JPS6365948A - Preparation of solid phase synthetic substance - Google Patents

Abstract

PURPOSE:To efficiently prepare a solid phase synthetic substance having high strength and high density, by grinding a compression molded article of a mixture composed of plural kinds of raw materials to form a particulate material with a particle size of 12mm or less and adjusting said material to specific particle size distribution by screening before heating the same at high temp. CONSTITUTION:Plural kinds of fine powdery raw materials 1, 2 as well as a reaction aid/binder 3 are respectively weight in a predetermined ratio by weighing machines 4, 5, 6 and charged in a mixer 7 to be uniformly mixed. The resulting mixture 8 is introduced into a press compression molding machine 9 to be formed into a predetermined shape by compression molding and the compression molded article 11 is crushed into a particulate material 13 having a particle size of 12mm or less by an attritor 12. The crushed particulate material 13 is treated with a screen 14 to be adjusted to particle size distribution of 1-5mm and received in the reaction container of a chemical synthesis process 15 to be heated to about 1,500-2,500 deg.C and a crystalline solid phase synthetic substance 16 is formed by solid phase reaction.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides ultrafine powder with a particle size of 100μ or less and ultrafine powder with a particle size of 100μ to
The present invention relates to a method for producing a solid-phase composite by combining multiple types of fine powder of about 1,000 microns (hereinafter simply referred to as fine powder).

(Prior art) Conventionally, when producing the above-mentioned in-phase composite, multiple types of raw material fine powders are uniformly mixed in a mixer, and the mixture is placed in a reaction vessel and heated at high temperature to cause a chemical reaction. The crystalline in-phase compound is t;).

(Problems to be Solved by the Invention) However, in the above method, the synthesis reaction efficiency is low even when heated at high temperature due to rough contact between the constituent particles of the mixture, and even when a composite is obtained, its strength and density was low. In addition, if there is a large difference in particle size or bulk density between the raw material fine powders to be combined, segregation may occur during the chemical synthesis process after mixing, resulting in an uneven mixing state and making it difficult to obtain a homogeneous solid phase composite. could not. Furthermore, the mixture of raw material fine powders was easily scattered and was difficult to handle.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for efficiently producing a homogeneous composite having high strength and density from a plurality of types of raw material fine powder.

Means for Solving Problem C) That is, the method for producing an in-phase composite according to the present invention involves uniformly mixing multiple types of raw material fine powder, compressing the mixture into a predetermined shape, and pulverizing the molded product. It is characterized in that it is formed into granules with a particle size of 12 mm or less, and the granules are allowed to rise as they are.

(Example) Hereinafter, the present invention will be explained in detail based on Examples. The drawings show the manufacturing process of the solid-phase composite according to the present invention, and show a plurality of types of raw material fine powder (1) (2) and a reaction aid. Agents, binders, etc. (3) are each weighed to a predetermined ratio using measuring machines (4), (5), and (6), and then put into a mixer (7) (Maller type or stamping type) to mix them uniformly. be done.

The mixture (8) of the raw material fine powder is then passed through a pressure compression molding machine (9).
) (press type or roll type) to compression mold into a predetermined shape, and the compression molded product (11) is further passed through a crusher (11).
2) Particle size 12M (hammer type, tooth type or roll type)
It is crushed to less than M. The thus crushed granules (13) are passed through a sieve (14) with a particle size distribution of 1 to 5 WI.
After being sized to N, it is placed in a reaction vessel (not shown) in the chemical synthesis step (15) and heated at approximately 1,500 to 2,500°C.
The mixture is heated in a range of 100 to 1000 mL, and a crystalline solid phase compound (16) is formed by an in-phase reaction.

Note that among the granules (13), those with a particle size of 1 tom or less are re-injected into the mixer (7) and turned into fine raw material powders (1) and (2).
Those mixed with others and having a particle size of 5 or more are re-injected into the crushing@(12) and crushed together with the compression molded product (11).

The granules (13) crushed to a particle size of 12 mm or less by the crusher (12) are separated into columns of fine powder and chemical synthesis process (15).
Depending on the in-phase reaction conditions in , it may be sent directly to the chemical synthesis step (15) without passing through the sieve (14).

Next, an example of producing an in-phase composite by the above production process will be shown below.

1st Example 40 parts by weight of silica powder (particle size of about 50μ or less, bulk density 0.6~), 40 parts by weight of graphite powder or oil coke powder (particle size of about 50μ or less, bulk density 0.7'/Δ), wood flour 18 parts by weight, 2 parts by weight of salt, 3 parts by weight of starch or PVA (polyvinyl alcohol) as a binder, and 15 parts by weight of water, and these weighed items were put into a Muller-type mixer, and the linear pressure was 2 parts by weight. Apply a load of μ to ~4 and rotate for 5 minutes to mix the raw materials uniformly.

Next, the mixture was applied to a press-type pressure compression molding machine for 2 to 4 hours.
Apply pressure of tOn/1, diameter 20mm, thickness about 10~
Make a 15 MM disc-shaped molded product. Thereafter, the molded product is crushed in a crusher to a particle size of 12 ml or less, placed on an upper cylinder, sized to a particle size distribution of 1 to 5 particles, and dried. The granules thus obtained were placed in a reaction container (not shown) and approximately 1.9
By heating at 00°C, an in-phase composite of silicon carbide with high strength and density was obtained.

In addition, in the pressure compression step, the mixture is applied to a roll-type pressure compressor to apply a linear pressure of 2 to 6 t00//crn,
A similar solid phase composite was obtained when compression molded into almond shapes with dimensions of 19X14X9 wings.

Further, the amount of this powder and salt added varies depending on the type of silica powder, graphite powder, or oil coke powder.

Second Example Boric acid powder (particle size approximately 50μ or less, bulk density o, s'/H)
40 parts by weight, graphite powder or oil coke powder (particle size approximately 50
Less than μ, bulk density 0.7? / scraps) 40 parts by weight, wood flour 18
Parts by weight, 2 parts by weight of salt, 3 parts by weight of starch or PVA as a binder, and 15 parts by weight of water were mixed, compressed and crushed in the same manner as in the first example to obtain a particle size distribution of 1.
This was made into granules of ~5 fl, placed in a reaction vessel (not shown), and heated to about 2,500°C in an electric furnace to obtain a solid phase composite of boron carbide with high strength and density.

Third Example Silicon powder (particle size approximately 50μ or less, bulk density 0.5 to 0.67
) and magnesium powder C particle size approximately 700μ or less, bulk density 0
．． 7-0.8-) in the same ratio or magnesium powder 80
The blending ratio was adjusted to about % by weight, and the same method as in the first embodiment was made under an inert atmosphere of nitrogen gas to form a uniform almond shape, which was then crushed into granules with a particle size of 12 feathers or less using a crusher. Then, the granules were placed in a reaction container (not shown), and
A homogeneous silica-magnesium solid-phase composite was obtained by heating at high temperature.

In addition, in the mixing process of this example, the mixing effect was almost the same even if a push-type mixer was used instead of the Muller-type mixer.

Fourth example tungsten powder c particle size 200μ or less, bulk density 4.5~
), about 90 parts by weight of graphite powder (particle size 501 mm or less, bulk density 0.2 or less, about 10 parts by weight, about 1 part by weight of PVA and about 1 part by weight of water as a binder, in the case of the first example) Mix uniformly in the same manner as above.Next, the mixture is compressed into an almond shape having dimensions of 19 x 14 x 9 using a roll pressure compression molding machine at a linear pressure of 2 to 6 tOn///I,
This was crushed and sized into granules of 1 to 5H, and the granules were placed in a reaction vessel (not shown), and then heated in an electric furnace to a size of about 1,500
C. to obtain a homogeneous tungsten carbide solid phase composite.

(Effects of the Invention) As is clear from the above description, the present invention involves uniformly mixing multiple types of raw material fine powders in a mixer, then pressurizing and compression molding the mixture before the chemical synthesis process, and further obtaining a predetermined particle size. Since the particles are crushed into granules in which the constituent particles are in close contact with each other, the solid phase reaction efficiency is high, and the strength and density of the resulting composite are also improved. In addition, even if there is a large difference in particle size or bulk density between the raw material fine powders to be combined (as in the third and fourth embodiments), by forming them into mixed diameter granules, segregation will not occur and a uniform mixing state will be maintained. Since it can be subjected to high-temperature reactions, a homogeneous internal phase compound can be obtained.

Furthermore, since the raw material fine powder is made into granules with mixed diameters, it does not scatter, making it easier to handle.

[Brief explanation of drawings]

The meat side shows the manufacturing process of the in-phase composite according to the present invention. ・夛〆 Patent applicant: Shinto Kogyo Co., Ltd. 1. ．．・Sito≦

Claims (1)

[Claims] Multiple types of raw material fine powders are uniformly mixed, the mixture is compression molded into a predetermined shape, the molded product is crushed to form granules with a particle size of 12 mm or less, and the granules can be used as is or with a particle size distribution of 1. A method for producing a solid-phase composite, which comprises sizing the particles to a size of ~5 mm and then subjecting the particles to a high-temperature heating reaction.