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The mineral chromite, with chemical composition FeCr 2O4 (ferrous chromic oxide), is a sub-metallic mineral belonging to the spinel group (with a generic formula of R +2 O.R +3 O 4). It is the only economic mineral mined for chromium, a steel-gray, radiant, hard metal used mainly for making stainless steel. Because of the high heat stability
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With indirect kilns, the outside of the kiln is heated instead, creating a more oven-like environment with diffused heating throughout. 4 – What fuels can rotary kilns use? Rotary kiln manufacturers have a wide variety of fuel choices, and kilns are often designed around the most optimal fuels for their desired use.
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Rotary kiln incineration is a desirable disposal option for steel-rolling oily sludge. However, ringing remains a key challenge in the highly efficient operation of rotary kilns. ... (3.1 mm) after 36 h of roasting at 1350 °C is greater than that (0.7 mm) after 12 h of roasting at 1200 °C. In the same zones of the refractory bricks, iron ...
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DOI: 10.2355/TETSUTOHAGANE1955.56.9_1157 Corpus ID: 138229300; A Study on the Reaction between Chromium Ore and Alkali during Roasting in Rotary Kiln @article{Asano1970ASO, title={A Study on the Reaction between Chromium Ore and Alkali during Roasting in Rotary Kiln}, author={Toyoshi Asano}, journal={Tetsu To …
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For the last 40 years, global economic growth has resulted in a rapid increase in the demand for a range of metals and metal oxides for high technology applications, including titanium dioxide (TiO 2) and chromium oxide (Cr 2 O 3) (Brown et al., 2015).This has led to a rise in the consumption of their mineral oxides, TiO 2 and Cr 2 O 3, derived …
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Fig. 1 provides an illustrative flowsheet of the traditional process used for producing chromic oxide (Cr 2 O 3) from chromite ore.During the initial stage, insoluble chromite ore is converted into water-soluble chromate. Roasting a mixture of chromite ore, sodium carbonate (Na 2 CO 3), limestone, and dolomite at 1100 °C for several hours …
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Compared with the traditional roasting process in a rotary kiln at 1200 °C, the oxidation and mass transfer are greatly intensified in the new process. Chemical conversion of chromium is above 99% and the recovery of chromium is raised by more than 20% while the reaction temperature is dropped by 900 °C. Thus the energy …
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Rotary kiln-electric furnace (RKEF) smelting is currently the world-wide mainstreaming process for ferronickel production from nickeliferous laterite ore, in spite of the high power consumption. In this study, aiming to provide some meaningful guidance for ferronickel production of RKEF smelting, reductive roasting followed by smelting
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However, it also had the disadvantages of high energy consumption, a low processing capacity, and inconsistent product quality (Zhu, 2008). Rotary kiln roasting was suitable for the treatment of iron ore with particle sizes of <30 mm but also had problems such as high energy consumption, a low processing capacity, the ease of "ring …
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However, pellet roasting in rotary kiln is quite different from static heat-hardening within moving grate, and the application of this model in industrial rotary kiln has not been verified. Grate model and kiln model have been intensively investigated, but the coupling of two models has been less discussed. ...
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Schematic of the iron ore heat treatment in the grate-kiln process, including the grate zones: updraft drying (UDD), downdraft drying (DDD), temperate preheat (TPH), and preheat (PH), and the kiln as well as the cooler zones: C1−C4. Figure 2. Schematic of a rotary kiln with a pellet bed and flame,showing the heat transfer mechanisms in the kiln.
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Pengfei rotary kiln uses rotary kiln as smelting equipment to sinter and roast iron, aluminum, copper, zinc, tin, nickel, tungsten, chromium, file and other metals in nonferrous metal smelting and processing industry. Recently, the application of rotary kiln in 600t / D spodumene firing line project has been realized.
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This study focused on the separation and enrichment of metals during the synergistic processing of blast furnace dust, electric arc furnace dust, and steel pickling sludge in a rotary kiln at high temperature. Research results indicate that Na 2 O, K 2 O, Rb 2 O, Cu 2 O, ZnO, CdO, PbO, Bi 2 O 3, and Sb 2 O 3 may be separated during …
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Request PDF | Recovery of chromium by calcium-roasting, sodium-roasting, acidic leaching, alkaline leaching and sub-molten technology: a review | Chromium is a major strategic mineral widely used ...
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Traditional oxidation roasting of chromite ore with sodium carbonate at temperatures in the range of 1100 °C in a rotary kiln has been replaced with a system …
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3 and chromium spinels or chromite in the roasting process was systemically investigated to reveal the effects of Na 2O·Al 2O 3 on chromium oxidation. The results of Na 2O·Al …
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The rotary kiln is a slightly inclined steel cylinder that rests on supports (bearing rollers) with an interior lining; it is equipped with a rotating motor that induces a …
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It is found that low-grade ferruginous chromite ore can be upgraded by reduction roasting, and 61.2% Cr2O3 was recovered with a chromium-to-iron ratio of 1.93 from a feed chromium-to-iron ratio of ...
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Cement kilns mainly use clinker for calcification, which can be divided into dry cement kilns and wet cement kilns. The metal chemical furnace is mainly used for the roasting and magnetization of light iron ore in the metallurgical industry and steel plants, the roasting of oxidized olive sauce, grapes, and magnesium, and the roasting and roasting of high …
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The oxidizing roasting cinder—containing 16.9% Pb, 30.5% Zn, 10.3% Fe and 25.1% S—was obtained from a Pb-Zn sulfide ore in the Hanyuan area of China by a flotation-rotary kiln oxidizing ...
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With the development of the rotary kiln -electric furnace (RKEF) process for the production of ferronickel alloy from laterite ores in China, the generation of ferronickel slag has exceeded 40 million tons in 2018 [1,2,3].However, it had a very low utilization percentage (<10%) [4, 5].Because ferronickel slag contains a relatively high amount of …
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ture range of 850–900 C in the rotary kiln for 2 h. The rotary kiln had 1.5 m diameter and 12.5 m length. The hot pre-reduced feeds were then charged into the electric furnace, and the molten ferronickel and slag were discharged through an outlet after smelting at 1550 ± 20 C for 4–6 h. The height and inner diameter of the electric furnace
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In addition, we specifically listed the application of metallurgical Rotary kiln, which is mainly used for magnetization roasting of lean iron ore in metallurgical steel plants; Chromium …
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The rotary kiln is a slightly inclined steel cylinder that rests on supports (bearing rollers) with an interior lining; it is equipped with a rotating motor that induces a turning motion. Such a gas/solid contactor was invented in the cement industry at the beginning of the 19th century. The advent of the rotary kiln is closely tied to the ...
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Cement rotary kiln is mainly used for calcining cement clinker, which can be divided into dry kiln and wet kiln. Metallurgical and chemical kilns are mainly used for magnetizing roasting of lean iron ore in iron and steel plants of metallurgical industry; oxidizing roasting of chromium and nickel iron ore; roasting of high-bauxite vanadium ore and clinker and …
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The results of this study provide an important reference for the fundamental application of rotary kilns in MoS 2 oxidation roasting by comparing the kinetics and agglomeration phenomena with those of previous studies under optimized conditions.
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A total of 20 runs of CCD experiments consist of 8 factor points, 6 pivot points and 6 center points. The responses to each of the experimental conditions concerning the dechlorination efficiency are listed in Table 3.Considering the operability of experiments, roasting experiments, the roasting temperature of run 2 and 16 was set …
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Key words: chromate; sodium aluminate; chromite; chromium spinel; oxidative roasting. 1 Introduction . Chromium salts play an important role in the national economy and are widely used in metallurgy, chemical industry, military, and machinery . [1,2] ... only 70%−85% in the rotary kiln for industrial lime-free roasting process, but Na 2O·Al ...
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ROTARY KILN CONSTRUCTION While FEECO rotary kilns are custom designed around the material to be processed, in general, there are some standard components that serve as the basic design of a rotary kiln. The diagram shown on page 8 illustrates some of the common standard components found on a basic direct-fired kiln. A diagram of an
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In Outokumpu process, the chromite ore is partly reduced in the rotary kiln during preheating, thereby reducing the amount of electric energy required for final smelting of …
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