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مقدمة هندسة المناجم Mining Engineering. التعدين. إستخراج وتركيز الخامات المعدنية لإستخلاص ما تحتوى عليه من عناصر نافعه. الخامات المعدنية هى تلك المواد المعدنية التى يمكن إستخراج وتركيز ما يوجد بها من عناصر مفيدة بطريقة إقتصادية كخامات الذهب والنحاس والحديد وغيرها. إستخراج الخامات.
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التعدين • إستخراج وتركيز الخامات المعدنية لإستخلاص ما تحتوى عليه من عناصر نافعه. الخامات المعدنية • هى تلك المواد المعدنية التى يمكن إستخراج وتركيز ما يوجد بها من عناصر مفيدة بطريقة إقتصادية كخامات الذهب والنحاس والحديد وغيرها .
إستخراجالخامات • إستكشاف وتقدير اكميات لخام • إعداد الخرائط الطبوغرافية والهندسية • وضع التصميمات الهندسية لعمليات الإستخراج • إنشاء الممرات وتدعيمها – نقل الخامات ورفعها – جمع الاعمال الخاصة
تركيز الخامات • دراسة الخام – تصميم لوحات إستخلاص الخامات الإقتصادية . • تنفيذ وتشغيل المجمعات الصناعية للتركيز .
Surface mining Surface mining is a type of mining in which soil and rock overlying the mineral deposit are removed. It is the opposite of underground mining, in which the overlying rock is left in place, and the mineral removed through shafts or tunnels.
Surface mining is used when deposits of commercially useful minerals or rock are found near the surface; that is, where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling (as would usually be the case for sand, cinder, and gravel).
Types of surface mining • There are four main forms of surface mining • Strip mining • Strip mining is the practice of mining a seam of mineral by first removing a long strip of overlying soil and rock .
2. Open-pit mining Open-pit mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit .
3. Mountaintop removal Mountaintop removal mining (MTR) is a relatively new form of coalminingthat involves the mass restructuring of earth in order to reach the coal seam as deep as 1,000 feet below the surface. It is used where a coal seam outcrops all the way around a mountain top.
4.Dredging Dredging is a method often used to bring up underwater mineral deposits. Although dredging is usually employed to clear or enlarge waterways for boats, it can also recover significant amounts of underwater minerals relatively efficiently and cheaply.
MINING • To define the ore from the waste rock, samples are taken at set intervals along surveyed lines within the pit. These samples areas sayed. Some of the harder areas require blasting to loosen the rock prior to excavation by hydraulic diggers. Dump trucks haul the rock to the primary crushers
2. CRUSHINGThe primary crushers - two Stammers and a jaw crusher -. break the larger rocks down to a size suitable for transport on the conveyor 3. TRANSPORTA rubber belted conveyor transports the ore and waste rock
4. GRINDING AND SIZINGOre is stockpiled at the mill before being fed into a S.A.G. mill with lime, water and steel balls. The larger particles from this mill are returned to the S.A.G. mill for more grinding. The finer particles receive more grinding in a ball mill 5. LEACHING & ADSORPTIONA slurry of ground ore, water and a weak cyanide solution is fed into large steel leach tanks where the gold and silver are dissolved. Following this leaching process the slurry passes through six adsorption tanks containing carbon granules which adsorb the gold and silver. This process removes 93% of the gold and 70% of the silver.
6. ELUTION & ELECTROWINNINGThe loaded carbon is fed into an elution column where the bullion is washed off. The wash solution—pregnant electrolyte—is passed through electrowinning cells where gold & silver is won onto stainless steel cathodes. 7. BULLION PRODUCTIONThe loaded cathodes are rinsed to yield a gold and silver bearing sludge which is dried, mixed with fluxes and put into the furnace. After several hours the molten material is poured into a cascade of moulds producing bars of doré bullion
8. WATER TREATMENTSome water from dewatering the mine, from the embankment underdrains and decantation from the tailings pond is recycled for use in the grinding circuit. Excess water is pumped to the Water Treatment Plant and treated to the required standards before discharge into the Ohinemuri River 9. TAILINGS DISPOSALWaste rock from the mine is used to build the embankment structure. The embankment retains the tailings slurry in a pond where solids settle and compact. Water is decanted off and used in the process plant or treated before it is discharged
Underground MiningMethods Prof. Dr.SalahEldien El-mofty
Room & Pillar • هي طريقة من طرق التعدين فيها بيتم تقسيم الخام الـــــي شئ اشبه بالبلوكات او المكعبات وتسمى (room) و بعد حش الخام واستغلاله من الـ Room يترك جزء من الخــــام لتدعيم المنطقة ومنع الانهيار فيهايسمي (pillar). • وبعد الانتهاء من جميع الـ Rooms المــوجوده فـــي المنجم يمكن استغلال اعمدة التدعيم -Pillar- وتسمى هــــذه العمــليه بعملية الـ depillaring أو pillar extraction • Said of a system of mining in which typically flat-lying beds of ore are mined in rooms separated by pillars
Room & Pillar (cont,) • Room-and-pillar mining involves driving tunnel-like openings to divide the coal seam into rectangular or square blocks. • These blocks of or pillars, are sized to provide support for the overlying strata. • The openings are referred to as rooms or entries.
LONGWALL • طريقة تعدين يتم فيها تقسيم الخام الى شرائح مستطيلة الشكل يفصل بينها ممرات, وبعد الانتهاء من شريحه تنقل المعدات للشريحه التاليه ويبداء الحش فيها .... وهكذا • A method of mining flat-bedded deposits, in which the working face is advanced over a considerable width at one time.
LONGWALL (cont,) • The workings advance (or retreat) in a continuous line, which may be several hundred yards in length. • The space from which the ore has been removed (the gob, goaf, or waste) either is allowed to collapse (caving) or is completely or partially filled or stowed with stone and debris.
LONGWALL (cont,) video
LONGWALL SUBSIDENCE • Ground water flow is altered • May need to drill wells deeper
LIKE A CITY, OR LARGEBUILDING, SERVICES MUST BE PROVIDED • Transport people (rail, rubber tired) • Transport supplies (materials / maintenance) • Transport product (coal) • Support roof • Provide electrical power • Provide fresh air (& suppress dust) • Provide fresh water • Get rid of waste water
Thank You..! Questions..?? underground methods