scholarly journals Influence of Different Carbon Content on Reduction of Zinc Oxide via Metal Bath

2022 ◽  
Vol 12 (2) ◽  
pp. 664
Author(s):  
Michael Auer ◽  
Christoph Wölfler ◽  
Jürgen Antrekowitsch
Keyword(s):  
Zinc Oxide ◽  
Carbon Content ◽  
Reduction Rate ◽  
Iron Alloy ◽  
Reaction Rates ◽  
Processing Temperature ◽  
Metal Bath ◽  
Waelz Process ◽  
Metal Recycling ◽  
Iron Bath

Electric arc furnace dust (EAFD) is an important secondary resource for the zinc industry. The most common process for its recycling is the pyro-metallurgical treatment in the Waelz process. However, this process focuses on the recycling of the zinc, whereas the recovery of other metals from the EAFD—such as iron and other alloying elements—is neglected. An up-to-date version of reprocessing can involve multi-metal recycling by means of a metal bath containing carbon. The use of a liquid iron alloy requires a higher processing temperature, which enables the reduction and melting of iron oxides as well as other compounds occurring in the dust. Furthermore, the Zn yield is higher and the reduction kinetics are faster than in the Waelz process. This paper is only focused on the zinc reduction in such a metal bath. In order to determine the influence of the carbon content in the molten metal on the reduction rate, experiments were carried out on the reduction behavior of zinc oxide using a synthetic slag. This slag, with a basicity B2 = 1, was applied to an iron bath with varying carbon contents. (0.85%, 2.16%, 2.89%, and 4.15%) The decrease in the zinc oxide concentration was monitored, along with the reaction rates calculated from these data. It was found that the reaction rate increases with rising carbon content in the melt.

scholarly journals Carbothermic Reduction of Zinc Containing Industrial Wastes: A Kinetic Model

2021 ◽  
Author(s):  
M. Leuchtenmueller ◽  
C. Legerer ◽  
U. Brandner ◽  
J. Antrekowitsch
Keyword(s):  
Mass Transfer ◽  
Zinc Oxide ◽  
Kinetic Model ◽  
Large Scale ◽  
Industrial Wastes ◽  
Oxide Reduction ◽  
Transfer Coefficients ◽  
Metallothermic Reduction ◽  
Metal Bath ◽  
Zinc Recovery

AbstractEffective recycling of zinc-containing industrial wastes, most importantly electric arc furnace dust, is of tremendous importance for the circular economy of the steel and zinc industry. Herein, we propose a comprehensive kinetic model of the combined carbothermic and metallothermic reduction of zinc oxide in a metal bath process. Pyro-metallurgical, large-scale lab experiments of a carbon-saturated iron melt as reduction agent for a molten zinc oxide slag were performed to determine reaction constants and accurately predict mass transfer coefficients of the proposed kinetic model. An experimentally determined kinetic model demonstrates that various reactions run simultaneously during the reduction of zinc oxide and iron oxide. For the investigated slag composition, the temperature-dependent contribution of the metallothermic zinc oxide reduction was between 25 and 50 pct of the overall reaction mechanism. The mass transfer coefficient of the zinc oxide reduction quadrupled from 1400 °C to 1500 °C. The zinc recovery rate was > 99.9 pct in all experiments.

Photocatalytic Treatment of Wastewater From 5–Fluorouracil Manufacturing

1996 ◽  
Vol 118 (1) ◽  
pp. 2-8 ◽  
Author(s):  
M. Anheden ◽  
D. Y. Goswami ◽  
G. Svedberg
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Substantial Reduction ◽  
Reduction Rate ◽  
Reaction Rates ◽  
Batch Experiments ◽  
Cod Reduction ◽  
Potential Use ◽  
Percent Decrease

This paper presents some of the experimental results from a study conducted to demonstrate the potential use of photocatalytic oxidation for decolorization and COD reduction of wastewater from 5–fluorouracil manufacturing. A series of batch experiments, were carried out using diluted solutions of the wastewater with 0.1 percent w/v TiO2. Low pressure mercury lamps were used to simulate the UV part of sunlight. The experiments showed that a complete decolorization and a substantial reduction of COD was achieved within 20 hours with a 20 percent solution. During the reaction period, the pH was noted to decrease considerably, indicating formation of acids. Adding hydrogen peroxide to the solution was found to significantly increase the reaction rates. Adding 2400 ppm of H2O2 gave an 80 percent decrease in color in one hour and a 70-80 percent decrease in COD in 20 hours. The influence of UV-light intensity was also examined. This experiment showed that with a UV-intensity of 15 W/m2, i.e., a cloudy day, the decolorization rate was still considerable, while the COD reduction rate was very low.

Flexible Electronics Based on InGaZnO Transparent Thin Film Transistors

2012 ◽  
Vol 521 ◽  
pp. 141-151
Author(s):  
Stephen J. Pearton ◽  
Wan Tae Lim ◽  
Erica Douglas ◽  
Hyun Cho ◽  
F. Ren
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Flexible Electronics ◽  
Thin Film Transistors ◽  
Light Emitting Diode ◽  
Light Sensitivity ◽  
Processing Temperature ◽  
Wearable Electronics ◽  
Glass Substrates ◽  
Indium Gallium

There is increasing interest in use of conducting oxide materials in new forms of transparent, flexible or wearable electronics on cheap substrates, including paper. While Si-based thin film transistors (TFTs) are widely used in displays, there are some drawbacks such as light sensitivity and light degradation and low field effect mobility (<1 cm2/Vs). For example, virtually all liquid crystal displays (LCDs) use TFTs imbedded in the panel itself. One of the promising alternatives to use of Si TFTs involves amorphous or nanocrystalline n-type oxide semiconductors. There have been promising results with zinc oxide, indium gallium oxide and zinc tin oxide channels. In this paper, recent progress in these new materials for TFTs on substrates such as paper is reviewed. In addition, InGaZnO transistor arrays show promise for driving laminar electroluminescent, organic light-emitting diode (OLED) and LCD displays. These transistors may potentially operate at up to an order of magnitude faster than Si TFTs. We have fabricated bottomgate amorphous (α-) indium-gallium-zinc-oxide (InGaZnO4) thin film transistors (TFTs) on both paper and glass substrates at low processing temperature (≤100°C). As a water and solvent barrier layer, cyclotene (BCB 3022-35 from Dow Chemical) was spin-coated on the entire paper substrate. TFTs on the paper substrates exhibited saturation mobility (μsat) of 1.2 cm2.V-1.s-1, threshold voltage (VTH) of 1.9V, subthreshold gate-voltage swing (S) of 0.65V.decade-1, and drain current onto- off ratio (ION/IOFFSubscript text) of ~104. These values were only slightly inferior to those obtained from devices on glass substrates (μsat~2.1 cm2.V-1.s-1, VTH ~0 V, S~0.74 V.decade-1, and ION/IOFF=105- 106). The uneven surface of the paper sheet led to relatively poor contact resistance between source-drain electrodes and channel layer. Future areas for development are identified.

VDM 601

Alloy Digest ◽  
2021 ◽  
Vol 70 (4) ◽  
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Carbon Content ◽  
Tensile Properties ◽  
Iron Alloy ◽  
Heat Treating ◽  
Coarse Grain ◽  
Nickel Chromium ◽  
Rupture Properties

Abstract VDM 601 (Nicrofer 6023 H) is a nickel-chromium-iron alloy with additions of aluminum and titanium. This alloy is specifically recommended for service above 550 °C (1020 °F) because of its superior creep-rupture properties resulting from its controlled carbon content and coarse grain size. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: Ni-769. Producer or source: VDM Metals GmbH.

Numerical Simulation for Direct Reduction of Pure Zinc Oxide Pellet Containing Carbon

2011 ◽  
Vol 194-196 ◽  
pp. 56-60
Author(s):  
Xiu Wei An ◽  
Jing Song Wang ◽  
Xue Feng She ◽  
Yin Gui Ding ◽  
Qing Guo Xue
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Zinc Oxide ◽  
Direct Reduction ◽  
Mass Conservation ◽  
Reaction Rates ◽  
Furnace Temperature ◽  
Pure Zinc ◽  
Rate Determining Step ◽  
Chemical Reaction Rates

Based on the equations of mass conservation, energy conservation and chemical reaction rates, a mathematical model of direct reduction for pure zinc oxide pellet containing carbon was built. On the basis of verifying the accuracy of the model by comparing calculated values with experimental results, the effects of furnace temperature, porosity and radius of pellet on the reduction were investigated. The calculated results revealed that the furnace temperature and the radius of pellet have significant effect while porosity has only a little. Thus it can be inferred that the rate-determining step for direct reduction in the pellet containing zinc oxide and carbon is heat transfer.

The Theoretical and Experimental Study on Making Low Iron Alloy from the Mixed Slag of Jinchuan Flash Smelting Furnace and JISCO Converter

2013 ◽  
Vol 803 ◽  
pp. 239-242
Author(s):  
Shuang Ping Yang ◽  
Jie Liu ◽  
Jian Wang ◽  
Xin Du
Keyword(s):  
Iron Reduction ◽  
Converter Slag ◽  
Reduction Rate ◽  
Iron Alloy ◽  
Equilibrium Concentration ◽  
Flash Smelting ◽  
Smelting Reduction ◽  
Comprehensive Utilization ◽  
Nickel Cobalt ◽  
Alloy Iron

Jinchuan nickel-copper flash smelting slag is rich in iron, nickel, cobalt and copper, and JISCO converter slag is rich in iron, manganese and high CaO, etc., the two kind slags were blended, and then smelted into low-alloy iron containing nickel, cobalt, copper and manganese with smelting reduction method, which is a new comprehensive utilization methods for the Double slag. The thermodynamic calculation results of the equilibrium concentration of Fe, Cu and Ni in low-alloy iron obtained by smelting reduction under experimental condition are in good agreement with experimental results. Iron reduction rate of Fe, Cu and Ni can be elevated to above 90% by smelting reduction, thus the comprehensive utilization of valuable metals can come true.

scholarly journals Modeling the Evolution of Trap States with Thermal Post-deposition Treatments in Sol-gel Indium Zinc Oxide TFTs

2021 ◽  
Author(s):  
Neel Chatterjee ◽  
Adam M Weidling ◽  
P. Paul Ruden ◽  
Sarah Swisher
Keyword(s):  
Zinc Oxide ◽  
Sol Gel ◽  
Amorphous State ◽  
Localized States ◽  
Oxide Thin Film ◽  
Processing Temperature ◽  
Wearable Electronics ◽  
Indium Zinc Oxide ◽  
Post Deposition ◽  
Oxide Tfts

<div>Metal oxides have been investigated for use in displays and wearable electronics, owing to their high mobility in the amorphous state. In solution-processed oxide thin-film transistors, post-deposition thermal processing significantly change the film’s transport properties, and is essential for high-performance devices. The mobility, bias stability and trapping-detrapping related hysteresis are improved with higher processing temperatures, which is generally attributed to decreased localized states which act as electron traps. Here we develop a model to validate that post-deposition processing indeed changes the density and properties of the localized states. We obtain good agreement between this model and the experimental data measured from sol-gel indium zinc oxide TFTs. When the processing temperature increases from 300 to 500 <sup>0</sup>C, the model indicates that the trap state density in the bulk semiconductor and at the interface decrease by a factor of 5 and a factor of 3, respectively. Furthermore, the localized states become shallower, and the band mobility increases at higher processing temperatures.</div>

scholarly journals Modeling the Evolution of Trap States with Thermal Post-deposition Treatments in Sol-gel Indium Zinc Oxide TFTs

2021 ◽  
Author(s):  
Neel Chatterjee ◽  
Adam M Weidling ◽  
P. Paul Ruden ◽  
Sarah Swisher
Keyword(s):  
Zinc Oxide ◽  
Sol Gel ◽  
Amorphous State ◽  
Localized States ◽  
Oxide Thin Film ◽  
Processing Temperature ◽  
Wearable Electronics ◽  
Indium Zinc Oxide ◽  
Post Deposition ◽  
Oxide Tfts

<div>Metal oxides have been investigated for use in displays and wearable electronics, owing to their high mobility in the amorphous state. In solution-processed oxide thin-film transistors, post-deposition thermal processing significantly change the film’s transport properties, and is essential for high-performance devices. The mobility, bias stability and trapping-detrapping related hysteresis are improved with higher processing temperatures, which is generally attributed to decreased localized states which act as electron traps. Here we develop a model to validate that post-deposition processing indeed changes the density and properties of the localized states. We obtain good agreement between this model and the experimental data measured from sol-gel indium zinc oxide TFTs. When the processing temperature increases from 300 to 500 <sup>0</sup>C, the model indicates that the trap state density in the bulk semiconductor and at the interface decrease by a factor of 5 and a factor of 3, respectively. Furthermore, the localized states become shallower, and the band mobility increases at higher processing temperatures.</div>

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