JPS6049092A - Method for separating ash of coal - Google Patents

Abstract

PURPOSE:To remove ash to the utmost limit, by pulverizing finely coal while dehumidifying the coal with hot air, and separating coal composition materials from mineral materials. CONSTITUTION:For example, coal with 15% ash content is finely pulverized to <=some tens of mum particle diameter (e.g. about 10mum) in a ball mill, etc. while dehumidified with dry air heated at <=200 deg.C, e.g. about 150 deg.C, and coal composition materials having <=2 specific gravity are then separated from mineral particles having about 5 specific gravity in a special cyclone, etc. The former is further floated in a vertical pipe, containing water, and placed in a magnetic field in the horizontal direction, dropped in the vertical pipe to remove the ash with wire nets placed perpendicularly to the pipe axis (horizontally) in many layers.

Description

[Detailed description of the invention] Unexploded 8A relates to an ash separation method that makes it possible to remove ash to the maximum limit by pulverizing coal. Since the oil crisis, due to the diversification of energy sources in the United States, The use of coal is attracting attention because of its abundant reserves and ease of handling.

This coal also has a mineral content of 15% on average in Japan's imported coal.
#Associate, disposal of coal ash remaining after combustion is a problem, 8
It includes drawbacks such as the generation of air pollution of 5 m* such as 02.

But the coal root #! 1JIXh As is well known, it is a plant material that does not inherently contain minerals. It is physically mixed with LC while plants, etc., which are the root substances of minerals, are buried in the strata and carbonized, and this is also supported by microscopic observation of the coal structure.

For this reason, it was expected that by pulverizing coal, it would be possible to separate the coal-based material from the mineral ash.

However, while minerals can be easily pulverized, the constituents of coal include resinite, whose root substance is soap and wax, exginite, whose root substance is pollen, spores, and the endothelium of young shoots, and aquatic algae. When vH pulverizable components such as alginite as the root substance are combined and pulverized by a grinder, ball mill, or directly operated pulverizer, the pulverized minerals are captured in the unpulverized coal composition material, resulting in a sufficient separation effect. I couldn't open it.

As shown in Figure 1, when coal is heated above 230°C, it separates from the coal, but when heated below 200°C, the water content of the silkworms evaporates, and the powder resistance is reduced to 200°C.
They discovered that ash can be easily pulverized by pulverizing it while dehumidifying it with air at temperatures below 0.9°C, and established an effective ash separation method using pulverized carbonization.

In other words, coal with an ash content of 15 cm is pulverized in a ball mill while dehumidifying with dry air heated to about 150°C until the grain size becomes around 10 μm, separated in a special cyclone, and the separated coal with a low ash content is horizontally crushed. Floating in water in a vertical tube placed in a field of direction, a vertical tube? was dropped, and the ash was removed through several layers of wire mesh placed perpendicular to the tube axis (water f plane).

This is the composition of coal! This is because the P2I substance has a size of several stories to several tens of micrometers, and if the particle size is pulverized to about 10 micrometers and 8 degrees, it can be separated into particles consisting of particles. And while the specific gravity of the coal composition is less than 2,
Since the specific gravity of mineral particles is about 5, they can be easily separated using the difference in specific gravity. Also, the ash is separated from the iron in the ash.

Figure 1 shows the characteristics of the Taiping era when heating coal.
At temperatures below 230°C, volatile matter including calorific value is generated. Figure 2 shows the experimental results of the cyclone artificial wind speed and the ash content in the exit coal when the coal is heated to 100°C and then pulverized and separated by a specially designed cyclone. Ash division 15.451
It has decreased to 13.5%. Ese 1 shows the results of an experiment in which ash was trapped in the mesh of a wire mesh in a magnetic field.

The ash content in the coal with an ash content of 14.4 - at the entrance was captured by the strong magnetism of the intersecting iron wire of the wire mesh, and the ash content of the captured material was extremely high at 44.2%. Trade in. This is all because the coal was finely pulverized, which made it possible to effectively utilize the effects of centrifugal force and magnetic fields, and pre-heating to drive out moisture is a necessary condition to facilitate pulverization and eliminate particles with large diameters. It is.

[Brief explanation of the drawing]

Figure 1 is a graph showing the deformation and weight reduction of coal due to heating; (b) Wind speed Figure 2

Claims (1)

[Claims] A coal ash separation method that involves pulverizing coal to particles of several tens of micrometers or less while dehumidifying it with air or the like at a temperature of 200°C or less, and separating coal constituent substances and mineral substances.