Table of Contents
- NDT Testing for mining equipment
- Types of NDT techniques in the Mining industry
- Emerging Trends in NDT for Mining Operations
- Key Mining Equipment Requiring NDT Testing
- Exploration and Resource Mapping Using NDT
- Limitations and Difficulties with NDT in Mining
- Companies providing NDT solutions for mining
- Key Takeaways
- References
Regular testing and inspection are very important in the mining sector for the smooth running of any ongoing process. There are certain rules and regulations that the mining business needs to follow, and these are accepted worldwide. There are many consequences, like equipment wear and tear, and environmental consequences that are attached to the excavation of important resources, and to counter this, structural stability is very important. Non-Destructive Testing (NDT) is especially useful in this situation. Identification of possible failures and ensuring smooth and safe mining, NDT plays a major role, and thus, the damage of equipment and minerals can be avoided. In mining, the most important factors are precision and safety, and to achieve this, NDT plays a major role, which in turn can significantly impact the profitability and productivity.
NDT Testing for mining equipment:
Components such as wiring, hydraulic cylinders, drills, bearings, circulating pumps, and motors must be inspected for defects because they are susceptible to failure. Because mining equipment can be complicated, a relatively small defect in one of these parts could eventually cause a bigger issue that affects the entire system. Even the same object may exhibit various failure patterns depending on the environment. A review of the materials used in the components of mining equipment can help determine which materials are appropriate for the task at hand.
Types of NDT techniques in the Mining industry:
1. Ultrasonic Testing (UT):
Ultrasonic testing UT is useful for testing corrosion and cracks in mining machines and important equipment. The interior flaws are detected using ultrasonic pulse waves on both metallic and non-metallic materials. UT can be used to test mining equipment like pressure vessels, pipelines, and weldings, which in turn helps in predictive maintenance more efficiently and reliably. This regular testing is essential as mining equipment is frequently subjected to heavy weights for a long time, which might result in failure of the equipment. The interior and inaccessible parts of the mining equipment can be tested for functioning effectively and safely, and for this, UT plays a crucial part.
Benefits of UT:
UT is generally faster than other techniques, so it saves time.
UT can be used for a wide variety of complex and unique shaft designs.
UT has a high probability of detecting critical defects.
2. Magnetic particle testing (MPT):
This NDT technique utilizes a magnetic field at the material surfaces to check the discontinuities. Any magnetic flux leakage is used to identify the cracks or discontinuities in the surface or underneath it, which is achieved by the creation of direct or indirect magnetic fields. After removing the impurities from the relevant components, ferrous particles, either dry or suspended, are added. In the place where there is a magnetic flux leakage, these particles accumulate there, allowing us to see the crack or other abnormality. However, unless colored magnetic particles are placed across the test zone, the issue will not be readily apparent.
Benefits of MPT:
Can be applicable for both smooth and rough surfaces.
Cracks and wear can be detected early, as microscopic surface cracks can also be detected.
Quick remediation can be done with the help of faster detection.
Useful for field inspection as magnetic probes are portable.
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3. Radiographic Testing:
Radiographic testing (RT) is a vital NDT approach that is widely used to inspect and maintain plant and equipment, which is critical to guaranteeing the continuous safety and profitability of mining operations. The weight of the material being carried frequently puts prolonged operational stress on the machinery and equipment on a mine site. RT employs X-rays and gamma rays to detect flaws, quantify corrosion, and measure wall thickness in ferrous and non-ferrous castings, welds, and forgings; it can detect both surface and internal discontinuities.
Mine operators employ the three main types of RT methods:
Conventional Radiographic Testing (RT):
In conventional radiography, an image of the component being checked is captured by a sensitive film that responds to the radiation emitted. After that, this picture can be inspected for signs of deterioration or defects.
Computed Radiography Testing (CRT):
A phosphor imaging plate is used in computed radiography (CRT), which replaces film for traditional radiography methods. This method is slower than direct radiography but far faster than film radiography. CRT requires several extra steps compared to direct radiography.
Real-Time Radiography (RTR):
RTR is a type of digital radiography that takes place in real time. Radiation is emitted via a device to operate RTR. These rays subsequently interact with a flat panel detector that has micro-electronic sensors or a specific phosphor screen.
Benefits of RT:
It is versatile as it can be applied to most of the materials.
RT inspection produces a visual image of internal voids and fabrications, which is easily interpretable.
Highly sensitive as it can detect small changes in thickness and density.
4. Thermography Testing (TT):
In mining applications, thermography testing is crucial because mining environments are frequently very dusty, and visible light or digital cameras will miss any potential defects. Because thermography uses an infrared wavelength, it can detect heat energy through most environmental conditions, including dust and smoke. Thermography's basic idea is that temperature changes can be detected because different materials emit infrared radiation at varying rates. Thermographers can identify problem areas and take action before they become more serious by examining these variances. Passive thermography, Active thermography, Flash thermography, and Vibro thermography are different types of thermography techniques that can be utilised in the mining industry based on different scenarios. Thermography can be used in the condition monitoring of conveyor belts and moving machinery parts, where a slight rise in temperature can be detected by a thermal image, as a result of which the belt can be slowed down instead of causing a sudden stop to the system.
Benefits of TT:
More information can be extracted by thermal images, including the rise in temperatures and cracks.
It is a non-contact method that can be achieved by a fixed camera.
Can be used for condition monitoring.
Emerging Trends in NDT for Mining Operations:
1. AI integration in NDT:
The integration of AI in NDT is changing the entire NDT industry by improving defect detection, forecasting failures, and optimizing maintenance plans. Conventional NDT techniques can often result in uneven results and human error as they heavily rely on correlation analysis and manual interpretation. The integration of AI has made these processes more efficient and scalable. In mining, AI-integrated NDT may be of great value as it reduces the risk of failures to a great extent, and future prediction also allows proper predictive maintenance of the types of machinery involved.
2. Predictive maintenance using NDT data:
The integration of AI with NDT helps in proper predictive maintenance of equipment, as the AI-based devices keep collecting data in real time, which is then analysed by NDT to predict an early failure. This results in increasing efficiency, avoiding breakdown and saving money. As mining is a very lengthy process to predictive maintenance might help in seamless functions of the entire process.
3. Drone-based inspections:
In mining sites, drones can be used to quickly examine areas for emergencies or to identify hazards using a variety of sensors. One area where drones can be useful is the detection of dangerous gas in deep mines. Drones can be extremely useful in a variety of mining applications, including 3D mapping, construction monitoring, mine rescue missions, gas storage detection, acid drainage monitoring, and landscape mapping.
4. Automation and Robotics in NDT for mining:
The application of Remote Operated Vehicles (ROVs) and Unmanned Arial Vehicles (UAVs) can greatly help in detecting defects in inaccessible areas in a mine. There are several benefits to using robots, starting with their ability to be used for a variety of tasks with a reasonable level of accuracy and ending with their affordability. With a variety of probes and measuring tools, the robotic arm can be used for surface scanning and vision-driven applications in addition to basic manipulation and targeted picking tasks.
5. 3D Imaging and Scanning:
Mining businesses may obtain precise information about almost every aspect of the physical operation more quickly with 3D scanning. The mining corporation can map tunnel profiles, stockpile quantities, pits, and caves in minutes. Compared to the original models or blueprints, these 3D data sets also increase accuracy on the real condition of the mine, its structures, systems, and equipment. Mining businesses can identify trouble regions, instabilities, and other hazards and take the necessary action much more easily when they have 3D scans of their equipment and mining locations.
Key Mining Equipment Requiring NDT Testing:
1. Wire rope:
Wire rope is one of the most important components in the mining industry. Wire ropes have a limited lifespan and are disposable. The wire rope's physical characteristics will alter while it is being serviced. The individual wires and strands align themselves at the start of service, increasing the breaking strength of the rope. Once it reaches its peak, it rapidly declines. One of the goals of a wire rope inspection or examination is to monitor the typical deterioration process so that the rope can be taken out of use before it becomes a safety risk. Finding unforeseen corrosion or deterioration is another advantage of the inspection and examination processes.
The entire length of the ropes should be examined during an inspection or routine assessment by a qualified individual.
The following areas might need closer examination:
a) The rope zones with the most cycles.
b) Accumulate points
c) Finishing touches
d) Sleeve equalization
e) Areas where drum wear is greatest
f) Sheaves
g) Rope sections operating in an unfriendly setting
Survey of Removal:
- Broken Wire:
If a rope breaks more than the allowed number of times, it must be thrown away. Additionally, when there are localized concentrations of wire breakage, it needs to be replaced.
- Diameter reduction:
Abrasion, corrosion, or localized breakdown of the rope core can all decrease diameter. "When the rope diameter is reduced by 90% of the nominal diameter in the case of six and eight strand ropes," the wire should be destroyed, under BS 6570.
- Corrosion:
Corrosion can be localized or widespread, internal or external. Wire rope should be thrown away under BS 6570 "when the wire surface is fully pitted or roughened, or if the wires are slack within the strands due to waste."
Types of rope deformation:
a) Waviness
b) Basket deformation
c) Loop formation
d) Loose wires
e) Nodes
f) Thinning of the ropes
g) Misplaced outer wires
h) Kinks
i) Flat areas
- Heat-induced damage:
When rope wires are heated to temperatures of 300 degrees Celsius or higher, their tensile strength is significantly decreased. It is necessary to dispose of wire ropes that have been exposed to high temperatures.
2. Conveyor belt:
A conveyor belt is another important equipment in mining whose proper maintenance is required for the smooth functioning of the mining process. The mining process can be stopped or delayed in case of any failure to this equipment. The main goal of the Conveyor Belt Scanning system is to identify steel cord, carcass damage, and splice irregularities through non-destructive testing while the conveyor belts are operating normally. Depending on the service, this can be done remotely, semi-remotely, or in the field. Neither stopping the conveyor belt nor having staff on site is necessary.
Technology can be used to reduce disruptions while scanning all types of steel cord conveyor belting since maintenance windows are getting smaller and access to downtime is becoming more restricted. The purpose of Steel Cord Scanning using the Magnetic Flux Leakage technology is to find damage or irregularities in conveyor belting's steel cords and splices that are not visible to the human eye. The technique detects areas of cord breakage, partially damaged, corroded cords, splice integrity, and carcass health problems while it is in operation. Depending on the system combination—remote, semi-remote, or complete conveyor inspection—this information is instantly available with no conveyor downtime, allowing full production to proceed with little to no disruption.
By measuring loss of metallic area (LMA) and identifying both inner and outside localized faults (LF), such as broken wires, strands, and pitting corrosion, the magnetic rope testing makes wire rope inspection possible. Different techniques can be used to measure when wire rope is being made and while various applications are being operated on-site and for doing so, the magnetic flux leakage principle can be used. During testing, the rope is magnetically saturated by strong magnets, and if there are no flaws, the leakage flux above the rope surface is constant. The leakage flux is disturbed by rope flaws like LMA and LF, and sensors are used to detect and process these disturbances.
3. Winders:
Winders are also an important aspect of mining, as it is used continuously to lower the wire ropes and sometimes elevators for carrying important tools and men for underground mining. Similar NDT tests can be applied to ensure safe functioning of it. To prevent overloading, winding systems should be designed to trip when excessive torque is detected. Overload protection systems must be inspected, tested, and maintained as part of the winder maintenance strategy.
4. Mine shaft:
Another important aspect of mining is the proper testing of mine shafts, and in the modern day, a wide variety of inspection techniques are used for mine shaft inspection, which include drones with cameras and sensors, robotic systems, and advanced monitoring software. These inspections are essential because a breakdown in the mine shaft can stop the mining operations, and it may also cause fatalities. These technologies combined can help in detecting defects that are not always visible to human eyes.
5. Mining trucks and excavators:
Regular testing of this equipment is compulsory, as they are constantly engaged with moving earth and excavation, so corrosion is quite common in this equipment. They are also subject to constant heavy loads, so fatigue and cracks may be very common, so early detection is necessary to carry on the process efficiently.
Exploration and Resource Mapping Using NDT:
1. Techniques for Geophysical NDT:
Application of electromagnetic methods and ground-penetrating radar (GPR) for the detection of mineral deposits and the evaluation of the geological conditions before going for excavation. GPR works by emitting radio waves of high frequencies to the ground, and the time which the waves to return to the receiver provides information about the structure, depth, and composition of underground layers.
2. Integrating NDT Data for Exploration:
Integration of NDT data with geological surveys can help mining companies to create more accurate models of the subsurface. This helps in more accurate exploration and eliminates the non-productive areas to reduce the risk of unnecessary excavation.
Limitations and Difficulties with NDT in Mining:
1. The difficulties in maintaining logistics to perform NDT in remote areas and mining locations that are inaccessible.
2. Reliability and accuracy of results are another challenge that primarily depends on the types of equipment used, the material type being inspected, and the skill of the labourer. To prevent this, regular calibration of the testing equipment is very important to obtain accurate results.
3. While dealing with small subsurface and complex geometries detection of defects is a challenge. In mining detection of even minute cracks is important for smooth operation.
4. The accuracy of the NDT inspection heavily relies on the environmental challenges. As in mining, the inspecting environments are challenging and remote and even underground, so it may hamper the accuracy of the results obtained. Proper measures have to be taken to mitigate these issues.
Companies providing NDT solutions for mining:
Key Takeaways:
The most common types of NDT techniques that are applied in mining are Ultrasonic Testing (UT), Magnetic Particle Testing (MPT), Radiography Testing (RT), and Thermography Testing (TT)
Integration of the emerging technologies with NDT will help in making the inspection process of mining industries more efficient and reliable. AI integration and NDT data analysis will improve the predictive maintenance process, thus resulting in a seamless process.
The introduction of drone-based inspection will help in reaching the difficult and inaccessible areas of the mine making the inspection process more efficient and safe.
NDT is also useful for inspection of geological areas for more accurate exploration and avoids unnecessary mining and excavation.
References:
- Applications of Non-Destructive Testing in Mining Operations
- Benefits of NDT in Preventive Maintenance for Mining Equipment
- Advanced NDT Inspection Solutions to Improve Mining Efficiency
- Role of Ultrasonic Testing in Enhancing Mining Industry Standards
- Non-Destructive Evaluation Strategies for Modern Mining Facilities
- Ultrasonic Testing Applications in Mining Industry
- Radiographic Testing Insights from Inspectioneering
- The Importance of Radiographic X-Ray Equipment in Mining
- Overview of Radiographic Testing in Materials Science
- Thermography as a Diagnostic Tool in Mining Operations
- Fundamentals of Radiographic Testing from ASNT
- The Role of Thermal Imaging in Dusty Mining Environments
- Drone Applications for Infrastructure Inspection in Mining
- Advantages of 3D Scanning in Mining Operations
- Remote Sensing Technologies for Mining Site Evaluation
- Application Note: Gear Cracking Detection in Mining Equipment
- Innovative NDT Solutions for Mining Conveyor Systems
- Predictive Maintenance Using NDT in Conveyor Belt Systems
- Enhanced Inspection Results in Mining via Eddyfi Technologies
- Steel Cord Scanning for Conveyor Belt Integrity
- Brochure: Non-Destructive Inspection of Conveyor Belts
- NDT Techniques Presented at APCNDT Conference
