JPH075287B2 - High abrasion resistant granular activated carbon manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing granular activated carbon, and more particularly to a method for producing granular activated carbon having improved wear resistance.

Conventionally, as a method of improving the wear resistance strength of granular activated carbon, a method of forming a synthetic resin film on the surface of activated carbon (Japanese Patent Publication No. Sho 49-18556) or granulation after compounding pitch or tar as a binder before granulation Methods for producing activated carbon are known.

However, the former method has a problem with the heat resistance of the synthetic resin forming the film and is not suitable for repeated use under high temperature conditions, and the latter method is not suitable for pitch or tar in order to improve wear resistance strength. It is necessary to increase the compounding amount of the above, and as a result, the specific surface area of the activated carbon is reduced and the adsorption performance is deteriorated.

The present invention solves the problems of the conventional method, and after a granulation step using a small amount of tar or pitch,
By coating the granular active material precursor obtained in any step before the activation treatment step, the purpose is to significantly improve the wear resistance strength without lowering the adsorption performance of the resulting granular activated carbon. It is a thing.

Therefore, the purpose is to produce granular activated carbon by carrying out carbonization and activation treatment after finely pulverizing coal and granulating it, or after the granulation step and before the carbonization step or before the carbonization step. The heating charcoal is coated with 2 to 15 parts by weight of pitch and / or tar with respect to 100 parts by weight of granulated coal or preheated charcoal, and an activation treatment is performed through a step of carbonizing the coal and the coated pitch and / or tar. It is achieved by doing.

Hereinafter, the present invention will be described in detail.

In the present invention, the raw material coal is 200 mesh screen 80
%, Finely pulverized, kneaded with a binder, and then molded using a molding machine such as an extrusion type or briquette type to obtain a shaped charcoal. If necessary, the formed coal is crushed to a predetermined particle size and sized to form granulated coal, and then the granulated coal is heat-treated at 300 to 900 ° C. in a non-oxidizing atmosphere to remove volatile hydrocarbons and the like, and carbonized. And obtain carbonized charcoal.

Here, if the carbonization treatment directly causes melt expansion,
In order to carry out uniform carbonization treatment, preheating treatment may be carried out at 200 to 400 ° C. to obtain preheated carbon, and then carbonization treatment may be carried out.

The features of the present invention are coal tar, coal tar pitch, petroleum pitch, etc. (hereinafter referred to as "pitches") which are usually used as a coating material for the granulated coal or preheated carbon after the granulation step and before the carbonization treatment step. Abbreviated as).), And the coating amount of Pitches is granulated coal,
It is preferable to set the range of 2 to 20 parts by weight relative to 100 parts by weight of preheated carbon.

Further, during the coating treatment, it is preferable to select the treatment temperature from the temperature range of 50 to 200 ° C. depending on the physical properties of the pitches in order to adjust the viscosity of the pitches. By using it, the viscosity of the pitches can be controlled.

The granular activated carbon precursor that has been subjected to such a coating process carbonizes the coating material pits simultaneously with the original carbonization step. For example, in the case where the granulated charcoal is subjected to the coating treatment, the preliminary heating treatment is subsequently carried out if necessary, and then the carbonization treatment is carried out. When the preheating charcoal is coated, the carbonization treatment may be carried out as it is.

Therefore, in the present invention, the activation treatment through the step of carbonizing the coated pitch and / or tar means that
It means that carbonization of pitch or tar is most preferably performed in the original carbonization step of granulated coal or preheated coal.

The granular activated carbon obtained by the method of the present invention has substantially the same adsorption performance and excellent abrasion resistance strength as compared with the conventional method.

Such a physical property is that the coating treatment is performed on a specific granular activated carbon precursor so that the addition amount of the pitches is small as compared with the conventional method, and in the method of the present invention, only the surface portion of the granular carbon is coated, and in the activation treatment, It is considered that this is because the uniform activation reaction is carried out without hindering the diffusion of the activation gas inside the granular carbon particles.

Further, in the granular activated carbon obtained by the method of the present invention, the coating materials such as pitches are homogenized with the base material after the carbonization treatment, and as a result, there is no problem in terms of heat resistance. Is also effective.

Next, the present invention will be described more specifically with reference to Examples.
The present invention is not limited to the following examples unless it exceeds the gist.

In addition, the vibration pulverization rate and the ball mill method strength were used as indexes of wear resistance strength, and the specific surface area was measured as an index of adsorption performance.

Vibration pulverization rate, ball mill strength and specific surface area were determined by the following measuring methods.

(Vibration dusting rate)

Put 5 g of the sample in a glass bottle with a plastic stopper of 46 cc in volume, place it in a paint conditioner (made by Red Devils), and vibrate for 15 minutes. Then, the sample is sieved with a 60 mesh sieve to measure the amount of fine powder generated, and the weight% of the fine powder under 60 mesh with respect to the test sample is taken as the pulverization rate.

[Ball mill strength]

Put 1g of sample and 20 steel balls with a diameter of 13mm into a stainless steel pot with an inner diameter of 50mm and a length of 50mm, and put the pot at a speed of 120rpm.
Spin for 15 minutes.

Next, the content excluding the steel balls is sieved with a 60 mesh sieve, and the weight% of the granules on the sieve to the test sample is defined as the ball mill strength.

〔Specific surface area〕

At the liquid nitrogen temperature, determine the adsorption isotherm of nitrogen, and use BE
Calculate the specific surface area by applying the T formula.

Example 1 Caking coal (CSN = 8) was crushed using a sample mill so that the total amount of 60 mesh sieve sieve and the amount of 200 mesh sieve sieve were 80% by weight.

100 parts by weight of this pulverized charcoal and carboxymethyl cellulose 2
40 parts of water containing 1 part by weight was mixed and then thoroughly mixed using a kneader.

The obtained mixture was molded into a cylindrical shape having a diameter of 4 mm and a length of 10 mm by using a pelletizer and then crushed to adjust the particle size to 2.83 to 0.84 mm.

Then, this crushed coal is heated at 280 ° C using a rotary kiln.
Air was aerated for 30 minutes to carry out a pre-heating treatment.

The preheated charcoal thus obtained was tested in a heating kneader, and at a temperature of 150 ° C., 4 parts by weight or 8 parts by weight or 12 parts by weight of coal tar pitch (softening temperature; 104 ° C.) crushed through all 36 mesh screens After the addition, the pits were coated by mixing for 10 minutes.

Then, using a rotary kiln, cover the carbonized charcoal with a combustion waste gas (oxygen concentration; 0.5% or less) by aeration.
Carbonization was performed by raising the temperature from ℃ to 700 ℃ at 3.3 ℃ / mm.

Using a rotary kiln, the resulting carbonized charcoal is aerated with a mixed gas of nitrogen and steam (steam concentration 50%), and 1000
Activation treatment was performed at ℃.

The yield (against charcoal), the pulverization rate, the ball mill method strength, and the specific surface area of the obtained activated carbon (a) were measured, and the results are shown in Table-
1].

For comparison, activated carbon (b) was produced under the same conditions as in Example 1 except that the pitch coating treatment was not performed when the pitch coating was not performed.

The yield of the activated carbon (b) and the measurement results of physical properties are also shown in [Table-1].

Example 2 Crushing coal of 2.83 to 0.84 mm was produced under the same production conditions as in Example 1, using a caking coal (CSN = 8) of a type different from that in Example 1.

The obtained crushed carbon was tested in a heating kneader, and at a temperature of 150 ° C, 8 parts by weight of coal tar pits (softening temperature; 100 ° C) crushed into 36 meshes were added and mixed for 10 minutes. A coating treatment of the same kind was carried out.

Then, the coated granulated coal was subjected to a preliminary heat treatment by using a rotary kiln by passing air at 280 ° C. for 60 minutes, and then a carbonization treatment and an activation treatment were carried out under the same conditions as in Example 1. did.

The yield (against carbonized carbon), the pulverization rate, the ball mill method strength, and the specific surface area of the obtained activated carbon (e) were measured, and the results are shown in Table-
2].

For comparison, activated carbon (f) was produced under the same conditions as in Example 2 except that the coating treatment of pitches was not performed and the coating treatment of pitches was not performed.

The yield and the physical property measurement results of the activated carbon (f) are also shown in [Table-2].

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Yamashita, Hiroshi Yamashita 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor, Yoshitaka Takeda, Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Address Sanryo Kasei Co., Ltd., Research Laboratory (56) Reference JP-A-59-45914 (JP, A)

Claims (1)

[Claims] 1. A method of producing granular activated carbon by finely pulverizing and granulating coal, and then carbonizing and activating the granulated coal, which is after the granulating step but before the carbonizing step or preheating. Coating the charcoal with 2 to 15 parts by weight of pitch and / or tar for 100 parts by weight of granulated coal or preheated charcoal, and activating treatment through a step of carbonizing coal and the coated pitch and / or tar A method for producing granular wear-resistant activated carbon having high wear resistance.