 5, so if it is molded and fired, it can be machined with a carbide tool; It was discovered that it has extremely excellent properties as a required ceramic material, and the present invention was achieved.

The present invention is characterized by using at least one of calcined phosphorous fertilizer or melted phosphorous fertilizer as the main raw material, adding a plastic clay material or an organic paste to this to form a prepared composition, and firing the composition. It is.

The calcined phosphorus fertilizer or melted phosphorus fertilizer used as a raw material in the present invention is usually a commercially available product. The processed material can be used as a raw material.

The raw material is used after being crushed, but in the case of calcined phosphorus fertilizer, it is sometimes dry crushed as it contains phosphoric acid which is soluble in water, but in the case of melted phosphorus fertilizer, it is sparingly soluble in water, so In addition to dry pulverization, wet pulverization is also possible. In order to produce the cementing effect of phosphoric acid during wet grinding, an aqueous solution of citric acid may be added during grinding to release lH from phosphate ions in the soluble phosphorus fertilizer. In the present invention, calcined phosphorus fertilizer or soluble phosphorus fertilizer contains zinc (Zn), magnesium (Mg), aluminum (AN), Zr (Zr), barium (Ba) during pulverization or in subsequent steps. ), titanium (Ti),
Potassium (K), sodium (Na), lithium (Li
), oxides such as silicon (Sj), hydroxides, fluorides, etc. can be added. These additives adjust the particle size of Avatai 1-based crystals in the ceramic material obtained, and react with excess phosphoric acid in the phosphorus fertilizer to allow the ceramic material to be heated at room temperature or low temperature (approximately 400 ml). ℃ or below), it produces a phosphoric acid cement-like substance, exhibits self-hardening properties during molding, and has the effect of increasing the density and strength of the resulting ceramic material. Furthermore, Z n % B a in the additive
, K, Na-Lr oxides, hydroxides,
Fluoride has the effect of reducing high-temperature viscosity, promoting apatite crystal growth, and lowering the firing temperature.
nO etc. are known as zinc phosphate cement.
Since it exhibits strong self-hardening properties, it can also be applied to molding such as when making cement concrete ID products. Also, ZrO2, A4203, Si02, MgO, Ti
It has been found that O□ is effective in increasing the high temperature viscosity and making the product have a microcrystalline structure.

The amount of the above additives added is generally 1 to 30% (by weight,
(same below). 5i02 etc. can be added up to about 30% (by weight, the same applies hereinafter), but K
It has been found through experiments that the appropriate content of alkali oxides such as 2O, Na2O, etc. is in the range of 1 to 5%, and that it is generally preferable to mix two or more of them.

The composition consisting of the above-mentioned phosphorus fertilizer and the above-mentioned additives added as necessary is prepared by adding water and, if desired, an organic paste to adjust the viscosity, and then subjected to casting molding, injection molding, powder pressure molding, and It is molded and fired using a normal ceramic molding method such as pressing.

In the case of the above-mentioned powder pressure molding, 1 to 3% organic glue such as CMC (carboxymethyl cellulose) PVA (polyvinyl alcohol) is added and placed in a mold with a moisture content of 5 to 10%, and generally 300 kg/cA or more A molded body is obtained by pressure molding at a pressure of 100 ml, but in the case of injection molding or cast molding, the moldability can be improved by adding 5 to 10% of plastic clay. In addition, during molding, by adding about 0.5 to 2.0% of sol of silica, alumina, lithium, zirconia, etc. and water gas, the reaction between these and the phosphate ions in the composition makes it viscous. The resulting composition can be easily molded.

In the present invention, when soluble phosphorous fertilizer is used as a raw material, the soluble phosphorous fertilizer is heated to 1100°C or higher to form fluoroapatite crystals in advance, and then the above-mentioned additives are added to adjust the composition. By forming, molding, and firing, a ceramic material with particularly excellent machinability is made into a tube! can do. When the pretreated composition is molded by a method such as cast molding or injection molding, a structure in which Avatai 1-crystals are layered and oriented within the molded body is obtained, resulting in a ceramic product with excellent machinability and strength. can be obtained.

In addition, instead of reheating the soluble phosphorus fertilizer at 1100°C or higher, the particle surface can be improved by treating pre-pulverized powder for soluble phosphorus with a size of about 200 mesh in pressurized steam in an autoclave at 180°C or higher. It was found that fluoroapatite crystals were precipitated on top, and a material with excellent machinability similar to the above was obtained. These heat-treated crystallized products may be used as they are, or they may be used again.
It may be used after heating to 100° C. to form even larger crystals.

As described above, according to the present invention, a composition prepared by using calcined phosphorous fertilizer or (and) soluble phosphorous fertilizer as raw materials and adding metal oxides, organic glue, and water as necessary is molded and fired. As a result, a ceramic material with excellent moldability, mechanical properties, etc. can be manufactured.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 For soluble phosphorus (commercially available "Yorin", manufactured by Shinera Kasei Co., Ltd.)
100 parts (by weight, hereinafter), 5 parts of hentonite,
and adding water to 5 parts of zinc oxide at a ratio of 1:1,
After grinding into a fine powder formulation of 200 mesh or less and dehydrating it to a water content of 13-15%, 2% silica sol was added and kneaded to prepare a plastic composition. 7. This composition was molded into an injection molding machine with an injection pressure of 50 kg/cflI.
It was injection molded into a pipe having a diameter of 100 mm and a wall thickness of 10 mm, and then the pipe was cut to obtain a plate-shaped molded product.

This molded body was irradiated with far infrared rays to dry to a moisture content of 8%, and then dried with hot air.
1- It was placed in a Lahas kiln and fired for 2 hours to obtain a sintered body. The obtained sintered body has a dense structure with an absorption rate of 0.8% and a Mohs hardness of 6, and can be ground with a carbide tool, and its bending strength is 850 kg/C or more. there were.

Example 2 A molding composition consisting of 70 parts of soluble phosphorus fertilizer (same as in Example 1), 30 parts of heavy phosphorus, and 5 parts of aluminum hydroxide was produced. Soluble phosphorus fertilizer was wet-milled, and heavy phosphorus was dry-milled. Powders of 200 mesh or less were used in each case, and commercially available aluminum hydroxide powders of 325 mesh or less were used. These dry powders were mixed in a mixer for 30 minutes, and 5% water was added to obtain a powder for molding. This molding powder was filled into a mold, and a pressure of 4.50 kg/cJ was applied using a hydraulic press to form a mold of 100×200.
The mackerel was formed into a plate-shaped body of xlOmm, and after drying, it was
Bake for 90 minutes in a roller hearth kiln at 200°C,
A sintered body was obtained. The physical properties of this sintered body were a water absorption rate of 1.5%, a Mohs hardness of 5, and a bending strength of 750 kg/csA. Moreover, this sintered body could be drilled with a carbide drill.

Example 3 A commercially available powder for soluble phosphorus (same as in Example 1) was pulverized to less than 200 mSg in an autoclave at 10 atm.
After being treated for a period of time, this was further baked at 1100° C. for about 3 hours. The obtained fired product was a weak sintered product in which large fluoroapatite crystals were formed. This sintered product was further crushed into a powder of 200 me/nos or less.

100 parts of the above soluble phosphorous fertilizer treatment, 5 parts of titanium oxide,
After mixing 15) powder of 200 mesh or less each of 5 parts of zinc oxide (ZnO) and 5 parts of cerizite clay in a mixer, 25% of 17% phosphoric acid solution is added and stirred and kneaded to obtain a viscous plasticity. The composition was kneaded for 20 minutes, and then heated and concentrated to a water content of 15%.
Supplied directly to the injection molding machine.

It was punched and molded into a pipe shape with a thickness of 100 mm and a wall thickness of IQ++ m, and then this was made into a plate-shaped molded product. This plate-shaped molded body was irradiated with far infrared rays for 20 minutes, further dried in a dryer at 100°C, and then supplied to a roller hearth kiln with a firing temperature of 1160°C and fired for 90 minutes to obtain a sintered body. The f47 sintered body has a Mohs hardness of 5 to 6, a water absorption rate of o, 6%,
With a bending strength of 800 kg/ad or more, it was possible to drill holes with a carbide drill, and it was also a material with excellent machinability that could be threaded.

Example 4 Alumina sol (sunsho When 10 parts of (manufactured by Kagaku Co., Ltd.) are added and stirred, thermosetting aluminum phosphate is produced by reacting with the phosphoric acid component eluted in the water, forming a viscous paste.

After vacuum degassing these paste-like materials, they were injected into a wooden mold for making a plate-like product with a thickness of 10 mm, dried and hardened, and then
After curing under far infrared rays at 50°C or higher, the material was fired at 1100°C to obtain a dense sintered body.

The obtained sintered body has a Mohs hardness of 6, is easy to drill with a carbide tool, and has a bending strength of 450 kg/
It was of crA.

As described above, the present invention utilizes the crystallinity of these raw materials to obtain a new ceramic material with excellent formability and machinability by using at least one of calcined phosphorous fertilizer and soluble phosphorous fertilizer as a main raw material. Can be done. In addition, the raw materials, calcined phosphorus fertilizer and soluble phosphorus fertilizer, are mass-produced as city 11 fertilizers, and are easy to handle and have stable quality. It is possible to make it into a stable in-vehicle production product.

Agent: Patent Attorney Kawakita Takecho

Claims (1)

[Claims] (1) Using one or more types of calcined phosphorous fertilizer or melted phosphorous fertilizer as the main raw material, adding additives thereto to form a prepared composition,
A method for producing a ceramic material, which comprises firing. (2. In claim 1, the molten phosphorus fertilizer is preheated to 1100°C or higher, or
A method for producing a ceramic material, characterized in that the raw material is a material treated under pressurized steam of C or higher.