Separation of titanium and silicon oxides during plasma-arc melting of quartz-leucoxene concentrate

2021 ◽  
Vol 5 ◽  
pp. 30-36
Author(s):  
A. A. Nikolaev ◽  
◽  
◽  
Keyword(s):  
Lower Layer ◽  
Energy Requirement ◽  
Graphite Crucible ◽  
Arc Furnace ◽  
Plasma Arc ◽  
Laboratory Plasma ◽  
Silicon Oxides ◽  
Arc Melting ◽  
Melting Separation ◽  
Oxide Particles

The aim of the work was investigation of separation of titanium’s and silicon’s oxides during plasma-arc melting of quartz-leucoxene concentrate from Yarega deposit. The melting was proceeded in laboratory plasma-arc furnace in graphite crucible at 16 – 40 kW of arc power. The microstructure and R-x phase analysis of solidified melt were investigated after arc melting. The melt separated on two layers. The upper layer consisted mainly of SiO2 in the form of glass, the lower layer — mainly of cemented titanium oxide particles ≈ 100 μm in dimension. TiO2, Ti8O15, Ti6O11, Fe3TiO3O10, Ti3O5 were observed. These particles formed during melting and moved throw liquid glass to the bottom of crucible with the speed of V ≈ 10–4 m/s. The separation of TiO2 and SiO2 required energy W ≈ 100 GJ/t of concentrate in laboratory plasma arc furnace. The possibility of industrial employment of the arc melting separation was discussed. The estimated energy requirement was about 5 GJ/t in 20-t arc furnace.

scholarly journals Comparison of Copper and Graphite Crucibles for Si Extraction from TiO2 - SiO2 System at Plasma-Arc Heating

2018 ◽  
Vol 5 (3) ◽  
pp. 128-130
Author(s):  
D. E. Kirpichev ◽  
A. A. Nikolaev ◽  
A. V. Nikolaev
Keyword(s):  
Temperature Field ◽  
Graphite Crucible ◽  
Arc Furnace ◽  
Plasma Arc ◽  
Dc Plasma ◽  
Sio2 System ◽  
Anode Spot ◽  
Arc Heating ◽  
Material Temperature ◽  
Made In

<p>Plasma arc recovery melting of the quartz-leucoxene concentrate is investigated. Experiments were made in laboratory DC plasma arc furnace in various crucibles. The best results are reached in a cold copper crucible. The temperature field of a pool is calculated in hot graphite and cold copper crucibles. It is shown that in a graphite crucible diameter of an anode spot is more, and density of current and material temperature in a spot is less, than in copper that is the reason of the worst refinements in a graphite crucible.</p>

A Study of Porous Slag with Plasma Arc Melting

2006 ◽  
Vol 45 ◽  
pp. 2224-2228
Author(s):  
Shuang Shii Lian ◽  
Chih Kang Chang ◽  
Chin Ching Tzeng
Keyword(s):  
Pore Formation ◽  
Plasma Arc ◽  
Laboratory Plasma ◽  
Arc Melting ◽  
The Future ◽  
Foam Slag ◽  
Plasma Melting ◽  
Arc Heating

The slag from steel plants or incinerators was tried to be recycled and be reused as foam materials through plasma arc melting. The study was intended to investigate the making of foam slag with laboratory plasma melting facilities. The investigated materials consisted of different mixtures of Al2O3、SiO2 、FetO、CaO and Na2O, with the fluxes that were necessary to examine the capability of pore-formation in the solidified ingots. It has been found that the foam slag could be obtained with the proper compositions and conditions of arc heating. The dimensions and distributions of pores were studied and correlated with the temperatures and compositions of slag. The results showed that the sizes of pores inside the solidified ingots were in the range of 1~5 mm, and the thickness of slag was around 20 mm. As to the distributions of the pores in the ingots of slag, further improvement would be needed in the future.

scholarly journals Electroplasma processing of medical and biological waste

2021 ◽  
Vol 2119 (1) ◽  
pp. 012039
Author(s):  
P V Domarov ◽  
A S Anshakov ◽  
V A Faleev
Keyword(s):  
Experimental Study ◽  
Arc Furnace ◽  
Plasma Arc ◽  
Technological Parameters ◽  
Laboratory Plasma ◽  
Biomedical Waste ◽  
Exhaust Gases

Abstract The article presents an experimental study of biomedical waste in the form of disposable masks. The study was carried out on a laboratory plasma arc installation with a capacity of 20 kg/h. During the experiments, the most important technological parameters were studied: the composition of the exhaust gases, the dependence of the exhaust gases on the temperature in the chamber of the plasma arc furnace, etc.

Formation of plasma arc anode spot on the rotating graphite crucible

2020 ◽  
Vol 5 ◽  
pp. 24-32
Author(s):  
A.A. Nikolaev ◽  
◽  
A.V. Nikolaev ◽  
D.E. Kirpichyov ◽  
◽  
...  
Keyword(s):  
Argon Plasma ◽  
Graphite Crucible ◽  
Optical Pyrometer ◽  
Arc Furnace ◽  
Plasma Arc ◽  
Uniform Heating ◽  
Anode Spot ◽  
Arc Current ◽  
Diffuse Spot ◽  
Spot Formation

Formation of anode spots on rotating graphite crucible in the plasma arc furnace was investigated. The size and temperatures of the spots were determined by means of photographs and optical pyrometer. Composition of the plasma in anode spot region has been calculated. Cylindrical crucible of 100 mm in diameter with an axial hole of 40 mm in diameter and 28 mm in depth was rotated with the speed of ~100 rpm. Cylindrical cathode of 50 mm in diameter had an axial channel of 24 mm in diameter. Argon was fed through the channel as plasma forming gas. Crucible and cathode were located in the steel water cooled chamber with a volume of 150 liters. The arc was several centimeters long, arc current was 560-630 A. It was shown experimentally that 23-25 kW argon plasma arc can forms contracted or diffuse anode spot. The current density of contracted spot is 1800  A/cm2, while that of diffuse spot is ~250 A/cm2. Contracted spot formation occurs on a cold crucible and accompanied by intensive evaporation of graphite in a spot region. The carbon vapor decreased ionization potential of plasma near the anode and promoted contraction. A uniform heating of the hole in crucible up to 2700 K is needed for transformation of the contracted spot into diffuse one. Such heating was attained by rotation of crucible. Thermal isolation of crucible also promotes diffuse spot formation. Poisson’s equation was solved, and the voltage falls in space charge zones were calculated for contracted and diffuse spots as 10.7 and 1.5 V respectively. It was assumed that the lesser voltage fall promotes the diffuse spot formation.

Preparation and characteristics of Ba1-xKxBiO3superconductors using the plasma-arc melting and rapid quenching method

1993 ◽  
Vol 41 (1-4) ◽  
pp. 175-178 ◽  
Author(s):  
M. Kamino ◽  
M. Iyori ◽  
H. Suzuki ◽  
K. Takahashi ◽  
Y. Yoshisato ◽  
...  
Keyword(s):  
Rapid Quenching ◽  
Plasma Arc ◽  
Arc Melting ◽  
Quenching Method

Refining effect of hydrogen plasma arc melting on hafnium metal

2006 ◽  
Vol 60 (21-22) ◽  
pp. 2604-2605 ◽  
Author(s):  
Joon Woo Bae ◽  
Jae-Won Lim ◽  
Kouji Mimura ◽  
Minoru Isshiki
Keyword(s):  
Hydrogen Plasma ◽  
Plasma Arc ◽  
Refining Effect ◽  
Arc Melting

Hydrogen effect on refining of Mo metal by Ar–H2 plasma arc melting

2010 ◽  
Vol 64 (21) ◽  
pp. 2290-2292 ◽  
Author(s):  
Jae-Won Lim ◽  
Kouji Mimura ◽  
Dai Miyawaki ◽  
Jung-Min Oh ◽  
Good-Sun Choi ◽  
...  
Keyword(s):  
Hydrogen Effect ◽  
Plasma Arc ◽  
Arc Melting

Reduction of Selected Metal Oxides in a Thermal Plasma Produced by a Nontransferred ARC Torch

1987 ◽  
Vol 98 ◽  
Author(s):  
Brent A. Detering ◽  
James A. Batdorf ◽  
Chien M. Wai
Keyword(s):  
Thermal Decomposition ◽  
Fourier Transform ◽  
Flow Field ◽  
Emission Spectroscopy ◽  
Plasma Plume ◽  
Particle Morphology ◽  
Arc Plasma ◽  
Plasma Arc ◽  
Transform Method ◽  
Oxide Particles

ABSTRACTPlasma flow field temperatures are determined in a nontransferred arc plasma using emission spectroscopy. This technique is then utilized to identify thermal decomposition and reduction products produced in the plasma plume when metal oxide particles are injected into the plasma arc. The processed particles are then studied using AAS, SEM, EDS and XRD to characterize the chemical changes that have occurred in the particles. A Fourier transform method is used to study changes in particle morphology.

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