JPS58127792A - Controlling spontaneous ignition of low-grade coal - Google Patents

Abstract

PURPOSE:To prepare low-grade coal which is solid and is not susceptible to spontaneous ignition, by adding a mixture of kerosene and pitch to low-grade pulverized coal sent from mine in the form of an aqueous slurry and granulating it by a wet process, followed by separation of water, compression molding and drying. CONSTITUTION:A small amount of water is added to mined brown coal 1 and the coal is pulverized (2) in a wet crusher to produce a pasty aqueous slurry. The slurry is led into pipeline via a delivery pump and is transported to consuming cities or shipping points (3). A mixed oil consisting of kerosene 5 and pitch 6 fed from a mixed oil tank 4 is added, as binder, to the aqueous slurry of slack coal and it is formed into granules by means of a wet granulating machine and is deashed (7). The oil-contg. granules are separated from water by screening in a water separation process (8) and are compression molded (9). Here, additional dehydration is performed to produce solid lumps. Water and kerosene contained in the formed product are removed in the next drying (oil recovering) process (10) and recovered kerosene is sent to the mixed oil tank 4 for reuse. The resultant formed coal is used, e.g., as household fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for suppressing spontaneous combustion of low-grade coal such as lignite when it is transported from a coal-producing area to a consuming area for use.

There are huge reserves of lignite in various countries around the world, and there are many large-scale open-pit coal fields, so it is expected that it will be used in the future. However, lignite has an extremely high water content and is highly reactive, making it prone to spontaneous combustion.

Therefore, in order to import lignite in large quantities and expand its use, it is important to develop dehydration treatment technology and technology to prevent spontaneous ignition.0 Conventionally, as a method of suppressing spontaneous ignition of lignite, the surface of the coal was coated with surfactant. Well-known methods include coating the surface of stored coal with clay or the like.

Also, truck transportation, rail transportation, pipeline transportation, etc. are well known as methods for transporting coal from coal producing areas to consumption areas. However, conventional methods for suppressing spontaneous combustion of coal are expensive because they use expensive materials such as oil and surfactants, and they also use clay, which causes clay to mix with the coal.
There were disadvantages such as increased ash content making it difficult to dehydrate lignite. Regarding the transportation method, considering the location conditions of the coal producing area and the handling of the objects to be transported, there was a problem that the amount of transportation was small and that it was environmentally destructive. Moreover, there were also problems with processing before and after transportation.

The purpose of the present invention is to solve such problems and obtain anhydrous low-grade coal that is strong and suppresses spontaneous combustion.After pulverizing the low-grade coal, water and (2) The slurry is transported, and then a mixed oil of kerosene and pitch is added to the water/slurry IJ- of the low-rank coal to completely granulate the oil-impregnated granulated coal by wet granulation, and then the oil-impregnated granulated coal is separated from water. After separation, the purpose is achieved by compression molding and then drying the compression molded oil-impregnated granulated coal.
By transporting low-grade coal such as brown coal with water and slurry, the amount of transport can be increased, and by using a mixed oil of kerosene and pitch as a binder, wet granulation is possible without the need for lipophilic treatment of low-grade coal. By performing ILF shrink molding and drying, it is possible to obtain strong anhydrous low-rank coal from which kerosene (low boiling point oil) can be recovered and which suppresses spontaneous combustion.

The method of the present invention will be explained in detail below based on the drawings showing one embodiment thereof. The figure shows each process related to the method of the present invention, which mainly includes pulverization, transportation, granulation, compression molding, and drying. Lignite mined in coal-producing areas (1)
is a 25 to 4 Qgx lump coal with a moisture content of 30 to 60%; first, a small amount of water is added to it, and it is pulverized using a wet pulverizer (2). As a result, a paste-like water/slurry with a relatively high concentration (ratio (3)) is obtained.

Next, this pulverized coal water/slurry is guided to the pipeline via a transport pump and transported to the consumption point or loading point (3)
do. Next, a mixed oil of kerosene (5) and bitch (6) from the mixed oil tank (4) is added to the transported pulverized coal water/slurry at a ratio of about 20% as a binder for the pulverized coal, and then mixed. , pulverized lignite is granulated using a wet granulator (7). Although the ash content of lignite (1) is originally low, it is deashed and crushed during the wet granulation (7) process.

Next, the coal is sent to a dehydration separation step (8), and after separating the oil-impregnated granulated coal from water (ash slurry) using a screen, it is led to, for example, a Blangerquibb frikerato machine and compression molded (9). In this compression molding (9), the oil-impregnated granulated coal is further dehydrated and becomes a strong molded product using pitch (about 6%) present in the oil-impregnated granulated coal as a binder. Next, the moisture and kerosene of the molded product obtained by compression molding (9) are removed in the next drying (oil recovery) step 01, of which kerosene is recovered and guided to the mixed oil tank (4) for reuse. use.

The briquette obtained by this drying step θQ is used, for example, as household fuel (4).

The method of the present invention has the following effects.

(1) Since low-grade coal is pulverized, a paste-like water/slurry with a relatively high concentration can be obtained, thereby increasing the amount of lignite transported.

(2) Wet granulation is performed by adding a mixed oil of kerosene and pitch to the water/slurry of low-rank coal, so wet granulation is possible without the need for lipophilic treatment of low-rank coal, and deashing is possible. Oil-impregnated granulated coal can be obtained.

(3) Since the oil-impregnated granulated coal obtained by # type granulation is relatively large (ls+m or more), it can be easily dehydrated and separated using a screen or the like.

(4) Since oil-impregnated granulated coal is separated from water and then compression molded, dehydration progresses further and a strong molded product with high density can be obtained.

(5) Since the compression-molded oil-impregnated granulated coal is dried, kerosene (low boiling point oil) can be recovered (5) in this drying process, and the consumption of expensive oil can be reduced.

(6) Molded coal obtained by drying is anhydrous and easy to handle, and does not generate dust during handling. Moreover, it is stable and suppresses spontaneous combustion, so it can be used as a household fuel.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention and are process diagrams showing each step of the method of the present invention. (1)...Lignite, (2)...Wet grinding, (3)...
・Water/slurry transportation, (4)...Mixing oil tank, (5)・
... Kerosene, (6) ... Pitch, (7) ... Wet granulation, (8) ... Dehydration separation, (9) ... Compression molding, (1
(>...Drying Agent Yoshihiro Morimoto (6) Procedural Amendment (Mutsu) April 1981 Mr. Commissioner of the Japan Patent Office 2 Name of Invention Law for Suppressing Spontaneous Ignition of Low-grade Soap 3 Person who makes the amendment Relationship to the incident Patent applicant 4th name (511) 4th director of Hitachi Zosen Corporation Address 1-6-174 Tachiuribori Nishi-ku, Osaka 550 Koamano Building Telephone Inusaka 06 (532) 4025 (main) Name (6808) Patent attorney Yoshihiro Morimoto5,
Date (shipment date) Showa year month
Day 6, the number of inventions increased by the amendment 7, the detailed description of the invention in the specification subject to the amendment, the scope of claims in the packing specification, all 8 drawings, the content of the amendment (1) q) Clear #l In the Detailed Description of the Invention in Book Kusunoki (1), 3rd line, ``granulation'' is corrected to ``manufacturing''. (2) On page 5, line 10, "wet granulation" is corrected to "granulation." e) As per the appendix of the claims of Ming #I (all appendices to the drawings (2)) 2. Claims ■: After pulverizing low-grade coal, water and water are delivered to the destination. Next, a mixed oil of kerosene and pitch is added to the water/nufry of the low-rank coal, and oil-impregnated granulated coal is made by wet granulation.
, Next, after separating the oil-impregnated granulated coal from water, compression molding is performed,
A method for suppressing spontaneous combustion of low-rank coal, which comprises drying the compression-molded oil-impregnated granulated coal. (3)

Claims (1)

[Claims] 1. After pulverizing the low-rank coal, transport the water and slurry to the destination, then add all of the mixed oil of kerosene and pitch to the water and slurry of the low-rank coal, and wet granulate it to produce oil-impregnated granulated coal. Granulate,
A method for suppressing spontaneous ignition of low-grade coal, which is characterized in that the oil-impregnated granulated coal is then separated from water and then compression-molded, and then the compression-molded oil-impregnated granulated coal is dried.