Transcript alumni-seminar-presentation-26-12-2016

Essentials of a need based Mining geological curriculum
– An academic necessity in the context of empowering
Mining Engineering graduates
Prof. R. Pavanaguru
Emeritus Professor(UGC) O.U.
Prof. S. Jayanthu
Prof, Mining Engg. NIT Roorkela
The Curriculum:
Preparation of standard curriculum is the Responsibility of
Academic bodies such as UGC, AICTE.
 Recently UGC (2016) made a detailed exercise to formulate
A national curriculum that will fit into the needs of applied
earth sciences including the Mining Geology for the first
degree students.
Considering the monumental contribution of Dr. MS Krishnan
(former Director, ISM and Head Mining Engineering Dept. O.U.),
an attempt has been made in to the real time concepts and
Practices of Mining geology which forms the back bone of
Mining engineering
 To provide in-depth treatment for the first
professional course in Mining Engineering It is
needless to mention that:
A perfect understanding of Mining Geology is
essential as it forms the fundamental requirement of
the subject such as basic geology, Prospecting,
exploration and availability for extraction.
Therefore, a need based professional curriculum is
a necessity to shape a professional mining graduate.
Further the planners of the syllabus formulation
observe that 2 to 3 weeks of Field training exposing
to different lithologies and a dissertation /project
work is mandatory.
Objectives
 Introduction to the ore geology, its processes and
petrogenetic controls of ore formation particularly in light
of the exhaustion of surface deposits.
 To enhance the students’ knowledge about importance
of metallic and non-metallic (industrial) mineral deposits
both in space and time.
 To comprehend the techniques of mineral prospecting
and exploration and the basics of UNFC categorisation
of mineral deposits based on the factor of geological
reliability.
A pragmatic approach on Mineral Fuels:
Atomic Minerals, Coal, shale gass, Petroleum and Gas
Hydrates.
To explain mineral economics.
GEOLOGICAL SIGNIFICANCE OF MINERAL RESOURCES
ORE:
Useful metallic minerals that can be mined for a PROFIT
varies depending upon technology, economics, and
politics; emphasis on profitability, technological feasibility,
and demands
CONCENTRATION FACTOR: Concentration is necessary for
profitable mining which is :
Variable with types of metals--Variable over time
Approximate Concentration Factor of Selected Metals prior to feasibility for mining
Peninsular India
 Exposes rock units from
Archaean metamorphites/
granitoids to the youngest
Quaternary alluvium.
 Geological and metallogenic
history
 Is the main repository of
economic minerals.
CLASSIFICATION OF MINERAL RESOURCES
Basis of Classification
1. Geological consideration
Quantum of Exploration

Geologic nature (mode of occurrence, shape, depth etc)
Common to most system of classification
2. Techno economic consideration
Mining Technology
Processing technology
(emphasis varies on different system of classification)
Various Processes in the Formation of Ore Deposits
1. Magmatism
Endogenic
Process
2. Sublimation
3. Hydrothermal process
4. Contact metamorphism/metasomatism
5. Sedimentation
Exogenic
Process
6. Residual / mechanical concentration
7. Oxidation / supergene enrichment
8. Evaporation
Igneous Host Rocks
• Plutonic hosts
– Layered mafic intrusions
• Rythmic layering in the form of alternating bands of mafic
and felsic minerals
• Host to chromite, magnetite, ilmenite and PGE’s
• Stratiform, great lateral extent eg Bushveld
– Komatiites
• Nickel-copper sulfide ores formed by the sinking of an
immiscible sulfide liquid to the bottom of a magma
chamber or lava flow. Liquation deposits.
• Sulfides usually accumulate in hollows at the base of the
magma forming conformable sheets or lenses
VMS deposits
 Volcanogenic massive sulphide (VMS) deposits are also
known as volcanic-associated, volcanic-hosted, and
volcano-sedimentary-hosted massive sulphide deposits.
They form from metal-enriched fluids associated with
seaflor hydrothemal convection. Their immediate host rocks
can be either volcanic or sedimentary.
VMS deposits are major sources of Zn, Cu, Pb, Ag and Au,
and significant sources for Co, Sn, Se, Mn, Cd, In, Bi, Te, Ga
and Ge. Some also contain significant amounts of As, Sb
and Hg. Historically, they account for 27% of Canada's Cu
production, 49% of its Zn 20% of it's Pb, 40% of its Ag and
3% Au
SEDIMENTARY /RESIDUAL PROCESSES
(Exogenic processes)
Banded Iron Formation
Layers of chert/quartzite with iron
oxide (hematite/Magnetite)
All over ~2 b.y.
SEDIMENTARY PROCESSES
carnotite, K2(UO2)2(VO4)2- 1-3H2O
Uranophane Ca(UO2)2SiO3(OH)2•5(H2O)
Stratiform
Deposits
Supergene Enrichment
• Groundwater reactions can lead to redistribution
of metals above the water table and facilitate secondary
sulphide Enrichment in the primary zone
Preamble of exploration
Remote-sensing data collection
Surface Geological mapping, sampling etc
PERSPECTIVE PLANNING AND PROSPECTING
- - Far reaching concepts of exploration, conservation and utilisation.
Geochemical mapping, sampling
Geophysical surveys, and
Integrated Geoscientific approach.
 Test drilling
ENVIRONMENTAL studies / IMPACT
AIR, WATER, AND LAND
ORE SEARCH
Controls of Localisation, Mineral Concentrations
Ore Shoots, Bonanzas
Ore-bearing strata and the inter-relationship
with structure, index mineralogy - metallogeny.
 It is easy to find ore deposit if known where to
look for it Calls for: Geological Guidance to
locate Ore deposits.
Mineralogical significance:
Relative abundance of minerals and Variation
in the proportion of minerals---index minerals
Rock Alteration Zones
 Physical Alteration
 Chemical Alteration
 Textural Alteration
Alterations:
Sericitisation, Silicification Tourmalinisation, Kaolinisation,
Prophylitization, Carbonatisation.
(generally observed in Hydrothermal deposits associated with alteration)
Some Common Diagnostic Cropping Colours of Common Metals
MINERAL OR
METAL
CROPPING COLORS
OXIDIZED COMPOUNDS
Iron sulphides
Yellows, browns, maroons,
reds
Goethite, hematite, limonite,
sulphates
Manganese
Black
Manganese oxides, wad
Copper
Green, blues
phates, oxides, native
Cobalt
B1ack, brilliant, pink
Oxides, "bloom" (erythrite)
Nickel
Greens
Nickel ‘bloom’ (annabergite),
garnierite
Molybdenite
Bright yellows
Wulfenite, molybdite
Silver
Waxy greenish
Chlorides, etc., native
Arsenic
Orange, yellows
Oxides
Bismuth
Yellow
Bismite
Cadmium
bight yellow
Cadmium oxide
Combinations of the band ratio images ferric iron (3/1) in red, hydroxyl minerals (5/7) in green
and (5/7 +3/1) in blue for picking alteration zones.
Sampling
Sampling is the process of taking small portion of
ore/mineral/rock such that the consistency of the
portion shall be the representative of the whole
—Baxter & Parks (1930)
Drill core sampling is necessitated because of :
Erratic behaviour of ore
Inconsistency of values
Random distribution of ore mineral and associated minerals.
Interdependency of sampling and geology
To project average distribution of values
Drilling from the surface into the deposit
is by far the most expeditious and
economical means of sampling an ore
. body that extends to depth. Over 95% of
mineral sampling today is performed by
drilling
The core can be split longitudinally onehalf being preserved for geologic study
and one-half is used for analyses
Preliminary megascopic Petrologic and
mineralogic Identification is done with the
help of a hand lens
Microscopic studies of thin polished
sections, soil and rock mechanics
information for pit or mine design generally
depends on laboratory testing and analyses
Core Splitter
STAGES OF PROSPECTING / EXPLORATION
STAGE OF ACTIVITIES
EARLY RECONNAISSANCE
(P-I)
EXTENDED RECONNAISSANCE
(P-II)
OBJECTIVES
WORK COMPONENT
Regional evaluation,
for identification of a
favourable geological
environment.
Synthesis of remote
sensing, geological
geophysical &
geochemical data,
and creation of data
base.
Identification of
exploration target
usually favourable
lithology, tectonic / or
structure.
Intensive
reconnaissance
including pitting,
trenching & scout
drilling
STAGE OF
ACTIVITIES
OBJECTIVES
Broad determination of strike
IST STAGE
extension, width of potential
PRELIMINARY mineralized zone, determination
EXPLORATION of grade of mineralization,
( E – I)
defining possible category of
resource as well as conditional
resource.
WORK COMPONENT
Geological,
geochemical
and geophysical method,
pitting, trenching & sinking
of wide spaced drill holes.
Systematic drilling to
2ND STAGE
Assessment of reserves
& intersect ore bodies,
PRELIMINARY average grades of ores up to mineralogical/chemical
EXPLORATION the probable category provides characterisation of ore
(E-II)
basis for prefeasibility study.
zone. The resource
estimation on the basis of
the economic viability/
cutoff grade.
Exploration of Mineral deposit
Favourable
Untimely
Unfavourable
After H.L. Hartman-1987
For Petroleum
Exploration
No.
Types
Typical examples
1
Quartz-Pebble-Conglomerate
type
2
Unconformity related
3
Vein type (hydrothermal or
d issemi nations )-5t ructu rally
controlled I stratabound
4
Sandstone type
5
Breccia complex
6
Intrussive
7
Volcanic
8
Metasomatites
9
10
Collapse breccia type
Phosphorite
11
Black shale
12
Lignite
13
14
Surficial I Fluvial valley fill
Metamorophic
Witwatersrand area, South Africa
Elliot Lake region, Canada
Athabasca basin, Canada
Alligator river basin, Australia
Beverlodge, Uranium City, Canada
Massif central, France
Schwatzwalder, USA
Oklo, Gabon
Grants, USA
Niger
Kazakhstan
Olympic Dam, Australia
Rossing, Namibia
Bancroft, Canada
Jiang Xi, China
Michelin, Canada
Ross Adams, USA
Kriverozhsky-Zheltye, Ukraine
Orphan lode and Hack Canyon, Arizona, USA
Montpelier, USA
Chattanooga, USA
Ranstad, Sweden
Slim Buttes, South Western Williston Basin, USA,
Czech Republic
Yeelerie, Australia
Forstau, Austria
15
Others
% of total
deposits
% of total
Uranium
resources
3.8
13.0
4.0
33.0
23.7
9.0
42.8
18.0
0.2
17.0
2.2
7.4
2.1
1.7
1.7
1.5
3.8
2.7
2.4
10.0
Real time Methods and Practices in Mining
Geology must be
carefully planned and
judiciously implemented.
Geo-genetic knowledge, in its totality,
identify target areas for a conceptual
exploration and evaluation which is the need
of the hour
Uranium mineralisation in carbonate host rock.
Tummalapalle Uranium Mine
LAMBAPUR URANIUM DEPOSIT
SRISAILAM
QUARTZITE
Altered zone
BASEMENT GRANITE