The minerals that are mostly used as ore for making iron are hematite Fe 2 O 3 and magnetite Fe 3 O 4. Iron and some alloys of iron are also magnetic.
Iron is about eight times heavier than water its relative density is 7. When iron is exposed to air it starts to turn back into iron oxide and the red powder that forms on the surface of iron is what we call rust.
You may have seen rust on old cars or old iron sheds. To make iron stronger and less likely to rust it can be combined with carbon and other elements to make steel. Steel pylon suspending overhead power lines. Iron in cast form has many specific uses e.
There are many different kinds of steel made by adding carbon along with other elements such as chromium, manganese, nickel, molybdenum to form a range of alloys with different properties e. By changing the proportions of these additional elements, it is possible to make steels suitable for a great variety of uses. The table below shows the special properties and uses of some iron compounds. Steel buildings, bridges such as the Sydney Harbour Bridge , reinforcing in concrete buildings, roofing, cladding, doors, fencing.
Animals need iron for making energy and carrying blood around the body foods rich in iron include red meat and liver, egg yolks and leafy green vegetables. Iron was the first element to be recognised as essential for people. A physician in successfully used iron to treat patients who were pale, lacking in energy and suffering from anaemia.
Iron is among the oldest metals known to humans. Paleolithic Man used finely ground haematite as body paint. Around BC, the Egyptians and Sumerians first used iron from meteorites to make beads, ornaments, weapons and tools.
The time line of Iron Age varied geographically; for instance the Hittites forged iron they heated it, then hammered it, then cooled it quickly to produce iron that was harder than the bronze that people had been using before around the period of - BC and similarly according to Tewari , archaeological evidence indicates iron working in India occurred around to BC.
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 factories and the invention of the railroad.
Geoscience Australia, Canberra. ASX Announcement 9 April Pellets are produced in a pelletising plant. ASX Announcement 20 August Annual Report. ASX Announcement 2 March Annual Report ASX Announcement 18 September ASX Announcement 14 June ASX Announcement 29 November ASX Announcement 12 October ASX Announcement 28 February Resources and Energy Quarterly, March Mineral commodity summaries Resources and Energy Quarterly, June ASX Announcement 31 July ASX Announcement 30 September ASX Announcement 15 March ASX Announcement 12 November ASX Announcement 21 January ASX Announcement 25 June ASX Announcement 8 April It measures the proportion of the sample that is magnetic and therefore the likely grade of magnetite concentrate at a given grind size.
The recovered magnetic and non-magnetic portions can be further analysed for chemical composition. ASX Announcement 25 September ASX Announcement 21 May ASX Announcement 24 April ASX Announcement 11 October ASX Announcement 16 December ASX Announcement 1 March ASX Announcement 25 February ASX Announcement 24 November ASX Announcement 28 June ASX Announcement 5 July ASX Announcement 28 May ASX Announcement.
ASX Announcement 5 August ASX Announcement 4 November Iron Ore. Year Demonstrated Resources Inferred Resources 3 Accessible EDR 4 Australian Mine Production 5 World Economic Resources 6 World Mine Production 6 Economic EDR 1 Subeconomic 2 Paramarginal Submarginal 24 43 24 83 23 42 23 81 23 40 23 82 23 38 23 85 24 36 24 87 23 34 23 86 20 33 20 83 18 29 18 81 17 23 17 89 Related Information. From this announcement OneSteel emerged as a totally independent competitive steelmaker and miner.
With OneSteel further rationalising its operations with the emergence of Arrium Mining, a dedicated exporter of iron ore, and supplier of iron ore to OneSteel's integrated steelworks at Whyalla. Arrium are the current major producers of iron ore from massive hematite deposits in the South Middleback Range. Limited outcrop and drilling has confirmed that the source of the anomalies is a magnetite-rich ironstone, commonly a BIF. These BIFs are described below in order of age.
Wilgena Hill Jaspilite, Middleback Ranges. It generally has a strong magnetic signature particularly so in Middleback Range, a discontinuous series of strike ridges of BIF extending north-south for 60 km. The source of the magnetic anomaly has been identified as magnetite-rich BIF beneath a cover of haematitic BIF averaging 90m thick. Returning to the Eyre Peninsula, there has been considerable resource drilling by several companies throughout the whole of the Eyre Peninsula on rocks of magnetite-bearing BIF.
Indeed the Eyre Peninsula region has been confirmed as a major iron ore province in South Australia. Drilling at the Warramboo prospect has identified the source as a metasedimentary magnetite-bearing gneiss of granulite facies, possibly originally a BIF.
Beneficiation testwork by a relatively simple grinding and wet magnetic separation process yielded a grade suitable for use in the production of DRI direct reduced iron feedstock. Published resource is 3. The Mount Woods Inlier contains considerable strike lengths of linear magnetic anomalies attributed to both BIF and magnetite-rich metasomatite, which interpretation has been confirmed by drilling.
There has been little exploration of these BIFs for iron ore. IMX Resources in drilled their Tomahawk prospect, and confirmed the source of the magnetic anomaly as a magnetite-bearing BIF. The Ooldea prospect lies on a magnetic anomaly associated with the Karari Fault Zone. The magnetic signature of the Karari Fault persists discontinuously for km to the northeast. Braemar ironstone facies occurs as a stratigraphic package of magnetite-rich ironstone associated with diamictite and is located in the Nackara Arc region of the Adelaide Geosyncline.
The rock has been described as 'Rapitan'-type BIF i. Its iron ore potential was assessed in the early s at the Razorback Ridge prospect. Since then several companies have entered into exploration for iron ore in the region including that part of the Braemar over the border in NSW , with most ground now held under tenure.
Unfortunately, phosphorus cannot be effectively removed from iron ores by fluxing and smelting during preparation of raw materials for the blast furnace process.
Small amounts of sulphur in iron also have significant deleterious effects on the final properties of products such as red and hot shortness.
Here, sulphur can exist as either iron sulfide FeS , which tends to promote cementite producing a harder iron, or as manganese sulfide MnS , which hardens the iron [ 18 ]. The content of S in ores can be decreased by roasting and washing during preparation of raw materials to be used in the blast furnace process.
There are minimum specifications for trace elements, including sulphur, phosphorus, and most of the transition metals. These specifications though are not usually applied to the ore only, but to the general blast furnace burden. The generalized iron ore specifications for P and S in commercial iron ores are given in Table 2.
It can be observed that the acceptable contents of phosphorus and sulphur in commercial ores should be lower than 0. Figure 3 illustrates the contents of P and S in iron ores from six of the major iron ore producing nations. It can be observed that most of the ores have S contents that are within the acceptable levels for the commercial ores.
According to the obtained results of chemical analysis, it should be pointed out that the S and P contents in iron ores from the Muko deposit are significantly lower compared to those of the other ores. This includes the high-grade iron ores from Brazil. Thus, Muko ores are within the general acceptable levels for commercial iron ores.
It can thus serve well as a raw material for iron production. According to the comparison analysis, the quality of most iron ores from Muko deposit is comparable with the best iron ores from Brazil and corresponds to the world high-grade ores which can be profitably exported. The microstructures and the distribution of the impurities within the matrix of iron ores from the six hills of Muko deposit were investigated and analysed by using light optical microscopy LOM and scanning electron microscopy SEM.
Optical examination of microstructures of iron ores show generally crystalline platy structure with fibres and granular structure. The grey hematite matrix structure contains dark inclusions which are believed to be concentrations of the impurities in the ore. Although the chemical composition of iron ores from most hills is similar, the observed microstructures of these ore samples have significant differences.
Typical micrographs of the samples and qualitative evaluation of the structure in the different Muko iron ores are given in Table 4. The various shapes of microstructure were classified into six categories.
It can be observed in Table 4 that the Type 1 microstructure is almost pure grey hematite matrix with small amounts of small size dark inclusions. Type 2 has mainly a grey crystalline platy structure with some area of fibrous texture. The dark impurity inclusions are located between crystalline plates and have a chaotic arrangement in the ore matrix.
The microstructure of Type 3 also contains the grey crystalline platy structure. However, the length of plates on average is significantly smaller in comparison with those found in the Type 2 microstructure. Moreover, the neighbouring crystalline plates have approximately the same direction in the matrix.
In this case, Type 3 looks as a very fine structure. In addition, Types 4 and 5 microstructures contain mainly the granular structure.
The dark impurity inclusions are located at the grain boundaries and within grains. It should be pointed out that the Muko iron ores contain different microstructure types in varying amounts.
The iron ores from the different hills have differing shapes of microstructure. As follows from Table 4 , the ore samples Ug3 c and Ug4 e exhibit generally the Types 1 and 2 microstructure, respectively, with a relatively low number of impurity inclusions. It is interesting to note that these samples have the highest content of total Fe The microstructure of Ug 1 sample a consists mostly of a fine structure Types 3 and 4.
The sample Ug2 b has various shapes of structures, which includes mainly the larger grains of hematite with dark inclusions Type 5 and fine crystalline platy structures Type 3. The ore samples Ug5 f and Ug6 d have a relatively large area with large irregular Type 5 and layer-shaped Type 6 dark inclusions within the structure. These samples, particularly Ug6 sample from Kashenyi hill, have the highest gangue content as observed from the chemical analysis.
The differences in the microstructure of the ore samples from the different hills of Muko deposit may be explained by the different natural conditions that prevailed during the formation of the ore [ 19 ]. To determine the composition of the main observed phases, a quantitative point analysis of the different zones in various types of microstructures was made in samples Ug2 b , Ug5 f , and Ug6 d.
The different phases that appear in these samples were identified in all the six iron ores. The location of the analysed zones and determined content of basic elements are shown in Table 5. The discovered impuritiy elements were Si, Al, and K. Although the structure of Zones 1 to 3 are different, the point analysis of these grain zones shows practically a pure Fe matrix with a very low content of Si 0.
The contents of Si and Al increase in the boundary between the matrix grains Zone 5 up to 2. Zones 4, 6, and 7 correlate with the largest dark impurity inclusions observed in Types 6 and 5 microstructures, respectively. These spots appear darker than the other phases.
Finally, it can be concluded that the results obtained from investigation of different microstructures and composition analysis of the various phases in iron ores of Muko deposit agree very well with the data of chemical compositions of these ores.
The typical results of X-ray diffraction analysis of iron ores from the different hills of Muko deposit are shown in Figure 4. According to obtained results of X-ray diffraction analysis, it can be safely suggested that all ore samples from Muko deposit were observed to be mainly of a hematitic nature.
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