Bord and Pillar Method

I. Introduction

The Bord and Pillar Method is a widely used technique in underground coal mining. It involves the extraction of coal through the creation of a network of tunnels, known as headings, and the formation of pillars to support the roof of the mine. This method is highly efficient and allows for the extraction of a large percentage of the coal reserves.

A. Importance of the Bord and Pillar Method

The Bord and Pillar Method is important in underground coal mining for several reasons. Firstly, it allows for the extraction of coal in a systematic and controlled manner, ensuring maximum recovery of the resource. Secondly, it provides a safe working environment for miners by providing support through the use of pillars. Lastly, it offers flexibility in terms of panel development and depillaring, allowing for efficient extraction of coal.

B. Fundamentals of the Bord and Pillar Method

The Bord and Pillar Method is based on the principle of leaving behind pillars of coal to support the roof of the mine. These pillars are left in a regular pattern, forming a grid-like structure. The size of the pillars and the distance between them are determined by various factors, including the strength of the coal seam, the depth of the mine, and the stability of the surrounding rock.

II. Size of headings, pillars, and panels

In the Bord and Pillar Method, headings are the tunnels that are driven into the coal seam to provide access for mining operations. Pillars are the blocks of coal left behind to support the roof. Panels are the areas between the headings and pillars where coal is extracted. The size of headings, pillars, and panels is influenced by several factors.

A. Explanation of headings, pillars, and panels

Headings are typically driven perpendicular to the strike of the coal seam, while pillars are left in a regular pattern to support the roof. Panels are the areas between the headings and pillars where coal is extracted. The size of headings, pillars, and panels can vary depending on the specific conditions of the mine.

B. Factors influencing the size of headings, pillars, and panels

The size of headings, pillars, and panels in the Bord and Pillar Method is influenced by various factors. These include the strength of the coal seam, the depth of the mine, the stability of the surrounding rock, and the equipment and techniques used for mining. The size of the pillars and the distance between them are determined to ensure the stability of the mine and the safety of the miners.

C. Calculation methods for determining the size of headings, pillars, and panels

The size of headings, pillars, and panels in the Bord and Pillar Method can be calculated using various methods. These include empirical methods, which are based on past experience and observations, and analytical methods, which involve mathematical calculations and computer simulations. The calculation methods take into account the specific conditions of the mine and the desired level of safety.

III. Development of panels

The development of panels in the Bord and Pillar Method involves the creation of headings and the extraction of coal from the panels. This process is carried out in a systematic manner to ensure maximum recovery of the coal reserves.

A. Process of developing panels in the Bord and Pillar Method

The process of developing panels in the Bord and Pillar Method begins with the driving of headings into the coal seam. These headings provide access for mining operations and serve as the starting point for the extraction of coal. Once the headings are in place, the coal is extracted from the panels using various techniques, such as drilling and blasting or continuous mining.

B. Equipment and techniques used for panel development

The development of panels in the Bord and Pillar Method requires the use of specialized equipment and techniques. This includes drilling machines, blasting equipment, continuous miners, and roof bolters. These tools are used to create headings, extract coal from the panels, and provide support to the roof of the mine.

C. Safety considerations during panel development

Safety is a top priority during panel development in the Bord and Pillar Method. Miners are required to follow strict safety protocols and use appropriate personal protective equipment. The mine is also equipped with safety features, such as ventilation systems and roof support systems, to ensure the well-being of the workers.

IV. Depillaring of panels

Depillaring is the process of extracting the pillars of coal in the Bord and Pillar Method. This is done after the coal has been extracted from the panels and involves the removal of the pillars to allow for the collapse of the roof.

A. Explanation of depillaring in the Bord and Pillar Method

Depillaring is an important step in the Bord and Pillar Method as it allows for the extraction of coal that is left behind in the pillars. This process involves the removal of the pillars in a systematic manner to ensure the safety of the miners and the stability of the mine.

B. Techniques and equipment used for depillaring

Depillaring in the Bord and Pillar Method is carried out using various techniques and equipment. These include pillar extraction machines, hydraulic jacks, and roof bolters. These tools are used to remove the pillars and provide support to the roof during the depillaring process.

C. Safety precautions during depillaring

Safety is of utmost importance during the depillaring process in the Bord and Pillar Method. Miners are required to follow strict safety protocols and use appropriate personal protective equipment. The mine is also equipped with safety features, such as roof support systems and monitoring devices, to ensure the well-being of the workers.

V. Conventional and mechanized depillaring schemes

In the Bord and Pillar Method, depillaring can be carried out using conventional or mechanized schemes. Each scheme has its own advantages and disadvantages.

A. Comparison of conventional and mechanized depillaring schemes

Conventional depillaring involves the manual extraction of pillars using hand tools and equipment. This method is labor-intensive and time-consuming but allows for greater control over the depillaring process. Mechanized depillaring, on the other hand, involves the use of machines and equipment to extract the pillars. This method is faster and more efficient but requires a higher initial investment.

B. Advantages and disadvantages of each scheme

Conventional depillaring has the advantage of providing greater control over the depillaring process. It allows for the selective extraction of pillars and the ability to adapt to changing conditions. However, it is labor-intensive and time-consuming. Mechanized depillaring, on the other hand, is faster and more efficient. It allows for the extraction of pillars on a larger scale and reduces the risk to miners. However, it requires a higher initial investment and may not be suitable for all mining conditions.

VI. Simultaneous development and depillaring

Simultaneous development and depillaring is a technique used in the Bord and Pillar Method to maximize the efficiency of coal extraction. It involves the simultaneous creation of headings and the extraction of coal from the panels.

A. Explanation of simultaneous development and depillaring in the Bord and Pillar Method

Simultaneous development and depillaring in the Bord and Pillar Method involves the creation of headings and the extraction of coal from the panels at the same time. This technique allows for the continuous extraction of coal and reduces the time required for panel development and depillaring.

B. Benefits and challenges of simultaneous development and depillaring

Simultaneous development and depillaring offers several benefits in the Bord and Pillar Method. It allows for the efficient extraction of coal and reduces the time required for mining operations. However, this technique also presents challenges, such as the need for careful planning and coordination of activities, and the potential for increased safety risks.

VII. Partial extraction

Partial extraction is a technique used in the Bord and Pillar Method to leave behind a portion of the coal reserves. This technique is employed in situations where complete extraction is not feasible or desirable.

A. Definition and purpose of partial extraction in the Bord and Pillar Method

Partial extraction in the Bord and Pillar Method involves leaving behind a portion of the coal reserves in the form of pillars. This technique is used when complete extraction is not possible due to geological constraints or when it is not economically viable. The purpose of partial extraction is to ensure the stability of the mine and maximize the recovery of the coal reserves.

B. Techniques and considerations for partial extraction

Partial extraction in the Bord and Pillar Method can be carried out using various techniques. These include the creation of larger pillars, the use of different pillar extraction methods, and the implementation of support systems. Considerations for partial extraction include the stability of the mine, the safety of the miners, and the economic viability of the operation.

VIII. Room and pillar methods

The Bord and Pillar Method is one of several room and pillar methods used in underground coal mining. It is characterized by the creation of headings and the formation of pillars to support the roof of the mine.

A. Overview of the room and pillar methods in underground coal mining

Room and pillar methods are a type of mining technique that involves the creation of rooms or tunnels for the extraction of coal. These rooms are separated by pillars of coal or rock, which provide support to the roof of the mine. The Bord and Pillar Method is one of the most commonly used room and pillar methods.

B. Comparison of the Bord and Pillar Method with other room and pillar methods

The Bord and Pillar Method differs from other room and pillar methods in terms of the size and spacing of the pillars, the method of extraction, and the equipment used. The Bord and Pillar Method is known for its regular grid-like pattern of pillars and its efficient extraction of coal. It is often preferred in situations where the coal seam is thick and the roof is stable.

IX. Real-world applications and examples

The Bord and Pillar Method has been successfully applied in numerous underground coal mining operations around the world. These operations have demonstrated the effectiveness and efficiency of the method.

A. Case studies of the Bord and Pillar Method in underground coal mining operations

There are several case studies that highlight the successful implementation of the Bord and Pillar Method in underground coal mining operations. These case studies provide insights into the challenges faced, the techniques used, and the outcomes achieved.

B. Examples of successful implementation of the Bord and Pillar Method

There are many examples of successful implementation of the Bord and Pillar Method in underground coal mining. These examples showcase the benefits of the method, such as high coal recovery rates, efficient extraction, and safe working conditions.

X. Advantages and disadvantages of the Bord and Pillar Method

The Bord and Pillar Method offers several advantages in underground coal mining. However, it also has some limitations and disadvantages.

A. Advantages of the Bord and Pillar Method

The advantages of the Bord and Pillar Method include high coal recovery rates, efficient extraction, and safe working conditions. The method allows for the extraction of a large percentage of the coal reserves and provides a controlled and systematic approach to mining.

B. Disadvantages and limitations of the Bord and Pillar Method

The Bord and Pillar Method has some limitations and disadvantages. These include the potential for subsidence, the need for careful planning and coordination, and the requirement for a large number of pillars. The method may not be suitable for all geological conditions and may require additional support systems.

XI. Conclusion

In conclusion, the Bord and Pillar Method is a widely used technique in underground coal mining. It involves the extraction of coal through the creation of headings and the formation of pillars. The method offers several advantages, including high coal recovery rates, efficient extraction, and safe working conditions. However, it also has some limitations and challenges that need to be considered. Overall, the Bord and Pillar Method is an effective and efficient approach to underground coal mining.

Summary

The Bord and Pillar Method is a widely used technique in underground coal mining. It involves the extraction of coal through the creation of headings and the formation of pillars. The method offers several advantages, including high coal recovery rates, efficient extraction, and safe working conditions. However, it also has some limitations and challenges that need to be considered. Overall, the Bord and Pillar Method is an effective and efficient approach to underground coal mining.

Analogy

The Bord and Pillar Method can be compared to a grid-like structure, where the headings are the vertical lines and the pillars are the horizontal lines. Just like the pillars provide support to the roof of the mine, the horizontal lines provide support to the structure. The extraction of coal from the panels can be seen as filling in the grid with a specific pattern, ensuring maximum efficiency and stability.