JPH04285690A - Production of humidified coal to be charged into coke oven - Google Patents

Abstract

PURPOSE:To obtain humidified coal preventing formation of dust by adding an oil as a binder to recovered pulverized coal, making the pulverized coal to false fine particles and blending the false fine particles with dried and adjusted raw material coal. CONSTITUTION:Pulverized coal recovered by a dust collector attached to a dryer, etc., is blended with an oil such as heavy oil, tar oil or tar sludge as a binder preferably by kneading after spraying, the pulverized coal is made into false particles having >=15mum particle diameter, which are mixed with dried and adjusted raw material coal, controlled to 2-7% water content to give coal to be charged into a coke oven.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a method for producing humidity-controlled coal, which is one of the methods for pre-processing coking coal to be charged into a coke oven, and particularly relates to a method for processing pulverized coal recovered by a dust collector. It is.

0002

[Prior Art] Pulverized coal collected in a dust collector that processes carrier gas in a dryer or a dust collector at a conveyor junction in the humidity-controlled coal method is coking coal that has been humidified in a kneader and then dried and adjusted. In other words, it was mixed with moisture-conditioning charcoal.

0003

[Problems to be Solved by the Invention] However, in the conventional method, water is sprayed onto the pulverized coal in a kneader, the pulverized coal is humidified and kneaded, and then mixed with the pulverized coal on a conveyor that transports the pulverized coal. There was a problem in that some of the moisture evaporated due to the sensible heat held by the container, causing dust to be generated again during transportation. An even bigger problem is that when the humidity-controlled coal mixed with humidified and kneaded recovered pulverized coal is charged into a coke oven, the pulverized coal generates dust. This is because sludge (ash) is mixed into the tar that is collected as a by-product and deteriorates the quality of the tar.

[0004] The present invention proposes a method for producing moisture-conditioned coal for coke oven charging, which makes it possible to prevent dust from being generated on the conveyor of recovered pulverized coal or when charging it into a coke oven, and which does not cause deterioration of tar quality. The purpose is to

[0005]

[Means for Solving the Problems] The present invention provides a method for drying and adjusting the moisture content of coking coal to 2 to 7% before charging the coking coal into a coke oven. Production of humidity-controlled coal characterized by adding oils such as heavy oil, tar oil, and tar slag to recovered pulverized coal as a binder, turning the pulverized coal into pseudo-particles, and mixing the pulverized coal with dry-adjusted raw material coal. It's a method.

[0006] As a method for adding oil such as heavy oil to the pulverized coal collected by a dust collector, it is desirable to spray oil onto the pulverized coal and knead it, thereby turning the pulverized coal into pseudo particles. Heavy oil is preferable as the oil, but tar oil, tar slag, etc. are also possible. Further, it is desirable to knead so that the particle size of the pseudo particles is 15 μm or more.

[0007]

[Effect] After leaving the dryer, the humidity control charcoal is heated to a temperature of 70 to 80℃.
When the pulverized coal collected in a dust collector and humidified and kneaded with water is mixed with moisture-conditioned coal on a belt conveyor, some of the moisture in the pulverized coal evaporates, the pseudo particles of the pulverized coal are destroyed, and coke is produced. Dust was generated during transportation to the furnace, and the quality of the by-product tar deteriorated when moisture-controlled coal was charged into the coke oven. 70~ by adding a binder and making it into pseudo particles.
Even when mixed with moisture-conditioned coal at 80°C, the evaporation of the oil as a binder is slight and the pseudo particles of pulverized coal are not destroyed. For this reason, there is little dust generated during transportation to the coke oven or during charging of coking coal, and there is no increase in sludge (ash) mixed in the coke oven byproduct tar, which deteriorates quality.

Incidentally, FIG. 3 shows the manufacturing process of raw material tar for binder pitch. When the by-product gas generated in coke 6 is cooled with ammonia water and the tar is liquefied, it is separated into coke oven gas and coarse tar. Aqueous ammonia and sludge are separated and removed from the crude tar in a tar box 7 by a sedimentation separation method. Furthermore, when this tar is centrifuged in a centrifugal separator 8, ammonia water and sludge are further separated and removed, and raw material tar for binder pitch is produced. When measuring the particle size distribution of sludge in tar at the inlet and outlet of this centrifugal separator, the results are shown in Figure 4 (
As shown in a) and (b). Comparing FIGS. 4(a) and 4(b), the inlet tar sludge contains sludge with a diameter of 15 μm or more, whereas the outlet tar sludge contains almost no sludge with a diameter of 15 μm or more. That is, most of the tar sludge with a diameter of 15 μm or more can be removed using a super decanter. Tar sludge with a diameter of 15 μm or less can be removed to some extent by increasing the capacity of the super decanter, but not only will the equipment and electricity costs be enormous, but at the same time QI (quinoline insoluble content), which is one of the qualities of tar, will also be removed. It is removed and becomes unsuitable as a binder pitch feedstock tar. Therefore, in order to reduce the amount of sludge in the tar and obtain a binder pitch raw material tar containing quinoline insoluble matter, it is preferable that the particle size of all the sludge in the tar at the inlet of the centrifugal separator is 15 μm or more.

[0009]

[Example] Fig. 1 shows an example of the humidity control charcoal manufacturing process. Coking coal has a moisture content of 8 to 10% and is transported on conveyor 1, and then transferred to dryer 2.
to go into. In the dryer, the coking coal is indirectly heated with steam to evaporate the water content, and enters the dust collector 3 together with air as a carrier gas. This carrier gas is accompanied by pulverized coal,
The gas from which the pulverized coal has been removed in the dust collector 3 is discharged to the outside of the system.

On the other hand, the recovered pulverized coal is mixed with moisture-controlled coal whose moisture content is adjusted to 2 to 7% in a dryer on a conveyor 5 after adding oil to it in a mixer 4 to form pseudo-particles, and then sent to a coke oven. Sent to 6. In the present invention, by adding oil such as heavy oil, tar oil, tar slag, etc. instead of water, the pseudo particles of pulverized coal are not destroyed by the sensible heat of the humidity-controlled coal until they are transported to a coke oven, and the coke Dust generation during charging into the furnace was reduced, and the quality of the by-product tar obtained by charging the coke oven with moisture-conditioned coal mixed with recovered pulverized coal and carbonizing it did not deteriorate. Figure 2 shows changes in the ash content of tar, which is one of the byproducts of coke ovens. Each sample in FIG. 2 is an average value for one month. Before the humidity control coal equipment started operating, sample No. From 1 to 5, the ash content in tar is 0.05%
It was about. Sample No. From 6th to 10th, when the humidity control coal equipment was in operation and water was added and mixed to the pulverized coal collected by the dust collector, the ash content in the tar exceeded 0.2%, and it was used as raw material tar for electrode pitch, etc. It was a poor quality tar that could not be used.

[0011]Use No. From 11th to 13th, the humidity control coal equipment was in operation and heavy oil was added and mixed with the pulverized coal collected by the dust collector, and the ash content in the tar had decreased to less than 0.1%, making it sufficient as raw material tar for electrode pitch. It has become of a quality that can be used for.

0012

Effects of the Invention In the present invention, oil is added to the pulverized coal recovered by the dust collector of humidity-controlled coal equipment, and the mixture is mixed with the humidity-controlled coal after it is turned into pseudo particles. Dust generation is suppressed when the coke oven is heated, and an increase in ash content in tar, a byproduct of coke ovens, is suppressed. As a result, coke oven by-product tar using the conventional moisture-controlled coal charging method had a high ash content and could only be used as fuel, but coke oven by-product tar using the method of the present invention was found to have additional materials such as electrode pitch. It has become available as a valuable raw material tar.

[0013] Further, the generation of dust during handling of moisture-conditioned coal can be suppressed, which has a great effect of contributing to environmental improvement.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a process for producing moisture-controlled charcoal according to the present invention.

FIG. 2 is a diagram showing a comparison of the ash content in the by-product tar of the method of the present invention and the conventional method.

FIG. 3 is a process diagram for producing tar.

FIG. 4 (a) is a graph showing the particle size distribution of tar sludge at the inlet of a super decanter, and (b) is a graph showing the particle size distribution at the outlet.

[Explanation of symbols]

1 Coking coal transport belt conveyor 2 Dryer 3 Dust collector 4 Mixer 5 Moisture-controlled coal transport conveyor 6 Coke oven

Claims (2)

[Claims] Claim 1: In a method of drying and adjusting the moisture content of coking coal to 2 to 7% before charging the coking coal into a coke oven, heavy oil,
A method for producing humidity-controlled coal, which comprises adding oils such as tar oil and tar slag as a binder to make pulverized coal into pseudo-particles, and mixing the resulting particles with dry-adjusted coking coal. 2. The method for producing moisture-conditioned coal for charging into a coke oven according to claim 1, wherein the particle size of the pseudo particles is 15 μm or more.