Preparation of Phosphorus by Carbothermal Reduction Mechanism in Vacuum

2011 ◽  
Vol 361-363 ◽  
pp. 268-274 ◽  
Author(s):  
Yu Cheng Liu ◽  
Qiu Xia Li ◽  
Yong Cheng Liu
Keyword(s):  
Carbothermal Reduction ◽  
Carbothermic Reduction ◽  
Reduction Process ◽  
Molar Ratio ◽  
Main Reaction ◽  
Reduction Mechanism ◽  
Element Analysis ◽  
Reaction Phase ◽  
System Pressure ◽  
Increasing Temperature

The purpose of this work was to investigated the carbothermic reaction of fluorapatite process by the means of thermodynamics analyses, XRD and element analysis, respectively. Thermodynamic calculations indicated that phosphorus can be prepared by heating the mixture of Ca5(PO4)3F2 and C at 1173K under the system pressure of 100Pa. CO cannot react with Ca5(PO4)3F2 in the carbothermic reduction process at 973-1873K and 100Pa. Experimental results demonstrated that phosphorus can be produced by the reaction between Ca5(PO4)3F2 and C, the main reaction phase is P2(g), CO(g), CaO and CaF2, and with increasing temperature, the greater degree of response. The best technology conditions, the molar ratio of Ca5(PO4)3F2 to C is 1:7.5 at 1723K for 1h when the system pressure was about 100Pa. This study to provide experimental evidence for preparation of phosphorus by carbothermal reaction of fluorapatite in vacuum.

scholarly journals Mechanism of CaF2 under Vacuum Carbothermal Conditions for Recovering Nickel, Iron, and Magnesium from Garnierite

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 129
Author(s):  
Wang ◽  
Gu ◽  
Qu ◽  
Shi ◽  
Luo ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Carbothermal Reduction ◽  
Inductively Coupled Plasma ◽  
Raw Materials ◽  
Reduction Process ◽  
Atomic Emission ◽  
Separation Process ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Nickel Iron

Nickel laterite ore is divided into three layers and the garnierite examined in this study belongs to the third layer. Garnierite is characterized by high magnesium and silicon contents. The main contents of garnierite are silicates, and nickel, iron, and magnesium exist in silicates in the form of lattice exchange. Silicate minerals are difficult to destroy so are suitable for smelting using high-temperature pyrometallurgy. To solve the problem of the large amounts of slag produced and the inability to recycle the magnesium in the traditional pyrometallurgical process, we propose a vacuum carbothermal reduction and magnetic separation process to recover nickel, iron, and magnesium from garnierite, and the behavior of the additive CaF2 in the reduction process was investigated. Experiments were conducted under pressures ranging from 10 to 50 Pa with different proportions of CaF2 at different temperatures. The experimental data were obtained by various methods, such as thermogravimetry, differential scanning calorimetry, scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and inductively coupled plasma atomic emission spectroscopy. The analysis results indicate that CaF2 directly reacted with Mg2SiO4, MgSiO3, Ni2SiO4, and Fe2SiO4, which were isolated from the bearing minerals, to produce low-melting-point compounds (FeF2, MgF2, NiF2, etc.) at 1315 and 1400 K. This promoted the conversion of the raw materials from a solid–solid reaction to a liquid–liquid reaction, accelerating the mass transfer and the heat transfer of Fe–Ni particles, and formed Si–Ni–Fe alloy particles with diameters of approximately of 20 mm. The smelting materials appeared stratified, hindering the reduction of magnesium. The results of the experiments indicate that at 1723 K, the molar ratio of ore/C was 1:1.2, the addition of CaF2 was 3%, the recovery of Fe and Ni reached 82.97% and 98.21% in the vacuum carbothermal reduction–magnetic separation process, respectively, and the enrichment ratios of Fe and Ni were maximized, reaching 3.18 and 9.35, respectively.

scholarly journals Recovery of zinc from zinc oxide dust containing multiple metal elements by carbothermal reduction

2021 ◽  
pp. 49-49
Author(s):  
F.-G. Lei ◽  
M.-T. Li ◽  
C. Wei ◽  
Z.-G. Deng ◽  
X.-B. Li ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Carbothermal Reduction ◽  
Carbothermic Reduction ◽  
Reduction Process ◽  
Zinc Content ◽  
Holding Time ◽  
Reduction Condition ◽  
Reduction Experiment ◽  
Effects Of Temperature ◽  
Optimal Reduction

A carbothermal reduction process simulating EAF process is used to handle the zinc oxide dust, and the zinc in the dust can be extracted and recovered efficiently. The crude zinc and lead-tin alloy were obtained finally. The effects of temperature, holding time, and reductant dosage on zincvolatilization rate were investigated, and the ?Pelletizing -Calcination-Carbothermic reduction? experiment was conducted. The resultsfound the optimal reduction condition was as follows: the temperature of 1300?C, reductant dosage of 14.04% and holding time of 120 min. After the calcination at 900?C for 120 min, the removal rates of fluorine, chlorine and sulfur in the dust were 98.18%, 96.38% and 28.58% respectively, and the volatilization rate of zinc was 99.83% in reduction process. The zinc content of the crude zinc was 68.48%.

The Synthesis of TiC Powders by Carbothermal Reduction Method in Vacuum

2014 ◽  
Vol 1064 ◽  
pp. 62-65
Author(s):  
Xue Tan Ren ◽  
Yan Chun Liu ◽  
Shui Hui Chen ◽  
Lai Guang Hou ◽  
Guo Long Wang ◽  
...  
Keyword(s):  
Carbon Black ◽  
Crystalline Phase ◽  
Carbothermal Reduction ◽  
Single Phase ◽  
Reduction Method ◽  
Raw Materials ◽  
Molar Ratio ◽  
Carbothermal Reduction Method ◽  
System Pressure

The TiC powders were synthesized by carbothermal reduction of TiO2in vacuum using the titania and carbon black as raw materials. The molar ratio of C to TiO2was 3:1. The crystalline phase, microstructure and morphology of the obtained samples were investigated by XRD and SEM. The results show that single-phase and well-crystallized TiC powders were obtained at 1300°C for 1h when the system pressure was 20 Pa. The particle morphologies are composed of fine grains about 200 nm.

Synthesis and Properties of Al4SiC4 by Carbothermal Reduction

2010 ◽  
Vol 434-435 ◽  
pp. 99-102
Author(s):  
Jian Li Zhao ◽  
Chang An Wang ◽  
Akira Yamaguchi ◽  
Jia Lin Sun ◽  
Xin Sheng Zhang
Keyword(s):  
High Temperature ◽  
Metal Oxide ◽  
Carbothermal Reduction ◽  
Reduction Process ◽  
Sem Analysis ◽  
Raw Material ◽  
Molar Ratio ◽  
Oxidation Properties ◽  
The Stability ◽  
Platelet Shape

Al4SiC4 is probably used as non-oxide raw material for high-temperature ceramics. Al4SiC4 was synthesized by using starting materials of metal-carbon, metal-oxide- carbon or carbides. In this paper, Al4SiC4 has been synthesized by using oxides (Al2O3 and SiO2) and carbon as starting materials through carbothermal reduction process. The oxidation properties in air and O2 atmosphere by TG method and the stability of the synthesized Al4SiC4 heated in moisture were investigated. Pure Al4SiC4 phase was synthesized when heating the mixture powder of Al2O3, SiO2 and C (C : Al2O3 : SiO2 = 8 : 2 : 0.8, in molar ratio) at 1700°C for 8h in flowing Ar atmosphere. The synthesized Al4SiC4 powder consists of platelet shape grains with size of 68μm length, 35μm width and 1μm thickness. Al4SiC4 obviously oxidized from 800°C when heated in flowing air or O2 atmosphere. When keeping Al4SiC4 powder in moisture, it was not observed to be reacted with water by XRD and SEM analysis.

Synthesis of Al4SiC4-Al8SiC7 Composite Powders by Carbothermal Reduction Process

2011 ◽  
Vol 399-401 ◽  
pp. 813-816 ◽  
Author(s):  
Chao Yu ◽  
Wen Jie Yuan ◽  
Jun Li ◽  
Hong Xi Zhu ◽  
Cheng Ji Deng
Keyword(s):  
Carbon Black ◽  
Carbothermal Reduction ◽  
Carbothermic Reduction ◽  
Heating Temperature ◽  
Reduction Process ◽  
Composite Powders

Tabular structure of Al4SiC4-Al8SiC7composites was successfully synthesized using a mixture of calcined bauxite, SiC and carbon black by a carbothermal reduction process. The effects of the amount of SiC addition and the heating temperature on synthesis of Al4SiC4-Al8SiC7composites by carbothermic reduction were investigated. The results show that SiC amount played an important role in the content of the final products. With the increasing of heating temperature, the Al4SiC4content increased and Al8SiC7content decreased in the products, which indicated the formation and growth of Al4SiC4were promoted.

scholarly journals Feasibility of fly ash as fluxing agent in mid- and low-grade phosphate rock carbothermal reduction and its reaction kinetics

2021 ◽  
Vol 10 (1) ◽  
pp. 157-168
Author(s):  
Biwei Luo ◽  
Pengfei Li ◽  
Yan Li ◽  
Jun Ji ◽  
Dongsheng He ◽  
...  
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Reaction Time ◽  
Carbothermal Reduction ◽  
Industrial Waste ◽  
Phosphate Rock ◽  
Molar Ratio ◽  
Low Grade ◽  
Carbon Excess ◽  
Fluxing Agent

Abstract The feasibility of industrial waste fly ash as an alternative fluxing agent for silica in carbothermal reduction of medium-low-grade phosphate ore was studied in this paper. With a series of single-factor experiments, the reduction rate of phosphate rock under different reaction temperature, reaction time, particle size, carbon excess coefficient, and silicon–calcium molar ratio was investigated with silica and fly ash as fluxing agents. Higher reduction rates were obtained with fly ash fluxing instead of silica. The optimal conditions were derived as: reaction temperature 1,300°C, reaction time 75 min, particle size 48–75 µm, carbon excess coefficient 1.2, and silicon–calcium molar ratio 1.2. The optimized process condition was verified with other two different phosphate rocks and it was proved universally. The apparent kinetics analyses demonstrated that the activation energy of fly ash fluxing is reduced by 31.57 kJ/mol as compared with that of silica. The mechanism of better fluxing effect by fly ash may be ascribed to the fact that the products formed within fly ash increase the amount of liquid phase in the reaction system and promote reduction reaction. Preliminary feasibility about the recycling of industrial waste fly ash in thermal phosphoric acid industry was elucidated in the paper.

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.

Copper Chemical Vapor Deposition using a Novel Cu(II) Precursor for Contact Via Filling Process

2007 ◽  
Vol 990 ◽  
Author(s):  
Hideaki Zama ◽  
Yuuji Nishimura ◽  
Michiyo Yago ◽  
Mikio Watanabe
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Hydrogen Reduction ◽  
Reduction Process ◽  
Chemical Vapor ◽  
Molar Ratio ◽  
Cu Films ◽  
Pure Cu ◽  
Substrate Temperatures ◽  
Advanced Generation

ABSTRACTChemical vapor deposition (CVD) of copper using both a novel Cu(II) β-diketonate source and hydrogen reduction process was studied to fill contact vias with the smallest diameter in the 32nm and more advanced generation chip. Pure Cu films were grown under the condition with the product of hydrogen partial pressure and H2/Cu source molar ratio being over 1,000,000. We succeeded in filling the 40-nm-diameter contact vias by optimizing the growth condition of the Cu-CVD in both substrate temperatures and reaction pressures.

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