lecture 17 resources 8 Ni Laterite

Question 1

how many countries produce iron ore

Answer 1

52

Question 2

how many countries produce steel

Answer 2

73

Question 3

how much iron on average in the earths crust?

Answer 3

5% iron, the deposits we need are 25%-30%

Question 4

what is the global iron ore production?

Answer 4

2.2 billion tonnes

Question 5

what is the worldwide market for iron ore?

Answer 5

400 billion US$

Question 6

Australia and Steel

Answer 6

major producer of ore but export most to China and Japan directly for steel.

Question 7

can you find them now

Answer 7

only occur at early earth history

Question 8

tom price western Australia, iron ore (general) geology

Answer 8

chemical sediments - ancient system - iron formation on shelf rocks.
iron rich water - oxidised - shallow oxygen rich water, upwelling waters from reduced to oxidised conditions - surface is oxygen rich and iron deposits are produced.
same time move from soluble iron 2 to iron 3 crystallising phase.

Question 9

how does iron ore differ from porphyry copper for redox reactions

Answer 9

iron ore = reducing conditions to oxidising
porphyry copper = oxidising to reduced

Question 10

do you need secondary processes?

Answer 10

yes, to enhance - may end up with faulting that introduce fluids that upgrade deposits.
gain of iron, loss of silica

Question 11

when did iron formation occur

Answer 11

almost entirely in ancient rocks - little blip of glacial cycles.

Question 12

What is a Nickel-laterite deposit?

Answer 12

Nickel ores formed by intensive tropical weathering of olivine-rich ultramafic rocks such as dunite and peridotite and their serpentinized derivatives, typically contain approximately 0.3% nickel.
The initial nickel content is strongly enriched in course of laterization.

Question 13

Does laterite form now? and what is laterite

Answer 13

yes, can view tropical environments and see laterite formation taking place at the present time.
Laterite: A clay-rich horizon, rich in iron and aluminium oxides formed by weathering of ultramafic igneous rocks in warm climates.

Question 14

Key facts about Ni

Answer 14

Ni = silvery white metal, malleable and ductile.
- resists corrosion used in alloys, coins. metal plating and catalysts.
- In USA 50% of all Ni production used in the production of stainless steel.

Question 15

what are the two types of Ni deposits - and which are we focussing on?

Answer 15

Laterites and Sulphides
- focus on laterites process.

Question 16

where do laterites form?

Answer 16

22 degrees north and south of equator - there are some away from this area but these used to be in this area and have moved further due to plate tectonics.

Question 17

Laterite Vs Magmatic sulphide

Answer 17

Laterite ores at the surface - inexpensive open-pits but difficult to beneficiate
sulphide ores require more expensive underground mining - more straightforward to beneficiate through smelter processes.
Sulfide ores currently have a cost advantage -however tend to be found in developed countries and are currently under threat from HPL techniques for laterites.

Question 18

problems with mining mountain tops

Answer 18

can cause problems with rivers down stream

Question 19

New caledonian - laterite profile

Answer 19

weathering in tropical environment - nickel concentrations increase, (overburden)
limonite (low grade)
limonite (ore)
saprolite (ore)
Altered ultramafic (bed rock)

mean latterite system produces 1.3% nickel.

Question 20

what do you need to form latterites

Answer 20

lack of seasonality like in the tropics
if you were faced with a diagram, you know that there is not seasonality for laterites.

Question 21

features of typical ni-laterite profiles

Answer 21

based on dominant ore mineralogy
- hydrous silicate = highest Ni concentrations
oxide component to all Ni laterites

Question 22

what does the type of NI-laterite profile formed depend on

Answer 22

climate
topography
Prorolith - original rock composition
Structures

Question 23

What are the latterite processing techniques and which are the most current?

Answer 23

very cheap and transforming the market: Acid leaching - works best for oxide profile
Carbon process
Smelting

Question 24

Summary of Nickel ore

Answer 24

two types - magmatic sulphide = pentlandite
- laterites = limonite
- laterite formed by intensive weathering of ultramafic rocks (peridotites in tropical climate
- Ni-Laterites mined in open pits (inexpensive)
- typical laterite profile -> relative mobility of elements.