阅读说明：本技术 一种炼焦过程中半焦收缩率的检测方法 (Method for detecting semicoke shrinkage rate in coking process ) 是由 张文成 任学延 顾建 于 2019-03-11 设计创作，主要内容包括：本发明公开了一种炼焦过程中半焦收缩率的检测方法,主要解决现有炼焦过程中半焦收缩率的检测精度低、检测结果不能满足配煤炼焦生产的技术问题。本发明一种炼焦过程中半焦收缩率的检测方法,包括以下步骤：1)制备炼焦煤试样；2)将炼焦煤试样置于试验装置的煤杯中；3)对试验装置煤杯中炼焦煤试样进行加热；4)操控计算机采集试验装置煤杯中炼焦煤试样的高度及温度数据并保存数据；5)计算炼焦过程中半焦收缩率。本发明方法检测精度高、检测成本低,能够准确表征炼焦过程中半焦到焦炭的过程收缩程度。(The invention discloses a method for detecting the semicoke shrinkage rate in a coking process, which mainly solves the technical problems that the detection precision of the semicoke shrinkage rate in the existing coking process is low, and the detection result cannot meet the requirements of coal blending coking production. The invention relates to a method for detecting the semicoke shrinkage rate in a coking process, which comprises the following steps: 1) preparing a coking coal sample; 2) placing a coking coal sample in a coal cup of a test device; 3) heating a coking coal sample in a coal cup of a test device; 4) the control computer collects the height and temperature data of the coking coal sample in the coal cup of the test device and stores the data; 5) and calculating the semicoke shrinkage rate in the coking process. The method has high detection precision and low detection cost, and can accurately represent the shrinkage degree of the process from semicoke to coke in the coking process.)

1. A method for detecting the semicoke shrinkage rate in the coking process is characterized by comprising the following steps:

1) preparing a coking coal sample, and preparing the coking coal sample for later use according to a method specified by the Chinese national standard GB/T479-;

2) placing a coking coal sample in a coal cup of a test device, weighing 150-250g of the coking coal sample for later use and placing the coking coal sample in the coal cup of the test device; the test device can be heated to 1200 ℃, and the heights of the samples at different temperatures are continuously measured in the heating process;

3) heating the coking coal sample in the coal cup of the test device, operating the test device to heat according to the set heating rate curve, wherein the temperature T is set in the heating rate curve₀、T₁、T₂And T₃And rate of temperature rise R₁、R₂And R₃Controlling parameters; at a temperature T₀To T₁In the process of (1), with R₁Continuously heating at the heating rate of (2); at a temperature T₁To T₂In the process of (1), with R₂Continuously heating at the heating rate of (2); at a temperature T₂To T₃In the process of (1), with R₃Continuously heating at the heating rate of (2);

4) the control computer collects the height and temperature data of the coking coal sample in the coal cup of the test device and stores the data;

5) calculating the semicoke shrinkage rate in the coking process, wherein the semicoke shrinkage rate in the coking process is (h)₁-h₂)/h₁100% of the total of₁Is temperature is T₂The height of the coking coal sample in the coal cup of the test device is mm; h is₂Is temperature is T₃The height of the coking coal sample in the coal cup of the test device is mm.

2. The method for detecting a semicoke shrinkage ratio during a coking process as claimed in claim 1, wherein the temperature-rising rate curve of the step 3) is set to a set temperature T₀At 25 ℃ and T₁At 250 ℃ and T₂Is 650 ℃ and T₃Is 1100 ℃ and the heating rate R₁At 8 ℃/min, R₂Is 3 ℃/min and R₃Is 3 ℃/min.

Technical Field

The invention relates to a method for detecting the performance of semicoke in the coking process, in particular to a method for detecting the shrinkage rate of semicoke in the coking process, and relates to the technical field of coal blending and coking.

Background

The coking process is the process from adding coal into coke oven to isolate air and heating for high temperature dry distillation until the coke is mature. During the heating process, the organic matter of coal undergoes a series of irreversible physicochemical changes with increasing temperature to form gas (coal gas), liquid (tar) and solid (coke). The heating process of the coal can be roughly divided into three stages, wherein the first stage is a drying and degassing stage before 300 ℃, and the second stage is a coal-bonding stage before 300-600 ℃ to form semicoke and generate coal gas; the third stage is 700-1000 ℃, condensation polymerization reaction is carried out, a small amount of coal gas is separated out, and semicoke is changed into a coke stage.

There are two shrinkages during coking, one shrinkage during the formation of the second stage char during the heating of the coal, and one shrinkage during the conversion of the third stage char into coke during the heating of the coal. The shrinkage measurement in the second stage of the coal heating process during coking is the change in volume during the formation of the char, which is the conversion from fluid to solid; in the third stage of the coal heating process, after the formation of the semicoke, the coal is subjected to a shrinkage stress, and if the shrinkage stress is greater than the strength of the semicoke, cracks are formed, so that the caking volume and strength of the coke are directly related to the shrinkage state in the third stage of the coal heating process.

In the existing detection of the coal tar, the shrinkage degree is only determined on the formation of the second-stage semi-coke, and the technical scheme adopted by the Chinese standard 'bituminous coal colloidal layer index determination method' GB/T479-2000 is as follows: filling a coal sample into a coal cup according to the specification, placing the coal cup in a special electric furnace, heating the coal cup to 600 ℃ on one side at a specified heating speed, and correspondingly forming three isothermal layer surfaces of a semi-coke layer, a colloidal layer and an un-softened coal sample layer; the maximum thickness Y of the colloidal body is measured by a probe, and the final shrinkage X is measured from the volume curve of the test. Because the shrinkage is twice in the coking process, the Chinese national standard (GB/T479-2000) stipulates that the shrinkage can be detected only once by taking 650 ℃ as the final temperature of the test, and has certain limitation.

The Chinese patent document with application publication number CN1963453A discloses a method for researching the shrinkage characteristic of semicoke in the coal pyrolysis process, and provides a method for researching the shrinkage characteristic of semicoke in the coal pyrolysis process, which is a method for accurately obtaining the shrinkage characteristic of semicoke in the coal pyrolysis process by taking a microscope and a hot stage as main experimental means, taking coal and micro-component particles thereof as research objects, obtaining the dynamic change characteristic of a sample in the pyrolysis process through a microscopic picture shot under the microscope and using an image analysis method. The method adopts an image analysis method, and intuitively obtains the segmentation characteristics of the semicoke shrinkage, factors influencing the ending temperature, other dynamic parameters and the like. The method adopts a microscopic hot stage, the amount of the used sample is small, the change of the coking process can be visually observed, but the quantitative analysis of the shrinkage ratio of the coke is difficult.

Chinese patent document of application publication No. CN104215163A discloses coke oven coal cake whole-course shrinkage monitoring equipment, which is coke oven coal cake whole-course shrinkage monitoring equipment, including the touch panel, the monitoring pole, the host computer, the touch panel is arranged in on the coke oven coal cake, the touch panel top is connected with the detection pole, the other end of detection pole passes outer barrel and extends to the blind end of interior barrel, be equipped with liquid in the outer barrel, the open end of interior barrel is arranged in below the liquid level of outer barrel, scale and detecting element are equipped with to the blind end of interior barrel, detecting element passes through the data line and is connected with the host computer. The device is arranged on a production coke oven, and the process of expansion and contraction change of the coal cake due to fusion, solidification, semicoke formation and coke can be determined through the position change of the scale relative to the graduated scale; according to the method, the coke oven coal cake is monitored and installed on the production coke oven in the whole process, and due to the poor environment condition of the coke oven, a large amount of tar generated by the coke oven can influence detection equipment, so that accurate measurement is difficult.

Disclosure of Invention

The invention aims to provide a method for detecting the semicoke shrinkage rate in the coking process, which mainly solves the technical problems that the detection precision of the semicoke shrinkage rate in the existing coking process is low, and the detection result cannot meet the requirements of coal blending coking production; the method provides a brand-new method for detecting the shrinkage performance of the semicoke in the coking process, and overcomes the defect of performance evaluation of the existing coking coal.

The semicoke shrinkage rate in the coking process is the volume shrinkage percentage of the semicoke from the semicoke to the coke maturation stage in the coking process. The larger the value of the semicoke shrinkage rate in the coking process is, the more easily cracks are formed in the process that the semicoke is converted into the coke in the third stage in the coking and heating process of the coking coal, and the poorer the lumpiness and strength indexes of the produced coke are.

The technical idea of the invention is that by utilizing the principle of coke formation in the coking process, based on the characteristic that the semicoke is once shrunk in the second-stage semicoke forming process in the coal heating process and is once shrunk in the process that the semicoke is converted into the coke in the third-stage semicoke forming process in the coal heating process, the semicoke shrinkage rate is measured through temperature control, and then support is provided for coke performance evaluation.

The invention adopts the technical scheme that a method for detecting the semicoke shrinkage rate in the coking process comprises the following steps:

1) preparing a coking coal sample, and preparing the coking coal sample for later use according to a method specified by the Chinese national standard GB/T479-;

2) placing a coking coal sample in a coal cup of a test device, weighing 150-250g of the coking coal sample for later use and placing the coking coal sample in the coal cup of the test device; the test device can be heated to 1200 ℃, and the heights of the samples at different temperatures are continuously measured in the heating process;

3) heating the coking coal sample in the coal cup of the test device, operating the test device to heat according to the set heating rate curve, wherein the temperature T is set in the heating rate curve₀、T₁、T₂And T₃And rate of temperature rise R₁、R₂And R₃Controlling parameters; at a temperature T₀To T₁In the process of (1), with R₁Continuously heating at the heating rate of (2); at a temperature T₁To T₂In the process of (1), with R₂Continuously heating at the heating rate of (2); at a temperature T₂To T₃In the process of (1), with R₃Continuously heating at the heating rate of (2);

4) the control computer collects the height and temperature data of the coking coal sample in the coal cup of the test device and stores the data;

5) calculating the semicoke shrinkage rate in the coking process, wherein the semicoke shrinkage rate in the coking process is (h)₁-h₂)/h₁100% of the total of₁Is temperature is T₂The height of the coking coal sample in the coal cup of the test device is mm; h is₂Is temperature is T₃The height of the coking coal sample in the coal cup of the test device is mm.

Further, the temperature T is set by the heating rate curve in the step 3) of the invention₀At 25 deg.C、T₁At 250 ℃ and T₂Is 650 ℃ and T₃Is 1100 ℃ and the heating rate R₁At 8 ℃/min, R₂Is 3 ℃/min and R₃Is 3 ℃/min.

The method is based on years of experimental study of the applicant, and the applicant finds that the formation of coke cracks and the shrinkage in the coking process have an obvious relationship through years of experimental study, and the detection of the coking shrinkage only at low temperature is not scientific; the applicant has also found that the most critical stage actually affecting the formation of cracks in the coke is the shrinkage of the char, which cracks form when the shrinkage stress of the coke is greater than the matrix strength of the coke; the method can accurately measure the semicoke shrinkage rate in the coking process of different coking coals and has important significance for coking coal evaluation and coke quality control.

The semicoke shrinkage rate in the coking process measured by the method can accurately represent the shrinkage performance of coke, overcome the defects of the existing detection method and make real and objective evaluation on coking coal with different qualities.

Compared with the prior art, the invention has the following positive effects: 1. the method fills the gap that the semicoke shrinkage rate in the coking process is the semicoke volume shrinkage detection from the semicoke to the coke mature stage in the coking process, puts forward the concept of the semicoke shrinkage rate for the first time, makes up the gap of the shrinkage degree representation in the semicoke to coke process, and has positive significance for researching the formation and control of coke cracks. 2. The colloidal layer survey device of usable coal is through controlling rate of rise of temperature and improving the intensification terminal point, surveys the semicoke shrinkage factor, the popularization and application of the index of being more convenient for. 3. The method has high detection precision and low detection cost, and can accurately represent the shrinkage degree of the process from semicoke to coke in the coking process.

Detailed Description

The present invention will be further illustrated below with reference to specific embodiments, which are to be understood as merely illustrative and not limitative of the scope of the present invention.