Types of Drill Machines Used in Open Pits

Introduction

In open pit mining, drill machines play a crucial role in the extraction of minerals and ores. These machines are used to bore holes into the ground, allowing for the insertion of explosives or other tools to break up the rock and extract the desired materials. There are several different types of drill machines used in open pits, each with its own unique features and capabilities. Selecting the right drill machine for specific drilling requirements is essential to ensure efficient and effective mining operations.

Rotary Drill Machines

Rotary drill machines are one of the most commonly used types of drill machines in open pit mining. These machines operate by rotating a drill bit to create a hole in the ground. The drill bit is typically made of hardened steel and is attached to the end of a rotating drill string. As the drill bit rotates, it cuts into the rock, creating a hole.

Some of the key components and features of rotary drill machines include:

• Drill string: The drill string is a series of connected drill rods that transmit the rotation and torque from the drill machine to the drill bit.
• Drill bit: The drill bit is the cutting tool that is attached to the end of the drill string. It is responsible for creating the hole in the ground.
• Drill head: The drill head houses the drill bit and provides support and stability during drilling operations.

Rotary drill machines offer several advantages, including:

• High drilling speed: Rotary drill machines can achieve high drilling speeds, allowing for efficient and rapid drilling operations.
• Versatility: These machines can be used for a wide range of drilling applications, including drilling blast holes, exploration drilling, and production drilling.
• Depth capability: Rotary drill machines are capable of drilling deep holes, making them suitable for deep mining operations.

However, there are also some disadvantages associated with rotary drill machines, such as:

• Limited hole diameter: Rotary drill machines are typically limited in the diameter of the holes they can create.
• Higher maintenance requirements: These machines require regular maintenance to ensure optimal performance and prevent breakdowns.

Real-world applications of rotary drill machines in open pit mining include:

• Blast hole drilling: Rotary drill machines are commonly used to drill blast holes for the placement of explosives in open pit mining operations.
• Exploration drilling: These machines are used to drill exploration holes to determine the presence and quality of mineral deposits.
• Production drilling: Rotary drill machines are also used for production drilling to extract minerals and ores from the ground.

Percussive and Rotary Percussive Drilling

Percussive drilling is a drilling technique that involves repeatedly striking the rock surface with a percussive tool to create a hole. This technique is commonly used in open pit mining for drilling shallow holes.

On the other hand, rotary percussive drilling combines the principles of rotary drilling and percussive drilling. It involves both rotating the drill bit and applying percussive forces to break up the rock.

When choosing between percussive and rotary percussive drilling, several factors need to be considered, including the hardness of the rock, the required drilling speed, and the desired hole diameter.

Selection of Drill Machines on the basis of Drillability

Drillability refers to the ease with which a rock formation can be drilled. It is an important factor to consider when selecting a drill machine for open pit mining operations. Different types of drill machines are suitable for different drillability conditions.

Factors that affect drillability in open pit mining include:

• Rock hardness: Harder rocks require more powerful drill machines to penetrate.
• Rock abrasiveness: Abrasive rocks can cause excessive wear on drill bits and other drilling components.
• Rock structure: The structure of the rock, such as the presence of fractures or faults, can affect drillability.

The selection of drill machines based on drillability involves assessing the rock properties and choosing a machine that is capable of drilling efficiently in those conditions. Case studies can provide real-world examples of drill machine selection based on drillability.

Computation of Productivity of Drill Machines

Productivity in drill machine operations refers to the amount of work done per unit of time. It is an important metric for evaluating the efficiency of drill machines in open pit mining. Several key parameters are used to compute drill machine productivity, including:

• Drilling rate: The rate at which the drill machine can penetrate the rock.
• Hole diameter: The size of the hole created by the drill machine.
• Drill string length: The length of the drill string used in the drilling operation.

Methods for measuring and calculating drill machine productivity include time studies, production records, and drilling performance analysis. Factors that can influence drill machine productivity include the rock properties, drill machine maintenance, and operator skill. Improving drill machine productivity can be achieved through proper maintenance, training, and optimization of drilling parameters.

Inclined Drilling

Inclined drilling is a drilling technique used to create holes at an angle to the horizontal plane. It is commonly employed in open pit mining operations to drill holes for slope stability analysis, geotechnical investigations, and other purposes.

Different types of drill machines are used for inclined drilling in open pits, including:

• Incline drills: These machines are specifically designed for drilling at angles and are equipped with features to ensure stability and safety.
• Rotary drill machines with angle drilling capabilities: Some rotary drill machines can be adjusted to drill at angles.

Inclined drilling presents several challenges and considerations, such as the need for specialized equipment, the risk of hole deviation, and the requirement for accurate angle measurement. Real-world examples of inclined drilling in open pit mining operations can provide insights into the practical application of this technique.

Conclusion

In conclusion, there are various types of drill machines used in open pit mining, each with its own advantages and disadvantages. Selecting the right drill machine for specific drilling requirements is crucial to ensure efficient and effective mining operations. Factors such as drillability, productivity, and inclined drilling capabilities should be considered when choosing a drill machine. Advancements in drill machine technology continue to improve the efficiency and safety of open pit mining operations.

Summary

Drill machines are essential in open pit mining for creating holes in the ground to extract minerals and ores. There are different types of drill machines used, such as rotary drill machines, which operate by rotating a drill bit to create a hole. These machines offer advantages such as high drilling speed and versatility but also have limitations such as limited hole diameter. Percussive and rotary percussive drilling techniques are used for shallow and deeper holes, respectively. The selection of drill machines is based on drillability, which considers factors like rock hardness and structure. Productivity of drill machines is computed based on drilling rate, hole diameter, and drill string length. Inclined drilling is used for creating holes at an angle to the horizontal plane and requires specialized equipment and accurate angle measurement. Selecting the right drill machine for specific drilling requirements is crucial for efficient and effective mining operations.

Analogy

Drill machines in open pit mining are like the tools used by a dentist. Just as different tools are used for different dental procedures, different types of drill machines are used for different drilling requirements in open pit mining. The dentist carefully selects the right tool based on the specific procedure and the patient's needs. Similarly, in open pit mining, selecting the right drill machine is essential to ensure efficient and effective drilling operations.