scholarly journals Influence of Desulfurization with Fe2O3 on the Reduction of Nickel Converter Slag

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2423
Author(s):  
Guangsheng Wei ◽  
Yun Wang ◽  
Rong Zhu ◽  
Lingzhi Yang
Keyword(s):  
Metal Oxides ◽  
Sulfur Content ◽  
Carbothermal Reduction ◽  
Converter Slag ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Copper Recovery ◽  
Desulfurization Rate ◽  
Residual Sulfur ◽  
Nickel Converter

Generally in the nickel converter slag, metals are mainly in the form of sulfides, which are difficult to separate from slag. Although metal oxides in the slag, such as NiO, CoO, and Cu2O, are easily reduced into metal using carbon, the presence of sulfur inhibits the reduction reaction. In this study, the addition of Fe2O3 to nickel converter slag produced desulfurized slag, which enhanced the carbothermal reduction process. Increasing the desulfurization rate promoted the conversion of sulfides into oxides in slag, which significantly increased the activity of NiO, Cu2O, and Fe2O3. However, the residual sulfur content had no significant effect on the activity of FeO and CoO, due to the high initial FeO content and cobalt existing mainly in the form of oxides. The optimum addition of Fe2O3 was 15.0 g per 100 g nickel slag, while the desulfurization ratio was 36.84% and the rates of nikel, cobalt and copper recovery were 95.33%, 77.73%, and 73.83%, respectively.

scholarly journals Thermodynamic analysis of interaction of components in the SIO2-C system: improvement of technical silicon production technological process

2021 ◽  
Vol 22 (2) ◽  
pp. 345-352
Author(s):  
Inga Janelidze ◽  
Gigo Jandieri ◽  
Tamar Tsertsvadze
Keyword(s):  
Technological Process ◽  
Thermodynamic Analysis ◽  
Carbothermal Reduction ◽  
Crystalline Silicon ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Technical Solution ◽  
Chemical Furnace ◽  
Interaction Of Components ◽  
Degree Of Extraction

In order to identify ways to improve the technological process of smelting metallic (crystalline) silicon of technical purity, a thermodynamic analysis of the interaction of components in the SiO2-C system is carried out that reveals the main factor in obtaining high-quality technical silicon is the elimination of superposition of the silicon carbonization process that is possible by carrying out a two-stage carbothermal reduction reaction, in that firstly the incomplete reduction of silica (SiO2) by solid carbon (C) is provided, accompanied by the release of new reacting gas components - SiO and CO, the subsequent interaction of which leads to the formation of the target product - technical silicon that is suitable for the production of modern solar energy converters. It is determined that main condition for highly efficient reduction reactions is the fine fractionness (<1 mm) of the used quartzite ore with keeping of a rational temperature range for its carbothermal reduction (1688-2000 K). It has been shown experimentally that the optimal technical solution for the implementation of this reduction process is to performt melting in a special plasma-chemical furnace-reactor with one liquid-metal subconducting electrode, with a reverse vertical feed of the reaction gases released at the first stage. The degree of extraction of silicon was on average 95%, and the degree of its purity was 97.2%.

Kinetics of Magnesium Removal from Garnierite by Carbothermal Reduction in Vacuum

2020 ◽  
Vol 996 ◽  
pp. 165-172
Author(s):  
Xu Peng Gu ◽  
Xiao Pan Zhang ◽  
Tao Qu ◽  
Ming Yang Luo ◽  
Lei Shi ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Carbothermal Reduction ◽  
Removal Rate ◽  
Reduction Process ◽  
Magnesium Silicate ◽  
Reduction Reaction ◽  
Sem Analysis ◽  
Exponential Factor ◽  
Chemical Reaction Kinetics ◽  
Kinetics Of

The removal of magnesium from garnierite in Yuanjiang area of Yunnan was performed by carbothermal reduction in vacuum. The effects of reduction temperature and reduction time on the removal rate of magnesium were investigated. The kinetics of the removal of magnesium by carbothermal reduction in vacuum was studied. The thermodynamic calculation results show that it is feasible to remove magnesium from garnierite by carbothermal reduction in vacuum. The experimental results show that the removal rate of magnesium in garnierite can reach 93.23% under the conditions of 1823K for 120min. The reduction process conforms to the chemical reaction kinetics model, which indicated that the reduction process is controlled by chemical reaction and whose expression is 1-(1-α)1/3=(-22850.1/T+2.6296) t, the apparent activation energy (Ea) and the pre-exponential factor (A) are 189.97 kJ/mol and 13.87 s-1, respectively. The results of XRD and SEM analysis show that the condensate obtained by carbothermal reduction in vacuum of the garnierite is magnesium, which is mainly obtained by the reduction reaction between magnesium silicate produced by the decomposition of serpentine in minerals and coal. At the same time, it is proved that it is feasible to directly extract magnesium metal from the garnierite.

scholarly journals Ultrafast carbothermal reduction of silica to silicon using a CO2 laser beam

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seok-Ho Maeng ◽  
Hakju Lee ◽  
Min Soo Park ◽  
Suhyun Park ◽  
Jaeki Jeong ◽  
...  
Keyword(s):  
Carbon Black ◽  
Laser Beam ◽  
Carbothermal Reduction ◽  
Gas Flow ◽  
Crystalline Silicon ◽  
Reduction Process ◽  
Reaction Chamber ◽  
Raman Shift ◽  
Influence Of Process Parameters ◽  
Laser Beam Intensity

AbstractWe report the extraction of silicon via a carbothermal reduction process using a CO2 laser beam as a heat source. The surface of a mixture of silica and carbon black powder became brown after laser beam irradiation for a few tens of seconds, and clear peaks of crystalline silicon were observed by Raman shift measurements, confirming the successful carbothermal reduction of silica. The influence of process parameters, including the laser beam intensity, radiation time, nitrogen gas flow in a reaction chamber, and the molar ratios of silica/carbon black of the mixture, on the carbothermal reduction process is explained in detail.

scholarly journals Titanium Carbide Nanocrystals Synthesized from a Metatitanic Acid-Sucrose Precursor via a Carbothermal Reduction

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hyunho Shin ◽  
Jun-Ho Eun
Keyword(s):  
Process Control ◽  
Titanium Carbide ◽  
Specific Surface ◽  
Surface Area ◽  
Pore Volume ◽  
Carbothermal Reduction ◽  
Crystal Size ◽  
Reduction Process ◽  
Specific Pore Volume ◽  
Metatitanic Acid

A TiC powder is synthesized from a micron-sized mesoporous metatitanic acid-sucrose precursor (precursor M) by a carbothermal reduction process. Control specimens are also prepared using a nanosized TiO2-sucrose precursor (precursor T) with a higher cost. When synthesized at 1500°C for 2 h in flowing Ar, the characteristics of the synthesized TiC from precursor M are similar to those of the counterpart from precursor T in terms of the crystal size (58.5 versus 57.4 nm), oxygen content (0.22 wt% versus 0.25 wt%), and representative sizes of mesopores: approximately 2.5 and 19.7–25.0 nm in both specimens. The most salient differences of the two specimens are found in the TiC from precursor M demonstrating (i) a higher crystallinity based on the distinctive doublet peaks in the high-two-theta XRD regime and (ii) a lower specific surface area (79.4 versus 94.8 m2/g) with a smaller specific pore volume (0.1 versus 0.2 cm3/g) than the counterpart from precursor T.

High surface area mesoporous SiC synthesized via nanocasting and carbothermal reduction process

2005 ◽  
Vol 40 (18) ◽  
pp. 5091-5093 ◽  
Author(s):  
AN-HUI LU ◽  
WOLFGANG SCHMIDT ◽  
WOLFGANG KIEFER ◽  
FERDI SCHÜTH
Keyword(s):  
Surface Area ◽  
Carbothermal Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Reduction Process

Reduction Kinetics of Mill Scale Briquettes by Using A3 Fine Coal as a Reductant

2021 ◽  
Vol 21 (4) ◽  
pp. 2563-2567
Author(s):  
Nguyen Hoang Viet ◽  
Pham Ngoc Dieu Quynh ◽  
Nguyen Thi Hoang Oanh
Keyword(s):  
Reaction Rate ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Reaction Rate Constant ◽  
Reduction Degree ◽  
Furnace Temperature ◽  
Time Duration ◽  
Mill Scale ◽  
Fine Coal ◽  
Kinetics Of

In this work, a mixture of mill scale with 5 wt% molasses as binder was pressed under pressure of 200 MPa to prepare briquettes. The reduction process was performed at the temperature of 1000, 1050, 1100, 1150 and 1200 °C in the bed of A3 fine coal as the reductant. The degree of reduction was evaluated at time duration of 15, 30, 45, 60, 90 and 150 minutes, after the furnace temperature reached the predetermined reduction temperature. The highest reduction degree is 94.7% at the reduction process temperature of 1200 °C. Reaction rate constant (k) increased from 4.63×10-4 to 5.03×10-3 min-1 when the temperature increased from 1000 to 1200 °C. The apparent activation energy of the reduction reaction (Ea) is about 95.6 kJ/mole.

scholarly journals Recovery of Fe, Ni, Co, and Cu from Nickel Converter Slag through Oxidation and Reduction

2018 ◽  
Vol 58 (12) ◽  
pp. 2191-2199 ◽  
Author(s):  
Yun Wang ◽  
Rong Zhu ◽  
Qizhou Chen ◽  
Guangsheng Wei ◽  
Shaoyan Hu ◽  
...  
Keyword(s):  
Converter Slag ◽  
Nickel Converter

On the carbo-thermal reduction of silica for carbon nano-fibre formation via CVD

2011 ◽  
Vol 1284 ◽  
Author(s):  
Alicja Bachmatiuk ◽  
Felix Börrnert ◽  
Imad Ibrahim ◽  
Bernd Büchner ◽  
Mark H. Rümmeli
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Carbothermal Reduction ◽  
Carbon Nanostructures ◽  
Reduction Process ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Thermal Reduction ◽  
Fibre Formation ◽  
Quartz Substrates

ABSTRACTThe formation of carbon nanostructures using silica nanoparticles from quartz substrates as a catalyst in an aerosol assisted chemical vapor deposition process was examined. The silica particles are reduced to silicon carbide via a carbothermal reduction process. The recyclability of the explored quartz substrates is also presented. The addition of triethyl borate improves the efficiency of the carbothermal reduction process and carbon nanotubes formation. Moreover, the addition of hydrogen during the chemical vapor deposition leads to the helical carbon nanostructures formation.

Printed air cathode for flexible and high energy density zinc-air battery

MRS Advances ◽  
2016 ◽  
Vol 1 (53) ◽  
pp. 3585-3591
Author(s):  
Soorathep Kheawhom ◽  
Sira Suren
Keyword(s):  
Metal Oxides ◽  
High Energy ◽  
Reduction Reaction ◽  
Open Circuit ◽  
High Energy Density ◽  
Ohmic Loss ◽  
Screen Printing Technique ◽  
Cathode Current ◽  
Discharge Potential ◽  
Zinc Air Batteries

ABSTRACTFlexible zinc-air batteries were fabricated using an inexpensive screen-printing technique. The anode and cathode current collectors were printed using commercial nano-silver conductive ink on a polyethylene terephthalate (PET) substrate and a polypropylene (PP) membrane, respectively. Air cathodes made of blended carbon black with inexpensive metal oxides including manganese oxide (MnO2) and cerium oxide (CeO2), were studied. The presence of the metal oxides in the air cathodes enhanced the oxygen reduction reaction which is the most important cathodic reaction in zinc-air batteries. The battery with 20 %wt CeO2showed the highest performance and provided an open-circuit voltage of 1.6 V and 5 – 240 mA.cm-2ohmic loss zone. The discharge potential of this battery at the current density of 5 mA.cm-2was nearly 0.25 V higher than that of the battery without metal oxides. Finally, the battery was tested for its flexibility by bending it so that its length decreased from 2.5 to 1 cm. The results showed that the bending did not affect characteristics on potential voltage and discharging time of the batteries fabricated.

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