Tribological analysis of motor grader edges applied in iron ore mining

Research on the automation of many types of construction equipment, including motor graders, is being actively conducted. In a motor grader cabin, the operator has difficulty observing the working environment because of a constructed field of view. Thus, workers rely on their experience and senses. Further, the working environment of the blade must be observed, and a control algorithm should be created to enable autonomous operation. In this study, a blade rotation control strategy considering the soil distribution was proposed. First, a co-simulation environment was constructed using RecurDyn for multibody dynamics analysis and EDEM for discrete element method simulation, and simulations were performed to determine the correlation between soil distribution and the blade rotation angle. Work quality and blade load were analyzed according to the simulation results. The optimal blade rotation angle according to soil distribution was obtained to develop the strategy for autonomous flattening and scattering work. The proposed control strategy was implemented in a 1/4 full-scale motor grader experimental setup. An experiment to evaluate work quality was conducted to validate the effectiveness of the proposed methods. The experimental results indicated that the proposed strategy effectively performed scattering work.

Motor graders are widely used in road maintenance and airport constructions. With powerful hydraulic blades, they can be used to create wide and smooth surface with slope. Yet, it is time-consuming and labor-intensive to use motor grader because measuring, proofreading, driving, and grading occur at the same time during the grading process. Addressing this issue, we developed a 3D guidance navigation and human-robot shared control system to help automate the grading control based on the measurement and design data, only leaving the steering task to human drivers. This solution can improve the productivity, efficiency and safety while constructing with motor graders. Specifically, this solution leverages RTK (real-time kinematics) receiver and IMU (inertial measurement unit) sensor to locate the position of the blade, and compares it with the design map, while the controller is adjusting the blade position according to the error from the comparisons. With the blade driven by two separate hydraulic cylinders, the control is coupled, which causes a “seesaw” effect. That is, the motion of one cylinder will affect the other one and cause jittering. To solve this problem, we designed an elevation controller with angle compensation to decouple the process and used the fuzzy logic control to optimize the speed and response of the system. The system was tested and validated on an industrial motor grader in both pilot testing and real highway construction fields. The test results showed that blade control automation can eliminate the labor survey. The proposed human-robot shared control technique can be extensively used to increase efficiency, productivity and safety while decrease labor cost for field operations in semi-autonomous construction machinery, orchard mowers.

Rollover protective structure (ROPS) is a critical safety system mounted on off-highway equipments, which serves as a safety structure for an operator survival during rollover accidents. ROPS is classified as single post, two post, four post, and multi-post; selection of this ROPS depends on the type of the application. Commonly used off-highway equipments are dump truck, articulated scrapers, dozers, water sprinklers, excavators, loaders, motor grader, etc.; among these equipments, motor graders were extensively used in off-highway and mining works. It is noticed from the accidents summary reported by the Directorate General of Mine and Safety, India, and Occupational Safety and Health Administration (OSHA), USA, that a significant failure was noticed by the motor grader ROPS structure. Hence, it is necessary to study the failure behavior and strength criteria of rollover protective structure. In the present research work, attempts are made to study the failure behavior and strength of a two-post motor grader (25 tons GVW) ROPS using finite element analysis (FEA) software ANSYS. Further, an interlock section was introduced in the ROPS column to minimize the overall size and to enhance the performance of the ROPS. Later, comparative analysis has been done on this ROPS in terms of maximum deformation, rate of energy absorption, and C.G height. It is evident from the results that proposed ROPS has 30% reduction in overall size, 5% reduction in weight, and enhanced C.G of height. Further, the proposed ROPS meets the performance requirement of existing standards.

Motor graders are a common type of nonroad vehicle used in many road construction and maintenance applications. In-use activity, fuel use, and emissions were measured for six selected motor graders using a portable emission measurement system. Each motor grader was tested with petroleum diesel and B20 biodiesel. Duty cycles were quantified in terms of the empirical cumulative distribution function of manifold absolute pressure (MAP), which is an indicator of engine load. The motor graders were operated under normal duty cycles for road maintenance and repair at various locations in Wake and Nash Counties in North Carolina. Approximately 3 hr of quality-assured, second-by-second data were obtained during each test. An empirical modal-based model of vehicle fuel use and emissions was developed, based on stratifying the data with respect to ranges of normalized MAP, to enable comparisons between duty cycles, motor graders, and fuels. Time-based emission factors were found to increase monotonically with MAP. Fuel-based emission factors were mainly sensitive to differences between idle and non-idle engine operation. Cycle average emission factors were estimated for road “resurfacing”, “roading,” and “shouldering” activities. On average, the use of B20 instead of petroleum diesel leads to a negligible decrease of 1.6% in nitric oxide emission rate, and decreases of 19– 22% in emission rates of carbon monoxide, hydrocarbons, and particulate matter. Emission rates decrease significantly when comparing newer engine tier vehicles to older ones. Significant reductions in tailpipe emissions accrue especially from the use of B20 and adoption of newer vehicles.

Heavy equipment plays an important role in construction work, especially road construction work. The advantage of using heavy equipment is that it can get the job done faster. Improper use of heavy equipment will cause losses, so an analysis of operational costs is very necessary. Accurate and complete calculation of heavy equipment operational costs will help companies to make decisions, especially from a financial perspective. The purpose of this study was to determine the analysis of the operating costs of heavy equipment, and to know the proper and proper handling of heavy equipment. Cost analysis on heavy equipment is expected to provide benefits to be able to plan heavy equipment management in a coordinated, effective and sustainable manner. This research was conducted on the project Peningkatan Jalan Alun-Alun Suka Makmue-Jalan Lingkar Timur Ibu Kota Tahap II which is located in the district Nagan Raya. This study uses a qualitative method with a descriptive approach, namely research that seeks to describe problem solving based on data that will be obtained in the field. This research was conducted on four types of heavy equipment, namely excavators, motor graders, vibrator rollers and water tanker trucks. The results of the calculation of the operational cost analysis of excavator heavy equipment Rp. 738,617 per hour, motor grader Rp. 572,401 per hour, vibrator roller Rp. 499,735 per hour and water tanker truck Rp. 348,859 per hour. From the results obtained, it shows that for heavy equipment excavators and motor graders there has not been a return on capital, while for heavy equipment vibrator rollers and water tankers there has been a return on capital. So for heavy equipment, vibrator rollers and water tanker trucks, it is feasible to replace them with new tools

The purpose of this paper was to review and analyse the world practice of combined open-pit and underground mining with further justification of its application at mining enterprises in Kryvyi Rih. The following methods have been used: analysis of practical experience in mining by the combined open-pit and underground method of the world’s most famous mines; generalisation of the shortcomings of technogenically destructive technologies of open-pit mining of iron ore raw materials and modern environmental problems of open-pit mining; calculations of the multifactorial structure of dependence in the operation of a mining enterprise on environmental losses; methods of analysis. It has been established that it is necessary to develop a comprehensive strategy for the transition from the existing open-pit mining technology to the technologies of open-pit and underground mining, taking into account the stress-strain state of the rock mass. The relationship between iron ore production at mining enterprises and environmental costs was established. The results of the calculations showed that 99.74% of the variability of environmental costs is explained by changes in the factors affecting the environment, which are calculated in the presented structure, and the remaining residuals are due to the effect of unaccounted factors. The paper investigated and developed transitional technologies with the formation of an underground mining complex on the side of a quarry. A review and analysis of the problems of transition from open-pit mining to the technology of combined open-pit and underground mining of iron ore raw materials was carried out. It was established that in the long-term planning of the development of mining enterprises for the future, preference should be given to the combined or underground mining method. Based on the practical experience of world mines with combined production, a comprehensive strategy for the transition from the existing open-pit mining technology to the technology of open-pit and underground mining has been developed, taking into account the stress-strain state of the rock mass. The practical significance is to develop the optimal technology in the future, taking into account the identified shortcomings and problems of the combined open-pit and underground method at world mines for the conditions of the Kryvyi Rih iron ore basin

Problem. Effective use of motor graders is impossible without the use of automatic control systems, especially in modern conditions of large volumes of road construction. However, among the large number of samples of such systems, which differ in various parameters, it is impossible to make an appropriate choice without a scientifically sound approach, taking into account the set of their characteristics. It was found that these systems are characterized by a large set of parameters, with the values of some of them unknown, and the reliability of the values of many parameters is questionable, i.e. the choice must take place in conditions of fuzzy information. The methods of choosing alternatives in conditions of uncertainty described in the literature, in particular when choosing technical systems based on Analytic Hierarchy Process and fuzzy set theory, are analyzed and the latter is taken to develop a method of choosing a motor grader ACS. The goal of the work is to increase the efficiency of motor graders in road construction due to the appropriate choice of ACS. The methodology of constructing the method is the theory of fuzzy sets. The economic, technical-operational and ergonomic groups of criteria for choosing a motor grader ACS are determined and substantiated. The construction of the method was performed to select the ACS in the 3D class. As the alternatives, the systems which are the leaders of this segment were chosen. The above criteria are a set of criteria. The solution to the problem of choice is an alternative that best meets the requirements of the whole set of criteria. The results of the work are the development of a method of fuzzy multicriterion analysis for the selection of a motor grader ACS in the class of 3D systems. Originality lies in constructing the method of choosing a motor grader ACS in conditions of fuzzy information on the basis of reasonable criteria. The practical value is the fact that the use of the developed method will allow to make a scientifically sound choice of the ACS of a motor grader taking into account the whole set of criteria.

The Mandalika circuit project is a large-scale construction project built in the Mandalika Special Economic Zone (SEZ), Central Lombok, West Nusa Tenggara (NTB). The 4.31 kilometer racetrack will have 19 bends, so it requires heavy equipment to improve the quality production and increase project efficiency. The analysis conducted to obtain the hourly productivity, operating cost, income and profit of excavators, dump trucks, motor grader, vibrator roller, and water tanker used in the worksite of Mandalika circuit. The hourly productivity for structural cut with a depth of 2 to 4 meter of excavator is 17.778 m3/h and dump truck 11.755 m3/h. The excavator production for stockpiling from excavated sources is 30.521 m3/h, dump truck 13.171 m 3/h, motor graders 1839.780 m 3 /h, vibrator roller 90.414 m 3 /h and water tankers truck 71,142 m 3/h. Motor grader production for road body preparation work is 362,222 m3/h, vibrator roller 126,851 m3/h and water tanker truck 62,250 m3/h. The hourly operating cost for the excavator is Rp. 718,048,581, motor grader Rp. 670,416,081, vibrator roller Rp. 609,423,907, and water tanker truck Rp. 380,806,081. The income and profit from the use of heavy equipment are Rp. 39,488,806,755 and Rp. 3,589,981,523.05.

Introduction. Nowadays there is sufficient number of the working bodies’ parameters, which allow performing technological operations in different conditions with minimal labor and energy resources. It is necessary to produce significant excavation during roads’ construction. Therefore, to perform such technological procedure excavation and road machinery are used. The motor grader is an earth-moving machine and is necessary for surface profiling, moving and construction materials’ level.The motor grader efficiency is determined by the performance criterion. World producers of earthmoving and road machinery associate the growth of quality and speed of work with the improvement of the executive working bodies. Moreover, new design variants of dumps are being developed, including design variants for motor graders. Such solution would allow to reduce the necessary number of passages along the construction site and to shorten the time for mounting the working body. The article presents the variant of the motor grader working equipment improving by installing the side working dump.Materials and methods. The calculated dependences of the main parameters of the motor grader are obtained, such as the coupling weight, the nominal traction force, the resistances arising in the operating mode when cutting and moving the ground, and the total engine power for the operating mode at 4 km per hour speed. Strength characteristics of the side working equipment of the motor grader are investigated. The analysis is carried out by using the Solid Software.Results. The results of the theoretical studies are presented graphically and reflected the stresses, displacements and deformations in proposed lateral working equipment of the motor grader. Using the Solid Works software product it is possible to determine the safety margin of the proposed design. The conducted research allows confirming the working capacity of the proposed technical solution.Discussion and conclusion. The proposed technical solution allows increasing the productivity of the machine while performing the planning works, while maintaining the specified accuracy of their implementation. In addition, such design allows profiling not only the horizontal surface, but also the embankment construction when the side blade is located at an angle of up to 20 degrees.

The North Ring Road of Tasikmalaya City itself is a road section that aims to reduce congestion in the center of Tasikmalaya city and as a candidate for exit access to the Getaci Toll Road with a length of 3.81 km. Pavement work is one of the works carried out after the first stage is completed on a road construction project. The role of heavy equipment is very necessary to speed up work. Heavy equipment productivity is related to limited time issues, environmental conditions, weather and other factors. The aim of this research is to determine the productivity of heavy equipment excavators, dump trucks, motor graders and vibrator rollers in class A aggregate material spreading work. which affects the work of spreading class A aggregate material. The method used in this research is quantitative descriptive, which is intended to collect information about existing events. The data that was obtained during this research was not only compiled and collected but also included analysis of the data so that the final results could be concluded. The results of research regarding productivity analysis and causal factors are that the excavator's hourly productivity is 92.731 m³/ hour, daily productivity is 556.38 m³/ day, cycle time is 29 seconds. Dumptruck hourly productivity is 8.57 M³/ hour, daily productivity is 59.99 M³/ day, cycle time 42 minutes. Motor grader productivity per hour is 336.15 M3/ hour, productivity per day is 2353.05 M³/ day, cycle time 0.85 minutes. The productivity per hour of the roller vibrator is 77.024 M³/ hour, the productivity per day is 539.17 M³/ day. The number of heavy equipment is 1 excavator unit, 9 units dumptruck, 1 unit motor grader, 1 unit roller vibrator, with the time required for the excavator 4 days, dumptruck 4 days, motor grader 4 days, roller vibrator 4 days.

Short-term production scheduling in open pit mines usually generates a scheme to enable mining operations to deliver the budgeted tonnes and grades to the mill while following the long-term mine plan. The goal of this paper is to develop and test an optimisation model for short-term open pit mine production scheduling. A multidestination mixed integer linear programming (MILP) model is proposed, which minimises the overall cost of mining operations including mining, processing, haulage, rehandling and rehabilitation costs. The model is solved by branch-and-cut algorithm using TOMLAB/CPLEX optimiser. The model incorporates buffer and blending stockpiles, horizontal directional mining, and decisions on ramps while controlling technical constraints. A monthly production schedule in an iron ore mine is developed over 12 months to illustrate the practicality of the developed model. Three scenarios with different mining horizontal directions are considered. The scenario with minimum number of drop-cuts is selected as the best practical schedule.

Exposure of mine workers to particulate matter (PM) in opencast mines is of major concern because of associated adverse health impacts. Dispersion of PM in such mines depends on their design and local meteorological conditions. With an increase in depth of mines, efficient vertical movement and the dispersion of PM away from mine working area become difficult. Therefore, studies on dispersion behavior of PM in opencast mines are needed. Measurements of PM concentration have been carried out in three opencast mines in India: (i) Malanjkhand Copper Project (MCP), (ii) Kiriburu Iron Ore Mine (KIOM), and (iii) Meghahatuburu Iron Ore Mine (MIOM). A total of 20 days of monitoring of PM and local meteorology were carried out in these three mines. The aims were to investigate the following: (i) vertical PM concentration profiles at different depths during mining operation, (ii) particle travel time and its relationship with mine depth, (iii) particle mass balance in terms of the dispersion and settling proportion, and (iv) the relationship of particle concentration with depth as it moves downward. Results show that the inhalable PM (10–20 μm) were ~22 and 36 % higher than the thoracic (4–10 μm) and alveolic (<4 μm) fractions of PM, respectively. Travel times of PM from ~10 m mine depth to surface are measured up to 17and 13 min for the KIOM and MIOM, respectively. Travel time was as high as ~1 h at MCP for source (workplace where mining operations are taking place) at a depth of 168 m. An empirical equation (R = 0.746, p = 0.034) showing relationship between particle travel time and depth is developed. About 23–39 % inhalable, 19–37 % thoracic, and 9–30 % alveolic PM settled inside the mine within a vertical distance of 18–20 m from the source and 30–47 % inhalable, 31–51 % thoracic, and 34–54 % alveolic PM escaped from the mine. The empirical equations for downward movement of PM predicted particle concentrations between 88 and 91 % of the measured value at 10 m depth and 75 and 95 % at 40 m. The findings of this work are important in understanding dispersion of occupational PM at the worksite and the associated exposure of mine workers.

This study object is industrial waste issue on the example of Ukraine: accumulation level, structure and its treatment possible ways. An analysis of waste sources available statistics on and their quantity was conducted. Іt is considered industrial wastes main component composition and corresponding types processing directions in Ukraine and abroad are analyzed. It is established the industrial waste accumulation level trends in Ukraine to increase year by year, and it's comparison with Gross Domestic Product shows an raw materials increase in the economy. Minor Downward Trends (2008–2009 and 2014–2016) illustrate decline in the industrial production during respective period. The largest industrial wastes producers are mining and processing industries. Six categories of industrial waste were identified, accounting for 4/5 of their total amount. These are sludge, «tails» and other iron ore wastes, iron ore mining wastes, limestone mining residues and waste from mining operations. Only iron ore tails enrichment technologies have been implemented at a sufficient level in Ukraine at present, but their processing level in terms of resource and energy savings is insufficient. The large relevant technologies have been introduced outside Ukraine and the most effective are includes maximum processing stages depth and included to technological production cycles. Based on this study results it is notes the best and most effective in the realities of Ukraine areas of waste management towards the implementation of 17 sustainable development goals are multi-component processing of six main categories of waste from the mining and processing industries. This approach avoids legal conflicts and has the highest environmental and economic effect.

The paper reports the story of successful rehabilitation of one of the world’s largest open uranium pits after mine closure in 1977 and its course to “Neue Landschaft Ronneburg – New Landscape Ronneburg” in which it was given back to the public within the initiative “Bundesgartenschau – Exhibition Federal Garden Show” in 2007. The authors drew on the experience G.U.B. Ingenieur AG gained during the rehabilitation process, including pivotal expertise in services such as planning, construction supervision and project management. The uranium open pit “Lichtenberg” was operated between 1958 and 1976 and covered an area of approximately 160 ha. With a pit depth of 240 m and open pit volume of 160 million m3 it was one of the world’s largest open uranium pits. It was part of an extensive mining region of the former German Democratic Republic, which occasionally produced more than 10% of the world’s total uranium production. The owner, Wismut mining company, was the world’s number three uranium producer. When uranium mining was discontinued and the operations associated with mining shut down, rehabilitation of the post-mining landscape began. These rehabilitation measures were focussed on restoring the environment to an ecologically vital condition and establishing conditions favourable for regional economic revitalisation. Technical rehabilitation processes started in 1994, with the overall vision of converting the mining-degraded surface lands into public assets through a completely new holistic approach to reconstruction and management. The challenges faced included: the absolute requirement for rehabilitation of the abandoned open pits and rock and waste dumps as part of mine closure operations; prevention of acid rock drainage (ARD) from abandoned uranium mine sites; and the requirement for socio-economic redevelopment of the regions influenced by mining operations. These challenges not only included technical questions but also huge social and economic tasks which had to be tackled, especially in a densely populated area with 200,000 inhabitants. The approach to rehabilitation included development of a vision for closure and implementation of management plans for the multi-functional re-use of mine sites. From a technical perspective this comprised of multi-barrier systems and site-specific solutions to deal with, for example, the geological, hydrological, geotechnical and climatic conditions within the open pit. The main characteristics of the project were the intensive mass movements that had occurred, the average number of employees (up to 12,000 over 15 years) and the costs of 600 million EUR available for rehabilitation of the open pit. By the time that rehabilitation was completed the open pit was backfilled, shaped and reconstructed. This was the basis for landscape development. The works were completed in 2007, and on April 1st the newly developed park-landscape “Neue Landschaft Ronneburg – New Landscape Ronneburg” was given back to the public as part of the Federal Garden Show Exhibition, which marked the highlight of the long development process from a heavily impacted mining region to an ambitious and prosperous region in the heart of Europe. From an open uranium mining pit to a new landscape architecture — a rehabilitation story of success R. Schwarz et al. 582 Mine Closure 2009, Perth, Australia

The formation of cell-(iron)mineral aggregates as a consequence of bacterial iron oxidation is an environmentally widespread process with a number of implications for processes such as sorption and coprecipitation of contaminants and nutrients. Whereas the overall appearance of such aggregates is easily accessible using 2-D microscopy techniques, the 3-D and internal structure remain obscure. In this study, we examined the 3-D structure of cell-(iron)mineral aggregates formed during Fe(II) oxidation by the nitrate-reducing Acidovorax sp. strain BoFeN1 using a combination of advanced 3-D microscopy techniques. We obtained 3-D structural and chemical information on different cellular encrustation patterns at high spatial resolution (4-200nm, depending on the method): more specifically, (1) cells free of iron minerals, (2) periplasm filled with iron minerals, (3) spike- or platelet-shaped iron mineral structures, (4) bulky structures on the cell surface, (5) extracellular iron mineral shell structures, (6) cells with iron mineral filled cytoplasm, and (7) agglomerations of extracellular globular structures. In addition to structural information, chemical nanotomography suggests a dominant role of extracellular polymeric substances (EPS) in controlling the formation of cell-(iron)mineral aggregates. Furthermore, samples in their hydrated state showed cell-(iron)mineral aggregates in pristine conditions free of preparation (i.e., drying/dehydration) artifacts. All these results were obtained using 3-D microscopy techniques such as focused ion beam (FIB)/scanning electron microscopy (SEM) tomography, transmission electron microscopy (TEM) tomography, scanning transmission (soft) X-ray microscopy (STXM) tomography, and confocal laser scanning microscopy (CLSM). It turned out that, due to the various different contrast mechanisms of the individual approaches, and due to the required sample preparation steps, only the combination of these techniques was able to provide a comprehensive understanding of structure and composition of the various Fe-precipitates and their association with bacterial cells and EPS.