鐵礦砂期貨周三 (9 日) 上漲，大連基準合約在連續 3 個交易日下跌後，強升逾 5%，因對供應的擔憂提振了原材料價格。 中國大連商品交易所交易量最大的鐵礦砂期貨，周三價格上漲 5.4%，至每噸 1191.50 元人民幣 (183.78 美元)。新加坡交易所 7 月鐵礦砂
- New Zealand
- United States
Ironsand is found many places in Europe, although it was rarely used for smelting. It is often found in association with volcanic or basaltic sands. For example, it is found in Tenerife, Spain, where the magnetite grains contain a very high amount of titanium and other impurities. The typical composition is 79.2% iron oxide, 14.6% titanium dioxide, 1.6% manganese oxide, 0.8% silica and aluminum oxide, and trace amounts of chromium. It can also be found in the River Dee, in Aberdeenshire, Scotland, containing 85.3% iron oxide, 9.5% titanium dioxide, 1.0% arsenic, and 1.5% silica and aluminum oxide.
Ironsand occurs extensively on the west coast of New Zealand's North Island. The sand makes up a large portion of the black-sand beaches on the North Island, as well as the surrounding sea floor. The magnetite in the sand contains fairly large quantities of titanium, and is sometimes referred to as titanomagnetite. It was produced from volcanic eruptions that occurred in the Pleistocene epoch, and is formed due to the oceanic erosion of the volcanic rock which is washed ashore by the waves to form the dunes of the black beaches. The magnetite is mixed with sand made from andesite and rhyolite.The sand mixture typically contains 5 to 40% magnetite. New Zealand had limited deposits of iron ore, but the deposits of ironsand were massive. It had been used by some early settlers to manufacture steel and pig iron, but the material could not be smelted in common bloomeries or blast furnaces. A few smelting companies formed in the late 19th and early 20th centuries, but were unable to proce...
Ironsand is found extensively around the US, especially in the area of New York, Southern California, New England, and the Great Lakes, where it is often mixed with a feldspar sand and sometimes bright grains of garnet. The magnetite from these areas often contains high amounts of chromium and titanium. In the 19th century ironsand was sometimes used as blotter sand for concrete and masonry work, or more rarely as raw material for steel production; one blacksmith in Connecticut used it for making bar stock.
- Mine Tailings
- Production and Consumption
- Abundance by Country
- See Also
Metallic iron is virtually unknown on the surface of the Earth except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths. Some iron meteorites are thought to have originated from accreted bodies 1,000 km in diameter or larger. The origin of iron can be ultimately traced to formation through nuclear fusion in stars and most of the iron is thought to have originated in dying stars that are large enough to collapse or explode as supernovae. Although iron is the fourth-most abundant element in the Earth's crust, composing about 5%, the vast majority is bound in silicate or more rarely carbonate minerals (for more information, see iron cycle). The thermodynamic barriers to separating 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. Prior to the industrial revolution, most iron was obtained from widely available goethit...
For every 1 ton of iron ore concentrate produced approximately 2.5–3.0 tons of iron ore tailings will be discharged. Statistics show that there are 130 million tons of iron ore discharged every year. If, for example, the mine tailings contain an average of approximately 11% iron there would be approximately 1.41 million tons of iron wasted annually. These tailings are also high in other useful metals such as copper, nickel, and cobalt, and they can be used for road-building materials like pavement and filler and building materials such as cement, low-grade glass, and wall materials.While tailings are a relatively low-grade ore, they are also inexpensive to collect as they don't have to be mined. Because of this companies such as Magnetation, Inc., have started reclamation projects where they use iron ore tailings as a source of metallic iron. The two main methods of recycling iron from iron ore tailings are magnetizing roasting and direct reduction. Magnetizing roasting uses tempera...
Lower-grade sources of iron ore generally require beneficiation, using techniques like crushing, milling, gravity or heavy media separation, screening, and silica froth flotationto improve the concentration of the ore and remove impurities. The results, high-quality fine ore powders, are known as fines.
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 per year.It is used primarily in structures, ships, automobiles, and machinery. Iron-rich rocks are common worldwide, but ore-grade commercial miningoperations are dominated by the countries listed in the table aside. The major constraint to economics for iron ore deposits is not necessarily the grade or size of the deposits, because it is not particularly hard to geologically prove enough tonnage of the rocks exist. The main constraint is the position of the iron ore relative to market, the cost of rail infrastructure to get it to market and the energy cost required to do so. 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....
Available world iron ore resources
Iron is the most abundant element on earth but not in the crust. The extent of the accessible iron ore reserves is not known, though Lester Brown of the Worldwatch Institutesuggested in 2006 that iron ore could run out within 64 years (that is, by 2070), based on 2% growth in demand per year.
Geoscience Australia calculates that the country's "economic demonstrated resources" of iron currently amount to 24 gigatonnes, or 24 billion tonnes. The current production rate from the Pilbara region of Western Australia is approximately 430 million tonnes a year and rising. Gavin Mudd (RMIT University) and Jonathon Law (CSIRO) expect it to be gone within 30–50 years and 56 years, respectively.These 2010 estimates require on-going review to take into account shifting demand...
In 2014 mines in the United States produced 57.5 million metric tons of iron ore with an estimated value of $5.1 billion. Iron mining in the United States is estimated to have accounted for 2% of the world's iron ore output. In the United States there are twelve iron ore mines with nine being open pit mines and three being reclamation operations. There were also ten pelletizing plants, nine concentration plants, two direct-reduced iron (DRI) plants and one iron nugget plant that were operatin...
Iron ores consist of oxygen and iron atoms bonded together into molecules. To convert it to metallic iron it must be smelted or sent through a direct reduction process to remove the oxygen. Oxygen-iron bonds are strong, and to remove the iron from the oxygen, a stronger elemental bond must be presented to attach to the oxygen. Carbon is used because the strength of a carbon-oxygen bond is greater than that of the iron-oxygen bond, at high temperatures. Thus, the iron ore must be powdered and mixed with coke, to be burnt in the smelting process. Carbon monoxide is the primary ingredient of chemically stripping oxygen from iron. Thus, the iron and carbon smelting must be kept at an oxygen-deficient (reducing) state to promote burning of carbon to produce CO not CO2. 1. Air blast and charcoal (coke): 2 C + O2→ 2 CO 2. Carbon monoxide (CO) is the principal reduction agent. 2.1. Stage One: 3 Fe2O3 + CO → 2 Fe3O4 + CO2 2.2. Stage Two: Fe3O4 + CO → 3 FeO + CO2 2.3. Stage Three: FeO + CO →...