JPS5880388A - Production of highly concentrated pulverized coal slurry - Google Patents

Abstract

PURPOSE:To produce a highly concentrated pulverized coal slurry which exhibits a high combustion efficiency when used in boiler and whose handling and transportation are easy, by subjecting froth obtd. from the flotation of a specified pulverized coal slurry, to a filter treatment. CONSTITUTION:A slurry 1 (having a solid concn. of 10-25wt%) of pulverized coal composed of at least 50% pulverized coal particles having a particle size of 200 mesh or below and a collector and/or a foaming agent such as diesel oil or pine oil are introduced into a flotator 2. Ash and sulfur component are removed as tailing. The resulting froth having a solid concn. of 15-30wt% is fed to a filter 3. Then the froth is treated with a dehydrating agent 7 such as dioctyl sodium sulfosuccinate. The resulting cakes having a solid concn. of 60wt% or above are mixed in an agitating tank 4 while adding a stabilizer 8 such as a water-soluble sulfonate salt to obtain a highly concentrated stabilized coal slurry which is then supplied through a pump 5 and a pipe 9 to a boiler for steam power generation.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention handles coal as a fluid fuel and produces a highly concentrated pulverized coal slurry that can be directly fed into boilers and other furnaces for various purposes. Transported in bulk by other means.
However, during these transportation operations, as well as the loading and unloading operations before and after the transportation, the pulverized coal (usually particle size Q, 5 ms or less) contained therein is blown away by the wind, causing the problem of dust generation.

Furthermore, coal originally exists below the earth's surface, and when it is mined, it is often observed that it reacts with oxygen in the air, generates heat, and spontaneously ignites.

This spontaneous ignition characteristic depends on the type of coal, but it is also related to the time it is left in the air, so it may ignite during coal storage, transportation, or cargo handling.

As described above, there are various handling problems in the bulk transportation of coal, and various solutions are being researched. Among these, the one that is currently attracting the most attention is high-concentration pulverized coal slurry, which handles coal in a liquid state. This process involves finely pulverizing coal and turning it into a liquid state using a small amount of water as a medium.It can be handled in the same way as petroleum, and when used for final purposes, such as combustion, it does not require a dehydration process.
It is desirable to increase the solids concentration of coal as much as possible so that it can be burned economically. However, coal is buried underground as an underground resource and contains a large amount of unburnt matter (ash) and sulfur, and there is a lot of ash and sulfur in 1 coal.

In view of this, the present invention provides a method for producing a highly concentrated pulverized coal slurry that includes a treatment step that reduces the content of ash and sulfur in coal.

An embodiment of the present invention will be described in detail below.

1 is a pulverized coal slurry having a solid concentration of 10 to 25% by weight and containing 50% or more of fine particles with a particle size of 200 mesh or less.

2 is a flotation machine, which is provided to obtain floss by partially deashing and desulfurizing the pulverized coal slurry. A collection agent and a foaming agent 6 are added to the flotation machine 2, and the pulverized coal slurry 1 is flotated to remove ash and sulfur content, and to achieve a weight concentration of 15 to 30%. You can get 70 s. The scavenger added here is:
Inorganic oils such as diesel oil, white kerosene, and kerosene,
As a foaming agent, methyl iso-butyl carbiturate (
MIBC), pine oil, etc. are used.

3 is a filter such as a disc type vacuum filter or a horizontal belt type vacuum filter. During this filtering process, a water releasing agent 7 is added, and the pulverized coal slurry is concentrated to form a cake with a weight concentration of 60% or more.

The water releasing agents used at this time are, for example, sodium di-octylsulfosuccinate, sodium di-octylsulfosuccinate, di-trimethylhexyl. Table 2 (Solid concentration after filter treatment) According to this table, solid concentration is 10 to
After filtering the 25% by weight pulverized coal slurry, a highly concentrated pulverized coal slurry with a solids concentration of 70% or more was obtained, and good results were obtained.

According to the present invention, it is possible to obtain a highly concentrated pulverized coal slurry that has been deashed and desulfurized and has a solid concentration of 60% or more, which not only improves the economic efficiency of handling and transportation, but also improves the efficiency of boilers during the combustion process. Not only improves combustion efficiency, but also reduces sulfur oxides.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a specific flowchart of the method of the present invention. 1...Pulverized coal slurry 2...Flotation machine 3...Filter 4...Agitator 5...Pump
6...Scavenger and foaming agent 7...Release agent
8...Stabilizer 9...Piping

Claims (4)

[Claims] (1) A pulverized coal slurry with a solid concentration of 10 to 25% by weight, containing 50% or more of pulverized coal particles with a particle size of 200 mesh or less, is led to a flotation process, and the partially deashed and desulfurized clean coal has a weight concentration of 15 to 25%. A method for producing a high concentration pulverized coal slurry 1), which is characterized in that it is made into a 70% slurry of 30%, and then subjected to a filter treatment step to form a highly concentrated slurry with a solid concentration of 60% or more. (2) Claim 1, characterized in that deashing is carried out by adding a scavenger and/or a foaming agent in the flotation step.
A method for producing a high-concentration pulverized coal slurry as described in . (3) A method for producing a high-concentration pulverized coal slurry according to claim 1 or 2, characterized in that in the filtering step, seven losses of clean coal are dehydrated using a water-repelling agent. (4) Items 1 and 2 of the above claims are characterized in that a stabilizer is added to the highly concentrated slurry. Or the method for producing a high concentration pulverized coal slurry according to item 3.