JPS61219860A - Coal carbonization testing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a coal carbonization test method, and more specifically, the present invention relates to a method for testing coal carbonization, and more specifically, the micro-reactivity of coke.
ity).

[Prior Art 1] Currently, the reactivity of carbonized coal or coke toward carbon dioxide is receiving considerable attention. The preferred test method for coke reactivity is the Nippon Steel Corporation method (hereinafter referred to as the NSC method) (COMA, 1981 report,
(Page 87), and the method involves heating a 200g sample of lump coke (20±1 arm) with precise dimensions at 1100°C.
and measuring the percent weight loss when placed in carbon dioxide for 2 hours. Special standard equipment has been devised to perform the NSC method, but not only is the equipment expensive, but the method is time consuming and very labor intensive.

That is, in order to evaluate coal or coal mixtures for industrial use, test coke must be produced, which requires up to one day. Subsequently, the method itself requires skilled laboratory personnel. It can be carried out by less skilled personnel in a coke oven plant and predicts and monitors the approximate properties of a coal charge or coal mixture charge on an industrial scale before actually producing coke. It would be of considerable assistance to coke oven plant operators to develop simpler, faster, and less expensive test methods that would allow for plant management. The greatest advantage would be if a test method were found that could avoid the need to produce test coke in a test or pilot furnace.
Although we cannot avoid all of the shortcomings of the NSC method, we do have a quick and easy method that avoids most of them and yields results that correlate very well with the results of the NSC method. I found a way.

Therefore, the present invention provides a method for evaluating the microreactivity of coke, in which a small amount of a fine powder sample of a representative coal or coal mixture is taken, and the sample is kept under inert gas conditions at a desired reactivity test temperature. A method for evaluating the microreactivity of coke consists of carbonizing it by heating until a weight is obtained, passing carbon dioxide at the desired test temperature over the carbonized sample, and measuring the weight loss within a certain time. It is on offer.

It will be readily understood from the above description that the raw material for the process of the present invention is not coke but coal.

We believe that the use of coal as a raw material is not something that has been previously advocated, and yet offers certain advantages that will become more apparent in the discussion below. It is preferred that the coal or coal mixture is crushed or crushed to suitable dimensions; for example, in tests that have been observed to correlate well with the NSC method, a suitable size range is 212-125 μm (72-120 British Standard Sieve). dimensions), and this dimensional range is used in British industry for charging coking coal (
For most similar analyses, the size range is often within the range of dimensions established for most similar analyses. The weight of the sample is not critical for the method of the invention; successful tests have been carried out with as little as 150 mg, although samples of about 10 g can be used in test methods suitable for plant use. is expected. However, it is important that the sample be representative, and a standard riffling procedure is used to sample a statistically representative sample.
There are known methods including edure).

The coal or coal mixture sample is heated to a predetermined temperature under inert gas conditions, preferably a stream of inert gas, conveniently nitrogen. However, any inert gas can be used. The predetermined temperature is usually in the range of 900 to 1200°C, and in the NSC method is 1100°C. Further, the heating rate may be any convenient rate for carrying out conventional carbonization in a furnace, such as a rate of about 5° C./min. If desired, about 5
00°C or higher, especially after the plasticity development stage (post-pl
Although the test can be sped up by heating at a faster rate than the previous one, problems due to rapid heating should be avoided since the method of the present invention can be repeated using small amounts of sample. Also, the carbonization time is about 3.5 hours instead of 17 to 20 hours in a coke oven. If the coal to be tested (B) is strongly agglomerated, it is desirable to physically separate the individual particles of coal to prevent agglomeration. Since the method of the invention is a microreactivity test and is not intended to simulate or obtain information about the overall reactivity of large quantities of coke,
It is necessary to form only char and not coke where melting occurs.

Reaction of the carbonized sample with carbon dioxide is preferably carried out by passing a stream of CO2 over the sample. Continuous monitoring of sample weight over time is preferred, but the sample may also be weighed before CO2 treatment and after a known period of CO2 treatment. The NSC method uses CO2 before passing and
It states that the weight should be weighed after the passage of time-open CO2; if a similar operation is used for comparison, weight loss is directly proportional to time, so weight loss up to 20% or a predetermined It has been found that the Co2 treatment can be carried out for hours. .

The method of the invention is carried out in a furnace in which a sample of coal or coal mixture can be heated and sequentially exposed to an inert gas and CO2, and the sample can be weighed continuously or at necessary points during the operation. is preferred.

It should also be remembered that there is a nearly linear relationship between the NSC method reactivity test results and the post-reaction strength (which involves tumbling the coke reacted with CO2 under standard conditions and measuring the failure rate). I want to be Therefore, it appears that the method of the invention can be used to obtain useful information about post-reaction intensity as well as microreactivity.

[Example] The present invention will be further explained with reference to Examples below.

Representative samples of various coals and coal mixtures were crushed and sieved to obtain coal fines with dimensions of 212-125 μm, and 1 g of this sample was carefully separated. The sample is loaded into the sample holder of a commercial thermobalance and then adjusted to the temperature at which the reactivity measurements are carried out at a heating rate of 5°C/min under conditions of nitrogen flow (400 wl/min), i.e. 1100 ml/min.
Heated to ℃. The thermobalance provided a continuous reading of weight and when the sample temperature and weight stabilized, the nitrogen was replaced with CO2 for 10 minutes. Each test of the present invention was completed within four hours, compared to the at least one day normally required to perform the NSC process, which consists of coking in a pilot furnace and then performing the operations described in the NSC process. We were able to.

For comparison purposes, 85% coking coal was sifted through a 3.35 mm sieve.
Let it pass! - The same coals and coal mixtures as described above were coked by crushing and charging wet (9% moisture) into a 250 kg pilot furnace. The pilot furnace was heated by gamma to maintain the smoke tube side of the furnace wall at 1180°C. After a normal carbonization time of 17 hours, the feedstock was removed and cooled with water. When the raw material was taken out, the temperature at the center of the raw material was about 1030°C. Obtained coke sample 2
00g was tested by the NSC method. The results of the NSC method reactivity and the microreactivity results according to the method of the present invention are plotted in the attached drawings. A slope of the best straight line was obtained as shown in the following equation: NSC method reactivity = 1,152 MR + 9,050 where M
R is the weight loss rate (%) after 10 minutes of the above-mentioned method of the present invention.
).

A correlation coefficient of 0.936 was found and the method of the invention
It appears to offer a valuable alternative to the SC method.

Although the method of the invention describes a special alternative to the NSC method, it is applicable to many other reactions carried out at the local level for the evaluation of coke and many types of carbonized solid fuels. It appears to offer an alternative to sex testing.

[Brief explanation of the drawing]

The figure is a graph showing the results of NSC reactivity and microreactivity according to the method of the present invention.

Claims (1)

[Claims] 1. A method for evaluating the microreactivity of coke, in which a small amount of a fine powder sample of a representative coal or coal mixture is obtained under inert gas conditions at a desired reactivity test temperature to a constant weight. A method for evaluating the microreactivity of coke, which consists of carbonizing it by heating it to a temperature of 100°C, passing carbon dioxide at the desired test temperature over the carbonized sample, and measuring the weight loss over a certain period of time. 2. The method of claim 1, wherein the coal or coal mixture sample has a particle size in the range of 125 to 212 microns. 3. The method according to claim 1 or 2, wherein the test temperature is within the range of 900 to 1200°C. 4. The method according to any one of claims 1 to 3, wherein the sample is heated at a rate of 5° C./min. 5. The method according to any one of claims 1 to 4, wherein the sample is continuously weighed in the heating step and the carbon dioxide treatment step. 6. The method according to claim 1, wherein the continuous weighing is performed using a thermobalance.