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Salt Extraction Process
The salt extraction process is an electrolytic method which may be used to extract valuable metals from slag, low-grade ores, or other materials by using molten salts. This method was developed by S. Seetharaman, O. Grinder, L. Teng and X. Ge at the Royal Institute of Technology in Sweden as part of a large Steel Eco-Cycle Project in 2005. Description In the first step of this process, the slag or other raw materials containing metal values of interest, e.g. chromium, is dissolved into the molten salt phase at a suitable temperature. A suitable flux must be found in order to achieve the dissolution of oxides. According to the Fajans' rules, AlCl3, as a covalent metal chloride, is able to release chloride ions, which then can effectively break the chemical bonds between metal and oxygen atoms, leading to the formation of corresponding soluble metal chlorides and capture of oxygen in Al2O3. AlCl3 was proved indeed to be a powerful fluxing agent in this regard. In the second ste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolytic
An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon dissolving, the substance separates into cations and anions, which disperse uniformly throughout the solvent. Solid-state electrolytes also exist. In medicine and sometimes in chemistry, the term electrolyte refers to the substance that is dissolved. Electrically, such a solution is neutral. If an electric potential is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons, while the anions are drawn to the electrode that has a deficit of electrons. The movement of anions and cations in opposite directions within the solution amounts to a current. Some gases, such as hydrogen chloride (HCl), under conditions of high temperature or low pressure can also function as electrolytes. El ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slag
Slag is a by-product of smelting (pyrometallurgical) ores and used metals. Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-products of recovering non-ferrous materials like copper, nickel, zinc and phosphorus). Within these general categories, slags can be further categorized by their precursor and processing conditions (e.g., Blast furnace (BF) slags, air-cooled blast furnace (ACBF) slag, basic oxygen furnace (BOF) slag, and electric arc furnace (EAF) slag) . Due to the large demand for these materials, slag production has also significantly increased throughout the years despite recycling (most notably in the iron and steelmaking industries) and upcycling efforts. The World Steel Association (WSA) estimates that 600 kg of by-products (~90 wt% is slags) are generated per tonne of steel produced. Composition Slag is usually a mixture of metal oxides and sili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-grade Ore
Grade most commonly refers to: * Grade (education), a measurement of a student's performance * Grade, the number of the year a student has reached in a given educational stage * Grade (slope), the steepness of a slope Grade or grading may also refer to: Music * Grade (music), a formally assessed level of profiency in a musical instrument * Grade (band), punk rock band * Grades (producer), British electronic dance music producer and DJ Science and technology Biology and medicine * Grading (tumors), a measure of the aggressiveness of a tumor in medicine * The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach * Evolutionary grade, a paraphyletic group of organisms Geology * Graded bedding, a description of the variation in grain size through a bed in a sedimentary rock * Metamorphic grade, an indicatation of the degree of metamorphism of rocks * Ore grade, a measure that describes the concentration of a valuable natural material in the surroundin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Institute Of Technology
The KTH Royal Institute of Technology ( sv, Kungliga Tekniska högskolan, lit=Royal Institute of Technology), abbreviated KTH, is a public research university in Stockholm, Sweden. KTH conducts research and education in engineering and technology and is Sweden's largest technical university. Currently, KTH consists of five schools with four campuses in and around Stockholm. KTH was established in 1827 as the ''Teknologiska institutet (Institute of Technology)'' and had its roots in the ''Mekaniska skolan (School of Mechanics)'' that was established in 1798 in Stockholm. But the origin of KTH dates back to the predecessor of the ''Mekaniska skolan'', the ''Laboratorium mechanicum'', which was established in 1697 by the Swedish scientist and innovator Christopher Polhem. The Laboratorium mechanicum combined education technology, a laboratory, and an exhibition space for innovations. In 1877 KTH received its current name, Kungliga Tekniska högskolan (KTH Royal Institute of Technol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, Finland to the east, and is connected to Denmark in the southwest by a bridgetunnel across the Öresund. At , Sweden is the largest Nordic country, the third-largest country in the European Union, and the fifth-largest country in Europe. The capital and largest city is Stockholm. Sweden has a total population of 10.5 million, and a low population density of , with around 87% of Swedes residing in urban areas in the central and southern half of the country. Sweden has a nature dominated by forests and a large amount of lakes, including some of the largest in Europe. Many long rivers run from the Scandes range through the landscape, primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fajans' Rules
In inorganic chemistry, Fajans' rules, formulated by Kazimierz Fajans in 1923, are used to predict whether a chemical bond will be covalent or ionic, and depend on the charge on the cation and the relative sizes of the cation and anion. They can be summarized in the following table: : Thus sodium chloride (with a low positive charge (+1), a fairly large cation (~1 Å) and relatively small anion (0.2 Å) is ionic; but aluminium iodide (AlI3) (with a high positive charge (+3) and a large anion) is covalent. Polarization will be increased by: * high charge and small size of the cation **Ionic potential Å Z+/r+ (= polarizing power) *High charge and large size of the anion **The polarizability of an anion is related to the deformability of its electron cloud (i.e. its "softness") *An incomplete valence shell electron configuration **Noble gas configuration of the cation produces better shielding and less polarizing power ***e.g. Hg2+ (r+ = 102 pm) is more polarizing than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Trichloride
Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms hexahydrate with the formula , containing six water molecules of hydration. Both are colourless crystals, but samples are often contaminated with iron(III) chloride, giving a yellow color. The anhydrous material is important commercially. It has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium metal, but large amounts are also used in other areas of the chemical industry. The compound is often cited as a Lewis acid. It is an example of an inorganic compound that reversibly changes from a polymer to a monomer at mild temperature. Structure Anhydrous adopts three structures, depending on the temperature and the state (solid, liquid, gas). Solid has a sheet-like layered structure with cubic close-packed chloride ions. In this framework, the Al centres exhibit octahedral coordination geometry. In contrast, has a more mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared light. The name of the element is derived from the Greek word χρῶμα, ''chrōma'', meaning color, because many chromium compounds are intensely colored. Industrial production of chromium proceeds from chromite ore (mostly FeCr2O4) to produce ferro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stainless Steel
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corrosion resistance, resistance to corrosion results from the chromium, which forms a Passivation (chemistry), passive film that can protect the material and self-healing material, self-heal in the presence of oxygen. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into Sheet metal, sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products. The biological cleanability of stainless steel is superior to both alumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromite
Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of FeCr2O4. It is an oxide mineral belonging to the spinel group. The element magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite (MgCr2O4). A substitution of the element aluminium can also occur, leading to hercynite (FeAl2O4). Chromite today is mined particularly to make stainless steel through the production of ferrochrome (FeCr), which is an iron-chromium alloy. Chromite grains are commonly found in large mafic igneous intrusions such as the Bushveld in South Africa and India. Chromite is iron-black in color with a metallic luster, a dark brown streak and a hardness on the Mohs scale of 5.5. Properties Chromite minerals are mainly found in mafic-ultramafic igneous intrusions and are also sometimes found in metamorphic rocks. The chromite minerals occur in layered format ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrowinning
Electrowinning, also called electroextraction, is the electrodeposition of metals from their ores that have been put in solution via a process commonly referred to as leaching. Electrorefining uses a similar process to remove impurities from a metal. Both processes use electroplating on a large scale and are important techniques for the economical and straightforward purification of non-ferrous metals. The resulting metals are said to be ''electrowon''. In electrowinning, an electrical current is passed from an inert anode (oxidation, made out of lead (Pb)) through a ''leach'' solution containing the dissolved metal ions so that the metal is recovered as it is deposited in an electroplating process onto the cathode (reduction, stainless steel, aluminium (Al), titanium (Ti)). In electrorefining, the anode consists of the impure metal (e.g., copper) to be refined. The impure metallic anode is oxidized and the metal dissolves into solution. The metal ions migrate through the acidic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
