JPS59226095A - Method for suppressing increase in water content of coal stored in yard - Google Patents

Abstract

PURPOSE:To prevent the increase in the water-content of coal for coking during the storage in a yard, by applying a coating film by spraying an asphalt emulsion on the surface of the stored coal. CONSTITUTION:An asphalt emulsion usually mixed with <=20% of coal tar is applied, e.g. by spraying, preferably without dilution, to the surface of coal stored in a yard. The amount of the emulsion is preferably 1-3 liters per 1m of the surface of the stored coal. EFFECT:The problems of heat generation and dust scattering of the caol can be solved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for suppressing an increase in moisture content while raw coal for coke production is stored in a yard.

The raw material coal used for coke production has a maximum particle size of 25 decoys, 8
The coal arrives at about 50 to 70 below fi, is stored in piles at a general coal yard, and is sequentially used as a raw material for coke.

The storage period of raw material coal stored in this coal yard is usually about 1 to 2 months, but during this time various problems such as rising moisture due to rain, heat generation due to oxidation, and scattering of powdered coal may occur. be.

When the moisture content of coal in the coal pile rises by 1% due to rain, etc., the amount of heat of carbonization in the coke oven increases by 15kcal/coa1k.
It is said that the increase will be around g. In addition, as the heat generation phenomenon progresses, not only is there a risk of ignition, but the caking properties of the raw coal decrease, leading to a decrease in coke strength (In addition, the scattering of powdered coal pollutes the surrounding environment. Not only that, but it also caused harmful effects such as causing dust pollution.

In order to solve these problems, various methods have been proposed in the past. For example, methods include coating the surface of deposited coal with alumina cement and then applying a resin coating, methods of spraying water or diluted surfactants on the surface of deposited coal for the purpose of preventing heat generation and dust scattering, and methods of applying various other chemicals. Methods such as diluting and spraying have been used, but the drugs are expensive and none of them have been sufficiently effective.

This invention addresses the current situation and proposes a method that exhibits a satisfactory effect in suppressing moisture rise.

That is, this invention provides a method for forming a film by spreading an asphalt emulsion on the surface of coal stored in a yard, and a method for forming a film by spreading an asphalt emulsion mixed with 20% or less coal tar on the surface of coal stored in a yard. The method is summarized.

7. Is the asphalt emulsion as fine as asphalt? , l: It is dispersed in water as particles, and has the inherent caking and waterproof properties of asphalt. It is usually dispersed in a dilute alkaline aqueous solution with a small amount of surfactant added as an emulsifier, or in a dilute acidic aqueous solution. Asphalt is dispersed, and the resulting asphalt (W) particles are stabilized with a negative or positive charge.

Therefore, it is easy to spray and has the inherent adhesiveness and waterproof properties of asphalt, so by spraying it on the surface of the coal stored in the yard to form a film, it is possible to prevent rainwater from entering the stored coal. Seepage is prevented and storage coal piles are prevented from collapsing due to rain. Moreover, as a result of suppressing the flow of air into the stored coal, the oxidation exothermic phenomenon of the coal is suppressed, and deterioration of caking property can be avoided. Moreover, asphalt, the main raw material for asphalt emulsion, is originally obtained from petroleum, so when it is charged into a coke oven and carbonized, that amount is recovered as gas, which has the effect of increasing the amount of gas generated. is expected. Therefore, the moisture content of raw coal does not rise while it is stored in a yard, and the problems of heat generation and dust scattering can be solved.

The asphalt emulsion may be diluted with water and then sprayed, but it is preferable to thinly sprinkle the emulsion as a undiluted solution, and the amount of spraying is preferably 1 to 31 per trI on the surface of the deposited coal.

In addition, the coal tar mixed into the asphalt emulsion is intended to effectively utilize the crude tar generated during coal carbonization in a coke oven, and in order to achieve the same effect as using asphalt emulsion alone, the mixing ratio must be 20%. It is desirable to limit it to the following.

Next, embodiments of the invention will be described.

Example 1 After eight piles of raw coal each weighing about 10 tons were loaded in a coal yard, a cationic asphalt emulsion was immediately spread over almost the entire surface of each coal pile at a ratio of 21/nl. In addition, for comparison, the remaining two coal piles were coated with alumina cement by spraying a 15% aqueous solution of alumina cement over almost the entire surface of the pile at a ratio of 1.51/-, and then coated with acrylic resin. 7 to 1 (l) aqueous solution was sprayed at 1.51/d, and in the other one, no drug was sprayed at all.

After leaving the coal for 60 days, the moisture content before and after storage of each coal pile was measured. In addition, the temperature at the center of each coal pile was measured at a predetermined time every five days. The results are shown in Table 1. In addition, the rainfall amount for 60 days when it was left to accumulate was 110 to 120M.
In July, the average temperature was 22-24°C.

Table 1 From the results in Table 1 above, when the asphalt emulsion is spread over the entire surface of the coal pile by implementing the present invention,
Compared to other conventional methods, there is no increase in moisture content during coal storage, and the heat generation temperature is much lower.

This is because with other chemicals, after coating, cracks occur in the coating layer due to sliding of coal particles due to rain or drought, but with the method of this invention, the coating layer after coating is mainly composed of asphalt. Because of this, it has viscoelasticity and waterproof properties, and the occurrence of cracks in the coating layer due to slippage of coal particles is extremely low.This is because it has a greater moisture reduction effect and weathering prevention effect than other coating methods.

Example 2 Crude tar, a product of coal carbonization in coke production, was mixed into a cationic asphalt emulsion in various proportions.
It was sprayed on a coal pile in a yard under the same conditions as above and tested.

The results are shown in Table 2.

Margin below Table 2 However, emulsion is an abbreviation for asphalt emulsion.

From the results in Table 2 above, it can be seen that when asphalt emulsion is mixed with tar of 20 or less, the mixing condition is good and the same effect as when asphalt emulsion is used alone is exhibited.

Therefore, if a coke oven that can recover tar as a by-product is installed, it is possible to effectively use homemade tar.

Claims (1)

[Scope of Claims] l A method for suppressing moisture rise in yard-stored coal, which comprises spreading an asphalt emulsion on the surface of yard-stored coal to form a film. 2. A method for suppressing moisture rise in yard-stored coal, which comprises spraying on the surface of yard-stored coal an asphalt emulsion mixed with 20 grams or less of coal tar to form a film.