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What is auto reduction? Provide a handful of examples. - Quora

Feb 08, 2018· Autoreduction or air reduction is very popular reaction in metallurgy. It is a process in which sulphide ores of less electropositive metals like Hg, Pb, Cu etc., are heated in air so as to convert part of the ore into oxide or sulphate which then...

A Study of Nickel and Iron Reduction Silicothermic Process ...

The obtained modeling results indicate the thermodynamic possibility of nickel and iron reduction from the CaO-SiO2-MgO-Al2O3-FeO-NiO-P2O5 oxide system by silicon of ferrosilicon. The degree of iron reduction increases from 88.8 to 91.4%, with an increase in the silicon concentration of ferrosilicon [Si]FeSi from 5 to 65%.

Preparation of Niobium Metal Powder by Two-Stage Magnesium ...

Magnesium vapor reduction of niobium pentoxide was studied using a laboratory system. Niobium powder was prepared by the magnesium vapor reduction at 1123 K for 5 hours and it contained about 8 mass % oxygen. However, the oxygen concentration could be decreased to 0.65% when it was prepared by double-step reduction by magnesium vapor and a chemical treatment.

Reduction of Metals (Extraction from Ore) - A-Level Chemistry

There are 3 main methods of extracting metals from their ore. They are reduction of the ore with carbon, reduction of the molten ore by electrolysis, and reduction of the ore with a more reactive metal. Extraction using carbon. Metals such as zinc, iron and copper are present in ores as their oxides. Each of these oxides is heated with carbon ...

Silicothermic process (Pidgeon process)

Ex.Lec 4 Extraction of Magnesium from ore oxide Dr. Ahmed Ameed 2 Fe 2 O 3 + 4SiO 2 + 11C 2(Fe)Si 2 + 11CO 3. Silicothermic Reduction of MgO by Ferrosilicon, at ~1400oC under Vacuum for 8-10 hrs. Highly Endothermic Reaction, the ratio of feed are 6 calcine dolomite: 1

SILICOTHERMIC REDUCTION OF DOLOMITE ORE UNDER …

dolomite ores by thermal reduction of magnesium oxide [1-3] using reactive metals (such as aluminum, silicon or their alloys) as a reductant [4-14] or from magnesium chlo-ride by an electrolytic process [15-18]. The recovery of the magnesium from dolomite ores by using silicon (silicothermic process) was investigated by many authors.

Calciothermic reaction - Wikipedia

Calciothermic reactions are metallothermic reduction reactions (more generally, thermic chemical reactions) which use calcium metal as the reducing agent at high temperature.. Calcium is one of the most potent reducing agents available, usually drawn as the strongest oxidic reductant in Ellingham diagrams, though the lanthanides best it in this respect in oxide processes.

Production of Ferroalloys - ScienceDirect

Thus, an ore rich in iron oxide will have high reducibility at relatively low temperatures. Accordingly, the reduction of chromic oxide in such ores will also occur at relatively lower temperatures with the likely formation of a carbon-rich chrome carbide (Cr 3 C 2 or Cr 7 …

Thermodynamic Simulation of the Silicothermic Reduction of ...

Abstract. The results of a thermodynamic simulation of the reduction of the elements of the oxide system corresponding to the chromium ore composition (%) 40 Cr 2 O 3, 21 FeO, 15 Al 2 O 3, 6 SiO 2, 16 MgO, 2 CaO, and 0.006 P 2 O 5 by the silicon of ferrosiliconickel (28 Fe, 65 Si, 7 Ni) are presented. The HSC Chemistry 6.12 software (Outokumpu Research Oy, Finland) is used for the simulation.

Silicothermic Process | Article about Silicothermic ...

silicothermic process[¦sil·ə·kō′thər·mik ′prä·səs] (metallurgy) Pidgeon process Silicothermic Process the production of metals and alloys by the reduction of ores or concentrates of metal oxides with silicon. The basis of the process is that the affinity of silicon for oxygen (a change in the isobaric potential of oxide formation) is ...

Production of Ferro- Manganese – IspatGuru

Jun 19, 2018· The rate of reduction of MnO to alloy is much less controlled by the Boudouard reaction since, at temperatures (greater than 1300 deg C) where most of the MnO is reduced, the reactivity of the coke, irrespective of the initial values tend to converge to broadly similar values. The reduction of the highest Mn oxide (MnO2) occurs in four steps.

Magnesium Ingot Production by silicothermic processing of ...

Magnesium ingot production by silicothermic reduction process Magnesium market Magnesium and its alloys due to their low density, higher weight to strength ratio, chemical reactivity, mechanical properties and etc. are suitable materials for automotive and aluminum alloying industries.

Kinetic Modeling of the Silicothermic Reduction of ...

A model was developed to describe the mixed rate control kinetics in systems with MnO-SiO2-CaO-Al2O3 slags and Fe-Si metal droplets. During the reaction of Fe-Si droplets and slag, Mn2+ transport was found to be part of controlling the system but could not sufficiently describe all initial conditions (chiefly, changes to initial silicon content). The current model describes the kinetics of the ...

silicothermic reduction of oxide ores - gieterijneede.nl

Silicothermic Reduction of Dolomite Ore Under Inert ... AbstractMagnesium metal was produced from dolomite ore under inert atmosphere using ferrosilicon as a reducing agent. The kinetics of the silicothermic reduction process was studied at a temperature range from 1150-1300 °C. ... silicothermic reduction of oxide ores - royalcrescentgroup.in.

Magnesium: extraction-Metalpedia

Magnesium: extraction; Brife introduction; Magnesium is found in solution in sea-water (about 1.3 kg m-3 magnesium) and in natural brines. It is also found extensively in the ores magnesite (MgCO3) and dolomite (MgCO3.CaCO3). Both of the two types of resources can be used as raw materials to manufacture magnesium metal.

Dielectric Properties of Silicothermic Reduction Chromite ...

The microwave absorption properties of chromite and the feasibility of microwave reduction chromite have been discussed. The results show that as the density increases, the dielectric properties of materials increase. The dielectric properties are the best (the value around 4.2) when the silica ratio is 0.5. Microwave penetration depth shows that chromite and the mixture have good wave ...

Thermodynamics of the Reduction Roasting of Nickeliferous ...

atmosphere at various temperatures. For the same reduction conditions, the limonitic ore exhibited a higher recovery and a lower grade of nickel in the ferronickel, than for the saprolitic ore. For the limonitic ore, decreasing the reduction potential re-sulted in an increased grade. Similarly, for the saprolitic ore, lowering the reduction

Why is the ore generally converted to an oxide and then ...

The concentrated ore must be converted into a form which is suitable for reduction. Usually the sulphide ore is converted to oxide before reduction. Oxides are easier to reduce. Thus isolation of metals from concentrated ore involves two major steps viz., (a) conversion to oxide, and (b) reduction of the oxide …

Extraction of Metals from Concentrated Ore: Reduction of ...

After concentration of ores, we must now extract metal from in it. This step will give us metal in its pure form i.e. the native form of metal. First, we must convert the ore to a suitable form. The metals need to be in an oxide form for the reduction process to be easier. Hence the ores are converted to oxides, so it is ideal for reduction.

Extracting metals - BBC Bitesize

Unreactive metals such as gold are found in the Earth's crust as uncombined elements. However, most metals are found combined with other elements to form compounds. An ore is a rock that contains ...

Kinetics and mechanism of silicothermic reduction process ...

The extent of reduction process was calculated according to the following formula: extent of reduction % = [(MgO 0 − MgO r) /MgO 0] × 100 where: MgO 0 is the initial total weight of magnesium oxide in the charge, and MgO r is the residual magnesium oxide weight unreacted in the produced slag at the end of the experiments.. To perform the reduction test, about 300 g of the start-up slag ...

Mining and Extraction: Oxide Ores - processes for ...

Most of the copper ores mined today are oxide or sulfide ores. Extraction of sulfide ores is covered in more detail in Copper Mining and Extraction: Sulfide Ores (11–14), but is introduced here because an important by-product of this process is used for the extraction of oxide ores.

Magnesium Production by the Pidgeon Process Involving ...

from quartz sand, coal, and iron oxide; (c) silicothermic reduction of calcined dolomite by ferrosilicon to magnesium. All three steps should benefit from application of concentrated solar energy as the source of high-temperature process heat, while the first two steps …

(278d) A Novel Process for Continuous Magnesium Metal ...

A novel process for continuous magnesium metal production by carbothermal reduction was designed and fabricated for testing as an efficient alternative to current silicothermic reduction methods. A complete ore-to-ingot process was demonstrated on a small pilot scale (up to 150 g/hr).

Reducing Metal Oxides - YouTube

Oct 27, 2011· Reducing Metal Oxides Jon Dicks. Loading... Unsubscribe from Jon Dicks? ... Hydrogen reduction of iron oxide - Duration: 2:00. Energy Materials 4,261 views. 2:00.

Extracting Metals by Reduction - todhigh.com

their ores: reduction with carbon ... Extraction of zinc by reduction Zinc oxide, ZnO, reacts with carbon at very high temperatures to form molten zinc and carbon monoxide. ... Extracting Metals by Reduction Author: Boardworks Ltd Subject: Boardworks GCSE Chemistry Created Date: