Mining Equipment Research Articles

Analysis of reciprocating hammer type impact wear apparatus

Repetitive impact wear of metals is caused by primary wear mechanisms removing material from the surfaces and is responsible either solely, or in part, for the failure of engineering components (e.g. automotive valvetrains, wheel-rail contacts, mining equipment). Fundamental work exists, but overwhelmingly considers the impact wear of a particular material or surface treatment.The mechanisms involved are variously oxidative, adhesion, abrasion, surface fatigue and plastic deformation. The dominance is controlled by stress, sliding conditions, impact energy, and the difference in material properties, particularly those of plastic deformation, between the two surfaces. There is a paucity of published work that solely investigates and characterises the fundamentals of impact wear.Impact wear test apparatus falls into two groups; projectiles propelled into a stationary target/specimen, or a target/specimen being repeatedly struck by a hammer. The former type is similar to that commonly used for erosive wear, so the reciprocating hammer/striker type design, was chosen for analysis here.Analysis was performed on specimens with impact wear scars that feature both material displacement and material loss, enabling comparison between different measurement techniques to be made. This provides a protocol for easier comparison of data, promoting improved models, and furthers the understanding of the apparatus’ performance.

Determining the Safe Distance for Mining Equipment Operation When Forming an Internal Dump in a Deep Open Pit

In the surface mining of mineral deposits, land resources suitable for agricultural purposes are inappropriately spent in large volumes. When mining deep open pits, overburden rocks are mainly transported to the surface. The optimal solution for reducing the area of disturbed lands is the placement of overburden rocks in internal dumps in the open pit. This is especially suitable when mining a mineral deposit with several open pits where at least one of them is depleted. Therefore, it is important to assess the feasibility of building an internal dump, based on the stability parameters of its slopes and the safe distance for placing mining equipment within its boundaries, which was the focus of this research. Numerical modeling with Slide 5.0 software was used to determine the stability of the dump slope inside the open pit and the safe distance from the upper slope edge for placing mining equipment. This reflected the geomechanical situation occurring within the boundaries of the dump formed in the open-pit field with a high degree of reliability. It was determined that the maximum standard safety factor values of the open-pit slopes are within the limits when the overburden rocks border on the hard bedrock (Ks.s.f ≥ 1.2). Under the condition where the dump slope bordered on sedimentations represented by clays, loams, and sands with a strength of 2–3 on the Mohs scale, the safety factor decreased by 22%. It was determined that the minimum safe distance from the outer contour of the dragline base to the upper edge of a single-tier dump was 15.5 m with a safety factor of 1.21. The maximum safe distance values in the range of 73.5–93 m were concentrated within the boundaries of sections 5–9, with a safety factor from 1.18 to 1.28. When the dragline was located within the boundaries of section 7, the dump construction works should be conducted only if the dump exist for up to 3 years. Based on the identified parameters, on the example of using the ESH-11/70 walking dragline, a technological scheme of its operation was developed with the allocation of safe boundaries for its placement when forming an internal dump. The results obtained are useful for the development of projects for the reclamation of depleted open pits.

Application and Analysis of Decision Support System in the Development Trend of Coal Science and Technology

This paper expounds the development of coal technology in China, points out the development of safe and efficient production technology and equipment in coal mines, and the research of coal production technology and equipment. It also explains the decision support system and its related technologies. By combining with the development of coal science and technology, the article mainly studies the current situation of coal science and technology development and compares it with the traditional information management system. The result shows that the reduction rate of energy consumption per unit output value of the decision support system in coal is 5% higher than that of the traditional information management system, It also shows that the decision support system can be suitable for decision-making of coal enterprises, and is conducive to the development of coal science and technology.

Machine vision based damage detection for conveyor belt safety using Fusion knowledge distillation

A belt conveyor system is one of the essential equipment in coal mining. The damages to conveyor belts are hazardous because they would affect the stable operation of a belt conveyor system whilst impairing the coal mining efficiency. To address these problems, a novel conveyor belt damage detection method based on CenterNet is proposed in this paper. The fusion of feature-wise and response-wise knowledge distillation is proposed, which balances the performance and size of the proposed deep neural network. The Fused Channel-Spatial Attention is proposed to compress the latent feature maps efficiently, and the Kullback-Leibler divergence is introduced to minimize the distribution distance between student and teacher networks. Experimental results show that the proposed lightweight object detection model reaches 92.53% mAP and 65.8 FPS. The proposed belt damage detection system can detect conveyor belt damages efficiently and accurately, which indicates its high potential to deploy on end devices.

Development of an In-Situ Simulation Device for Testing Deep Pressure-Preserving Coring Tools under High-Temperature and Ultrahigh-Pressure Conditions

With the increasing mining depth of deep mineral resources, the underground temperature and pressure also increase, which requires more advanced mining equipment. Therefore, to adapt to the special application scenario of the research and development of pressure-preserving coring tools under the extreme environmental conditions of deep strata, in this study, an in-situ simulation device under high-temperature and ultrahigh-pressure conditions is developed. The principles and methods of applying temperature and pressure to the device are expounded. Furthermore, the two main modules of the device are analyzed and studied experimentally. On the one hand, a segmented simulated coring test cabin is constructed, and pressure testing of the test cabin is carried out. The results show that the test cabin with inner diameters of 150 mm and 500 mm runs stably under the working condition of a pressure up to 190 MPa (considering the influence of temperature of 150 °C), and the cabin remains in the stage of elastic deformation. There is no leakage of pressure or fluid in the whole test process. On the other hand, the performance of the driving module is tested. The results show that the driving module can provide a stable rotation speed of up to 150 r/min when the sealing pressure is 140 MPa. Therefore, the device can be applied to carry out simulated coring test and is suitable for the research and development of pressure-preserving coring tools in deep extreme environments, which may promote the development of deep mining engineering.

An evaluating-while-cutting method for interface measurement -based on signals from dynamic contact force

In coal mining industry, direct measurement on rock proportions is difficult due to various rock material properties. Aiming at identification of coal and rock interface, the paper proposed a method by indirect measurement on rock proportions with contact force and some measures to improve the measurement accuracy as well. To establish the measurement model, cutting forces under different kinds of working states are studied with theoretical analysis and the relations between rock proportions and dynamic force are established. For validation, general circumstances with various rock properties and motion parameters in mining process are studied and estimation results of rock proportions in those circumstances are analyzed. Results show that the measurement accuracy is stable even if parameters related with rock properties and drum working parameters are different. Therefore, the mentioned parameters are no longer essential in advance for indirect measurement of rock proportion. In addition, stochastic fragmentation of coal or rock always leads to fluctuation on measurement accuracy. With the improved cluster method, the mean accuracy of this model are close to 90% and sometimes, the measurement accuracy is even more than 95%. The method in this paper is meaningful for identification of coal and rock interface and in this way could guide the shearer drum to avoid hard rock to reduce the damage on mining equipment.

Assessment Possibilities of the Quality of Mining Equipment and of the Parts Subjected to Intense Wear

The equipment in underground mines provides a continuous production flow, depending on the way their quality is preserved during their operation. The TR-7A scraper conveyer subassemblies, which function in the Jiu Valley coal basin and are subjected to abrasion wear, showed a high failure frequency (chains, chain elevators, and driving and turning drums), as well as the hydraulic couplings and certain electric equipment of the same machinery. The data collected following the TR-7A scraper conveyer at work allowed the parameters to be determined that characterise the reliability and maintainability of the above-mentioned components, the failure modes, and their effects. Using calculation methods, the interpretation of the results has been facilitated, with a view to reducing maintenance costs and obtaining an 80% reliability for the components with the most failures, in the case of the TR-7A scraper conveyer.

Influence of retained austenite on abrasive wear performance of bainitic steels

Bainitic steels exhibit improved strain hardening and comparable ultimate tensile strength and hardness properties as compared to quenched and tempered steels giving bainite the possibility of replacing martensitic steel in certain wear susceptible components, e.g. earthmoving and mining equipment. The influence of retained austenite morphology and mechanical stability in abrasion-resistant bainitic microstructures generated in a medium C, high Si AISI 9260 is investigated in the present study. Evaluation of critical phase transformation temperatures and production of carbide free bainitic microstructures were performed using dilatometry. Hardness measurements, X-ray diffraction, and microscopy were employed to evaluate these heat treatments. The overarching goal of this work is to develop a scientific understanding of interrelationships between retained austenite in bainitic steels and wear performance evaluated with dry sand/rubber wheel wear testing. A correlation between lower austempering temperatures and higher hardness was observed due to both microstructural refinement, as well as a higher content of martensite. Wear results show a complex relationship between austemper temperature and wear resistance, suggesting a dependence on sample hardness, austenite content, and austenite morphology.

Feasibility study of using cogeneration plants at Kuzbass coal mines

The paper considers the problem of reducing greenhouse gas emissions in the process of coal mining during the coal mine methane utilization in power supply systems. An algorithm to form recommendations for the implementation of CMM generation is presented. A simulation model for one of the Kuzbass coal mines was developed in the PowerFactory software application. The simulation model considers the uneven nature of the power consumption of mining equipment. As a result of modeling, daily power consumption profiles and voltage levels in the coal mine power supply system were determined before and after the implementation of the proposed measures. Based on the results, the technical and economic effects was estimated, which consisted in reducing the direct and indirect carbon footprint, electricity and capacity fees. It has been established that the cost of carbon dioxide emission quotas significantly affects the investment attractiveness of cogeneration projects. Based on the results, recommendations are given to stimulate the development of small generation in coal mines.

Design and manufacture of four wheel tractor for medium size work rice farming

<span>Indonesia is located at the equator occupy areas north and south of its bearing atmosphere where about 270 million people live the land of very rich soil and are also rich in mineral sediment demanded heavily for today's technology including nickel, bauxite, lithium, and aurum with its close articles such as thin and uranium. So numerous heavy mining equipment works around the clock. Unfortunately, the other potential products of the rich soil were somehow neglected as the nation left such activities to its traditional practice by utilizing man and animal to cultivate the plantation, so that the productivity of the land from the surface is very minimal such that the average productivity of the soil only reach 27% compared to its champion in the developed countries per acre per year. The study on such low soil productivity is caused by two main problems, such that the lack of massive soil processing technology and low attraction for the worker to pursue their career in farming as more money is offered by the transportation sector being an online transport business. This article is a series published on the tractor research initiative that aims to provide a functional medium tractor powered by a 30 HP engine that can do the basic work of a tractor including lifting soil on the surface so that oxygen will fill up the soil and the mineral can reach the root of the plant life on it and kill the unfavorable weeds in the process. The article will discuss all functional elements of the tractor and necessary specifications from design, manufacturing, and final assembly. Further publications will involve optimal design and construction to head for the final products of its commercial endeavor.</span>

Technology of combined fixing of preparatory products for efficient use of suspended monorail roads

Purpose. Justification of the parameters and design of the system of combined fastening of the monorail pond of the suspended monorail roads in formation underground workings to reduce dynamic loads on the elements of the arch fastening and the mining massif during the delivery of large-tonnage loads and equipment to preparatory pits and assembly chambers. The methods. The recommended method of substantiating the technological schemes of auxiliary transport, focused on the use of multifunctional mining equipment of the new generation, adapted to the modern conditions of performing assembly and dismantling works and preparing new mining pillars for cleaning extraction, which is based on the modeling of the parameters of the interaction of the rolling stock of suspended monorail roads with arch fastening elements and side rocks during transportation of large-tonnage cargoes. Findings. According to the results of research into the operational parameters of suspended monorail roads as part of a highly adaptive transport and technological system for the delivery of large-tonnage cargo, it was established that to reduce dynamic loads on the elements of the arch fastening and the mining massif in the specific conditions of the mines of Western Donbass, the most promising option is the two-level anchor fastening of the monorail stand and preparatory product. The originality. Innovative technical solutions to increase the operational reliability of the arch attachment during the transportation of large-tonnage loads and reduce dynamic loads on the mining massif by redistributing them to adjacent links of the monorail pond and modernizing the transport and technological system are substantiated. Practical implementation. It has been proven that during the intensification of cleaning and preparatory work, reasonable technical and technological solutions meet the requirements for the timely preparation of new mining pillars and are considered as a promising direction for improving the current schemes of auxiliary transport for the mines of the region and ensuring the operational parameters of mining transport equipment of a high technical level in the specific conditions of the mines of the Western Donbass.

Investment Project Analysis of PT. Berau Coal Block 5-6 Binungan Using Discounted Cash Flow Method

The evaluation of business projects that have high complexity and uncertainty will require a thorough study since the coal mining industry is a business that has extremely high costs as well as a high risk where there are many uncertainty elements that impact this sector. Blocks 5 and 6 are locations that have previously been mined by PT. Berau Coal in an effort to boost output. PT. Berau Coal now wants to reopen the block 5-6 region to optimize the area that was previously deemed unproductive for mining in an effort to boost coal output there. To assess if the block 5–6 region can be mined once more in an endeavor to increase PT. Berau Coal's production reserves, an analysis is thus required. PT. Berau Coal currently uses the Discounted Cash Flow (DCF) approach to determine the viability of an investment. The mathematical results of the DCF technique will be taken into account by management when making mining decisions. Further research is required to be able to maximize shareholder value because this technique has a restriction in that it does not offer flexible project for management. We obtain an NPV of $14,44 million, an IRR of 67,98%, and a Payback Period of 3.4 years based on the results of the DCF calculations performed on the Block 5-6 project from the mine plan for PT. Berau Coal. There are a number of preparations that must be made for the mining plan for this project, including the building of farm roads to replace existing roads that are part of the mining plan and pumping operations to lower the water level in the mining plan area. There is no new investment required because the infrastructure for mining equipment is already a part of the contractor selection component and the infrastructure for processing coal already uses it.

A VR-based interactive teaching and practice environment for supporting the whole process of mining engineering education

ABSTRACT Due to the complex and dangerous nature of underground industrial sites, there is an urgent need to improve practical teaching abilities. In this paper, a VR-based interactive teaching and practice environment is proposed for teaching mining equipment processes under laboratory conditions. This environment integrates a digitised design, a virtual simulation platform, and a VR interactive product operation. This VR interactive environment includes the structural cognition of mining equipment, the actual operating conditions, and the actual operation of electronic control. Moreover, this system integrates a series of virtual reality human–machine interaction hardware, so that the students can quickly learn the operating conditions and the states of the actual underground production. This system helps them comprehensively learn the mechanical, electrical, communication, control, and mining methods involved in the mining equipment. Finally, this system provides a virtual practice path for training innovative engineering technicians.

Determination of the Accuracy of the Straight Bevel Gear Profiles by a Novel Optical Coaxial Multi-Ring Measurement Method.

Straight bevel gears are widely used in mining equipment, ships, heavy industrial equipment, and other fields due to their high capacity and robust transmission. Accurate measurements are essential in order to determine the quality of bevel gears. We propose a method for measuring the accuracy of the top surface profile of the straight bevel gear teeth based on binocular visual technology, computer graphics, error theory, and statistical calculations. In our method, multiple measurement circles are established at equal intervals from the small end of the top surface of the gear tooth to the large end, and the coordinates of the intersection points of these circles with the tooth top edge lines of the gear teeth are extracted. The coordinates of these intersections are fitted to the top surface of the tooth based on NURBS surface theory. The surface profile error between the fitted top surface of the tooth and the designed surface is measured and determined based on the product use requirements, and if this is less than a given threshold, the product is acceptable. With a module of 5 and an eight-level precision, such as the straight bevel gear, the minimum surface profile error measured was -0.0026 mm. These results demonstrate that our method can be used to measure surface profile errors in the straight bevel gears, which will broaden the field of in-depth measurements for the straight bevel gears.

Mathematical model of the closed-loop system of excavator bucket positioning

Purpose. Study on energy consumption of mechatronic systems of mining excavators during the full production cycle, development of energy efficiency criterium for the production cycle of mining excavators, which ensures an increase in the technical and economic indicators of the operation of powerful mining equipment. Methodology. Mathematical modeling of electro-mechanical system of “front shovel” excavator, determination indicators of the production cycle, development of the criterion of energy efficiency of the mining excavator’s operating cycle taking into account the theory of technical systems efficiency. Findings. A mathematical model of a complete electro-mechanical system of an excavator with “generator-engine” electric drive has been developed, which includes a model of the mechanical part of the excavator. The closed-loop bucket positioning system makes it possible to implement various movement trajectories during the operating cycle. Numerical characteristics of energy consumption and duration for various movement trajectories of the working bodies of the excavator are obtained. A new criterion of energy efficiency of mechatronic systems of mining excavators is proposed. Originality. For the first time, a mathematical model has been proposed of an integral electro-mechanical system of an excavator according to the “front shovel” scheme, which includes models of electric drives of all mechanisms and a synchronous drive motor, as well as a model of the mechanical part of the excavator; this makes it possible to increase the accuracy of determining the excavator’s energy consumption and the operating cycle time. A criterion of energy efficiency is proposed, which takes into account the amount of resource costs, the overall result and the duration of the excavator’s operating cycle. Practical value. A mathematical model of the electromechanical system of an excavator with an electric drive according to the “generator-motor” system has been developed, which, taking into account the solution of the direct and inverse problems of the kinematics of the mechanical system of the excavator, makes it possible to compare parameters of various trajectories of movement of the excavator. The implementation of a closed system for positioning the excavator bucket in three-dimensional space was proposed, which creates conditions for increasing the level of automation of mining excavators. A criterion of the energy efficiency of the excavator’s technological cycle is proposed, which takes into account resource costs and the technological cycle duration.

Methods of mining machine components reconditioning and hardening by means of concentrated energy fluxes

Introduction. The value of resources is becoming increasingly important to mining proprietors, since the maintenance of mining equipment is quite expensive. Increased scope and cost of repairs are largely determined by the quality of mining machines and equipment operation in production environment, as well as by their reliability and maintainability. The costs of preventive maintenance are over the limit by 40–50%, in most instances, due to equipment shutdowns caused by subsystem failures. Components with hidden defects as well as the methods of components reconditioning that do not ensure long-term operation cause a significant overrun of costs for breakdown maintenance. The quality of mining equipment maintenance is in direct relationship with the effective methods of components reconditioning, including the methods of components hardening both during their manufacture at machinebuilding plants and during their repairs at repair works that carry out complex, mainly major repairs of mining equipment. Adherence to the flow process of reconditioning/hardening of the component surface in contact with another component is of great importance. Therefore, to preserve fixed assets, in particular, mining and transport equipment, it is essential to find that reconditioning methods which allow to preserve consumer properties and operability of equipment for a sufficiently long time. Subject matter. The article provides an overview of methods of mining machine components reconditioning/hardening involving concentrated energy fluxes. In the authors’ opinion, these are the most effective methods to increase the resource and reliability of mining machine components by 2–3 times. The choice of components reconditioning/hardening method depends entirely on the service centre capacities, necessary technological equipment availability, personnel qualifications and, most importantly, economic feasibility of using a particular method of reconditioning/hardening. Research objective is to consider the most effective methods of mining machine components reconditioning/hardening. Methods of research include the interpretation of a number of experiments conducted at mining enterprises to obtain comparative characteristics of the most effective methods of mining machine components reconditioning/hardening. Research results. The most effective methods of components reconditioning/hardening are identified and recommended practices are provided. Conclusions. It has been established that the application of a particular components reconditioning/hardening method should be based on the data from tribological maps, as well as necessary equipment availability and economic feasibility.

Parametric model for a cutting edge contour of the geokhod cutting body blade

a parametric model for a cutting body blade cutting edge contour of geokhod, which is a new class of mining equipment. The research relevance is due to the need to create a unified methodology for forming the cutting body cutting edge for geokhods of various sizes, since the cutting edge design parameters are heavily dependent on geokhod geometry and force parameters. The research objective is to obtain parametric equations for determining the geometric coordinates of the points of the geokhod cutting body blade cutting edge in Cartesian coordinates. Methods of research. The paper describes the principles of parameterization of the complex geometry of geokhod cutting body blade cutting edge. Research methods include the study of blade edge geometry, as well as its design parameters dependence on geokhod’s force and design parameters. To achieve that, analytical dependencies were selected from the method of calculating the cutting body force parameters, and then parametric functions affecting the cutting body cutting edge geometry were selected. Results. As a result, a geometric model of the cutting body cutting edge in a parametric form was obtained. To demonstrate the formation of the blade cutting edge contact with rock based on the obtained parametric-time dependencies, a computer program was developed with the calculated values probability construction. The dependence between the cutting edge geometry and the geokhod design parameters dictated the modeling of the cutting edge shape for geokhods of different diameters. Conclusions. The obtained parametric expressions for calculating the coordinates of geokhod cutting body contact make it possible to build contact lines of the blade and the rock mass according to the input data. Is has also been proved that geokhod cutting edge shape depends on the geokhod diameter, and its geometric parameters will be individual for each type of geokhod

Dynamic Response Difference of Hydraulic Support under Mechanical-Hydraulic Co-Simulation: Induced by Different Roof Rotation Position and Hysteresis Effect of Relief Valve

As key supporting equipment in coal mining, hydraulic supports are vulnerable to impact pressure from roof movement and deformation. In this paper, a mechanical-hydraulic co-simulation platform for hydraulic supports is established. Moreover, the rationality of the simulation platform is verified. Based on this platform, the rigid-flexible coupling impact dynamics model of hydraulic support is built. Finally, by delaying the opening time of the relief valve, the energy dissipation problem of the relief valve hysteresis effect on the hydraulic support system under the rotary impact is discussed. The results indicate that the rotary load acting on the hydraulic support decreases gradually with the backward movement of the roof rotary position, which causes the peak pressure in the column to decrease (by 69 MPa). The hinge point load of different parts shows different load transfer laws. The hysteresis effect of the relief valve prolongs the energy release time of the system, increasing the pressure in the column by 23 MPa. The instantaneous opening speed of the relief valve spool reaches 15.7 m/s, and the hinge point between the top beam and the column is most sensitive to the hysteresis effect (impact coefficient increases by 0.63).

Formalization beyond legalization: ENAMI and the promotion of small-scale mining in Chile

This article explains how ENAMI, the Chilean National Mining Company (ENAMI), has legalized and formalized artisanal and small-scale mining (ASM). The experience reveals how promoting formalization strategies that provide much broader support for ASM, beyond mining licenses and tenure rights (i.e., legalization), defined as formalization (e.g., geological data, mining equipment, and skills transfer programs), is vital. Information gathered from secondary sources and semi-structured interviews reveals that while legalization of ASM has been largely successful in Chile, there are still challenges in terms of formalization, especially improvement of exploration and production. Furthermore, ENAMI needs to modernize its own installations and development model to afford ASM greater opportunities of becoming a sustainable and competitive business activity.

A Novel Denoising Approach Based on Improved Invertible Neural Networks for Real-Time Conveyor Belt Monitoring

Powerful belt conveyor is the crucial transportation equipment for coal mining. Keeping its stable operation is essential to ensure the coal mining efficiency. At present, damage detection systems based on machine vision are widely studied and deployed. Clear images are the foundation for successful damage detection. However, in the harsh environment of underground coal seam, it is difficult to capture high-quality images, which limits the performance of the machine vision-based techniques for the conveyor belt damage detection. To solve this issue, an image denoising and enhancement approach is proposed based on the invertible neural network (INN). First, a new res-block is introduced to improve the feature extraction ability of the proposed model. Then, to take advantage of the INN architecture, input images are split by the generative flow (GLOW) coupling block in the forward path and the noise among the high-frequency (HF) features is discarded in the inverse path. An improved trainable guided filter (TGF) is proposed to reconstruct the HF images. Besides, an improved multiple loss function is designed to keep detailed feature information and eliminate the effect of noise. The comparisons and experimental results demonstrate that the proposed denoising INN (DeINN) presents excellent image denoising ability and outperforms several existing popular methods. Finally, a real-world application demonstrates that the proposed DeINN satisfies the industrial requirements on belt damage detection.