Wyniki wyszukiwania - BazTech

1

Fracture Mechanism of Hard Main Roof and Determining the Width of Coal Pillars when Extracting Flat-lying Coal Seams

Le Quang Phuc, Dao Van Chi, Nguyen Phi Hung, Vu Thai Tien Dung

Inżynieria Mineralna

|

2023

|

no. 2, vol. 1

271--280

EN

In underground coal mining, the stability of roadways and gob-side entry depends on the coal pillar width. An unreasonable width of the coal pillar will cause the roadway to be in a dangerous zone of influence of the abutment pressure, leading to severe roadway deformation. This paper studies the fracture mechanism of the hard main roof and reasonable coal pillar width to protect the stability of gob-side entry driving. The research results show that when mining a coal seam under a hard main roof, the console of the main roof on the edge of the coal seam has the form of hinge structure. The great load of the roof layers and the rotation of the console are the main causes leading to the variation of the stress field in the coal seam. According to the development law of the stress field, after the main roof completes the collapse process, the peak of the maximum stress will move deep into the solid coal seam, and on the edge of the coal seam it will form a low-stress zone. Research results from the case of Seam #11 of Khe Cham coal mine, Vietnam show that the gob-side entry will be well stabilized when the narrow coal pillar between it and the boundary of the gob is 4–5 m.

2

Research, Calculation and Proposal of Ventilation Solution for Duong Huy Coal Mine when Mining Down to -250 m Depth

Dao Van Chi, Le Tien Dung, Vu Thai Tien Dung, Nguyen Hong Cuong

Inżynieria Mineralna

|

2021

|

no. 2

513--520

EN

At present, according to the extraction plan in the year 2020 of Duong Huy Coal Company - Vinacomin, the mining is divided into three main zones: Central Zone extracts 06 faces; South Zone extracts 2 faces and Northeast Zone extracts 2 faces. The designated total production of all zones is 1,880,000 tons/year. To ensure the production of each mining zone, exhaust fan stations are installed at ventilation roadway adits with a total of 05 main fan stations. However, in the near future, to ensure and maintain production activities, the mine is being planned and operated using 03 main fan stations. The calculation results for the reasonable working mode of fan stations are as follows: for fan station FBCDZ8-№32B at level +47 m, airflow is 167.69 m3 /s and air pressure is 243.74 mm H2O; for fan station 2K56- №30 level +40 m, airflow is 123.37 m3 /s and air pressure is 324.79 mm H2O; for fan station FBCDZ-8- №32B at level +44 m, airflow is 167.69 m3 /s and air pressure is 354.99 mm H2O.

3

Development of Support Plan and Operation Scheme for Semi-mechanized Longwall Face of Coal Seam 10T, Nam Khe Tam Mine – 86 Company, Dong Bac Corporation

Vu Trung Tien, Le Tien Dung, Vu Thai Tien Dung

Inżynieria Mineralna

|

2021

|

no. 2

321--330

EN

Support plans and operation schemes of mine faces are critical technical documents in underground coal mining management. The development and selection of a reasonable support plan and operation scheme of the face are complicated because they involve many factors. In specific mining conditions, developing and selecting an appropriate support plan and operation scheme will improve the working efficiency of equipment, increase labor productivity, and ensure workers' safety. This article researched a mining technology for the thin seams, focusing on coal seam 10T in Nam Khe Tam coal mine, 86 Coal Company. From the analysis of geo-mining conditions, the article developed and selected a reasonable support plan and operation scheme for the face in coal seam 10T. After being used in the field, the support plan and operation scheme have brought the face efficiency and safety.