JPS5827797A - Granulation of coal - Google Patents

Abstract

PURPOSE:To granulate coal with a small amount of oil without using tar, by blending dehydrated powdered coal with a low carbonization degree with an oil (and a surface active agent) with stirring. CONSTITUTION:After coal is dehydrated to a dehydration ratio of >=20% (preferably >=60%), or after it is dehydrated and crushed (compressed and crushed by preferably a rod mill, ball mill, etc.), it is blended with water to give usually 1-65wt% water slurry of coal, and the slurry is blended with an oil (preferably fuel oil C, etc.) alone or both the oil and a surface active agent with stirring, so that it is granulated. The amount of the oil is <=30wt% based on the slurry, and the amount of the surface active agent is sufficiently 0.005-1wt%.

Description

[Detailed description of the invention] The present invention relates to a method for granulating coal.

In recent years, due to the depletion of petroleum energy, the use of coal has been reaffirmed, and various ways of using it are being considered. Among these, there is active research and development into water souffle, including a method for improving handling by making a water slurry by pulverizing coal and mixing it with water, and a method for pulverizing coal entirely in water to create a water slurry for deashing.

Coal-water souffle-free requires the recovery and dehydration of coal from water prior to combustion, and as there is currently no economical and effective method for recovering and dewatering, coal-water souffle-free technology has not seen widespread use. do not have.

Therefore, the present inventors focused on adding oil to coal-water souffle and granulating it as a method for recovering from stone Rt-water. We established a method of granulating it using a small amount of oil and a surfactant, and we have a prospect of practical application.

However, when using the above method, the granulation of lignite, sub-bituminous coal, and bituminous coal with a low degree of carbonization was insufficient, and there were major problems in turning these coals into water slurries.

Honbunshu's field granulation technology was developed because, despite the fact that there are vast reserves around the world, its use is limited because it contains many wrinkles and is prone to spontaneous combustion.

It is useful for the nurturing effects of horizontal legs, sub-takuzaku charcoal, and low-carbonization grade charcoal.

Regarding Honbunshu, there have been a few cases in which granulation has been successfully achieved by using oil and tar, and by using a very large amount of oil. However, it was not economical, and there was a great deal of difficulty in putting it into practical use.

Under such circumstances, the inventors of the present invention have thoroughly investigated the possibility of granulation using a small amount of oil without using Tar/L', and as a result, they have succeeded in granulation using an innovative method that is generally unthinkable. We have succeeded in this and have now provided the present invention.

In other words, for the right leg - water-soak-free strip, low-carbonization pulverized coal that has been subjected to a dehydration operation is used as coal, using a coal granulation method that uses oil alone or both oil and a surfactant to stir. This is a coal granulation method characterized by the following.

The low carbonization powder coal subjected to the dehydration operation Kpf3 of the present invention is obtained by pulverizing low carbonization coal and then dehydrating it, or preferably by crushing it after dehydration, and more preferably compressing and pulverizing it.

Low carbonization grade stone I# (hereinafter referred to as stone) is lignite, argentine coal,
It is a coal with a low degree of carbonization and a carbon content of 85 or less (anhydrous, ashless basis), preferably 80 or less. That lignite, ilI! Any kind of low-carbonization grade trigonum can be used, regardless of where it is produced.

Next, dehydrating coal is difficult no matter which method you use. For example, inert gas such as combustion exhaust gas or heated nitrogen gas
- Dehydration may be carried out by heating using a direct heating method, indirect heating method using stiffening steam or heating oil, etc., or dehydration may be performed using a method such as vacuum dehydration or pressure dehydration. good.

It is necessary to dewater the coal until the dehydration rate reaches 20% or more, a ratio of 40% or more, and more preferably 60% or more.

If you perform the dehydration operation like this, it will turn into coal! ! ! The degree of lipophilization of a surface increases depending on its dehydration rate.

Next, the pulverization can be carried out by a compression method, an impact method, a shinshin method, a #type method, or any other pulverization method. In particular, the granulation effect of Tomomonokeno is very remarkable when compressed and pulverized.

When compressing and pulverizing, it is possible to use a combination of a roll type or press type method that performs only compression and any of the above-mentioned pulverization methods.

In addition, it is very convenient to use methods such as a compression type or impact type pulverization method that performs compression and pulverization at the same time.

Commonly known large compression crushers include the Zowo Crusher, Corn Kufutsu V-Year, and Roll Kufutsu V-Year, which are capable of compression crushing because they crush stones by inserting them into a certain gap. Loft mills, ball mills, etc. are known as impact-type large-scale pulverizers, and they can perform compression pulverization in which a rod or ball is placed in a cylinder, and the coal is crushed by the impact of the rod or ball falling as it rotates.

For compression and pulverization, it is sufficient to have a compressive strength of usually 4 I/cm2 or more, preferably lo#/l:iml'' or more.

However, both pulverization and compression pulverization are limited to the models mentioned above.

The particle size of the lime pulverized by this method, preferably compressed and pulverized, is not particularly limited, but it is generally smaller than 1011, and the particle size can be changed depending on the purpose.

The dewatering operation of the present invention is not simply dewatering, but is for surface modification of lime, and is fundamentally different from the purpose of conventional dewatering. By dehydrating the coal and exposing the lime surface to the air, it has the effect of changing the hydrophilicity of the surface to more lipophilic, and accordingly, the adsorption power between the coal and oil increases, and even with a small amount of oil, the limestone surface becomes more lipophilic. It can be agglomerated and granulated.

Furthermore, granulation properties can be further improved by crushing, preferably compressing and crushing the dehydrated lime. This is because parts that have hitherto been difficult to come into contact with air are exposed to static electricity through pulverization, and the coal surface is further modified to become lipophilic.

In addition, when compressed and pulverized, there are K effects in addition to the effects of pulverization.

Since the pores of the coal are destroyed and the amount of oil absorbed is reduced, it is possible to granulate efficiently with a lower amount of oil.

Next, the coal concentration in the coal-water slurry is not particularly limited, but is usually about 1 to 65%, preferably 10 to 50%, and the coal concentration can be changed depending on the purpose.

The water used here includes all types of water, and among these, river water, well water, tap water, etc. are convenient and can be obtained in large quantities.

In order to adjust the pH'ft of Mayu's water, use hydroxide power A.
Even if an alkali such as /Vum or sodium hydroxide is added, the effects of the present invention will not change.

Oil melts used for granulation, crude oil or various wood fractions obtained from crude oil, such as kerosene, light oil, A heavy oil, B heavy oil, C heavy oil, shale oil or ethylene cracked residual oil - 1 is a mixture of various wood oils, etc. Refers to mineral oils such as oils generally used as fuel, lubricating oils, and cleaning oils, and also includes mixtures thereof.

Among these, heavy oils such as O heavy oil are particularly preferred because they are inexpensive.

This oil is the coal K in the coal-water slurry to be granulated.
An amount of less than 30 m is sufficient, and the effect of the present invention is so great that coal can be granulated even with an amount of less than 100, for example, so there is no need to add a large amount.

The method of adding oil is, for example, oil alone, oil with a surfactant dissolved in advance, or O/W using a surfactant.
Any method can be used, such as adding gold stone back to emulsified oil in a mold and adding water solute Kff, but it is more effective to coat the coal surface with oil in advance, then make a coal-water slurry and granulate it. This is the preferred method.

In other words, there is a method of coating coal with oil in advance. The oil is made by dissolving the surfactant' into an o/'w type emulsified oil using a surfactant. This is a method of making and granulating water souffle. Among them, the method of coating the coal surface with an o/v type emulsified oil using a surfactant is the most excellent in its granulation effect.

However, the method is not limited to these methods, and the granulation effect is significantly exhibited no matter which method is used to add the oil.

Surfactants are nonionic surfactants, anionic surfactants, and cationic surfactants that are generally used for coal granulation.

These surfactants can of course be used alone, but two or more types may be used in combination.

It is sufficient to add the surfactant in an amount of o, oos to 1 weight percent, preferably 0.01 to 0.5 weight Ik%, based on the coal in the coal-water slurry to be granulated. The surfactant may be used directly after being dissolved in a solvent such as isopropyl alcohol, ethyl cellosolve, butyl cellosolve, etc.

That is, since the effects of the present invention are excellent, there is no need to particularly limit the method of addition.

The granulation method basically requires only a simple operation of complete stirring, and may be either a patch type or a continuous type.

As a stirrer for performing such stirring, for example, an inbef type, a rotating disk type, a seed type, etc. can be used, and granulation can be caused by simply performing low shear stirring. However, the model, stirring rotation speed, and stirring time of these stirrers are not limited.

Since the granulated material is granulated into large particles, it is easily dehydrated by a filtration method, a centrifugation method, or the like. Note that due to the unique effect of the present invention, the ash present in the coal is not granulated and floats in water, so it is separated from the coal in this step.

The feature of the present invention is that after washing with stone*t-ta water,
Alternatively, after dehydration, water is added to the pulverized coal, preferably compressed and pulverized, to create a water slurry, and the mixture is stirred using oil alone or both oil and a surfactant.
The method is to granulate with only a small amount of oil without using tars/l, which is difficult to obtain in large quantities.

Next, examples of the present invention will be shown, but the present invention is not limited to these examples.

Example Dehydrated coal, or dehydrated coal, is further compressed and pulverized, and water is added to the nine stones to make a coal-water souffle of a predetermined concentration. To this, add oil alone or oil in which a surfactant has been dissolved in advance, or may be made into an O/W type emulsified oil with a surfactant, and mix under predetermined conditions.

After the granulation process, the granulated coal was filtered through a 1-16 Metsushi S free from salt water, and the granulated coal remaining on the sieve was dried, then clarified, and calculated using the following formula.

Among them, the coal particle size in the water soup before being subjected to the test, 20
0 bath 60% m 48"on O, 0%. The test results are shown in Table 1. As is clear from the wood surface, by carrying out the granulation method of the present invention, it is possible to use Tar A/. It was confirmed that granulation with a granulation rate of 80 or more was possible without using oil and with a small amount of oil, and that the effects of the present invention were extremely excellent.

On the other hand, when non-dehydrated stone st- is used, the granulation rate is below the 301 line even if the oil is used in an amount of 70% or more based on the coal, and the granulation rate is hardly granulated.

*1 Weight % based on coal (dry coal) ◆2 Post-addition: Coal-Water Soft Free Lt-14 After conditioning, oil overlay Before adding emulsified oil &: Oil'! Or after coating the coal surface with milk f and oil in advance , water was added to adjust the coal-water souffle *3 Stones #4 to #A12 were dehydrated and then crushed.

Coal No. 413 was dehydrated, compressed using a roll-type compactor, and then pulverized.

applicant Dai-Kogyo FGJ Iku Co., Ltd.

Claims (2)

[Claims] (1) In the coal granulation method in which oil alone or both oil and surfactant are used and stirred in a coal-water solute system, it is recommended to use low-carbonization powder coal that has undergone dehydration as the coal. Characteristic coal granulation method. (2) The coal granulation method according to claim 1, wherein low-carbonization powder coal that has been subjected to a dehydration operation is obtained by crushing, preferably compressing and crushing the dehydrated coal.