Balakrushna Padhi | Alagappa University, Karaikudi, Tamil Nadu, INDIA (original) (raw)

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Papers by Balakrushna Padhi

Journal of Public Affairs, 2020

Journal of Materials Science Letters, 1993

Formation of ceramic fibres through natural fibre substrates has now been well established [1-4].... more Formation of ceramic fibres through natural fibre substrates has now been well established [1-4]. SIC-, Si3N4-, A1203-SiO 2-and A1203-Fe203-based fibres were produced using rice husk, and fibres from jute, coconut husk and sisal. This process consists essentially of ...

Journal of Materials Science, 1990

Journal of Materials Science Letters, 1991

International Journal of Environment and Waste Management, 2014

ABSTRACT

X-Ray Spectrometry, 1989

The structural characterization of alumina fibres obtained from an aluminium salt and three natur... more The structural characterization of alumina fibres obtained from an aluminium salt and three natural fibres (jute, sisal and coir) was examined by EDXRF and XRD. Elemental composition spectra from EDXRF of fibres pyrolysed at 1200 and 140O0C are presented and the results are compared with those obtained by wet chemical analysis and atomic absorption spectrometry. XRD diffractograms of the same samples are also shown. The evolution of the a phase of alumina with increase in pyrolysis temperature was examined. Scanning electron micrographs of alumina fibre with jute fibre are also presented.

Journal of scientific and industrial research

The salient features for production ofceramic fibres from various plant materials using substrate... more The salient features for production ofceramic fibres from various plant materials using substrate mechanism of digestion with salt solution, followed by coking (350°C) and pyrolysis (HX)()°C) are presented. Micrographs of alumina particulates have been obtained using saw dust as well as cellulose powder. The diameter of the alumina particulates formed from saw dust are in the range 0.25-0.37 mm while the diameter of those based on ceUulose is 0.34 mm. Production of zeolite type silicate and aIuminosilicate from rice husk is also reported.

TMS Light Metals

During production of alumina from bauxite using dilute sodium auminate liquor and steam is requir... more During production of alumina from bauxite using dilute sodium auminate liquor and steam is required. After removal of precipitated aluminium hydroxide crystals from the sodium aluminate solution. it is then concentrated in multiple effect evaporators. Water vapors so generated are collected at about 90°C and is alkaline in nature with pH value In the range of 9.5-10.5. Out of total generated, condensate 60% of the condensate is used for process dilution/washing in plant and 40% of condensate has to be utilized for some other purpose or disposed off. The exchange of aluminum and sodium by the resins were studied by using FTIR spectroscopy and Ion electrophoresis. The outlet water had a pH 7.0 and the conductivity of 0.2 micro siemen/cm, which is suitable for high. pressure boiler feed water. The mechanism of exchange properties and preventation of aluminum hydroxide gel precipitation in the resin bed has been discussed in present paper.

Indian Journal of Chemical Technology

The sintering of Bayer's process waste residue: Red mud along with magnesium oxide and sodium car... more The sintering of Bayer's process waste residue: Red mud along with magnesium oxide and sodium carbonate is adopted for recovery of aluminum and sodium followed by leaching. This is facilitated by the high temperature reaction of magnesium oxide sodium carbonate and DSP in the red mud to produce an insoluble dimagnesium silicate, magnesium ferrite, magnesium titanate and a soluble sodium aluminate. A variation of the red mud magnesium oxide sodium carbonate sinter process using half the magnesium oxide of existing methods has been investigated. The magnesium to silicon ratio was reduced from 2 to 1 producing a sodium magnesium silicate (Na 2 Mg 2 SiO 4) rather than the dimagnesium silicate (Mg 2 SiO 4) insoluble phase produced in the existing above sinter method. Synthetic red mud magnesium oxide sodium carbonate sinter products were investigated to understand the phases produced during sintering at varying temperatures and the chemistry of extraction. The target phases and morphological behaviors were seen in XRD and SEM and the highest extractions were produced from a sinter temperature of 900°C for 4 h. A two-stage (105°C / 60 min, 105°C / 240 min) water or caustic leaching process was found to be most effective for extraction. Sodium and aluminum extractions were 99 and 98.7% respectively. The experimental method devised was then used to treat red mud and the target phases were produced. An extraction of sodium and aluminum respectively was achieved. Silicon extractions were below 2%.

The objective of this study was to explore the sintering and leaching provision of Bayer's proces... more The objective of this study was to explore the sintering and leaching provision of Bayer's process waste residue (Red Mud). The chemical composition of red mud was ~16.07% Al 2 O 3 , ~53.75% Fe 2 O 3 , ~4.24% TiO 2 , ~8.25% SiO 2 , ~3.82% Na 2 O, ~0.148% V 2 O 5 , ~0.02% MgO, ~0.157% MnO, ~0.085% Ga 2 O 3 , ~0.007% ZnO, 0.099% K 2 O, ~11.83% LOI (loss on ignition) and rare earth elements in ppm label. The effect of Na 2 CO 3 additive, MgO and Na 2 CO 3 additives, sintering temperature, sintering time and leaching time on the efficiency of alumina extraction from red mud was investigated. Studies show that it was possible to extract alumina from red mud with highest extraction efficiency of 98.70%. The formation of Na 2 MgSiO 4 , Mg 2 SiO 4 , MgTiO 3 and Mg 2 Fe 2 O 5 phases during sintering of red mud with MgO and Na 2 CO 3, enhance alumina extraction efficiency. X-ray diffractometer and Scanning Electron Microscope studied the formation of Na 2 MgSiO 4 , Mg 2 SiO 4 , MgTiO 3 and Mg 2 Fe 2 O 5 phases.

Indian Journal of Chemical Technology

Structural properties of alumina fibre produced through the natural fibre route M !'md &. H ~ !'"... more Structural properties of alumina fibre produced through the natural fibre route M !'md &. H ~ !'"..1h, N.m"n.!! .\Iuminium CIlmp,my LId. I)amanjlxll cr.. OOX. Koraput. Or;"sa. Ind.a Rt.~c!ivcd II IA"C.:mht.'r l'Ii'i'l: a,'u:plcJ .'1 July ('NO Alumina fibre has Ix."t!n produc~d at 1400•C through thC'rmochcmicaltreatment of aluminium salts and naturalfihre. Morphological features of the fibn: have heen studied by optical microscopy and SC'dnning elcx:tron microscopy. XRDstudics indicate the pyrolyscd product to he ~-alumina. Particle size analysis ofthe fihre is also presented. It is shown that the morphology of the fihrcschangc with the catalysts used. The initial fihre structure also atTcx:ts the properties of the timll product. Results of loss on ignition along with analyses in AAS and X-r .. y fluorescence confirm the product to he alumina.

Powder Metallurgy

AI-metal composites using sisal fibre based alumina fibre were made by means of the powder metall... more AI-metal composites using sisal fibre based alumina fibre were made by means of the powder metallurgy method. The tensile strength of the composites produced shows a 50 % increase and a decrease in elonga tion of approx. 85 % with 4 % of the fibre. The density values of com posites at various temperatures are given. Micrographs of alumina fibre distribution in the metal are also provided. The elongation behaviour of the fibre during fracture is explained with regard to its structure. pmi 24 (1992) [1) 2,70

Lindsay/Light, 2011

ABSTRACT

E-Journal of Chemistry, 2011

The red mud BaO-Na2CO3sinter process can be used in combination with the Bayer process to recover... more The red mud BaO-Na2CO3sinter process can be used in combination with the Bayer process to recover sodium and aluminium from the red mud waste and direct it back to the process stream. This is facilitated by the high temperature reaction of BaO-Na2CO3and De-silication product (Sodalite) (DSP) in the red mud to produce an insoluble di-barium silicate, barium titanate, barium ferrite and a soluble sodium aluminate. A variation of the red mud BaO-Na2CO3sintering process using half the barium oxide of existing methods has been investigated. The barium to silicon ratio was reduced from 2 to 1 producing a sodium barium silicate (Na2BaSiO4) rather than the di-barium silicate (Ba2SiO4) insoluble phase produced in the existing BaO-Na2CO3sinter method. Synthetic BaO-Na2CO3sinter products were investigated to understand the phases produced during sintering at varying temperatures and the chemistry of extraction. The target phases and morphological behaviors of sinter products were seen in XRD a...

Journal of Public Affairs, 2020

Journal of Materials Science Letters, 1993

Formation of ceramic fibres through natural fibre substrates has now been well established [1-4].... more Formation of ceramic fibres through natural fibre substrates has now been well established [1-4]. SIC-, Si3N4-, A1203-SiO 2-and A1203-Fe203-based fibres were produced using rice husk, and fibres from jute, coconut husk and sisal. This process consists essentially of ...

Journal of Materials Science, 1990

Journal of Materials Science Letters, 1991

International Journal of Environment and Waste Management, 2014

ABSTRACT

X-Ray Spectrometry, 1989

The structural characterization of alumina fibres obtained from an aluminium salt and three natur... more The structural characterization of alumina fibres obtained from an aluminium salt and three natural fibres (jute, sisal and coir) was examined by EDXRF and XRD. Elemental composition spectra from EDXRF of fibres pyrolysed at 1200 and 140O0C are presented and the results are compared with those obtained by wet chemical analysis and atomic absorption spectrometry. XRD diffractograms of the same samples are also shown. The evolution of the a phase of alumina with increase in pyrolysis temperature was examined. Scanning electron micrographs of alumina fibre with jute fibre are also presented.

Journal of scientific and industrial research

The salient features for production ofceramic fibres from various plant materials using substrate... more The salient features for production ofceramic fibres from various plant materials using substrate mechanism of digestion with salt solution, followed by coking (350°C) and pyrolysis (HX)()°C) are presented. Micrographs of alumina particulates have been obtained using saw dust as well as cellulose powder. The diameter of the alumina particulates formed from saw dust are in the range 0.25-0.37 mm while the diameter of those based on ceUulose is 0.34 mm. Production of zeolite type silicate and aIuminosilicate from rice husk is also reported.

TMS Light Metals

During production of alumina from bauxite using dilute sodium auminate liquor and steam is requir... more During production of alumina from bauxite using dilute sodium auminate liquor and steam is required. After removal of precipitated aluminium hydroxide crystals from the sodium aluminate solution. it is then concentrated in multiple effect evaporators. Water vapors so generated are collected at about 90°C and is alkaline in nature with pH value In the range of 9.5-10.5. Out of total generated, condensate 60% of the condensate is used for process dilution/washing in plant and 40% of condensate has to be utilized for some other purpose or disposed off. The exchange of aluminum and sodium by the resins were studied by using FTIR spectroscopy and Ion electrophoresis. The outlet water had a pH 7.0 and the conductivity of 0.2 micro siemen/cm, which is suitable for high. pressure boiler feed water. The mechanism of exchange properties and preventation of aluminum hydroxide gel precipitation in the resin bed has been discussed in present paper.

Indian Journal of Chemical Technology

The sintering of Bayer's process waste residue: Red mud along with magnesium oxide and sodium car... more The sintering of Bayer's process waste residue: Red mud along with magnesium oxide and sodium carbonate is adopted for recovery of aluminum and sodium followed by leaching. This is facilitated by the high temperature reaction of magnesium oxide sodium carbonate and DSP in the red mud to produce an insoluble dimagnesium silicate, magnesium ferrite, magnesium titanate and a soluble sodium aluminate. A variation of the red mud magnesium oxide sodium carbonate sinter process using half the magnesium oxide of existing methods has been investigated. The magnesium to silicon ratio was reduced from 2 to 1 producing a sodium magnesium silicate (Na 2 Mg 2 SiO 4) rather than the dimagnesium silicate (Mg 2 SiO 4) insoluble phase produced in the existing above sinter method. Synthetic red mud magnesium oxide sodium carbonate sinter products were investigated to understand the phases produced during sintering at varying temperatures and the chemistry of extraction. The target phases and morphological behaviors were seen in XRD and SEM and the highest extractions were produced from a sinter temperature of 900°C for 4 h. A two-stage (105°C / 60 min, 105°C / 240 min) water or caustic leaching process was found to be most effective for extraction. Sodium and aluminum extractions were 99 and 98.7% respectively. The experimental method devised was then used to treat red mud and the target phases were produced. An extraction of sodium and aluminum respectively was achieved. Silicon extractions were below 2%.

The objective of this study was to explore the sintering and leaching provision of Bayer's proces... more The objective of this study was to explore the sintering and leaching provision of Bayer's process waste residue (Red Mud). The chemical composition of red mud was ~16.07% Al 2 O 3 , ~53.75% Fe 2 O 3 , ~4.24% TiO 2 , ~8.25% SiO 2 , ~3.82% Na 2 O, ~0.148% V 2 O 5 , ~0.02% MgO, ~0.157% MnO, ~0.085% Ga 2 O 3 , ~0.007% ZnO, 0.099% K 2 O, ~11.83% LOI (loss on ignition) and rare earth elements in ppm label. The effect of Na 2 CO 3 additive, MgO and Na 2 CO 3 additives, sintering temperature, sintering time and leaching time on the efficiency of alumina extraction from red mud was investigated. Studies show that it was possible to extract alumina from red mud with highest extraction efficiency of 98.70%. The formation of Na 2 MgSiO 4 , Mg 2 SiO 4 , MgTiO 3 and Mg 2 Fe 2 O 5 phases during sintering of red mud with MgO and Na 2 CO 3, enhance alumina extraction efficiency. X-ray diffractometer and Scanning Electron Microscope studied the formation of Na 2 MgSiO 4 , Mg 2 SiO 4 , MgTiO 3 and Mg 2 Fe 2 O 5 phases.

Indian Journal of Chemical Technology

Structural properties of alumina fibre produced through the natural fibre route M !'md &. H ~ !'"... more Structural properties of alumina fibre produced through the natural fibre route M !'md &. H ~ !'"..1h, N.m"n.!! .\Iuminium CIlmp,my LId. I)amanjlxll cr.. OOX. Koraput. Or;"sa. Ind.a Rt.~c!ivcd II IA"C.:mht.'r l'Ii'i'l: a,'u:plcJ .'1 July ('NO Alumina fibre has Ix."t!n produc~d at 1400•C through thC'rmochcmicaltreatment of aluminium salts and naturalfihre. Morphological features of the fibn: have heen studied by optical microscopy and SC'dnning elcx:tron microscopy. XRDstudics indicate the pyrolyscd product to he ~-alumina. Particle size analysis ofthe fihre is also presented. It is shown that the morphology of the fihrcschangc with the catalysts used. The initial fihre structure also atTcx:ts the properties of the timll product. Results of loss on ignition along with analyses in AAS and X-r .. y fluorescence confirm the product to he alumina.

Powder Metallurgy

AI-metal composites using sisal fibre based alumina fibre were made by means of the powder metall... more AI-metal composites using sisal fibre based alumina fibre were made by means of the powder metallurgy method. The tensile strength of the composites produced shows a 50 % increase and a decrease in elonga tion of approx. 85 % with 4 % of the fibre. The density values of com posites at various temperatures are given. Micrographs of alumina fibre distribution in the metal are also provided. The elongation behaviour of the fibre during fracture is explained with regard to its structure. pmi 24 (1992) [1) 2,70

Lindsay/Light, 2011

ABSTRACT

E-Journal of Chemistry, 2011

The red mud BaO-Na2CO3sinter process can be used in combination with the Bayer process to recover... more The red mud BaO-Na2CO3sinter process can be used in combination with the Bayer process to recover sodium and aluminium from the red mud waste and direct it back to the process stream. This is facilitated by the high temperature reaction of BaO-Na2CO3and De-silication product (Sodalite) (DSP) in the red mud to produce an insoluble di-barium silicate, barium titanate, barium ferrite and a soluble sodium aluminate. A variation of the red mud BaO-Na2CO3sintering process using half the barium oxide of existing methods has been investigated. The barium to silicon ratio was reduced from 2 to 1 producing a sodium barium silicate (Na2BaSiO4) rather than the di-barium silicate (Ba2SiO4) insoluble phase produced in the existing BaO-Na2CO3sinter method. Synthetic BaO-Na2CO3sinter products were investigated to understand the phases produced during sintering at varying temperatures and the chemistry of extraction. The target phases and morphological behaviors of sinter products were seen in XRD a...