introduction to iron ore

AW / Introduction to Iron Ore & Iron Ore Mining / 2013

Protective Coatings, Mining Concept

- An Introduction to Iron Ore & Iron Ore Mining



Overview

Introduction to Iron Ore

Top Iron Ore Producing Countries

Iron Ore Mining

Iron Ore Processing

Direct Shipping Ore

Hematite

Magnetite

Iron Ore Stockyards & Transportation

Iron Ore Export/Transportation

Supporting Infrastructure

Supporting Slides

Protective Coatings Cube systems

References



INTRODUCTION TO IRON ORE



Iron ores are rocks and minerals from which metallic iron can be economically extracted

- The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, deep purple to rusty red

The iron itself is usually found in the following forms:

- Magnetite (Fe3O4) - (72% Fe)

- Hematite (Fe 2O3)

- (70% Fe)

- Goethite (Fe 2O3s H 2O) - (63% Fe)

- Limonite (FeO(OH).n(H2O))

- a mixture of hydrated iron oxides (up to 60% Fe)

- Siderite (FeCO 3)

Hematite and Magnetite are the most common types of iron ores extracted by mining companies, the latter being a variant of another iron deposit called Taconite

- (Taconite = BIFs (Banded Iron Formations))

What is Iron Ore?



What is Iron Ore?

Iron (Fe) is one of the most abundant rock -forming elements, constituting about 5% of the Earth's crust

It is the fourth most abundant element after oxygen, silicon and aluminium

And after aluminium, the most abundant and widely distributed metal

Iron is indispensable to modern civilization and people have been skilled in its use for more than 3000 years

However, its use only became widespread in the 14th century, when smelting furnaces (the forerunner of blast furnaces) began to replace forges

About 98% of world iron ore production is used to make iron in the form of steel



Banded Iron Formations

Most of the world's important iron ore resources occur in iron - rich sedimentary rocks known as Banded Iron Formations (BIFs)

BIFs are almost exclusively of Precambrian age (i.e. greater than 600 million years old)

BIFs occur on all continents

In many instances they are mined as iron ores, but most importantly they are the source rocks for most of the large high -grade concentrations of iron ore currently mined throughout the world

Example of BIFs



Iron ore mining



What is Iron Ore?

Hematite and Magnetite deposits are most commonly found in banded iron formations (BIFs)

BIFs are a class of sedimentary rocks that can be dated as far back as the Proterozoic Econ (2500 -500 mill yrs ago) , and are found ww. These ore deposits consist of several layers alternating between hematite, magnetite, and many other mineral quartzes such as chert and silica The amount of iron found in BIFs typically varies from 20% to 35%, but percentages of more 55% do occur less frequently

quantities of iron (usually Hematite) Means they can be fed directly into iron making blast furnaces Most reserves already depleted Magnetite and taconite ores experience a longer, more effortful separation process

Iron ore is the raw material used to make pig iron, which is one of the main raw materials to make steel

98% of the mined iron ore is used to make steel



Magnetite I

Magnetite is an iron oxide mineral generally black in colour and highly magnetic, the latter property aiding which helps in the beneficiation of magnetite ores

Magnetite mineral contains 72.4% iron, which is higher than hematite but the presence of impurities results in lower ore grade, making it more costly to produce the concentrates used in steel smelters

Magnetite mining is an emerging industry in Australia with large deposits in the Pilbara region of WA being developed

Like hematite ores, magnetite ores require initial crushing and screening, but undergo a second stage of processing that relies on the magnetic properties of the ore and involves magnetic separators to extract the magnetite and produce a concentrate.

Magnetite is increasing its presence in world production



Magnetite II The key economic parameters for magnetite ore being economic are the crystallinity of the magnetite;

the grade of the iron within the banded iron formation host rock and the contaminant elements which exist within the magnetite concentrate

The size and strip ratio of most magnetite resources is irrelevant

A BIF can be hundreds of meters thick, extend hundreds of kilometers along strike, and can easily come to more than three billion or more tonnes of contained ore

The typical grade of iron at which a magnetite -bearing banded iron formation becomes economic is roughly 25% iron

This can generally yield a 33% to 40% recovery of magnetite by weight, to produce a concentrate grading in excess of 64% iron by weight

The typical magnetite iron ore concentrate has less than 0.1% phosphorus, 3 7% silica and less than 3% aluminium



Magnetite



Hematite

Hematite iron ore deposits are currently exploited on all continents except Antarctica, with the largest intensity in South America, Australia and Asia

Hematite is an iron oxide mineral

It is non -magnetic and has colour variations ranging from steel silver to reddish brown. Pure hematite mineral contains 69.9% iron

-

Been the dominant IO mined in Australia since the early 1960s and approximately 96% of Australia's iron ore exports are high grade hematite

High grade hematite ore is referred to as direct shipping ore (DSO) because it is mined and the ores go through a relatively simple crushing and screening process before being exported for use in steel making. Australia's hematite DSO from the Hamersley region in WA averages from 56% to 62% iron

Hematite ores dominate the world production of iron ores and are sourced mainly in Australia and Brazil



Hematite



DSO - Direct Shipping Ore DSO deposits (typically composed of hematite) are currently exploited on all continents except Antarctica

Largest intensity in South America, Australia and Asia

The predominant minerals in DSO are usually the ferric iron oxides hematite (Fe 2O3), goethite (FeO(OH) and/or limonite (FeO(OH).nH 2O)

Most large hematite iron ore deposits are sourced from altered banded iron formations and rarely igneous accumulations

DSO deposits are typically rarer than the magnetite -bearing BIF or other rocks which form its main source or protolith rock, but are considerably cheaper to mine and process as they require less beneficiation due to the higher iron content

DSO ores can however contain significantly higher concentrations of penalty elements, typically being higher in phosphorus, water content (especially pisolite sedimentary accumulations) and aluminum (clays within pisolites)

Export grade DSO ores are generally in the 62 64% Fe range



Iron Properties

Iron is unusual in being magnetic (magnetite)

if you dangle a piece it will turn to face north -south

Iron is a silver -grey metal which quickly corrodes or rusts (it forms a red powder called iron oxide) when exposed to air and water.

Iron is quite soft and easily worked, but when made into steel iron is very strong

Iron has a very high melting point of 1535oC



Iron Ore Facts

iron ore

Most IO mines are open cut -

Iron is the world's most commonly used metal

Steel, of which iron ore is the key ingredient, representing almost 95% of all metal used each year

Other applications of iron include: Production of magnets

Catalytic functions

Medicinal purposes

Pigmentation of inks, dyes, paints, make -up



Usage of Iron Ore I

From ore to produce: 1. Iron ore is extracted from surface rock, crushed and sorted

2. Transported to customers (smelters), usually by ship

3. Iron ore is smelted in by the customers in blast furnaces, by feeding the furnace ore and coke and very hot air is blasted in

4. The chemical reactions that take place form a mixture of molten iron and slag

5. The dense iron sinks to the bottom of the furnace and is tapped of once

6. Pig iron is used to produce steel or is further refined to produce commercially pure iron



Usage of Iron Ore II Cast iron:

Partly refined iron containing up to 5% carbon

Is very hard, but brittle, and is ideal for molded parts like car engine blocks

Wrought iron

Nearly pure iron mixed with a glass - like material

Is softer than cast iron and does not rust

Used in outdoor furniture, railings and other decorations

Steel

The most common form of iron

Contains around 1% carbon

Stainless steel

Contains chromium, making it very rust restistent

Is ideal for vehicle parts, hospital equipment and cooking utensils

Tool steel

Extremely hard, heat treated steel that is used in metalworking tools



The earth's magnetic field is due to the iron (and nickel) in its core, so when we use a compass we are making use of the iron underneath us

Iron is amongst the oldest metals known to humans. Paleolithic Man used finely ground haematite as rouge! Around 4000 BC, the Egyptians and Sumerians first used iron from meteorites to make beads, ornaments, weapons and tools

The Iron Age was from 1300 - 1100 BC, when the Hittites were the first to forge iron (they heated it, then hammered it, then cooled it quickly to produce iron that was harder than bronze, which people had been using before)

By the time of the Roman Empire, iron was being used for beds, gates, chariots, nails, saws, axes, spears, fishhooks and tools for sharpening



During the Middle Ages, with the introduction of the iron cannon and cannon ball, the consumption of iron increased to overtake copper and bronze as the most widely used metal

In the late 19th century the Age of Steel began, with wooden ships giving way to steel, machinery coming to the factories, and the invention of the railroad

Today we use 20 times more iron (in the form of steel) than all other metals put together

Steel is one of the world's most recycled products, with about 60% of steel available for recycling going back into making new steel



TOP IRON ORE PRODUCING COUNTRIES

Thabazimbi iron ore mine, South Africa



Top IO Producers in the World

the world's sea -borne iron ore exports of about 1 billion tons a year

- rd place

Top 10 IO producing countries:

1. China

2. Australia

3. Brazil

4. India

5. Russia

6. Ukraine

7. South Africa

8. USA

9. Canada

10. Iran



Production & Reserves by Country

Note: The mine production estimate for China is based on crude ore, rather than usable ore, which is reported for the other countries



Top IO Producers by Company

Mining iron ore is a high volume low margin business, as the value of iron is significantly lower than base metals

It is highly capital intensive, and requires significant investment in infrastructure such as rail in order to transport the ore from the mine to a freight ship

For these reasons, iron ore production is concentrated in the hands of a few major players



Iron Ore in China

2011 figures: 43% or 1200Mt

trade

Used for domestic demand and overseas fabrication work

Chinese demand for iron ore whether imported or domestically produced is the key determinant of the outlook for the global iron ore market in the short run



Iron Ore in Australia

Australia has some of the largest iron ore deposits of their type and has a

iron ore

WA accounted for 97% of the nations total production and total exports in 2011 and about 25% of the global production

Markets: Asia, especially China, Japan & South Korea

28 billion tonnes with Western Australia accounting for about 98 per cent.

Dominated by 3 main players:

BHP Billiton

7 mines, 1 port and rail network

Rio Tinto

13 mines, 3 shipping terminals at 2 ports and almost 1400km

of rail network

Fortescue Metal Group (FMG)

3 mines, 1 port and rail network



Iron Ore in Brazil

Main areas for iron ore mining is found in the states of

Para: Carajs area (Serra Norte, Serra Sul, Serra Leste & Serra So Flix)

frequently exceeds 60%

Other important reserves:

Corumb in the state of Mato Grosso do Sul

Rio do Peixe Bravo, Guanhes & Morro do Pilar in the state of Minas Gerais

IO production dominated by Vale

-born iron ore market



Iron Ore Demand & Supply 2010 -2018



Iron Ore in India

The total recoverable reserves of iron ore in India are about

9,602 million tones of hematite

3,408 million tones of magnetite

Principal states producing IO:

Chhattisgarh, Madhya Pradesh, Karnataka, Jharkhand, Odisha, Goa, Maharashtra, Andhra Pradesh, Kerala, Rajasthan & Tamil Nadu

years:

2007: 21%

2011. 11%

2012: ca. 5%

Export bans (due to environmental issues like illegal logging)

Estimated that India will end 2013 as a net importer of IO

The largest steel producers, TATA Steel & Steel Authority of India Ltd (SAIL), have their own IO mines



Iron Ore in Russia Russia is one of the few countries with a developed ferrous metallurgy that can completely cover its domestic requirements for iron ore from its own resources

This is due to the presence of significant reserves of iron ore in the country, amounting to approximately 55Gt (55,000Mt) in 2011

However, in contrast to Australia and Brazil, the average iron content in the

iron ores are insignificant

Also extremely uneven distribution of iron -ore reserves within the country

IO deposits are located in the Urals and Siberia regions with the Kursk Magnetic Anomaly (KMA) being Russia 's major iron ore mining region

Production of crude iron ore in the country :

Central Federal District (CFD) accounts for 44 -47%

Northwest Federal District (NWFD) is responsible for 21 -23%

Urals Federal District (UFD) for 22 -23%

Most of Russia 's iron ore mining companies form part of large steel enterprises that are vertically integrated



The top consumer of all countries is China

Being the largest importer and largest producer of IO in the world

China imported 687 Mt of iron ore in 2011, accounting for 61% of global imports

ore, with 296 Mt or 43% of its iron ore imports coming from Australia

Australia is also the dominant supplier to Japan and South Korea, supplying 62% and

respectively

Brazil supplies around a quarter of total iron ore imports to China, Japan and South Korea



Historically IO prices have been decided in closed -door negotiations between the small number of miners and steelmakers dominating both spot and contract markets

Traditionally, the first deal reached between these two groups sets a benchmark to be followed by the rest of the industry

market -based pricing

Index -Vale, Rio Tinto and BHP Billiton



Iron Ore Market: 2011 -2013 trends

Declining demand in China led to drops in spot prices for iron ore, and the delay, cancellation, or reorganization of major production improvement projects worldwide

Global prices declined steadily since 2011, and in September 2012, they reached the lowest benchmark prices since 2009 at US $86

Mixed expectations to IO prices:

Different scenarios: high vs low prices

Highly dependent on the Chinese economy Poor growth figures for China = lower IO price

Source: SEB Commodities Monthly 26 th of March 2013



Volatile market

- Price fluctuations

2007: less than $40/t

2012, Sept: $86/t

2013, March: $145/t

Forecasts for 2013 averages are:

US$127/t and US$121/t



IRON ORE MINING Surface & Underground Mining



Introduction to IO Mining & Processing

Iron ore can, compared to some of the

other substances being mined like gold

and nickel, be relatively simple to

process

Iron ore is extracted, sorted, blended

and washed before being transported to

customers (Direct Shipping Ore), but if

the grade of ore being mined is of

poorer quality it experience a longer,

more effortful beneficiation process



Iron Ore Mining

Iron is mined almost exclusively in surface operations

The most predominant surface mining methods used to extract iron ore are open -pit and open -cut methods

Underground IO mining does also exist

Largest underground IO mine is Kiruna mine in Sweden w/ 26mill mtpa (pictured below)



What to Consider Before Excavation Starts?

What is the quality of the ore?

Overburden and stripping ratios are important in determining whether a deposit will be mined

The stripping ratio describes the unit of overburden that must be removed for each unit of crude ore mined

Stripping ratios increase with the quality of the ore being mined and cost factors related to beneficiation and transportation



Extraction Methods

The decision to employ underground or surface mining techniques is dependent on the proximity of the ore body to the surface

Historically, underground mining methods, including caving and stopping, were commonly used to extract iron ores

Underground methods are very expensive compared to open -pit and open -cut methods

volumes required to make the development economically viable

Open -pit and open -cut mining are considered to be the least expensive extraction techniques



IO Surface Mining

Surface mining methods are designed to extract ore from surface deposits

Overburden, the soil and rock material that overlies the mine area, is removed to expose the ore deposit

The ore bench is drilled, blasted, and hauled to a plant for beneficiation

Overburden may be continually removed during the life of the mine as the highwall is cut back to permit deepening of the pit



Overview of Iron Ore Mining



Stage 1 : Exploration, Evaluation & Planning

Ore bodies are identified and quantified by using a range of geological, geophysical and metallurgical techniques

Example being drilling for samples

The data from the exploration activities are logged, mapped, analyzed and interpreted through models

A detailed plan of which ore bodies to mine in what sequence, to deliver the required product quality at an appropriate cost, is developed

The process of mine planning commence many years before a mine is developed and continues on a day - to -day basis once the mine is operational



Stage 2 : Clearing of Overburden, Drilling & Blasting

1. Areas for open -pit mining are selected using the mine plan

2. Overburden removed to expose the ore deposit

- Overburden is then loaded by large hydraulic shovels into production trucks, which haul it to contour dumps

3. Identified areas are tagged

4. Holes are drilled in an appropriate pattern by rigs

5. Drill holes are fitted with an explosive and charged

Most used explosive is ANFO (Ammonium Nitrate/Fuel Oil)

6. The resulting blast breaks the material to a size required for digging



Tagged and drilled holes



Video: http://www.minesurveyor.net/ssblast.php
http://www.minesurveyor.net/ssblast.php



Stage 3 : Loading & Hauling

The broken material is loaded for transport by face shovels, excavators or front -end loaders into haul trucks

Haul truck will then bring the ore material to the processing plant

Though haul trucks are commonly used, overland conveyors are sometimes used to transport partially crushed feed at sites where there are long distances between the pits and process plants



Equipment Used for Surface Mining of IO

Drilling Rigs




Loaders: Front - end Loaders




Face Shovels / Excavators




Dump/Haul Trucks



IRON ORE PROCESSING



Iron Ore Processing: Intro

Although iron is the fourth most abundant element in the Earth's crust, comprising about 5%, the vast majority is bound in silicate or more rarely carbonate minerals

The amount of forces it takes to separate pure iron from these minerals are formidable and energy intensive, therefore all sources of iron used by human industry exploit comparatively rarer iron oxide minerals, primarily hematite and magnetite

Historically, much of the iron ore utilized by industrialized societies has been mined from predominantly hematite deposits with grades in excess of 70% Fe

Increasing iron ore demand, coupled with the depletion of high -grade hematite ores WW and led to development of lower -grade iron ore sources, principally the utilization of magnetite and taconite(BIFs)



Iron Ore Processing II

Historically, most iron ore was simply crushed and shipped directly to a blast furnace

Currently, some ores are high enough in iron content (greater than 50 percent) to be sent directly to furnaces without beneficiation activities other than crushing and washing

Most ores extracted today, however, must undergo a number of beneficiation procedures to upgrade the iron content and prepare the concentrate for the blast furnace



Iron Ore Processing II

Very low grade Iron ore cannot be used in metallurgical plants and needs to be upgraded to increase the iron content and reduce the gangue content

Gangue is the unwanted minerals which are an intrinsic part of the ore rock itself

A process adopted to upgrade ore is called Beneficiation;

Iron ore is upgraded to a higher iron content through a variety of processes whereby extracted ore from mining is separated into mineral and gangue, the former suitable for further processing or direct use

Iron ore is being beneficiated all round the world to meet the quality requirement of Iron and Steel industries. However, each source of Iron ore has its own peculiar mineralogical characteristics and requires the specific beneficiation and metallurgical treatment to get the best product out of it

Choice of the beneficiation treatment depends on the nature of the gangue present and its association with the ore structure

Several techniques such as washing, jigging, magnetic separation, advanced gravity separation and flotation are being used to enhance the quality of the Iron ore



Iron Ore Processing III

Processing of IO ranges from simple crushing and screening to a standard size, through to processes that beneficiate or upgrade the quality of the iron ore products

The process the ore goes through depends on the grade of ore being mined!

Beneficiation or upgrade is done by physical processes, which remove impurities by differences in particle density or size gravity or size separation

The processing may be wet or dry



Iron Ore Processing IV

The required Size for Pellet Plant feed differs from the different types of iron ore:

DSO: 6mm

Hematite:



Beneficiation

mining is reduced to particles that can be separated into mineral and waste, the

Beneficiation means the following as applied to iron ore: milling (crushing and grinding); washing; filtration; sorting; sizing; gravity concentration; magnetic separation; flotation; and agglomeration (pelletizing, sintering, briquetting, or nodulizing)

Milling and magnetic separation are the most common methods used

Flotation is primarily used to upgrade concentrates from magnetic separation by reducing the silica content of the concentrate

Most beneficiation operations will result in the production of three materials:

a concentrate

a middling or very low -grade concentrate, which is either reprocessed (in modern plants) or stockpiled

a tailing (waste), which is discarded in tailings dams



General Processing of Iron Ore

First step in iron ore processing is always liberation with the goal of to free iron -bearing particles

This process consists mostly of crushing and grinding

The ore must be ground to a particle size sufficiently close to the grain size of the iron -bearing mineral to allow for a high degree of mineral liberation

ref. required size for pellent plant feed for the different types of ore

Prior to grinding, the ore is crushed in up to six stages, depending on the hardness of the ore

One or two stages of crushing might be done at the mine before being shipped to the processing facility(primary & secondary crushing)



General Processing 1: Crushing Initial/Primary crushing

The crusher systems used are usually gyratory or jaw crushers

Cone crushers and High Pressure Grinding Roll are usually used for secondary and tertiary fine crushing

After going through the primary crushing the ore is stored in a crushed ore stockpile (COS)

In certain processed we also find Secondary and even Tertiary crushing happening after the initial crushing

Often making use of cone crushers or jaw crushers

The crushers are usually feed using vibrating feeders



Crushers

Gyratory Crusher



Crushers II

Primary crushing plant with gyratory crusher for iron ore and overburden

The crusher is directly fed from two sides by means of dump/haul trucks



From Sino Iron project, WA, Australia



Crushers III

Jaw Crushers

Primary crushing machine used for coarse crushing plant in mine ore mining process

Cone Crusher

Mainly used in secondary or tertiary stone crushing process



High Pressure Grinding Roll

Consists out of two rollers with the same dimensions, which are rotating against each other with the same circumferential speed

The special feeding of bulk material through a hopper leads to a material bed between the two rollers

The bearing units of one roller can move linearly and are pressed against the material bed by springs or hydraulic cylinders

The pressures in the material bed are greater than 50 Mpa

In general they achieve 100 to 300 MPa.

By this the material bed is compacted to a solid volume portion of more than 80%



Feeders

Feeders are in charge of feeding material to the different units in the processing of iron ore:

Crushers

Screens

Different forms of feeders dependent on the need of the process/material

Vibrating feeder

Apron feeder



General Processing 2: Screening

Main purpose of using screens is to remove undersize material from the feed to the next crusher and allow for a closed -circuit operation of the fine crushers

As a result screening is carried out at various stages in the crushing process

Screens are basically box frames into which sheets of screen meshes of the required apertures are inserted, clamped and tensioned

Screens are usually "multi -deck", i.e. two or more screen meshes are stacked vertically within the screen frame

The whole screen is coupled to its support frame by springs or resilient rubber mountings and are made to vibrate by a rotating transverse shaft. The shaft is machined to be unbalanced, and when driven by an electric motor by v -belts, the required vibratory motion to agitate the aggregate is imparted.



Vibrating screens Linear vibrating screen

Screening in operation



General Processing 3: Further Crushing/Grinding/Milling

After crushing and screening the material is further reduced by wet grinding in rod mills or ball/pebble mills

The rod and ball mills are in closed -circuit with classification systems such as cyclones

An alternative to crushing (after primary crushing) is to feed some coarse ore directly to a wet or dry semi -autogenous or autogenous grinding mills

Followed by pebble/ball mills, rod mills or tower mills

The liberated particles should be removed from the grinding circuits as soon as they are formed/freed, with larger particles returned for further grinding/milling

It should be noted that the grinding/milling solutions available are numerous, dependent on what is most economical and beneficial for the ore being processed



Autogenous Grinding/Semi -Autogenous Grinding Mills

Autogenous Grinding (AG) are so -called due to the self -grinding of the ore:

a rotating drum throws larger rocks of ore in a cascading motion which causes impact breakage of larger rocks and compressive grinding of finer particles

Semi -autogenous grinding mills (SAG) are essentially autogenous mills, but utilize grinding balls to aid in grinding like in a ball mill

A SAG or AG mill is generally used as a primary or first stage grinding solution

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