Andy Lloyd - ICVL Mozambique - The geology of the Moatize coal basins

transcript

THE COAL DEPOSITS OF MOZAMBIQUE P R ES E N T ED BY A N DY L LOY D

D R AW I N G O N F F F P R ES E N TAT I ON S F R O M : -

• J O H N H A N COX ,

• LO P O VA S CO N CE L ES ,

• & G AV I N A N D R E WS .

Overview Regional Geology

Karoo Basins of Mozambique • Early History

• Tectonic Setting

General Geology

Tete Province focus

Exploration learnings

Summary • So what’s in the ground

• Geology vs Economy

Elephants in the room or

Elephant country?

What do we mean by coal Geologically • Coal (from the Old English term col, which has meant "mineral of fossilized

carbon" since the 13th century) is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulphur, oxygen, and nitrogen.

Economically • That which can be mined for economic benefit.

And for Mozambique? • Which numbers are to be believed?

• What numbers are important?

Extractable Coal Economic Coal Un-economic Coal Geological Coal

Early History First coal documented in 1859 by Richard Thornton on one of Dr Livingstone’s expeditions.

“Mr. Thornton stated that the coal, which was dug by natives from an outcropping seam on the bank of the River Muntizi, showed no tendency to cake; was free-burning; contained very little sulphur or iron although a large proportion of ash along with a small amount of gaseous matter “

Early geological investigations in the area were undertaken by Guyot (1882), Lapierre (1883), Zeiller (1883), Kuss (1884) and Potonié (1899). These authors mainly described the lithostratigraphy of coal bearing seams in the lower part of the Karoo Supergroup around Moatize.

Commercial mining in the Moatize Coalfield commenced in the early 1900s on a small scale.

Regional Geology

Extensional Tectonic Setting

Karoo Basins of Mozambique

Metangula Coal Field

Tete Province

Chicoa – Mecúcoè

Sanagoe - Mefidizi

Moatize

Basement Contact

Vúzi Formation - Tillites

Moatize Formation

Chipanga – The 1st thick coal

Matinde Formation

Cadzi Formation

Productive Sequence Outcrop

Facing East

Possible Chipanga Tillites

Low angle faults – possibly 100m’s of throw

Channel Roof

Building a Facies model

• Re-logging old core

• Integrating with Geophysics

• Looking for geological fundamentals

Just Productive Series coal? Coal Outcrop in

Matinde Formation

Coal development in the tillites

ICVL’s Zambeze Geology

Faulting on Macro and Micro scale

Geology –D Seam (Upper Chipanga)

View of North wall and D-Seam

Erosional “roof” contact

Fining up sequence of a migrating channel

Resulting in a thinner coal seam

Channel 1 Channel 2

Coal Bearing Unit

Lachelt (2004)

VALE (2009)

Moatize Sections

Generalised section through Moatize Basin

Gavin Andrews, 2014

Intrusives

Coal Seams

Drilling Challenges

Productive Sequence – formational Cartoon – ICVL Seam names.

Chipanga

Palaeontology

Vertebraria Paracalamites Glossopteris

Palynology

Palynology Protohaploxypinus-Vittatina-Guttulapollenites-

Lueckisporites Sub-Assemblage

Converting stratigraphy to time

MUCANHA-VÚZI SANÂNGOÈ MOATIZE

Metangula

Coal Type log comparison

What about the coal, are they seams and do they have ply´s?

Coking, Thermal, Domestic What are the different types of coal?

Vitrinite bands in mixtures of bright to dull coals within bands of siltstone and mudstone.

Coking Coal – Thermal Coal - Discard

The finer you go the more coking coal you get.

It´s a question of liberation and processing efficiency – more from Mark Cresswell later.

Properties of Mozambiquan coal In general, the Mozambican Permian coals are: • Rank: Bituminous (from high to low volatile bituminous) coals, occasionally

anthracitic

• Type: Vitrinite dominant, Very low Liptinite content,

• Ash yield : generally high,

• Minerals are finely intergrown with the organic matrix, thereby posing difficulties in liberation during beneficiation

Petrography • Dominance of vitrinite; Low content of liptinite (Mucanha-Vúzi) or almost

absence (Moatize-Minjova-Mutarara).

• References to the petrography of coals from other regions were found only for Metangula coals:

• Chipanga Seam (Benga): V content of 72% (Top), 77 & 78% (Middle) 72 & 79% (Bottom)

• Mineral-rich (28% - 48%);

• Vitrinite varying from 36% to 51%;

• Liptinite in the range 2% to 3%

Coal Type log • Up to 60 coal seams in the basin

(seam >1m)

• Seams thickness’s up to 90m

• Interburdens average 40-50m

• Coal characteristics • Sulphur – 1%

• Phos – 0.07%

• Vols – 20-35%

• Coke Yields – 5-60%

• Rank – 0.8-1.7

• Additional Thermal Yields – 10-30%

• Potential resources • Faulted

• Seams show varying continuity

• Intrusions become more prevalent to the east

ICVL Zambeze

ICVL Benga Vale

ICVL Tete East

Eta Star

Cahora Bassa

Fluvial River channel system?Discordant

lenses

Marsh system with thick (approx. 20-30m) coal

packages consisting of interbanded coal and

mudstone. Sandstone partings commonly display

coarsening up sequences.

Thicker upper

seams0.03 0.9

River Channel

and Marsh

Transition zone between the underlying river

channel system with a series of abandoned

channels and the overlying marsh system with

thick mudstone dominated packages.

Discordant

lenses N+0.02 1.1

FluvialRiver channel system with a series of abandoned

channels. Seams are less correlatable.J,K,L,M 0.01 1.0

H,I 0.08 0.9

F,G 0.06 0.8

E 0.08 0.8

D 0.08 0.9

C 0.11 0.7

B 0.01 0.9

A 0.00 1.3

Glacial Glacial till deposited by melting glaciers.

Intrusive

The Tete Complex is the basement rock

consisting of serpentinised gabbro; the basement

includes intrusive stocks and plutons.

Post Glacial outwash fans and channels. Lake

and marsh system at top of sequence containing

C-seam.

River channel system with correlatable seams.

Braided DeltaBraided delta system with interchannel coal

formation.

Fluvial

Era PeriodSuper-

groupGroup

Depositional

Environment

Post Glacial

Depositional ProcessCoals

ContainedFormation Stratigraphy

Coal Characteristics

Product Coal

1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8

WHOLE SEAM DENSITY (SG)

Schematic of Coal Seams and Yield

% of Seams in Basin Coking Coal yield

Coal Qualities Moatize: • increase in rank with depth: from 1,28% in Grande Falésia (Bituminous B) to

1,51% in S. Pinto (Bituminous A).

• %VR varies from 1,16% in Top Chipanga Seam to 1,27-1,29% in Middle Chipanga and 1,27-1,37 in Bottom Chipanga, i.e., increases with depth.

Minjova:

• %VR ranging between 1,36-1,43% - MVB (or Bituminous B) to these coals

Mucanha-Vúzi:

• lower rank than Moatize, %VR that varies between 1,00-1,10%, approximate border between HVB-MVB (Bituminous B).

Mutarara:

• %VR between 1,93-3,86%, showing an anthracitic stage, some coal in LVB (many dolerite intrusions)

Metangula:

• No information available on reflectance of coals from the Basin. Reports refer to Bituminous C-D

http://portals.flexicadastre.com/mozambique/en/

Active exploration licences @20th July 2015

Exploration Focus Vale

Minas de Revuboé

Beacon Hill

Ncondezi

ETA Star

Midwest

Coal of India Limited

KingHo

Various Private Companies

Resources and Reserves Lack of reliable numbers fail to illustrate the real situation.

The Mining Directorate of Mozambique (DNM, 2012) compiled a table of coal reserves (JORC) with the information provided by the coal companies and with more recent updates:

TOTAL of 29,342 Mt, • Measured/Indicated – 11,924 Mt • Inferred – 17,248 Mt

Notes • Numbers apply to 12 licenses only from Moatize-Ncondézi-Mutarara & Sanângoè-

Mefidézi • Chicôa-Mecúcoè: CAMEC (2009) refers to 3,6 Bt of coal reserves (included in

Sanângoè-Mefidézi figures • Niassa Province, no information

Data originally presented by Lopo Vasconceles in 2014

How much “coal” is there in Mozambique?? • Possibly >30Bt of Geological Coal • Moatize (Vale) – >4Bt

• ICVL – >10Bt

• Minas de Revuboé – 1Bt

• ETA Star – 2Bt

• Jindal – 0.7Bt

• KingHo – 0.5Bt

• ENRC – 3Bt

• How much is extractable? • Yield – 30%

• Interburdens – 40-50m

• How Deep?

• At current coal prices?

• At current Infrastructure costs?

Extractable Coal

Economic Coal

Un-economic Coal

Geological Coal 30Bt

Reality Check – Cost of product

Infrastructure

Rail Opex

Rail Fees

Port Costs

Mining

Waste Mining

Coal Mining

Rail load out

Royalties

Comparable to Global Average?

Cost components in Coal Mining

Waste Mining

Coal Mining

Rail Costs

Rail Fees

Port Costs

Current Coal Price

3 year average

Coal Price

Cost Pit to Port

30Bt of Coal – 5% Economic

Zoom o right Expanded on right

Expanded on right

Zoom on ight Expanded on right

Elephants – “country” rather than “room” Significant resources – multiple Bt resources.

But – costs structures need to be addressed.

Mozambique Coal is part of the Southern African Karoo system, multiple mines tackle similar challenges – learn from them.

There is now technical expertise in coal mining in Mozambique, it should be utilised.

Going forwards – unlocking value needs:- • The right people

• The right balance of risk – smart rather than prescriptive

• The right expertise

• Honour the geology

• Understand the products and markets

What does this mean for Mozambique? Coal resource base changes on daily basis – but the geological coal does not.

Mozambique Factors • Mining Costs

• Infrastructure

Global Factors • Coal Price

The Moatize basin has the potential to produce a large percentage of the world’s Coking coal, but only if the current cost regime is reduced

and the coal price recovers.

Andy Lloyd - ICVL Mozambique - The geology of the Moatize coal basins

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