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Some Effects on the Temperature of the Mine Air at the Heading Face

Nguyen Van Quang, Nguyen Van Thinh, Nguyen Cao Khai, Pham Van Chung

Inżynieria Mineralna

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2021

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no. 2

423--432

EN

Currently, with the increase in mining output leading to deeper mining levels, the volume of heading face serving production has also increased. The thermal environment tends to worsen when digging deep due to the geothermal's effect, which increases the air temperature at the heading face. According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 300C. To ensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amount of air to ensure a favorable environment for workers. With the forced ventilation method, the duct position is usually arranged on the side, and the distance from the duct mouth to the heading face is determined to ensure that l < 6√s. In this study, a numerical simulation method by Ansys CFX software is applied to study the influence of several factors such as duct position, air temperature of duct, and roughness characteristics of roadway on the temperature of the mine air at the heading face. The models are set up with six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better than models 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models have different wind temperatures, and we can see the significant influence of the inlet air temperature of the duct on the thermal environment of the heading face. The results show that with the model T = 297.15K, the temperature value on the roadway length is guaranteed as specified < 303K. The result is a reference for determining the duct position and cool for the high-temperature heading face.

2

A Solution to Ensure Ventilation when Expanding the Area of Cam Thanh Underground Coal Mine, Ha Long Coal Company, Vietnam

Nguyen Cao Khai, Nguyen Van Tinh, Nguyen Phi Hung, Nguyen Van Quang

Inżynieria Mineralna

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2021

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no. 2

533--542

EN

In the process of underground mining, the mining system changes for various reasons. One of the main reasons is changes in the mining production plans, especially the scales and outputs. Nowadays, coal mines in Vietnam have been expanding in width and depth, and so have the mines’ ventilation systems. Consequently, there will be changes in the alteration of the structure of the design ventilation system, which reduces the effectiveness of the ventilation and does not meet the main objective of mine ventilation, directly affect the safety of the working environment in the mine. Therefore, it is necessary to research the improvement of the ventilation system with the development and specific conditions of underground coal mines in Vietnam, improving the efficiency of the ventilation work and assuring the safety of the mine environment. Cam Thanh coal mine, Ha Long coal company, Vietnam, is the case study for this research. The article considers the plan of increases the mining output by more than 1.5 times, propose solutions to improve the ventilation system accordingly, helping the company proactively implement the production plan, ensure the working environment's safety, and reduce the costs of mine ventilation.

3

Current Situation and Solutions to Advanced Ventilation Efficiency in Giap Khau Coal Mine Area, Hon Gai Coal Company of Viet Nam

Nguyen Cao Khai, Nguyen VanThinh, Nguyen Phi Hung, Dao Van Chi, Nguyen Van Quang

Inżynieria Mineralna

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2020

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no. 2, vol. 1

209--219

EN

Mine ventilation aims to dilute toxic gas concentrations, dilute dust concentrations, remove them from the mine and ensure pleasant microclimate conditions in the mine, especially at work sites. Currently, in underground coal mines in general and in Giap Khau mine area, Hon Gai coal company, in particular, is in the process of converting the mining area into deep, as well as increasing output. Therefore, it is important to ensure that ventilation is a top priority in long-term occupational safety and meets the plan to increase coal production. In this study, we have evaluated the current state of ventilation in Giap Khau mine area. From those research results, on the basis of computational research methods, we have come up with reasonable solutions to change and improve ventilation efficiency for the mine in the condition of complicated mining plan and technology characteristics are still limited compared to those in the world. Specific solutions solve 2 problems: First, ensure ventilation for the current mining operation stage; Secondly, we have researched and proposing suitable solutions for ventilation of Giap Khau area mine when it has to increase production and move down to an adjacent project at a deeper level.

PL

Zwiększająca się głębokość pokładów węgla w kopalniach podziemnych ogólnie mówiąc a szczególnie w kopalni Giap Khau i związany z nią wzrost temperatury pierwotnej górotworu są powodem pogarszania się warunków mikro-klimatycznych pracy górników i wystąpienia zagrożenia klimatycznego w przodkach górniczych. Wentylacja ma na celu rozrzedzenie stężeń gazów toksycznych, rozrzedzenie stężeń pyłów, usunięcie ich z kopalni oraz zapewnienie przyjemnych warunków mikroklimatycznych. W artykule, przedstawiono wyniki oceny aktualnego stanu wentylacji w kopalni Giap Khau i odpowiednie rozwiązania, które pozwalają poprawić efektywność systemu wentylacji zwalczając zagrożenie klimatycznych kopalni.