JPH10236877A - Production of sprayed granular powder of carbonaceous powder by spraying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a binder added slurry of carbonaceous powder having a higher concn. and low viscosity and fit to produce sprayed granular powder by spraying while using a small amt. of a dispersant by using a polymer dispersant selected from among condensed ammonium naphthalenesulfonate, a styrene-acrylic acid copolymer and a styrene-maleic acid copolymer as the dispersant. SOLUTION: When an aq. slurry of carbonaceous powder is produced, 1-5 pts.wt. condensed ammonium naphthalenesulfonate and/or 0-3 pts.wt. styrene- acrylic acid copolymer and/or 0-3 pts.wt. styrene-maleic acid copolymer is added a dispersant to 100 pts.wt. of the carbonaceous powder. The resultant slurry to carbonaceous powder is regulated to 20-70wt.% water content and <=500cP viscosity and it is spray-dried to obtain the objective granular powder. The slurry contains a binder such as a wax emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an aqueous treatment method for carbonaceous powder. More specifically, the present invention relates to an aqueous treatment method of carbonaceous powder necessary for obtaining a carbonaceous powder slurry for producing granular powder for press molding and CIP molding in producing a carbon material.

[0002]

2. Description of the Related Art Most of ordinary carbon materials are binary carbon materials composed of aggregate carbon particles and binder carbon. Petroleum coke, coal coke, and the like are used as aggregate carbon particles, and coal tar pitch, coal tar, and the like are used as binder carbon. A standard molding method of a two-component carbon product is to mix aggregate carbon particles and binder carbon and then pulverize the mixture to obtain a molded carbon material by press molding.

In order to obtain a uniform carbon material, it is necessary to uniformly disperse the aggregate carbon particles and the binder carbon, and at the same time, uniformly fill the powder into a press die. Granular powders have a high fluidity and can be uniformly filled to every corner even in a complicated press mold, so they are used in the preparation of ceramic raw materials. In order to obtain this granular powder, a raw material, a dispersant, and a binder are dispersed in water to form a slurry, which is then sprayed with an atomizer and dried with hot air. At this time,
The sprayed droplets become spherical due to surface tension and are dried during falling. This device is generally called a spray dryer. When a carbon material is press-formed, if a granular powder composed of aggregate carbon particles and binder carbon can be used, binary carbon, that is, aggregate carbon and binder carbon is uniform, and the filling density in the mold is high. Uniform filling can be performed. Therefore, a higher molding density can be realized as compared with the conventional press molding of the mixed and pulverized raw materials.

[0004] However, in order to obtain such granular powder, a slurry of carbonaceous powder is indispensable as described above, but such a water-based treatment method cannot be found by the conventional aqueous dispersion method of carbonaceous powder. Was. For example, as a use for dispersing carbonaceous powder in water, there is a particle size analysis of pigments and raw materials in which carbon black is dispersed in water, and an aqueous treatment has already been performed with a dispersant such as ammonium polycarboxylate or sodium linoleate. However, in this case, a slurry suitable for preparing a granular powder could not be obtained due to a large amount of a dispersant or a large amount of water.
The reason why the carbonaceous powder does not disperse in the aqueous system is considered to be that the carbonaceous powder is hydrophobic and porous. However, in the conventional aqueous treatment method, slurry treatment suitable for producing granular powder cannot be performed. It was possible.

[0005]

SUMMARY OF THE INVENTION Based on the above presumption, the present invention improves the dispersibility of carbonaceous powder in water under a condition of higher concentration and lower viscosity with a small amount of a dispersant, and binds the slurry to the slurry. It is an object of the present invention to provide an aqueous treatment method of carbonaceous powder for producing a slurry of carbonaceous powder suitable for production of granular powder to which an agent is added.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, it has been found that adding a specific amount of one or more polymer dispersants gives a good result. Were found, and the present invention was completed. That is, in producing an aqueous slurry of carbonaceous powder, 1 part by weight of condensed ammonium naphthalenesulfonate is used as a dispersant per 100 parts by weight of carbonaceous powder.
A slurry of carbonaceous powder, wherein 0 to 3 parts by weight of a styrene acrylic acid copolymer and / or 0 to 3 parts by weight of a styrene maleic acid copolymer are added. Is the way.

Hereinafter, the present invention will be described in more detail. In the present invention, condensed ammonium naphthalenesulfonate, a styrene acrylic acid copolymer, and a styrene maleic acid copolymer are used in combination or alone as a dispersant. Of these, the ammonium salt of condensed naphthalene sulfonic acid is a condensed naphthalene sulphonate, which shows good dispersibility for ammonium salts and sodium salts, and all other salts. It is not preferable because impurities remain. In the case of an ammonium salt, it is preferable that it contains few impurities because it is almost volatilized in a temperature range where carbonization occurs (800 ° C. or higher). The addition amount of these naphthalene sulfonate dispersants is preferably 1 to 5 parts by weight based on 100 parts by weight of the carbonaceous powder. If it is out of this range, the viscosity of the slurry will be high, and it will not be possible to spray with a spray dryer.

On the other hand, the styrene-acrylic acid copolymer has a styrene / acrylic acid copolymerization ratio of 1 or more,
Those having a weight average molecular weight of 5,000 to 15,000 are preferably used. The amount of addition of these copolymers was 1
0 to 3 parts by weight per 100 parts by weight is preferred. If the amount is more than this range, foaming becomes severe, so that a dense granular powder cannot be obtained.

The styrene-maleic acid copolymer preferably has a copolymerization ratio of styrene-maleic anhydride of 1 to 3 and a weight average molecular weight of 1500 to 3000.
Those obtained by esterifying a part or all of maleic anhydride in the copolymer, and furthermore, sodium or ammonium salts of the esterified maleic acid are also preferable. However, in the same manner as above, when sintering after molding is considered, ammonium salts are preferred. The addition amount of these copolymers is preferably 0 to 3 parts by weight based on 100 parts by weight of the carbonaceous powder. If the amount is more than this range, the viscosity of the slurry becomes high, and a slurry suitable for producing a granular powder cannot be obtained.

[0010]

According to the method of the present invention for treating an aqueous carbonaceous powder,
It has become possible to produce a carbonaceous slurry having a higher concentration and a lower viscosity with a smaller amount of dispersant than before. In addition, the use of this carbonaceous slurry makes it possible to produce a granular powder for press molding a carbon material.

[0011]

Embodiments of the present invention will be described below.

[0012]

Example 1 A wide-mouth bottle made of 5000 cc polyethylene was used as a ball mill pot, 2400 g of distilled water was added thereto, and zirconia balls (φ = 5 mm) were used as cobblestones for 2500.
g, 60 g of a 40% aqueous solution of a condensed naphthalenesulfonic acid ammonium salt dispersant (trade name, Rome PWA-40, manufactured by SAN NOPCO LIMITED), and 34% aqueous solution of a styrene acrylic acid copolymer dispersant (trade name, manufactured by Johnson Co., Ltd.) 10 g of Joncryl 62) and 50 g of a wax emulsion as a binder were mixed well in a ball mill. Then, while mixing with a ball mill, petroleum-based coke (trade name GL5 made by Chuetsu Graphite Co., Ltd.)
1500, particle size 500 mesh) and pitch powder 110 (trade name CIKU, manufactured by Osaka Gas Chemical Co., Ltd.)
0 g was added. The ball mill mixing time was 144 hours.
The obtained carbonaceous powder slurry had a water content of 46.9% and a viscosity of 4
20 cp, pH = 8.0 (10 ° C.).

[0013]

Example 2 40 g of a condensed naphthalenesulfonic acid ammonium salt dispersant (Roma PWA-40), 8 g of a styrene acrylic acid copolymer dispersant (Joncryl 62),
A slurry was prepared in the same manner as in Example 1, except that 2100 g of distilled water and 2200 g of self-sintering mesophase carbon (trade name: mesocarbon microbeads manufactured by Osaka Gas Chemical Co., Ltd.) were used as carbonaceous powder. The slurry of the obtained mesophase carbon powder has a water content of 47.7%,
The viscosity was 480 cp and the pH was 7.8 (10 ° C.).

[0014]

Example 3 Example 1 was repeated except that the styrene-acrylic acid copolymer dispersant was replaced by 10 g of a styrene-maleic anhydride copolymer dispersant (trade name: SMA resin, manufactured by Arco Chemical Asia Pacific Limited). A slurry was prepared in the same manner as described above. The slurry of the obtained carbon powder had a water content of 46.9% by weight, a viscosity of 400 cp, and a pH of 8.0.
(10 ° C.).

Comparative Example 1 A slurry was prepared in the same manner as in Example 1 except that ammonium polycarboxylate was added as a dispersant in an amount of 0 to 10% by weight based on 100 parts by weight of the carbonaceous powder. The viscosity of the obtained slurry exceeded 1000 cp, and a slurry suitable for producing a granular powder could not be obtained.

Comparative Example 2 A slurry was prepared in exactly the same manner as in Example 1 except that sodium linoleate was added as a dispersant in an amount of 0 to 10% by weight based on 100 parts by weight of the carbonaceous powder. The viscosity of the obtained slurry exceeded 1000 cp, and a slurry suitable for producing a granular powder could not be obtained.

[0017]

As described above, according to the aqueous treatment method for carbonaceous powder of the present invention, a low-viscosity, high-concentration carbonaceous slurry suitable for preparing granular powder can be realized.

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI C04B 35/622 C04B 35/00 D

Claims (2)

[Claims] 1. One or two of condensed ammonium naphthalenesulfonate, styrene acrylic acid copolymer and styrene maleic acid copolymer as a polymer resin dispersant for a carbonaceous powder or an organic substance. A method for producing a slurry for obtaining a spray granular powder of carbonaceous powder, characterized by using the above. 2. A method for producing a spray granular powder of carbonaceous powder, wherein the slurry of claim 1 is spray-dried using a carbonaceous powder slurry prepared to have a water content of 20 to 70% by weight and a viscosity of 500 cp or less. .