The reduction of chromite in the presence of silica flux

1/3/2006 As mentioned earlier above, the effect of silica addition on reduction of chromite at 1300 °C was minimal at all the particle sizes and at all levels of silica addition.At higher temperatures of 1400 °C and 1500 °C, the influence of silica was strong at an optimum level of 7.5% addition.A typical plot is illustrated in Fig. 1.The results for 1400 °C and 1500 °C were very similar due to

Effect of silica on the carbothermic reduction of chromite

This was due to the diluent effect of SiO 2 on the contact between graphite and chromite. Increase in the carbon content of the charge resulted in higher critical silica contents. Two mechanisms

The reduction mechanism of chromite in the presence of a

The reduction behavior of a natural chromite from the Bushveld Complex of South Africa was studied at 1300 °C to 1500 °C. Reduction was by graphite in the presence of silica. Thermo-gravimetric analysis, X-ray diffraction (XRD) analysis, energy-dispersive X-ray analysis (EDAX), and metallographic analysis were the experimental techniques used

(PDF) Reduction mechanism of chromite spinel with carbon

According to Kadarmetov,' the silicon and carbon con-tents of the alloy depend on the quantity and quality of the lump chromite ore charged to the submerged-arc furnace and on the amount of

Chromite an overview ScienceDirect Topics

The chromite glaze problem has been assumed to be the formation of fayalite (ferrous orthosilicate Fe 2 SiO 4 with a melting point of 1205°C) as the reaction product between silica and chromite. Fayalite is not magnetic and so cannot be separated from the sand magnetically. During the re-cycling of the sand, this low melting point constituent therefore builds up, lowering the refractoriness

Smelting of high-carbon ferrochrome from chromium

28/4/2017 Smelting of high-carbon ferrochrome from chromium agglomerate produced with alumina-silica flux. A. G. Kaliakparov 1, A. V. Suslov 1, B. N. Nurmaganbetova 2, Yu. G. Yaroshenko 3, A. V. Zhdanov 3 & Zh. O. Nurmaganbetov 2 Steel in Translation volume 47, pages 65 69 (2017)Cite this article. 29 Accesses. Metrics details. Abstract. In a test melts, high-carbon ferrochrome is produced

PROCESS FOR EFFECTIVE UTILIZATION OF LOW GRADE

time, temperature, reductant and flux on the reduction process is examined primarily to establish the recoveries of the Fe, Cr and Ni metal values. 3 RESULTS AND DISCUSSION 3.1 Effect of temperature and time The dried green pellets prepared with stoichiometric carbon (18.4g) and silica (3.0g) and 4.7g CaO (lime flux) are subjected to various temperatures in the range of 1000 0C to 1400 0C for

Chromium processing Britannica

For this reason, while a ferrochromium of very low carbon content (less than 0.1 percent) can in principle be produced in a single stage of smelting, in practice not all carbon is eliminated owing to the presence of magnesia, alumina, and silica in the ore and the use of silica as a flux to lower the melting point of the slag. In practice, therefore, the primary product is usually a high

Kinetics and mechanism of smelting reduction of fluxed

18/7/2013 Experimental studies on the smelting reduction of fluxed carbon–chromite composite pellets in Fe–Cr–C–Si alloys were carried out at 1520–1600°C. The reduction reaction was found to be favoured by high temperatures, a high lime addition in the pellets, a long pellet dissolution time, and a moderate melt Cr content. For a given CaO addition, however, the reduction rate initially

Veining (metallurgy) Wikipedia

Veining can be reduced or avoided by the use of more refractory non-silica sands (zircon, chromite etc); by flux additives which lower the temperature of silica transition to tridymite or cristobalite, or which sinter the sand increasing resistance to failure; or by organic additives which are decomposed to carbon at high temperature, which then bonds to silica increasing strength, imparting

Process for effective utilization of low grade chromite

Effect of carbon (coal) additionAnthracite coal is used as carbon source for reduction process of low grade chromite overburden. The carbon content in the charge was varied from 20% less than stiochiometry (14.7g) to 20% excess (22g) in order to understand the effect of carbon addition on the total metal recoveries at 1400 0 C. The theoretical requirement of carbon for reduction of Fe, Cr and

An Improved DC-Arc Process for Chromite Smelting

were assumed to be LG6 chromite fines, duff anthracite and coal, limestone, silica, electrodes, and air. Slag, metal, gas, dust, and solids form the basis of the furnace product streams. The solid stream has been incorporated in order to provide for excess carbon fed to the unit and is assumed to leave the furnace with the slag. Slag is assumed

(PDF) COAL BASED DIRECT REDUCTION OF

Effect of coal additionAnthracite coal is used as carbon source for reduction process of pre-oxidized chromite ore. The charge composition used consists of 100g preoxidized chromite ore, 15.6g quartz, 5g lime and 1.5g bentonite as binder. The amount of quartz to be used in the reduction experiments is estimated based on the theoretical requirement of silica in order to form the alumino

WO2010103343A1 An improved process for production

A method for improved process for production of High Carbon Ferrochrome (HCFeCr) and Charge Chrome comprising: blending dried chrome concentrate and chromite fines in all possible proportions to form raw feed ore; subjecting the raw feed ore to the step of mixing hydrated lime, molasses and bentonite as the binders to the said mixture to form briquetting mixture feed; forming briquettes from

Method for producing low carbon ferrochrome from

8/10/2019 A method and system for recovering a high yield of low carbon ferrochrome from chromite and low carbon ferrochrome produced by the method. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers.

Understanding the long-term carbon-cycle: weathering of

A classic example of an ancient and long-term carbon-sink. Photo: author. The silica from the silicic acid is used similarly by organisms such as the abundant planktonic diatoms: H 4 SiO 4 = SiO 2 + 2H 2 O. silicic acid = silicon dioxide + water. Significantly, via the calcium carbonate-generating part of the chemical process, there is a net loss of readily-mobile carbon: we start with twice

Pasheema_International

Pasheema’s Chromite sand has been selected and used in foundries as a result of its unique combination of properties. View products. The unique characteristics and proven performance of our supplied Chromite sand provides a means for foundrymen to cast tough jobs and produce high quality castings, compared to silica sand View Products. Pasheema’s offered Chromite Sand has an

Ceramic Foundry Sand SuperSand Ceramsite

Refractory Engineers offers a unique Foundry Sand by the name of SuperSand. SuperSand is a ceramic sand. SuperSand is a spherically shaped bauxite sand manufactured by melting bauxite in an Electric Arc Furnace followed by a proprietary spraying process. SuperSand beaded foundry sand provides a unique combination of spherical shape grain, chemistry, and physical properties that result in