JPS59135286A - Preparation of highly concentrated aqueous slurry of coal - Google Patents

Abstract

PURPOSE:To de-ash coal efficiently and prepare a highly concentrated aqueous slurry of coal, by crushing and pelletizing coal and preparing an aqueous slurry from a mixture of the pellets and pulverized fine particles. CONSTITUTION:Coal is crushed in a crusher 1, pulverized in a pulverizer 2 and is sent to a classifier 6 for separation into pulverized coal and fine particle coal. The pulverized coal containing condensed ash is sent to an oil granulating tank 7, while the fine particle coal is pulverized in a pulverizer 2' and is sent into a slurry preparation tank 3. In the granulation process, oil, surfactant and water are fed into a preparation tank 10 from an oil tank 8, a surfactant tank 9 and a water tank 4 respectively and the mixture is led into the oil granulation tank 7. The resultant granulated coal is dehydrated in a dehydrator 11 such as filter press and is sent to the slurry preparation tank 3 together with pulverized coal from the pulverizer 2' and is mixed with water from the water tank 4, surfactant from a surfactant tank 5 for preparation of coal slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for efficiently deashing coal and obtaining a highly concentrated coal-water slurry.

Traditionally, coal water slurry was used as a means of transporting coal.
The coal concentration at that time was about 50% by weight, but if the coal concentration is increased, it can be used as a means of transportation and can be burned as is in a boiler, which is advantageous since operations such as dehydration are not required.

Hereinafter, an outline of a conventional coal-water slurry preparation method using a dry pulverization method will be explained with reference to FIG.

Coal is coarsely crushed by a coarse crusher 1 such as a dry hammer crusher or a show crusher, and then finely crushed by a fine crusher 2 such as a Raymo mill or a tube mill, and then sent to a slurry preparation tank 5 and a water tank 4. The filtrate sent from the surfactant tank 5 is mixed with the surfactant from the surfactant tank 5 to prepare a coal water slurry. As a surfactant, anionic surfactants such as Vi2-ethyl-xyl polyphosphoric acid anhydride salt, Na salt containing condensed monotintalene sulfonic acid, ammonium salt, geloxyethylene alkyl ether, geloxyethylene alkyl Phenyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, f-lyoxyethylene.

E such as lyoxypropylene block copolymers.

Nonionic surfactants such as lyoxyethylene derivatives, fatty acid monoglycerides, and fatty acid ester derivatives such as sorbitan fatty acid ester are used, and the amount added is from 01 to
2% by weight, preferably 0.5 to 1% by weight.

The coal-water slurry prepared in the slab preparation tank 6 is converted into a coal-water slurry and a slurry pipe.

However, in this method, the ratio of coal in the coal-water slurry is as low as 50 to 55'%, and the efficiency of slurry transportation is low, and troubles (during slurry transport, such as clogging of pipes due to ash content of the coal-water slurry) are common. There wasn't.

The purpose of the present invention is to provide a coal-water slurry preparation method that improves the drawbacks of the conventional method.
From 8 degrees, 200 mesh bath 2' O ~ 60%, preferably L < H 55 ~ 45% mlk crushing i is suppressed, the fine powder portion where the ash is concentrated is separated, and this separated fine powder portion is subjected to oil hot granulation method. Deashing 5 The coal quality is sized, the sized coal is fed to the coal-water slurry preparation line, and the coal ratio in the coal-water slurry is adjusted to 70 to 7 by adjusting the particle size distribution of the pulverized coal.
The aim is to improve the weight to about 5g6.

In other words, in the present invention, the vortex of pulverizing coal: □ produces ash □
Separate the fine powder part where the content is concentrated, and perform deashing by granulating the fine powder part, tray, and granulating the coal into pellets.
The pellets are mixed with finely pulverized outer fine particles from the fine powder portion, and a coal-water slab preparation tank is prepared from this mixture. The present invention relates to a method for preparing a highly concentrated coal-water slurry.

The method of the present invention will be explained with reference to FIG. Components in FIG. 2 with the same reference numerals as in FIG. 1 have the same functions and effects, so their explanation will be omitted.

In the figure, the degree of pulverization in pulverizer 2 when moving from pulverizer N to classifier B varies depending on the type of coal.
・00'7 Tsushiyubus (74μm or less) 20~-6□''
A range of 0% is appropriate, and 200 mesh baths 55 to 4
A range of 5% is particularly preferred. The classifier 6 is a dry or wet classifier, preferably with a sieve mesh of 200 to 525 meshes, which separates pulverized coal from fine granule coal, and sends the pulverized coal with concentrated ash to the oil-temperature granulation tank 7. , for fine coal, use a pulverizer 21
The slurry is finely ground and sent to the slurry preparation tank 5.

For oil hot granulation, an 8Vi oil storage tank, a 9V surfactant storage tank, and 14 water tanks are shown. Oil, surfactant, and water are sent from these to an emulsion preparation tank 10 to prepare an emulsion. Structure/paddy seed 7vc is led. Oil C, heavy oil, light oil, heavy oil, kerosene, coal-based oil (creosote, oil, etc.) used at this time are preferably 10 to 50% by weight based on the pulverized coal VC from the classifier 6. is 20. ~25
% by weight. As the surfactant, an alkanolamide type or polyoxyalkylene type nonionic surfactant is used. It is added at a rate of

On the other hand, the pulverized coal from the classification machine 6 is also sent to the oil temperature granulation tank 7, and water is sent from the water tank 4 so that the impurity concentration is 5 to 50% by weight. is agitated, granulated, and collected. Here, the particle size of the granulation lip is determined by the amount of emulsion oil added, and the relationship between the two is as shown in Figure 5. Alternatively, a method may be adopted in which sized charcoal of 1.2 to 5 ml+ is prepared, water containing ash is separated, and then pulverized to the desired particle size using a crusher such as a homogenizer.

The granulated coal (sized coal) thus obtained is dehydrated in a dehydrator 11 such as a fill-no-press, and is sent to a slurry preparation tank 5 together with pulverized coal from a pulverizer 21, where water from a water tank 4 is removed. , a coal water slurry is prepared with the surfactant from surfactant tank 5. The ratio of pulverized coal and demineralized granulated coal is 10 (]
':' 0 to 40, especially 100:.10-50 is preferable, and when there is too much deashing, granulation, and charcoal, a portion of the charcoal is returned to the pulverizer 2I through the squeegee line 111.

As shown in the figure, in the method of the present invention, by mixing granulated coal sized to an appropriate size, the coal concentration in the coal-water slurry can be increased to 70 to 75% by weight, compared to the conventional method where the coal concentration is about 50% by weight. In addition, since the amount of ash in the coal-water slurry is reduced, troubles such as pipe clogging that occur during transportation can be reduced.

FIG. 4 shows another embodiment of the present invention in which oil-hot granulation is performed in multiple stages. Components with the same reference numerals as those in FIGS. 1 and 2 have the same functions and effects, so a description thereof will be omitted.

In the figure, reference numeral 171 denotes an oil-added granulation tank, in which granulated coal having a different particle size from the oil-temperature granulation tank 7 is prepared by changing the amount of added oil, and both granulated coals are sent to the dehydrator 41. The ratio of both granulated coal 7 and 7' is determined by looking at the particle size distribution curve of the entire coal including the granulated coal. By performing multi-stage granulation in this way, the width of the grain size distribution of granulated coal is narrow as shown in Figure 5-1 in single-stage granulation, making it difficult to achieve the distribution required for high concentration of slurry. However, in multi-granulation granulation, the width of the particle size distribution becomes wider as shown in Figure 5-2, making it relatively easy to achieve the distribution necessary for increasing the slurry concentration, and increasing the coal concentration in the slurry. Connect.

As an example, the sample coal is Australian bituminous coal (Warkworth coal, ash content 17.
Using 0 wt % 1, pure coal of about 1 several cm was coarsely crushed to less than 5 cm using a hammer crusher, and then finely crushed using a magnetic ball mill.

In the pulverization process using a magnetic ball mill, the degree of pulverization of coal is 2.
00 mesh (74μm) bus 55 weight - 20
It was classified using a 0 mesh sieve, and the material on the sieve was further ground again until it had a 200 mesh sieve of 0 to 80 inches.

The material under the 10,001 sieve was deashed and granulated (sized) using an oil temperature granulation method. Oil temperature granulation conditions are coal slurry concentration 10% and water temperature 50℃.
, oil temperature is based on pure coal (dry-Ash Free l
The granulation time was 60 minutes. As a surfactant, alkanolamide type nonionic surfactant:
100 ppm of N-24 manufactured by Sanyo Chemical V4 was added to the coal.

Furthermore, a coal water slurry (high concentration slurry) was prepared using the above-mentioned 200 mesh pass y 5 weight i% pulverized coal and granulated coal using a lab body spar stirrer made by Tokushu Kakoki, and a comparison was made with the case where granulated coal was not used. I did it. The surfactant for water slurry preparation is nonionic F-5 manufactured by Daiichi Kogyo Seiyaku ■.
006 was used.

Particle Size Distribution Coal Water Slurry Preparation Results By mixing pulverized coal (200 mesh pass 75% by weight) and granulated coal at a ratio of 70150 (weight ratio), the slurry concentration could be increased from 695 to 72% by weight. .

[Brief explanation of drawings]

Figures 2.4 and 2.4 are flow sheets showing the outline of a coal-water slurry preparation method incorporating a deashing process by flotation, with Figure 1 relating to the conventional method and Figure 2.4 relating to the method of the present invention. It is something. FIG. 5 is a graph showing the relationship between the amount of added oil and the particle size in the oil-cooled granulation VC of the present invention, FIG. 5-1 is the particle size distribution during the first stage granulation, and FIG. The figure shows the particle size distribution during multistage granulation. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] In the process of pulverizing coal, the fine powder part where the ash content is concentrated is separated, and the fine powder part is deashed by hot oil granulation, and the coal substance is granulated into pellets. A method for preparing a highly concentrated coal-water slurry, which comprises mixing a fine part with finely ground particles and preparing a coal-water slurry from this mixture.