JPS58113297A - Granulation of low-grade coal - Google Patents

Abstract

PURPOSE:To obtain oil-containing deashed coal granules which can be dehydrated easily with a screen and has water-absorption preventing property, by making the surface of coal powder during the drying process, slurrying the powder in water, and granulating in water using an oily substance as a binder. CONSTITUTION:The surface of coal powder, e.g. brown coal powder, is made oleophilic during drying process by adding and mixing a solution of thermosetting resin to the coal and curing the resin with heat. After the treatment, the powder is slurried in water, granulated in water using an oily substance as a binder, and separated from water to obtain oil-containing deashed coal granules having a diameter of about 0.5-1.5mm.. EFFECT:The spontaneous ignition and the dust generation are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for granulating low-grade coal with a high moisture content, such as lignite.

Traditionally, the method of transporting coal from production areas to consumption areas has been to crush the coal, add water to it, suspend it, make a slurry of an appropriate concentration, and transport it through pipes, and then add oil after transportation. The method of granulation and dehydration is known as the most efficient transportation method.

That is, mineral oil is added to an aqueous slurry of pulverized coal containing ash, the coal is granulated in water using this as a binder, and the oil is separated from the ash slurry to obtain oil-containing deashed granulated coal. - There is an agglomeration method (also called oil granulation method, hereinafter referred to as "rOA method"). It is well known that this OA process is effective for granulation, dewatering, and ash removal from coal after slurry transportation. This OA method is a technique that utilizes the difference in oil wettability between coal and ash, and the condition is that the coal content is lipophilic.

In other words, it is difficult to apply this OA decision when transporting a slurry of low-grade coal, such as lignite, which has a high moisture content and strong wood affinity. The reason for this is that low-grade coal such as lignite has a high moisture content, so the slurry concentration during transportation is low, resulting in low transportation efficiency.Also, lignite has a strong wood-philicity during dehydration after transportation, so dehydration using the conventional OA method is difficult. The dehydration efficiency is low, and even if dehydrated, there is a risk of spontaneous combustion due to fine coal particles, and environmental protection is difficult due to dust generation and ignition during storage and cargo handling.

Therefore, an object of the present invention is to make it possible to apply KOA determination of low-rank coal such as lignite.

That is, the present invention adds and mixes a thermosetting resin solution to coal particles that are being dried, coats the surfaces of the coal particles with the thermoset resin to make them lipophilic, and then converts the coal particles into an aqueous slurry. granulated coal by adding an oily substance as a binder to the aqueous slurry of the hind limbs, granulating the coal particles in water, and separating it from the water to obtain oil-impregnated demineralized granulated coal. This paper proposes a grain method.

According to this method, low-grade coal such as lignite #! The OA method can also be applied to

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Lignite containing 30-7G'% moisture is pulverized to a fine powder and dried. Drying is performed using combustion exhaust gas to prevent ignition within the crusher. The degree of drying is conditioned by the use of the final product, oil-impregnated demineralized granulated coal.
For the ninth stage of lipophilization treatment, the water content should be 30% or less. The lipophilization treatment is performed by spraying and adding a thermosetting resin liquid solution. Since it is thermosetting, it is thermosetted at the same time as it dries, forming a KIIR fat film on the surface of the coal particles. The resin solution used for this lipophilization treatment is preferably based on 4 to 7% dry charcoal.

Even if the amount of resin is increased, the effects on water reabsorption, granulation, and dehydration remain the same. This lipophilized coal is suspended in water to prepare an aqueous slurry.

In this state, an oil to serve as a binder, such as heavy oil C, is added to the slurry transported 4I in this state, mixed and dispersed with a high-speed stirrer, and adhered to coal particles to form an agglomerated state.

When this is introduced into a granulator and granulated, the diameter is 0.5 to 1.
5 m of oil-impregnated demineralized granulated coal is obtained.

This is a granulated material that can be easily dehydrated using a screen or the like.

Although surface coating materials such as paints are commonly used as thermosetting resins, other substances such as natural tree sap, such as latex (rubber sap) and rosin (pine tar) can also be used. , regional provisions? Depending on the type of t-, it is easily available and inexpensive.

When the above treatment is used in a lignite transportation system, Ktf,
For example, slurry is treated to make it lipophilic at the source before being transported.
There are methods to obtain oil-impregnated deashed granulated coal by granulation and dehydration treatment at the loading dock after transportation, and oil-impregnated deashed granulated charcoal by lipophilization treatment, slurry adjustment, and granulation and deashing treatment at the base of the mountain. There are methods of transporting by slurry transport or by normal transportation methods such as railways.

Next, the present invention will be explained in detail. The coal used in the experiment was lignite from Indonesia, with a moisture content of approximately 4396 and an ash content of approximately 2%.
It is. The sample charcoal was ground in a ball mill to a 1 mm 90% pass (median diameter 0.35 mm), and then dried in a constant temperature dryer to a constant weight of 107°C. 4% thermosetting (alkyd type) resin solution was added to this pulverized coal in a dry atmosphere, and the mixture was thoroughly kneaded to coat the surface of the pulverized coal particles with the resin.
10% pulverized coal using a homogenizer (Kabu RPM)
A water slurry was prepared. Next, 17% of heavy oil A was added to this pulverized coal/water slurry, and a high-speed stirrer (120GOr
The pulverized coal was agglomerated with oil mixing for 3 minutes using pm). This pulverized coal aggregate is processed using a batch type wet granulator (20 GOr).
pm) for 6 minutes to obtain granulated coal divided by oil-impregnated oil-removed and ash granulated coal. The oil-impregnated demineralized granulated coal had grown to α5 mm or more, and could be easily separated from water (formerly the ash slurry) using a screen with an opening of α293 m. The water content after centrifugal dehydration of dehydrated and separated nine-go oil demineralized granulated coal is approximately 26%.
The ash content was 1.5% based on the results of industrial analysis.

As described above, according to the present invention, it is possible to granulate hydrophilic low-grade coal containing a large amount of water inside particles such as brown coal into pulverized coal, and the following effects can be expected. - (1) The water content of granulated coal that has been subjected to lipophilic treatment, granulation, and centrifugal dehydration is 26%, which is nearly half of the water content of the original coal, and has the effect of preventing water absorption in the coal.

(2) Granulated coal grows to α5ffIO11 or more,
Screen (opening α293nm) allows for easy dehydration.

(3) Ash content after screen dehydration (1.5%) #i,
It is lower than the raw ash ash content (2%) (has a deashing effect) (
4) By using a thermosetting resin for lipophilic treatment, a reduction in oil consumption can be expected.

(5) Because granulated coal is coated with oil, it has no effect of preventing spontaneous combustion, and since there is no fine powder, there is no secondary pollution due to the generation of dust, and environmental conservation can be achieved. pollution can be prevented.

(6) Lipophilization Since a thermosetting resin with stronger hydrophobicity than an oily substance is used for I&C, it is easier to slurry coal particles compared to the case of lipophilization with an oily substance.

[Brief explanation of the drawing]

The drawing is a 70-chart illustrating the method of the invention. Agent Yoshihiro Morimoto Procedural Amendment (Self-Control, Incident Indication 1982 Patent Application No. 211312 No. 2)
, Name of the invention: Low-quality granulation method 3, Relationship with the case of the person making the amendment Name of patent applicant (511) Hitachi Zosen Corporation 4 Name of agent (6808) Patent attorney Yoshihiro Moto 5,
Date (shipment date) Showa year month
Day 6, the number of inventions increased by the amendment 7, the detailed description of the invention column of the specification subject to the amendment - all 8 drawings, the content of the amendment (υ detailed description of the invention in the specification ■ page 1 In line 14, page 2, line 11, line 14h, and line 16 of the same page, the words ``brown selection'' are corrected to ``bronchaku.'' ■Page 6, lines 7 to 8 Correct the phrase "Pelletize the low-grade method after fine granulation" to "Pelletize the low-grade method after fine granulation." ■Page 6, line 16, "Compared to less (has a deashing effect)".'' should be corrected to ``The deashing effect is less than that.'') Correct the entire drawing as shown in the attached sheet.

Claims (1)

[Claims] 1. A thermosetting resin solution is added to and mixed with the coal particles being dried, and the surface of the coal particles is covered with the thermoset resin to make it lipophilic, and then the coal particles are aqueous. Low-grade coal characterized by slurrying, adding an oily substance as a binder to the aqueous hind limb slurry, granulating coal particles in water, and separating from the water to obtain oil-impregnated demineralized granulated coal. granulation method.