Device and method for testing free fluidity of coking coal in thermoplastic state

Abstract

The invention, which belongs to the field of coal blending coking, discloses a device and method for testing free fluidity of coking coal in a thermoplastic state. In the prior art, only the Gieselerfluidity, the Aoya expansion degree, the caking index and the gelatinous layer index are used as coal quality indexes and the Gieseler fluidity as a common coal thermoplastic index has problems: the quality characteristics of colloid cannot be directly represented, coke generated by different coking coals cannot be well distinguished, and performance detection of the coking coals is incomplete. According to the invention, the coal is crushed, the vitrinite is enriched, and coal press cakes are made; the coal press cakes are arranged on a tray and are heated; a permeation distance and a connecting line length after pavement are measured and are used as new coal thermoplastic characteristics to express physical property that different coals influence a carbon structure and a pore wall structure after coking. Therefore, a novel method is provided for coal quality detection; the coal quality detection means are enriched; and the help and support are provided for correct use of different coking coals in coal blending.

Description

technical field [0001] The invention relates to the technical field of coal blending and coking, and more specifically relates to a device and method for testing the free flowability of coking coal in a thermoplastic state. Background technique [0002] Thermoplasticity refers to the property that a substance can flow and deform when heated, and can maintain a certain shape after cooling. Coking coal belongs to bituminous coal, and has certain cohesiveness, and can be coked under the coking conditions of chamber coke oven. When coking coal is pyrolyzed, it begins to soften when it reaches 300°C, and it is in a thermoplastic state when it reaches 550°C. Coal particles will undergo melting, flow, expansion, foaming, and then solidify. There are differences in quantity and quality of colloids, which lead to different coking characteristics in the above-mentioned pyrolysis process, thus forming different semi-coke structures, so the carbonaceous structure characteristics of the...

AI Technical Summary

Problems solved by technology

The quality characteristics of colloids are the main influencing factors for the formation of different semi-coke structures (pore structure and pore wall structure) in the thermoplastic process, but at present, the Giggler fluidity cannot be directly characterized because the colloids are composed of gas-liquid-solid three-phase, The different viscous properties of the colloid itself will produce different analytical results for the Kiwi fluidity, which is related to the characterization method of the test

There are three problems with Gie’s fluidity as a commonly used coal thermoplastic index. First, the real viscosity of high fluidity coal is underestimated, because colloids are a pseudoplastic fluid in the thermoplastic process, which conforms to the apparent viscosity with shear The characteristics of the rate increase and decrease, Kishi's measurement is pseudoplastic flow; second, the reliability of high fluidity is doubtful, because in the thermoplastic process, due to the Weissenberg effect, there may be a gap between the inner wall of the crucible and the colloid. There will be gaps, which will cause the agitator to run idly and the fluidity value will be too large; the third is that the different inert content in the coal will have a greater impact on the fluidity results

Theoretically, high fluidity will produce a thin pore wall structure with high porosity, which will lead to weakening of coke strength

[0004] After searching, the Chinese patent application number: ZL201811278207.X, the title of the invention is: a detection method and device for the correlation of coking and coalization behavior, and the application date is October 30, 2018. The device provided by the application consists of a control system, Coking coalization system, electronic balance, colloidal viscosity and thickness detector, internal pressure detector, volume deformation detector, pressure control system; under constant capacity or constant load conditions, real-time and synchronous detection of coking coalization Viscosity and thickness of colloids, volatile analysis rate and precipitation rate, internal pressure and volume expansion and contraction of colloids, etc.; by processing data, the correlation curve of coking coalization behavior and the change of probe resistance can be obtained. According to the resistance curve, the gelatinous layer is divided into the resistance rising area, the resistance falling area, the resistance constant area and the resistance steeply rising area, and the thickness of the gelatinous layer, the thickness of each structural area at different carbonization times, and the characteristic carbonization Behavior and colloidal viscosity characteristic parameters; but the essence of the application is the improvement of the Kiwi fluidity test, without considering the fluidity of the colloid is the main factor affecting the charcoal structure and pore wall structure after coking One, so no protocol was designed to detect the fluidity of colloids

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