外文翻譯--掘進(jìn)機(jī)在采礦和隧道業(yè)中的應(yīng)用-閱讀頁(yè)
2025-06-06 06:48本頁(yè)面
【正文】 ignificant amount of effort has been placed over the years on increasing the ability of roadheaders to cut hard rock. Most of these efforts have focused on structural changes in the machines, such as increased weight, stiffer frames and more cutterhead power. Extensive field trials of these machines showed that the cutting tool is still the weakest point in hard rock excavation. Unless a drastic improvement is achieved in bit life, the true hard rock cutting is still beyond the realm of possibility with roadheaders. The Earth Mechanics Institute(EMI) of the Colorado School of Mines has been developing a new cutter technology, the MiniDisc Cutter, to implement the hard rock cutting ability of disc cutters on roadheaders, as well as other types of mechanical excavators (Ozdemir et al, 1995). The fullscale laboratory tests with a standard transverse cutterhead showed that MiniDisc Cutters could increase the ability of the roadheaders for hard rock excavation while providing for lesser cutter change and maintenance stoppages. This new cutting technology holds great promise for application on roadheaders to extend their capability into economical excavation of hard rocks. In addition, using the minidisc cutters, a drum miner concept has been developed by EMI for application to hard rock mine development. A picture of the drum miner during fullscale laboratory testing is shown in Figure2. Figure2: Drum Miner Cutterhead FIELD PERFORMANCE DATABASE Performance prediction is an important factor for successful roadheader application. This deals generally with machine selection, production rate and bit cost estimation. Successful application of roadheader technology to any mining operation dictates that accurate and reliable estimates are developed for attainable production rates and the acpanying bit costs. In addition, it is of crucial importance that the bit design and cutterhead layout is optimized for the rock conditions to be encountered during excavation. Performance prediction enpasses the assessment of instantaneous cutting rates, bit consumption rates and machine utilization for different geological units. The instantaneous cutting rate (ICR) is the production rate during actual cutting time, (tons or m3 / cutting hour). Pick consumption rate refers to the number of picks changed per unit volume or weight of rock excavated, (picks / m3 or ton). Machine utilization is the percentage of time used for excavation during the project TableI: Classification of the Information in the Database INFORMATION GROUP DETAILS General Information Type/purpose of excavation (roadway, railway, sewer, mining gallery, etc.), contractor, owner, consultant, location, starting and pletion date, etc. Roadheader Information Manufacturer, condition of the roadheader (new, refurbished, direct reuse), specifications of roadheader, machine weight, cutterhead power and diameter, bit number and type, ancillary equipment (automatic profile control, water sprays, grippers, etc.) Technical and Operational Information Excavation length, depth, and gradients, dimensions of excavation profile, operator experience, cutting sequence at the face, daily and weekly mining hours, muck evacuation system, ground support system, etc. Rock Mass Information For Each Rock Zone Geological origin, number and character of geological zones, hydrogeological conditions, rock mass classifications, RQD, bedding properties, joint set properties (orientation, spacing, roughness, filling, etc.) Intact Rock Information For Each Rock Zone Rock cuttability properties, uniaxial and tensile strength, elasticity modulus, surface hardness, texture (porosity, mineral / quartz content
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