1. Mining Methods

2. 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 AN
M 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

3.  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

4. Quặng sắt (hệ tầng sắt phân dải)
Quặng vàng

5. Mining methods
 There are two  Underground
main types of  Surface
mines.
 Placer
1) Surface Mining
 Leaching/solution
(Placer)
2) Subsurface
Mining (Solution)

6. 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

7. http://www.uky.edu/KGS/coal/images/minmethd.gif

8. Shape of Ore Body

9.  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

10. Surface
 Strip
 open pit
 quarry

12. versus

13.  Minerals are located too deep for surface
mining
 Shafts and passageways are dug into the
ground to reach the ores.

14. Type of Ore
 Is the ore mineral soluble in water?
 Can the ore be melted?

15. When do you use Surface Mining?
 Large tonnage
 High rates of production
 Overburden (including rock) is thin

16. Strip Mining of Coal
Kansas Geological Survey

17. Open Pit Mining

18. Open-pit Mining

19. Strip Mining

20. Contour Strip Mining

21. Mountaintop Mining

22. machinery used in open-pit
mining

25. Drilling in pit

26. Crushing in pit

27. Loading ore in pit

28. Placer
mining
http://www.homestead.com/theclaimpost/PlacerMiningMethods.html

29. http://www.uky.edu/KGS/coal/images/minmethd.gif

30. Underground Mining

31. When do we mine underground?
 The ore deposit is deep
 Ore body is steep
 Grade is high enough to cover costs

33. Some types of underground mining
 Room and Pillar
 Cut and Fill
 Long wall (coal)
 Shrinkage Stoping
 Block Caving

34. Room and Pillar

35. Room and pillar

36. 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

37. Cut and Fill

38. Cut-and-fill method

39. 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.

40. Long Wall

41. 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.

42. Shrinkage Stoping

43. 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.

44. Block Caving
www.ivanhoe-mines.com/s/Mongolia_ImageGallery

45. 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.

46. Solution mining
http://www.saltinstitute.org/images/saltdome.gif
http://web.ead.anl.gov/saltcaverns/desc/index.htm

47. Solution Mining

48. Beneficiation
Means of separation of ore mineral from
waste material (or gangue minerals)
Also known as Liberation

49. 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

54. Refining the Ore
Smelting
removes the metal from the ore mineral by a
variety of ways
Heap Leaching
removes metal from the ore by solution

55. Iron in review
 Blast Furnace
 3CO + Fe2O3 2 Fe + 3CO2 (gas)
 4CO + Fe3O4 3Fe + 4CO2 (gas)

56.  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

57.  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.

58. 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

59. Result at Kidd Creek

60. 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