Truck and Shovel Versus In-Pit Conveyor Systems: a Comparison Of The Valuable Operating Time (original) (raw)
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The purpose of this research is to investigate the factors which affect the performance of the loading and hauling equipment at Skorpion zinc mine, Na-mibia and also to find possible solutions to eliminate them, so that the weekly Zinc Oxide and ex-pit waste tonnages required could be produced. This is due to the high demand of Zinc on the market. The investigation on road conditions was focused on the effects of rolling resistance, grade resistance and road widths from the road between bench 540 in pit 103 to the Zinc oxide medium grade stockpile. Cycle time data were obtained by time and motion study of the load/haul/dump cycle from bench 540 loading site to the stockpile. The data used for equipment matching by queuing theory (excel modelling) was obtained when the loaders where loading Arkose at different loading sites. The effects of different weather conditions i.e. mist, rain and wind on production where determined by collecting actual shift production tonnages and comparing with target shift production targets during this conditions. The results produced from time and motion studies show that the haul trucks have an average availability of 80.4% and utilization at 49.7% which are very low when compared to the benchmark value of 89% and 69% for availability and utilization respectively. Decline in performance time is caused by factors such as daily safety meetings, lunch breaks, blasting, tools break down and the daily machine service. Rolling resistance is also one of the factors affecting production time at the mine. The rolling resistance of different segments was determined by roughness defect scores (RDS). From calculations, it is clearly seen that if the RR could be reduced to 2% on every road segment, then each cycle period per truck can be reduced by 1.24 minutes. This will increase the production of the haulers and decrease the operating cost. It was recommended that the wearing course of the road surface be treated with a bitumen based dust suppression product in order to keep the surface's rolling resistance to an absolute minimum (i.e. RR = 2%) [1]. The current average hauling road width is 15.987 m while the correct road width at Skorpion Zinc Mine must be 21.35 m to prevent bunching of trucks. It is therefore recommended that the haul roads be widened to 21.35 m width per segment.
Optimization of shovel-truck system for surface mining
Journal of The South African Institute of Mining and Metallurgy, 2009
Introduction In a surface mining operation, a materials handling system is composed of loading, hauling and dumping subsystems. Effective and efficient materials handling systems can be developed only through a detailed consideration of these subsystems in a systems analysis framework. The transport of material from production faces to dumping sites is accomplished by rail, truck, belt conveyor or hydraulic transport. Shovel-truck systems are most common in open pit mining. Two available techniques to analyse these systems, linear programming and queuing models, are used and compared in this study. The most important factor in every operation is profitability. Productivity of equipment used is an important factor of profitability. Profitability can be increased by optimization of the equipment combination used. Therefore the first goal in these models is to maximize productivity and hence increase production, which in turn will result in cost reduction. Studies conducted for the tru...
Performance Metric Development to Measure Overall Vehicle Effectiveness in Mining Transportation
Applied Sciences
Several performance metrics to measure the effectiveness of manufacturing equipment have been studied, and one of the most used is overall equipment effectiveness (OEE). However, its application and development in the road transportation sector remains little studied. The purpose of this paper is to establish a new metric derived from OEE to measure the overall effectiveness of coal mining transportation and apply this metric to actual operation. This study employed in-depth interviews and Delphi techniques to explore the specific metrics. Three rounds of Delphi involving mining experts, academia, and consultants identified six potential metrics to measure coal mining transportation operations that contributed to a new metric to measure mining transportation overall vehicle effectiveness. This paper also discusses a case study of how this newly developed metric was tested and applied to the actual operation of the truck fleet at a coal-hauling company in Indonesia. According to the ...
Investigation of Excavator Performance Factors in an Open-Pit Mine Using Loading Cycle Time
Engineering
This study presents the effect of excavator model, loading operation location, shift availability and truck-shovel combination on loading cycle time and productivity of an open-pit mine. The loading cycle time was used to assess the material loading system performance which is one of the key components of the total cycle time for material transportation in an open-pit mine. Loading is among the components of cycle time during which material is being handled. The data analyzed was collected from a computerized dispatch system at GGM from which 62,000 loading dispatches per month involving several shifts, 14 excavators and 49 trucks were loaded. About 4465 dispatches per excavator and 1276 dispatches per truck were assessed using loading cycle time data for each dispatch for a period of four months (between August and December). Under fixed tonnage loaded and waste type (33 t of non-acid forming waste rock), it was observed that loading cycle time depends on excavator model, location and truck being loaded. Average cycle times, PDFS and CDFS of loading cycle time series were used to identify differences in performance under different situations. It was concluded that shift availability for excavators, loading location, excavator model and truck-shovel combinations strongly affect the productivity during loading process in an openpit mine.
Capacity-based performance measurements for loading equipment in open pit mines
Journal of Central South University, 2019
The purpose of this study is to develop an integrated framework for capacity analysis to address the influence of systematic hazardous factors on the haulage fleet nominal capacity. The proposed model was made to capture unexpected risks for mining equipment based upon data-driven method considering different scenarios. Probabilistic risk assessment (PRA) was employed to quantify the loss of production capacity by focusing on severity of failure incidents and maintainability measurements. Discrete-event simulation was configured to characterize the nominal capacity for mining operation. Accordingly, the system capacity was analyzed through the comparison of nominal and actual capacity. A case study was completed to validate the research methodology. The past operation and maintenance field data were collected for shovel operation. The discrete-event simulation was developed to estimate the rate of shovel nominal capacity. Then, the effects of undesirable scenarios were assessed by developing the PRA approach. The research results provide significant insights into how to enhance the production capacity in mines. The analyst gets a well judgment for the crucial elements dealing with high risk levels. A holistic maintenance plan can be developed to mitigate and control the losses.
Literature Review on Hauling Equipment Productivity Using Cycle Time Calculation
2018
The construction industry is one of the largest industries in the world. The need for mechanization arises due to the magnitude & complexity of the project. Proper use of appropriate equipment contributes to economy, quality, safety, speed and timely completion of the project. Hence construction equipments play an important role in any construction process. Hauling equipments are used for moving material from one location to another. Productivity of equipment reflects in the whole project performance. Estimating actual productivity is hence an essential element in calculating the time and cost required to complete construction work. Productivity of hauling equipment can be estimated by measuring the cycle time. It is the period required to complete one cycle of an operation or a function from start to finish. Cycle time is used in differentiating the total duration of a process from its run time. In this paper, a literature review was conducted in order to identify the most signific...
REM - International Engineering Journal, 2018
This article aims to evaluate the use of a truck factor for off-highway trucks in open pit mine operations, thus reducing error on material movement and mine production data entry. This method is current for a copper mine located in South East Pará, Brazil. With a dispatch system, the truck factor is calculated using three data inputs called measured t, dump t and excavator load time. This dispatch system, designed to upload real time data from each truck, acquires measured load information by a truck weightometer and provides the basis for long-term, medium-term and mainly shortterm planning. Due to the significant impacts toward mine planning, through data error, a payload truck factor system provides data assurances in place of potential failure of onboard weighing. However, when using a system that is reliant on actual data, caution must be applied when replacing information with assumed fixed figures, thus forming the discussion on which this article attempts to review by providing overview on both the positive and negative impacts of implementing a truck factor system to an open pit mining using a dispatch system.
REM - International Engineering Journal
A significant cost in the operating budget of most mining operations arises from purchasing and maintaining haulage trucks. Recently, in-pit crushing and conveying (IPCC) has been subject to research because of its potential to reduce haulage costs. The objective of this study is to identify early on in a project, by means of a decisionmaking method, whether or not the semi-mobile IPCC (SMIPCC) is an appropriate alternative to the conventional truck haulage method on the loading and hauling approaches. This method is based on cost analysis and the evaluation of environmental impacts, being successfully tested at an existing open-pit mine, where the results indicated that the IPCC was the most cost-effective option for the operation. Although the IPCC's initial CAPEX was 60% higher than the conventional approach, the IPCC's OPEX was 43% lower, resulting in a 28% reduction of the life-of-mine net present cost (NPC).
Some research to determine the capacity of truck haulage in open-pit mining
2016
This paper presents the results obtained from research on determining the capacity of the truck haulage in open-pit mines for extracting metals. As a case study in this paper is taken the truck haulage in the copper mine "Buchim"- Rep. of Macedonia, where the data is taken from the SkyLinks system for dispatching a truck haulage and all the data is statistically processed. Comparison is made between the technical and the exploitation hour capacity of trucks and also is proposed guidelines for increasing the exploitation capacity as a very important technical parameter.
Measuring the effectiveness of mining shovels
Electric and hydraulic shovels are the dominant loading machinery in surface mining operations. Despite their critical role in production and their high capital and operating costs, no reliable and comprehensive quantitative performance metric is available. In this paper, a stochastic shovel effectiveness (SSE) measure is proposed for the purpose of quantifying the performance effectiveness of these shovels. The SSE is based on the widely used method of overall equipment effectiveness (OEE) in the manufacturing industry. The OEE measures the performance effectiveness of equipment by multiplying its mechanical availability, utilization and production quality. In manufacturing processes, quality rate is the ratio of the total number of products minus the number of defective products – equivalent to the number of acceptable products – to the total number of products. The SSE similarly uses the mechanical-availability and utilization terms, but instead of quality rate it uses a new parameter named bucket rate. The variability or randomness of the input data, that is, availability, utilization and bucket rate, are further incorporated into the SSE, and a final stochastic SSE distribution is derived in the form of a probability density function. One hydraulic and one electric shovel in a surface mining operation were selected to test the validity of the proposed method. The SSE scores for the two shovels, operating continuously for one year, were derived and compared. As with the OEE, the three-parameter SSE method yielded more representative results for overall performance measurement than a single-parameter approach. Using Monte Carlo simulation, a three-parameter Weibull and a normal distribution were derived for quantifying the overall effectiveness of hydraulic and electric shovels, respectively. As a decision aid, the proposed methodology promises to render a more informative tool than traditional metrics for mine equipment maintenance and management.