Chuong 2 khai thac va che bien
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Chuong 2 khai thac va che bien

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  • Bingham Pit
  • Bingham from the air: Google Earth
  • Photo I took at Bingham. 4 km in diameter 1 km in depth, at its zenith 400000 tons of rock per day
  • Tabular, shallow, strong
  • Steeping dipping ore

Chuong 2 khai thac va che bien Chuong 2 khai thac va che bien Presentation Transcript

  • Mining Methods
  • E X P L O R A T IO N L O C A T E & D E F IN E D E P O S IT S E L E C T M IN IN G (M IL L IN G ) M E T H O D D E S IG N , S E L E C T S C A L E & T E C H N O L O G Y W ASTE CLOSURE IN F R A S T R U C T U R E HUM ANM ANAG EM ENT S E R V IC E S RESOURCES PLAN & SCHEDULE F E A S IB IL IT Y ? T E C H N IC A L E C O N O M IC A L NO YES E N V IR O N M E N T A L S O C IA L P O L IT IC A L NO S U S T A IN A B L E
  •  Mining is extracting ore or minerals from the ground An ore is a natural material with a high concentration of economically valuable minerals that can be mined for a profit
  • Quặng sắt (hệ tầng sắt phân dải)Quặng vàng
  • Mining methods There are two  Underground main types of  Surface mines.  Placer 1) Surface Mining  Leaching/solution (Placer) 2) Subsurface Mining (Solution)
  • What determines the type of mining? Underground v.s. Surface Mining v.s. Solution – Depth of below surface – Size of the ore body – Shape of the ore body – Grade – Type of Ore
  • http://www.uky.edu/KGS/coal/images/minmethd.gif
  • Shape of Ore Body
  •  Mineral deposits are on or near the surface of the Earth and are removed. There are 3 types of surface mines: 1. Open-pit: removes large, near surface deposits of minerals such as gold and copper. Mined downward in layers 2. Quarries: stone, crushed rock, sand, gravel 3. Strip Mining: removing surface coal in strips up to 50 m wide x 1 Km long
  • Surface Strip open pit quarry
  • versus
  •  Minerals are located too deep for surface mining Shafts and passageways are dug into the ground to reach the ores.
  • Type of Ore Is the ore mineral soluble in water? Can the ore be melted?
  • When do you use Surface Mining? Large tonnage High rates of production Overburden (including rock) is thin
  • Strip Mining of CoalKansas Geological Survey
  • Open Pit Mining
  • Open-pit Mining
  • Strip Mining
  • Contour Strip Mining
  • Mountaintop Mining
  • machinery used in open-pit mining
  • Drilling in pit
  • Crushing in pit
  • Loading ore in pit
  • Placer mininghttp://www.homestead.com/theclaimpost/PlacerMiningMethods.html
  • http://www.uky.edu/KGS/coal/images/minmethd.gif
  • Underground Mining
  • When do we mine underground? The ore deposit is deep Ore body is steep Grade is high enough to cover costs
  • Some types of underground mining Room and Pillar Cut and Fill Long wall (coal) Shrinkage Stoping Block Caving
  • Room and Pillar
  • Room and pillar
  • Room and Pillar mining is commonly done in flat or gently dipping bedded ore bodies less ore is left behind in pillars the roof to collapse and fill in the stope
  • Cut and Fill
  • Cut-and-fill method
  • Cut and Fill mining is a method of short hole mining used in steeply dipping or irregular ore zones The ore is mined in horizontal or slightly inclined slices, and then filled with waste rock, sand or tailings. Either fill option may be consolidated with concrete, or left unconsolidated.
  • Long Wall
  • Longwall mining Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically 1–2 m thick). The longwall panel (the block of coal that is being mined) is typically 3–4 km long and 250–400 m wide.
  • Shrinkage Stoping
  • Shrinkage Stoping is a short hole mining method which is suitable for steeply dipping orebodies. The method is similar to cut and fill mining with the exception that after being blasted, broken ore is left in the stope where it is used to support the surrounding rock and as a platform from which to work. Only enough ore is removed from the stope to allow for drilling and blasting the next slice. The stope is emptied when all of the ore has been blasted.
  • Block Cavingwww.ivanhoe-mines.com/s/Mongolia_ImageGallery
  • Block Caving Block Caving is used to mine massive steeply dipping orebodies (typically low grade) with high friability. An undercut with haulage access is driven under the orebody, with "drawbells" excavated between the top of the haulage level and the bottom of the undercut. The drawbells serve as a place for caving rock to fall into. The orebody is drilled and blasted above the undercut, and the ore is removed via the haulage access. Due to the friability of the orebody the ore above the first blast caves and falls into the drawbells.
  • Solution mininghttp://www.saltinstitute.org/images/saltdome.gif http://web.ead.anl.gov/saltcaverns/desc/index.htm
  • Solution Mining
  • BeneficiationMeans of separation of ore mineral from waste material (or gangue minerals)Also known as Liberation
  • What does it entail? Crushing and Grinding – Ball mill or rod mill Separation – Density (e.g. diamonds with a jig) – Magnetic properties – Electric properties – Surface properties
  • Refining the OreSmelting removes the metal from the ore mineral by a variety of waysHeap Leaching removes metal from the ore by solution
  • Iron in review Blast Furnace 3CO + Fe2O3 2 Fe + 3CO2 (gas) 4CO + Fe3O4 3Fe + 4CO2 (gas)
  •  Sắt được trích xuất ra từ các quặng của nó, chủ yếu từ hêmatit (Fe2O3) và magnêtit (Fe3O4) bằng cách khử với cacbon trong lò luyện kim sử dụng luồng không khí nóng ở nhiệt độ khoảng 2000 °C. Trong lò luyện, quặng sắt, cacbon trong dạng than cốc , và các chất tẩy tạp chất như đá vôi được xếp ở phía trên của lò, luồng không khí nóng được đưa vào lò từ phía dưới. Than cốc phản ứng với ôxy trong luồng không khí tạo ra mônôxít cacbon: – 2 C + O2 → 2 CO Cacbon mônôxít khử quặng sắt (trong phương trình dưới đây là hêmatit) thành sắt nóng chảy, và nó trở thành điôxít cacbon: – 3 CO + Fe2O3 → 2 Fe + 3 CO2
  •  Chất khử tạp chất được thêm vào để khử các tạp chất có trong quặng (chủ yếu là điôxít silic cát và các silicat khác). Các chất khử tạp chất chính là đá vôi (cacbonat canxi) và đôlômit (cacbonat magiê). Các chất khử tạp chất khác có thể cho vào tùy theo các tạp chất có trong quặng. Trong sức nóng của lò luyện đá vôi bị chuyển thành vôi sống (CaO): – CaCO3 → CaO + CO2 Sau đó ôxít canxi kết hợp với điôxít silic tạo ra xỉ. – CaO + SiO2 → CaSiO3 Xỉ nóng chảy trong lò luyện (điôxít silic thì không). Ở phần dưới của lò luyện, xỉ nóng chảy do nhẹ hơn nên nổi lên phía trên sắt nóng chảy. Các cửa lò có thể được mở để tháo xỉ hay sắt nóng chảy. Sắt khi nguội đi, tạo ra gang thô, còn xỉ có thể được sử dụng để làm đường hay để cải thiện các loại đất nông nghiệp nghèo khoáng chất.
  • Sulphide Minerals Are sometimes roasted (pyrit: FeS2) – Heated in air without melting to transform sulphides to oxides 4FeS2 + 11O2 = 2Fe2O3 + 8SO2 2SO2 +  O2  = 2SO3 SO3 + H2O  = H2SO4   – Gives off H2S and SO2 – Then oxides processed like Fe
  • Result at Kidd Creek
  • Heap Leaching In this process, typically done for Au. Weak solutions of NaCN (0.05%) percolate through the material leaching out the desired metals. The solutions are collected and the metals are precipitated