MINE MACHINERY:3108
ASSIGNMENT ONE
AUGUST 15, 2023
GWANDA STATE UNIVERSITY
STUDENT G0210888D
1. Reliability refers to the extent to which your machines and methods produce consistent
and stable results. Machine reliability is the ability of a machine to operate, with the
desired output characteristics, without failure or downtime.
Factors that affect reliability in mining machinery and equipment
Design – Design ensures that products and systems perform a specified function within
a given environment for an expected lifecycle
Maintenance - An ineffective maintenance plan and inadequate machine and
equipment maintenance will result in a lot of breakdowns and dangerous machine
operation. An effective maintenance programme will make plant and equipment more
reliable. Fewer breakdowns will mean less dangerous contact with machinery is
required, as well as having the cost benefits of better productivity and efficiency.
Additional hazards can occur when machinery becomes unreliable and develops
faults.
Environmental conditions – the environment in which equipment is used has many
factors that can affect reliability. For example, high temperature, temperature changes,
high humidity or corrosive environments tend to cause failures.
2. DEFINITIONS
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Bucket Fill factor - The fill factor is the percentage of an available volume in a
hauler body, bucket or bowl that is actually used. For example, a fill factor of 87
percent for a hauler body means that 13 percent of the rated volume is not being
used to carry material.
Swell factor - Swell factor refers to the increase in volume or size of a material
after it has been excavated or extracted from its original state. It is commonly
used in construction or mining to account for the additional volume that the
material occupies when it is transported and placed in its final destination. The
swell factor is a ratio that represents the increase in volume as a result of the
material's displacement, compaction, used in construction and mining industries
to estimate the amount of extra material that needs to be removed or accounted
for when planning projects. Swell factor is typically expressed as a ratio or
percentage and is determined by comparing the volume of the material in its
natural state to its volume after excavation.
Mechanical availability - Mechanical availability is a performance measure of
how often a machine or equipment is ready to operate. It is calculated as
the percentage of time that the machine is capable of producing energy or
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work. It depends on the reliability and maintainability of the machine or
equipment
Continuous Excavation - Continuous excavation refers to a method of excavation
where the digging process is ongoing without interruptions. This method is
commonly used in construction and mining projects where large amounts of soil
or rock need to be removed continuously to allow for the progress of the project.
Continuous excavation may involve the use of heavy machinery such as
excavators, bulldozers, or tunnel boring machines to constantly dig and remove
materials from the site. Of soil, rock, or other materials need to be removed
continuously in order to create trenches, foundations, tunnels, or open pit mines.
In continuous excavation, specialized equipment such as excavators, backhoes,
or bucket-wheel excavators are employed to remove the material from the
ground. These machines are capable of working continuously without the need
for frequent stopping and starting.
Cyclic Excavation - Cyclic excavation, also known as cyclic mining or cyclic
loading and unloading, refers to a mining technique where the extraction of
material from a mine is done in a cyclical manner. Instead of continuously
extracting material, cyclic excavation involves a repetitive sequence of
excavation, hauling, and unloading.
In cyclic excavation, the mining process is divided into two main stages:
excavation and hauling. During the excavation stage done in a cyclical manner.
Instead of continuous extraction, cyclic excavation involves a repetitive process
of digging out material for a certain period of time, followed by a period of resting
or unloading.
In cyclic excavation, a series of steps are typically followed:
1. Excavation: The initial step involves digging out the material, such as ore or
minerals, from the mine using excavating equipment like loaders, bulldozers, or
drilling rigs.
2. Haulage: Once the material is excavated, it is transported out of the mine using
trucks, conveyor belts, or other means of transportation.
3. Unloading: After the material is removed, the mine is allowed to rest or unload
for a certain period of time. This allows for the stabilization of the ground and
the release of stresses built up during excavation.
4. Support: During the unloading phase, necessary support structures like pillars
or beams may be installed to ensure the stability of the mine and prevent caveins or collapses.
5. Re-entry: After the unloading phase, the mine is re-entered, and the process of
excavation begins again. This cycle of excavation, haulage, unloading, support,
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and re-entry is repeated until the desired amount of material is extracted or until
the mine is no longer economically viable.
Cyclic excavation is often used in underground mining operations, where
stability and safety are crucial. By allowing the mine to unload or rest
periodically, cyclic excavation helps to mitigate the risk of ground instability and
reduce the potential for accidents. It also allows for better planning and
management of mining operations, as the cyclical nature of the process can help
optimize productivity and resource utilization.
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A scrapper in mining is a heavy-duty machine used to excavate and remove large
amounts of soil, rock, or other materials from the earth's surface. The main
purpose of a scrapper is to cut, transport, and unload material efficiently and
quickly, making them an essential tool in various mining operations.
Some attributes of a scrapper in mining:
1. Size and Power: Scrappers are typically large machines, capable of carrying
and removing massive quantities of material. They are equipped with powerful
engines and robust drivetrains to handle heavy loads.
2. Bowl Capacity: Scrappers have a distinctive bowl or hopper at the front, which
is hydraulically operated. The bowl has a high capacity and can hold a substantial
amount of material, ranging from 20 to 45 cubic yards, depending on the size of
the scrapper.
3. Cutting and Loading Mechanism: The front of the scrapper is equipped with a
curved cutting edge blade that digs into the soil or rocks. It can penetrate the
ground and pull the material into the bowl. Some scrappers also have additional
features like teeth or ripper shanks to loosen densely packed materials.
4. Ejection Mechanism: Once the bowl is filled, the scrapper transports the
material to a designated dumping site. The ejection mechanism lifts the front of
the scrapper, tilts the bowl, and releases the load at the desired location.
5. Mobility: Scrappers are designed for off-road usage and are equipped with
sturdy wheels or tracks for better maneuverability on rough terrain. They can
move quickly between excavation and dumping sites, improving efficiency in
mining operations.
6. Operator Controls and Safety Features: Scrappers have ergonomic operator
cabins equipped with controls and displays to operate the machine effectively.
Additionally, safety features like roll-over protection structures (ROPS) and seat
belts are essential for the operator's protection.
7. Maintenance and Durability: Scrappers need regular maintenance to ensure
their smooth functioning. They are built to withstand heavy use and adverse
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conditions typically found in mining environments. Regular inspections,
lubrications, and repairs are necessary to keep them in optimal working
condition.
8. Support Equipment: Scrappers often work in conjunction with other mining
equipment, such as bulldozers, loaders, and haul trucks. They may require the
support of these machines to facilitate efficient operations.
Overall, scrappers play a vital role in mining operations by efficiently excavating
and removing large quantities of material, contributing to the productivity and
profitability of mining activities.
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Some of the advantages of Bucket Wheel Excavators (BWEs) in mining include:
1. High production capacity: BWEs are known for their ability to achieve high
production rates. These machines can remove large volumes of material in a short
amount of time, making them highly efficient in mining operations. BWEs are
capable of excavating several thousand tons of material per hour.
2. Reduced labour requirements: BWEs are designed to operate autonomously,
requiring minimal human intervention. This reduces the need for a large
workforce in the mining operation, making it more cost-effective.
3. Selective mining capability: BWEs are equipped with advanced technology
that allows them to selectively mine specific layers or quality of materials. This
helps in extracting only the desired resources, resulting in reduced waste and
increased profitability.
4. Environmental friendliness: BWEs have a lower environmental impact
compared to other mining equipment. They produce less noise and dust,
minimizing the disturbance to the surrounding environment.
5. Improved safety: BWEs are designed to work in a controlled and predictable
manner, reducing the risk of accidents and injuries to the workers. This enhances
overall safety in the mining operation.
6. Cost-effective operation: BWEs offer a cost-effective solution for mining large
deposits of low-grade resources. Their high production capacity and low labor
requirements make them efficient and economical in extracting and processing
materials.
7. Versatility: BWEs can be utilized in various mining applications, including
coal, lignite, phosphate, and other bulk materials. They can adapt and operate in
different geological conditions, making them versatile in different mining
environments.
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8. Continuous operation: BWEs are capable of continuous operation for
prolonged periods without the need for frequent maintenance or downtime. This
ensures uninterrupted production, maximizing output and revenue.
Overall, BWEs offer a range of advantages in mining, including high production
capacity, reduced labour requirements, selective mining capability,
environmental friendliness, improved safety, cost-effectiveness, versatility, and
continuous operation. These factors make them a valuable and efficient
equipment in large-scale mining operations.
3. Factors to consider when selecting a dump truck and a hydraulic shovel:
1. Capacity: One of the most important factors to consider is the capacity or size of the
dump truck and hydraulic shovel. The capacity should match the required volume and
weight of the materials being moved. This will ensure efficient and effective operations.
2. Engine Power: The engine power of both the dump truck and hydraulic shovel is
crucial for their performance. A powerful engine will facilitate faster loading and
unloading volume of material that will be moved and the size of the job site. It is
important to ensure that the dump truck and hydraulic shovel can handle the required
load without any overload or inefficiency.
2. Power and Performance: The power and performance of both the dump truck and
hydraulic shovel are crucial factors. They should have sufficient horsepower and torque
to operate efficiently and effectively. The dump truck should have enough power to
haul the material and the shovel should have sufficient digging force and lifting
capacity.
3. Reliability and Durability: Dump trucks and hydraulic shovels are expensive
equipment and require a significant investment. It is important to select models that are
known for their reliability and durability. Consider factors such as the brand reputation,
maintenance needs, and the availability of spare parts and service support.
4. Fuel Efficiency: Fuel consumption is an important consideration when selecting
dump trucks and hydraulic shovels. Look for models that are known for their fuel
efficiency, as this will help reduce operating costs and minimize environmental impact.
5. Maneuverability: Dump trucks and hydraulic shovels need to navigate through
different terrains and job sites. Consider the size, turning radius, and maneuverability
of the equipment to ensure that they can easily operate in the intended working area.
6. Operator Comfort and Safety: The comfort and safety of the operators should not be
overlooked. Look for features such as ergonomic controls, comfortable seating, good
visibility, and safety features like ROPS (Roll Over Protective Structure) and FOPS
(Falling Object Protective Structure).
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7. Maintenance and Support: Consider the ease of maintenance, availability of service
networks, and the manufacturer's reputation for after-sales support. Selecting
equipment from a reputed manufacturer with a strong distribution and service network
can save time and money in the long run.
8. Cost: Last but not least, consider the initial cost as well as the ongoing operating
costs of the dump truck and hydraulic shovel. Strike a balance between the initial
investment and the operational efficiency to ensure a cost-effective solution.
By considering these factors, one can make an informed decision and select the right
dump truck and hydraulic shovel that meets the specific requirements of the project.
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