Test Method of Sealing Performance of Hazardous Gas Sealing Material in Mine

Abstract: hazardous gas is a potential threat to mine safety, and the application of sealing materials is one of the effective methods to reduce the concentration of hazardous gas in the mine. Based on the test of sealing performance of hazardous gas sealing material in mine, this paper evaluates its sealing ability to hazardous gas, and introduces the parameters, application and test process of VAC-V2 Differential Pressure Gas Permeability Tester based on test principles, so as to provide reference for the research and application of relevant polymer materials.

Keywords: mine, hazardous gas, sealing material, sealing performance, air tightness, gas permeability, gas transmission rate, differential pressure gas permeability tester

In the process of mining and resource exploitation in closed underground environment, hazardous gas emission is often encountered. If not handled properly, it is easy to cause major safety incident, such as personnel suffocation, gas explosion and so on. Therefore, controlling the concentration of hazardous gas in the mine at a safe level can effectively avoid the occurrence of safety incident. The traditional method is to dilute harmful gas and discharge it out of the mine by strengthening the ventilation inside the mine, but it is a waste of valuable resources such as natural gas and bring serious pollution to the environment. The new wall sealing technology can block harmful gas in the wall, reduce the amount of harmful gas seepage and control the concentration of harmful gas in the mine, it is a conducive way to the development and utilization of gas resources such as natural gas, and reduce environmental pollution.

The sealing properties to hazardous gas is the key factor to the designed purpose of the sealing material. This paper introduces a test method for testing the sealing property of plugging material to gas.

Sample

In this test, a sealing material made of polymer material is used as the test sample.

Standard

Sealing performance to hazardous gases refers to the ability of sealing materials to prevent hazardous gases from permeating outwards, which can be expressed by gas transmission rate. This test uses the principle of differential pressure method to test the carbon dioxide transmission of samples. The test process is in accordance with ISO 2556 – Plastics — Determination of the gas transmission rate of films and thin sheets under atmospheric pressure

Test instrument

In this paper, VAC-V2 Differential Pressure Gas Permeability Tester is used as the test instrument to test the carbon dioxide transmission rate of samples, which is independently developed and produced by Jinan Labthink Instruments Co., Ltd.

Figure 1 VAC-V2 Differential Pressure Gas Permeability Tester

Test process

(1) Cut 3 pieces of 97 mm diameter specimen from the prepared sample.

(2) Apply a thin layer of vacuum grease evenly on the outer edge of the test area of the 3 test chambers of the test instrument, and then place filter paper and specimen in the test area in turn, and gently press the contact part between the specimen and the test chamber to remove bubbles. Close the upper cover of the test chamber and tighten it.

(3) The instrument is connected to the carbon dioxide gas source, the sample name, test temperature, humidity, test mode and other parameters are set on the control software, the vacuum pump is turned on, click start test, and the test starts.

(4) The instrument runs s test according to the set parameters, and the test results will be displayed after the test.

Test result

The arithmetic mean value of the test results of 3 specimens is taken as the gas transmission rate of the sample. The carbon dioxide transmission rat of the sealing material measured in this test is 651.345 cm³/(m²·24h·0.1MPa).

Conclusion

Gas sealing performance is one of the key performance indexes of sealing materials. Good gas sealing performance can significantly reduce the leakage of hazardous gas into the mine, and improve the safety and environment of mining. In this paper, carbon dioxide permeability is used to evaluate the sealing performance of sealing material samples. The test process is simple, the instrument is easy to operate, due to the high intelligence of the instrument, human factors have little effects on the test results, the test results are accurate, reliable, and reflect the true gas sealing performance of the tested materials. The test conditions of this paper are 23 ℃ and 0% RH. Because the temperature and the humidity under the mine is high, to test the gas sealing performance of the sealing material under the actual application condition, users can set the test temperature and humidity conditions. In addition, the instrument can also be applied to the test the sealing performance of sealing material to other gases.

Jinan Labthink Instruments Co., Ltd, is dedicated to providing customers with packaging testing solutions and helping the manufacturers to reach their goals of quality and safety assurance through improvement of packaging testing techniques and development of high-end packaging testing instruments. The newly introduced C series barrier testing systems adopting self-sensing technology revolutionarily improved the testing accuracy, efficiency and automation, realized the paradigm shift of packaging barrier testing instruments. For more information please visit www.labthink.com