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Author: Admin | 2025-04-28
1. This material is intended for use in lectures,presentations and as handouts to students, and isprovided in Power point format so as to allowcustomization for the individual needs of courseinstructors. Permission of the author andpublisher is required for any other usage. Pleasesee [email protected] for contact details.Hassan Z. [email protected] 2016Prof. Dr. H.Z. Harraz PresentationTopic 6: Mining MethodsPart II: Surface Mining-Planning andDesign of Open Pit Mining 2. Outline of Topic 6:1) Definition of Open pit Mining Parameters:1.1.) Basic Concept1.2) Open pit Mining method1.3) Bench1.4) Open Pit Bench Terminology1.5) Bench height1.6) Cutoff grade1.7) Open Pit Stability:i) Pit slopeii) Pit wall stabilityiii) Rock strengthiv) Pit Depthv) Pit diametervi) Water Damagevii) Strip Ratio (SR)1.8) Open-pit mining sequence1.9) Various open-pit and orebody configurationsWe will explore all of the above in Topic 6.Prof. Dr. H.Z. Harraz PresentationFebruary 2, 20162) Limit or Ultimate Pit Definition:2.1) Introduction2.2) Manual Design2.3) Computer Methods2.4) Learchs-Grossman method2.5) Floating cone method3) Open pit Optimization:3.1) The management of pit optimization3.2) A simple example3.3) The effects of scheduling on the optimaloutline4) Optimum production scheduling5) Materials handling Ex-Mine6) Waste disposal:6.1) Dump design6.2 ) Stability of mine waste dumps6.3) Mine reclamation Example of Open Pit Mining Methods 3. 1) Definition of Open Pitmining parametersProf. Dr. H.Z. Harraz PresentationFebruary 2,3 4. Although the basic concept of an open pit is quite simple, the planning required to develop a large deposit for surface mining isa very complex and costly undertaking. At one mine, it may be desirable to plan for blending variations in the ore so as to maintain, as nearly as possible, a uniformfeed to the mill. At another operation it may be desirable to completely separate two kinds of ore, as for example, a low- grade deposit whereone kind of "oxide" ore must be treated by acid leach, but a second kind of "sulfide" ore must be treated by differentmethods. The grade and tonnage of material available will determine how much waste rock can be stripped, and there is often anultimate limit to the pit that is determined more by the economics of removing overburden than a sudden change in the oredeposit from mineral to non-mineral bearing material. The ultimate pit limit and the slope of the pit walls are therefore determined as much by economics and engineering as bygeological structure. Material that is relatively high grade may be left unmined in some awkward spot extending back toodeeply beneath waste The typical large open pit mining operation that has been in production for 10 years and more is operating under conditionsthat could not possibly have been foreseen by the original planners of the mine. Metal prices, machinery, and milling methods are constantly changing so that the larger operations must be periodicallyreevaluated, and several have been completely redeveloped from time to time as entirely different kinds of mining and millingoperations.1.1) Basic ConceptProf. Dr. H.Z. Harraz PresentationFebruary 2, 2016 5. Sometimes the preliminary stripping of the waste overburden is contracted to firms specializing inearthmoving. Mining is usually done by track-mounted electric shovels in the large operations, and byrubber-tired
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