JPH0329274B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is applicable to water slurry containing a high concentration of carbonaceous solids such as coal, oil coke, and petroleum pitch, which have excellent combustibility and storage stability (hereinafter referred to as high concentration coal/water slurry). ) and its apparatus. [Prior Art] In recent years, due to the instability of petroleum supply, the development of technology for effectively utilizing carbonaceous solids such as coal, oil coke, and petroleum-based pitch has been progressing. For example, various techniques for effectively utilizing these carbonaceous solids include pyrolysis, gasification, combustion, alternative fuels for blast furnace-injected heavy oil in the steel industry, and alternative fuels for heavy oil in cement kilns. However, in these various utilization technologies, carbonaceous solids are difficult to handle because they are solid at room temperature, and there is a risk of pollution due to dust scattering and dust explosions, making it difficult to use carbonaceous solids. It's summery. Therefore, it is desirable to convert these carbonaceous solids into a fluid to facilitate handling and prevent pollution and danger. On the other hand, in order to reduce the cost of transporting carbonaceous solids, it is effective to transport them in the form of a fluid. For the above purposes, it is effective to make a slurry as a method of fluidizing carbonaceous solids, but this slurry can be pyrolyzed, gasified, combusted, blown into a blast furnace, or used as fuel for a cement kiln. In order to use the slurry, it is necessary to make the slurry highly concentrated and to prevent solid particles suspended in the slurry from settling and solid-liquid separation. Conventionally, as a wet pulverizer for producing highly concentrated coal/water slurry, coal, water, and a dispersant are supplied to a one-chamber ball mill 1 as shown in Fig. 5, and pulverized and mixed to obtain a stable slurry. There are known methods such as the one shown in FIG. 6, in which coal, water, and a dispersant are supplied to a one-chamber rod mill 2, and then pulverized and mixed to obtain a stable slurry. A method of obtaining a stable slurry using a ball mill consisting of two or more chambers is also known. [Problems to be solved by the invention] In order to improve combustibility and storage stability, it is desirable that the content of coarse particles (150 μm or more) is low in the highly concentrated coal/water slurry, and in order to reduce the slurry viscosity. It is desirable that the content of fine particles (10 μm or less) be high. However, when a ball mill 1 as shown in Fig. 5 is used, the content of coarse particles increases, and when a rod mill 2 as shown in Fig. 6 is used, the slurry viscosity is high and the grinding power becomes large, making it uneconomical. Problems arise, such as being a target. The present invention was made to solve the above-mentioned problems, and aims to provide a method for producing a highly concentrated coal/water slurry having excellent combustibility and storage stability, and an apparatus therefor. [Means and effects for solving the problems] The method for producing a highly concentrated coal/water slurry of the present invention will be described with reference to FIG. - The method for producing water slurry is characterized in that coal is pulverized by a rod-type wet pulverizer 3 and then pulverized by a ball-type wet pulverizer 4. Moreover, the apparatus of the present invention partitions the rotating cylinder of the wet crusher into two or more chambers in the longitudinal direction by a porous partition plate,
It is characterized by the fact that the chamber on the entrance side is filled with rods, and the chambers after that are filled with balls. Hereinafter, the apparatus of the present invention will be explained in detail based on the drawings. FIG. 2 shows an example of the apparatus of the present invention. The rotating cylinder 5 of the wet crusher is divided into two chambers in the longitudinal direction by a porous partition plate 6, the first chamber on the inlet 7 side is filled with rods 8 to form the rod type wet crushing section 3, and the second chamber is filled with balls. 10 to form a ball type wet grinding section 4. 9 is a mixer, and 11 is an outlet. FIG. 3 shows another example of the device of the invention.
In other words, the rotating cylinder 5 is separated by two porous partition plates 6.
The first chamber on the entrance 7 side is filled with rods 8 to form a rod-type wet grinding section 3, and the second and third chambers are filled with balls 10 to form ball-type wet grinding sections 4a and 4b. was formed. As shown in FIGS. 2 and 3, when the rod-type wet grinding section 3 and the ball-type wet grinding section 4 are integrated, there is an advantage that the cost is reduced because there is only one control system. As the dispersant used in the present invention, anionic, cationic, nonionic surfactants, etc. may be used alone or in combination, and are appropriately selected depending on the type of coal. Specifically, anionic surfactants include fatty oil sulfate salts,
Higher alcohol sulfate salts, nonionic ether sulfate salts, olefin sulfate salts,
Alkylaryl sulfonate, dibasic acid ester sulfonate, dialkyl sulfosuccinate, acyl sarcosinate, alkylbenzene sulfonate, alkyl sulfate ester salt, polyoxyethylene alkyl (alkylphenol) sulfate ester salt, alkyl phosphoric acid Ester salt, dialkyl sulfosuccinate ester salt, acrylic acid or/
and maleic anhydride copolymers, polycyclic aromatic sulfonates, or formalin compounds, etc. As cationic surfactants, alkyl amine salts, quaternary amine salts, etc. are used, and nonionic surfactants Examples include polyoxyalkyl ether, polyoxyethylene alkyl phenol ether, oxyethylene/oxypropylene block polymer, polyoxyethylene alkylamine, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, alkyltrimethylammonium chloride, alkyldimethylbenzylammonium chloride. , alkylpyridinium salts, polyoxyethylene fatty acid esters, aliphatic alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, polyhydric alcohol fatty acid esters, fatty acid ethanolamides, etc. As amphoteric surfactants, alkyl Betaine, etc. are used, and amine compounds such as 1,2,3 monoamines and diamines, higher alkyl amino acids, etc. are used, and preferably sodium naphthalene sulfonate, its formalin condensate, and the sodium salt of sulfonated dicyclopentadiene are used. and sodium acetate, and the amount is 0.001 to 5% by weight, preferably 0.05 to 1.5% by weight based on the carbonaceous solid.
% by weight is added. In addition, in the present invention, a stabilizer is added as necessary, and examples of the stabilizer include alkali metal salts of carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), alkali metal salts of polyacrylic acid, and polyacrylic acid. vinyl alcohol,
Gums such as starch, karaya gum, mixtures of karaya gum and polyacrylamide, polysaccharides modified with polyacrylates, alkali metal salts of alginic acid, bentonite, gum arabic, guar gum, locust bean gum, tragacanth gum, britain gum, Senegal gum, crystal gum, etc. etc. are used, and 0.0001~ for carbonaceous solids
It is added in an amount of 5.0% by weight, preferably 0.001 to 1.5% by weight. The stabilizer is usually supplied at the outlet of the ball wet mill or at the rear of the ball wet mill. [Example] Examples and comparative examples are listed below. Example Using a wet crusher with an inner diameter of 480 mm and a length of 960 mm, a porous partition plate was installed 480 mm from the inlet, the first chamber was filled with rods, the second chamber was filled with balls, and the second chamber was filled with rods and balls.
Following the flow shown in the figure, coal with an HGI of 50 was pulverized to a high concentration to produce a highly concentrated coal/water slurry with a slurry concentration of 66% and a 200 mesh passing rate of 80%.
As a dispersant, 0.8% by weight of sodium salt of naphthalene sulfonic acid formamide condensate was added based on coal, and as a stabilizer, 0.005% by weight of sodium salt of carboxymethyl cellulose was added based on coal.
Added. The results were as shown in the following table and Figure 4. Comparative Example 1 Using a pulverizer of the same size as that used in the example but without a porous partition plate (filling only balls),
According to the flow shown in FIG. 7, a highly concentrated coal/water slurry having the same concentration and particle size as in the example was produced.
The types and addition rates of raw material coal, dispersant, and stabilizer were the same as in Examples. The results were as shown in the following table and Figure 4. Comparative Example 2 Using a rod-type wet crusher with an inner diameter of 480 mm and a length of 960 mm (dimensions are the same as in the example), highly concentrated coal and water with the same concentration and particle size as in the example were prepared according to the flow shown in Figure 8. A slurry was produced. The types and addition rates of raw coal, dispersant, and stabilizer were the same as in the examples. The results were as shown in the following table and Figure 4.

〔Effect of the invention〕

As explained above, the present invention has a higher proportion of fine particles, lower product slurry viscosity, and less grinding power, making it more economical than using a conventional ball mill. Compared to the conventional method, it is possible to produce a highly concentrated coal/water slurry with a lower coarse particle content and excellent combustibility and storage stability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the method of the present invention, FIGS. 2 and 3 are explanatory diagrams showing an example of the apparatus of the present invention, and FIG. 4 is a particle size distribution diagram of slurry in Examples and Comparative Examples. FIGS. 5 and 6 are explanatory diagrams showing an example of a conventional device, and FIGS. 7 and 8 are explanatory diagrams of a comparative example. 1... Ball mill, 2... Rod mill, 3... Rod type wet grinding section, 4, 4a, 4b... Ball type wet grinding section, 5... Rotating cylinder, 6... Porous partition plate, 7... Inlet, 8... Rod, 9... Mixing Machine, 10...Ball, 1
1...Exit.

Claims (1)

[Claims] 1. A method for producing a highly concentrated coal/water slurry by mixing coal, water, and a dispersant, including pulverizing the coal in a rod-type wet pulverizer and then in a ball-type wet pulverizer. A method for producing a highly concentrated coal/water slurry characterized by: 2. A highly concentrated coal/water slurry characterized in that the rotating cylinder of a wet crusher is partitioned into two or more chambers in the longitudinal direction by a porous partition plate, and the chamber on the inlet side is filled with rods, and the subsequent chambers are filled with balls. Manufacturing equipment.