الفهرس | Only 14 pages are availabe for public view |
Abstract Research in the area of mineral resources and mining engineering has significant interest in recent years. The national economy in Egypt can be very much supported from exploitation of its mineral resources. Assiut Cement Company (ACC) is one of the major cement producers in Egypt, producing about five million tons of cement yearly. This research has been carried out at the limestone quarries of this company as part of research activities in response to the national interest of research in the field of mining industry. This study focused on the main operations in surface mining, drilling, blasting and loading and transportation. Drilling operation part: A good distribution and implementation of equipment and machines along the quarry faces is considered a challenge to the mining engineer or the quarry operator. These equipment cost large investments in the production processes and need high skill to be efficiently distributed and operated. In this investigation, study of the optimum distribution of the available drilling machines of different specifications and capacities along the faces of the lime stone quarry of Assiut Cement Company has been carried out. A mathematical model has been used to find and analyze several alternatives and to choose the best alternative. Calculation of the minimum number of drilling machines that satisfy the annual production plan has carried out to decrease production costs. Blasting operation part: This part presents the measurements and analysis of ground vibrations induced by bench blasting operations in limestone quarry at Assiut Cement Company (CEMEX), in Egypt. The objective of this vibration analysis, is to establish specific site relationships that can be used to determine safe explosive quantity per delay for various distances from buildings. For this purpose, blasts have been recorded using five seismographs to record ground vibrations events. Buildings and constructions close the quarry area have been given the first priority in these measurements. Ground vibration components were measured for each blasting event. After carrying out statistical analysis, the site-specific parameters were determined to predict the peak particle velocity. Also this analysis establishes prediction curves of maximum charge per delay versus distance for different damage criteria. These curves enables control of blasting in order not to damage the nearby buildings, especially plant buildings and structures. The particle velocities and frequency values of all blast events were evaluated according to German DIN 4150 in order to determine the damage risks of the nearby structures. Material handling part: In the process or manufacturing industry, raw materials and products need to be transported from one manufacturing stage to another. Material handling equipment are designed such that they facilitate easy, cheap, fast and safe loading and unloading with least human interference. Determining the optimum number of haul units for a quarry is a task of critical importance. Regardless of the size or number of haul units used in a quarry, the hauling system’s total production can never exceed the productivity of the loading facility. This study presents an optimized haul unit number based on the excavator characteristics. Belt conveyor system can be employed for easy handling of materials beyond human capacity in terms of weight and height. This study discusses the design calculations and considerations of belt conveyor system for limestone using 3 rolls idlers, in terms of size, capacity and speed to be handled as well as its maximum loading capacity. That is in order ensure fast, continuous and efficient movement of crushed limestone while avoiding halt or fatalities during loading and unloading. |