Jiann-Yang Hwang | Michigan Technological University (original) (raw)

Papers by Jiann-Yang Hwang

A coal cleaning research by means of surface magnetic I economic feasibilities of this technology... more A coal cleaning research by means of surface magnetic I economic feasibilities of this technology have been demonstrated in this study. Both are competitive to that of the froth flotation approach for coal cleaning.

Particles of a magnetic material coated with a hydrophobic surfactant are dispersed in an organic... more Particles of a magnetic material coated with a hydrophobic surfactant are dispersed in an organic solvent extractant to produce a magnetic solvent extractant which can be used in solvent extraction processes. Phase separation of an organic phase, carrying the com ponent to be separated, from the aqueous phase can be accelerated by applying a magnetic field to the organic phase. After removal of the organic phase, a magnetic field can be applied to the aqueous phase to remove any residual organic phase and thereby enhance the degree of separation.

Electroplating is one of the most important parts in the modern manufacturing industry. All of ou... more Electroplating is one of the most important parts in the modern manufacturing industry. All of our modern electronics need some sort of electroplating process to help it achieve its goals. From smartphone, computer, heavy machinery, decoration, to motor vehicle, almost everything that we used nowadays need electroplating in some ways. However, at the same time electroplating factory can do much harm to the natural environment. Electroplating industry produce 2.7 billion gallons of wastewater in China every year. And most of it won’t be treated to the required level and all go to the river and ocean. This causes a big issue for the environment. Dr. Hwang and Futianbao Environment Protection Technology Ltd. developed a new way to treat the electroplating wastewater. We called it “SCR”, “S” means separation, “C” means concentration and “R” means recycle. The world leading edge “SCR” technology was successfully developed in 2016 by our R&D team which leads by Dr. Hwang. This technology comprehensively not only uses various physical and chemical separation technologies to achieve salt concentration and crystallization, but also recycles heavy metal from the wastewater and reuse reclaimed water. This technology meets the “zero emission” requirement in China. At the same time, it achieves the goal of harmful waste reduction and resource recycling

Degreasing wastewater is a common type of wastewater produced from surface degreasing process in ... more Degreasing wastewater is a common type of wastewater produced from surface degreasing process in the electroplating industry. It has the characteristics of high pH, high oil content, and high COD value. This paper studies COD reduction of degreasing wastewater by UV/H2O2 oxidation process, and factors that affect COD removal rate. Those include H2O2 dosage, feeding method, and pH value. The optimized reaction condition was found to be pH of 3, the molar ratio of H2O2 to COD at 1:1 with continuous feeding of H2O2. A maximum COD removal rate of 91% can be achieved after 4 h of reaction

Ceramics International, 2019

This study presents a new approach to enhance preparation of superior-quality refractory material... more This study presents a new approach to enhance preparation of superior-quality refractory materials by microwave sintering of the mixture of ferronickel slag and sintered magnesia with addition of alumina up to 10 wt %. It was shown that in the process of microwave sintering, the proper addition of alumina could contribute to formation of forsterite with fine and relatively uniform particle size. It also promoted the generations of high melting point magnesium aluminate spinel (MgAl 2 O 4), magnesium iron aluminate spinel (MgFe 0.6 Al 1.4 O 4), and magnesium aluminum chromate spinel (MgAl 0.5 Cr 1.5 O 4) which replaced magnesium chromate spinel (MgCr 2 O 4) formed during sintering without addition of alumina, eventually improving refractoriness and other properties of the resulting refractory material. By adding 4 wt % alumina to the mixture of slag and 25 wt % sintered magnesia for sintering at 1250°C in only 20 min, the resulting refractory material obtained refractoriness of 1790°C. Compared with that prepared in the absence of alumina, the refractoriness was increased by 156°C. The method proposed in this study has good potential in improving valorization of ferronickel slag into value-added materials, exhibiting both apparent economic and environmental benefits.

Characterization of Minerals, Metals, and Materials 2016, 2016

Solidification treatment is used to treat hazardous wastes for disposal and to remediate the cont... more Solidification treatment is used to treat hazardous wastes for disposal and to remediate the contaminated land. It is an increasingly popular technology for redevelopment of brown fields since treated wastes can often be left on-site, which can improve the site’s soil for subsequent construction. In order to find home for the dredged sludge from the Pearl River Estuary Channel in China, the potential uses of treated dredged sludge by solidification treatment as valuable structural fill was investigated. Structure fills were prepared under various formula and curing conditions. Modulus of elasticity was detemined at 7 days, 14 days and 28 days with different types of load application. Atterberg limit, compactibility and CBR values are reported. The relationship between the microstructure and engineering properties of treated sludge are examined. The results clearly show the technical benefits by stabilizing soft soils with Hydraulic ash-slag cementitious materials. XRD and DTA-TG tests were carried out on certain samples to characterize the hydraulic compounds formed.

Particles o f a nonmagnetic material are rendered mag netic by contacting their surfaces with a m... more Particles o f a nonmagnetic material are rendered mag netic by contacting their surfaces with a magnetizing reagent comprising water containing particles of a mag netic material, each o f which has a two layer surfactant coating including an inner layer and an outer layer. The inner layer covers the magnetic particle and is a monomolecular layer of a first water soluble, organic, heteropolar surfactant containing at least 3 carbon atoms and having a functional group on one end which bonds with the magnetic particle. The outer layer coats the inner layer and is a monomolecular layer of a second water soluble, organic heteropolar surfactant containing at least three carbon atoms and having a hydrophobic end bonded to the hydrophobic end o f the first surfactant and a functional group on the other end capable of bonding with the particles to be magnetized.

Metallurgical and Materials Transactions B, 2015

A (Cu,Ni)/(10NiO-NiFe 2 O 4) cermet was tested as an inert anode for aluminum electrolysis in Na ... more A (Cu,Ni)/(10NiO-NiFe 2 O 4) cermet was tested as an inert anode for aluminum electrolysis in Na 3 AlF 6-K 3 AlF 6-AlF 3 melt at 1173 K (900°C), and its corrosion behavior was studied. The results show that the low-temperature Na 3 AlF 6-K 3 AlF 6-AlF 3 bath is beneficial, improving the service conditions. With the combined effects of the electrolyte composition and the nascent oxygen during electrolysis, the metal phase (Cu,Ni) at the surface of anode will not be leached preferentially, but be transferred into the aluminates including FeAl 2 O 4 , NiAl 2 O 4 and CuAl 2 O 4. This is helpful for the anode to improve its corrosion resistance.

Hwang/Characterization, 2012

Nickel oxide nanoparticles were synthesized using sodium dodecyl sulfate as the surfactant and ur... more Nickel oxide nanoparticles were synthesized using sodium dodecyl sulfate as the surfactant and urea as the hydrolyzing agent and different calcination temperatures and time were selected for preparation. Nitrogen adsorption (BET), X-ray diffraction (XRD) and scanning electron microscope (SEM) were subsequently used to characterize the prepared samples. The effect of an external electric field on hydrogen adsorption over a prepared nickel oxide was carried out. The electric filed was introduced by a piezoelectric element, which is capable of autogenously generating charges under hydrogen pressure. Increased hydrogen adsorption was obtained from this study, which indicated a stronger interaction between the adsorbent surface and hydrogen

Journal of Minerals and Materials Characterization and Engineering, 2011

The morphology and elemental characteristics of Kuru Cassiterite ore deposit was performed by the... more The morphology and elemental characteristics of Kuru Cassiterite ore deposit was performed by the combination of different instruments. This is vital to obtain accurate mineralogical, surface properties and compositions of the ore. Mineral particles were prepared on epoxy resin, polished and analyzed by a SEM coupled with an EDS. X-ray diffraction showed that the ore contained different minerals of cassiterite, coffinite, siderophyllite,ilmenite, qartz, rutile, manganocolumbite, zircon, tilleyite and monazite. Further quantitative analysis using inductive coupled plasma-optical emission spectrometry gave the elemental analysis as follows;

Journal of Minerals and Materials Characterization and Engineering, 2005

Different metals were tested to determine if microwave irradiation can heat liquid metals. Temper... more Different metals were tested to determine if microwave irradiation can heat liquid metals. Temperature profiles of different molten metals under microwave radiation revealed that molten metals are primarily microwave reflectors. To explain this phenomenon, microwave heating mechanisms and skin depths of conductors have been introduced. The influences of resistivities on metal skin depths are also discussed.

Journal of Minerals and Materials Characterization and Engineering, 2012

Model for prediction of the concentration of tin extracted during potassium hydroxide leaching of... more Model for prediction of the concentration of tin extracted during potassium hydroxide leaching of cassiterite has been derived. The model: A = Nt 1.53 , indicates that the concentration of tin extracted is dependent on the residence time. It was found that the validity of the model is rooted in the expression LogA = Log(Nt 1.53). Tin extraction per unit time as obtained from experiment and derived model are 2.6666 and 2.6268 mg/min respectively. The maximum deviation of the model-predicted concentration of dissolved tin from the corresponding concentration obtained from the experiment was found to be less than 8%, which is quite within the acceptable deviation limit of experimental results and hence, impacting about 92% confidence coefficient on the model.

Hwang/2nd International, 2011

2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hw... more 2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hwang, Jaroslav/ Drelich, Jerome Downey, Tao Jiang, and Mark Cooksey TMS (The Minerais, Metals & Materials Society), 2011 ... MICROWAVE ASSISTED ...

Hwang/2nd International, 2011

Peng, Z., Hwang, J.-Y., Huang, X., Andriese, M. and Bell, W.(2011) Microwave Field Attenuation Le... more Peng, Z., Hwang, J.-Y., Huang, X., Andriese, M. and Bell, W.(2011) Microwave Field Attenuation Length and Half-Power Depth in Magnetic Materials, in 2nd International Symposium on High-Temperature Metallurgical Processing (eds J.-Y. Hwang, J. Drelich, J ...

Hwang/2nd International, 2011

2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hw... more 2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hwang, Jaroslaw Drelich, Jerome Downey, Tao Jiang, and Mark Cooksey TMS (The Minerals, Metals & Materials Society), 2011 ... Zhiwei Peng1, Jiann-Yang Hwang1, ...

Jiang/4th International, 2013

The microwave reflection loss (RL) of ferric oxide is studied in the temperature range from 297 t... more The microwave reflection loss (RL) of ferric oxide is studied in the temperature range from 297 to approximately 1400 K at frequencies of 915 and 2450 MHz. It is shown that the maximum microwave absorption with RL of -38.46 and -35.97 dB can be obtained for ferric oxide having thicknesses of 0.03 and 0.01 m at 915 and 2450 MHz, respectively. The maximum absorption peak with RL below -10 dB is in a 250 K temperature range from 723 to 973 K at 915 MHz, which shifts to the range between 823 and 1073 K at 2450 MHz. This migration is in good agreement with the variation of the dielectric loss tangent of ferric oxide

Steel is a basic material broadly used by perhaps every industry and individual. It is critical t... more Steel is a basic material broadly used by perhaps every industry and individual. It is critical to our nation's economy and national security. Unfortunately, the American steel industry is losing competitiveness in the world steel production field. There is an urgent need to develop the next generation of steelmaking technology for the American steel industry.

This research addresses the high priority research need for developing inert anode and wetted cat... more This research addresses the high priority research need for developing inert anode and wetted cathode technology, as defined in the Aluminum Industry Technology Roadmap and Inert Anode Roadmap, with the performance targets: a) significantly reducing the energy intensity of aluminum production, b) ultimately eliminating anode-related CO 2 emissions, and c) reducing aluminum production costs. This research intended to develop a new electrometallurgical extraction technology by introducing microwave irradiation into the current electrolytic cells for primary aluminum production. This technology aimed at accelerating the alumina electrolysis reduction rate and lowering the aluminum production temperature, coupled with the uses of nickel based superalloy inert anode, nickel based superalloy wetted cathode, and modified salt electrolyte. Michigan Technological University, collaborating with Cober Electronic and Century Aluminum, conducted bench-scale research for evaluation of this technology. This research included three sub-topics: a) fluoride microwave absorption; b) microwave assisted electrolytic cell design and fabrication; and c) aluminum electrowinning tests using the microwave assisted electrolytic cell. This research concludes that the typically used fluoride compound for aluminum electrowinning is not a good microwave absorbing material at room temperature. However, it becomes an excellent microwave absorbing material above 550°C. The electrowinning tests did not show benefit to introduce microwave irradiation into the electrolytic cell. The experiments revealed that the nickel-based superalloy is not suitable for use as a cathode material; although it wets with molten aluminum, it causes severe reaction with molten aluminum. In the anode experiments, the chosen superalloy did not meet corrosion resistance requirements. A nicked based alloy without iron content could be further investigated.

Jiang/4th International, 2013

Magnetic iron sulfide ore particles heat rapidly by microwave (MW) irradiation generating plasma ... more Magnetic iron sulfide ore particles heat rapidly by microwave (MW) irradiation generating plasma during oxidation of surfaces. The high temperatures produced by the exothermic event decompose local portions of samples forming a differentiated flux of partially melted silicate (si-mt) with entrained metal-sulfide (sul-mt) droplets. The si-mt forms crystals of olivine (Ol) in Ca-rich pyroxene (Cpx) melt that resorbs a portion of iron sulfide (Po). The immiscible sul-mt droplets of (Fe,Ni,Cu)1-xS contain magnetic subsolidus Ni-pyrrhotite (Ni-Po) with Cr-bearing ferrospinel (Mag). Sub-micron sized flecks of Au are found on the surface of a sul-mt droplet with scanning electron microscope (SEM)

A coal cleaning research by means of surface magnetic I economic feasibilities of this technology... more A coal cleaning research by means of surface magnetic I economic feasibilities of this technology have been demonstrated in this study. Both are competitive to that of the froth flotation approach for coal cleaning.

Particles of a magnetic material coated with a hydrophobic surfactant are dispersed in an organic... more Particles of a magnetic material coated with a hydrophobic surfactant are dispersed in an organic solvent extractant to produce a magnetic solvent extractant which can be used in solvent extraction processes. Phase separation of an organic phase, carrying the com ponent to be separated, from the aqueous phase can be accelerated by applying a magnetic field to the organic phase. After removal of the organic phase, a magnetic field can be applied to the aqueous phase to remove any residual organic phase and thereby enhance the degree of separation.

Electroplating is one of the most important parts in the modern manufacturing industry. All of ou... more Electroplating is one of the most important parts in the modern manufacturing industry. All of our modern electronics need some sort of electroplating process to help it achieve its goals. From smartphone, computer, heavy machinery, decoration, to motor vehicle, almost everything that we used nowadays need electroplating in some ways. However, at the same time electroplating factory can do much harm to the natural environment. Electroplating industry produce 2.7 billion gallons of wastewater in China every year. And most of it won’t be treated to the required level and all go to the river and ocean. This causes a big issue for the environment. Dr. Hwang and Futianbao Environment Protection Technology Ltd. developed a new way to treat the electroplating wastewater. We called it “SCR”, “S” means separation, “C” means concentration and “R” means recycle. The world leading edge “SCR” technology was successfully developed in 2016 by our R&D team which leads by Dr. Hwang. This technology comprehensively not only uses various physical and chemical separation technologies to achieve salt concentration and crystallization, but also recycles heavy metal from the wastewater and reuse reclaimed water. This technology meets the “zero emission” requirement in China. At the same time, it achieves the goal of harmful waste reduction and resource recycling

Degreasing wastewater is a common type of wastewater produced from surface degreasing process in ... more Degreasing wastewater is a common type of wastewater produced from surface degreasing process in the electroplating industry. It has the characteristics of high pH, high oil content, and high COD value. This paper studies COD reduction of degreasing wastewater by UV/H2O2 oxidation process, and factors that affect COD removal rate. Those include H2O2 dosage, feeding method, and pH value. The optimized reaction condition was found to be pH of 3, the molar ratio of H2O2 to COD at 1:1 with continuous feeding of H2O2. A maximum COD removal rate of 91% can be achieved after 4 h of reaction

Ceramics International, 2019

This study presents a new approach to enhance preparation of superior-quality refractory material... more This study presents a new approach to enhance preparation of superior-quality refractory materials by microwave sintering of the mixture of ferronickel slag and sintered magnesia with addition of alumina up to 10 wt %. It was shown that in the process of microwave sintering, the proper addition of alumina could contribute to formation of forsterite with fine and relatively uniform particle size. It also promoted the generations of high melting point magnesium aluminate spinel (MgAl 2 O 4), magnesium iron aluminate spinel (MgFe 0.6 Al 1.4 O 4), and magnesium aluminum chromate spinel (MgAl 0.5 Cr 1.5 O 4) which replaced magnesium chromate spinel (MgCr 2 O 4) formed during sintering without addition of alumina, eventually improving refractoriness and other properties of the resulting refractory material. By adding 4 wt % alumina to the mixture of slag and 25 wt % sintered magnesia for sintering at 1250°C in only 20 min, the resulting refractory material obtained refractoriness of 1790°C. Compared with that prepared in the absence of alumina, the refractoriness was increased by 156°C. The method proposed in this study has good potential in improving valorization of ferronickel slag into value-added materials, exhibiting both apparent economic and environmental benefits.

Characterization of Minerals, Metals, and Materials 2016, 2016

Solidification treatment is used to treat hazardous wastes for disposal and to remediate the cont... more Solidification treatment is used to treat hazardous wastes for disposal and to remediate the contaminated land. It is an increasingly popular technology for redevelopment of brown fields since treated wastes can often be left on-site, which can improve the site’s soil for subsequent construction. In order to find home for the dredged sludge from the Pearl River Estuary Channel in China, the potential uses of treated dredged sludge by solidification treatment as valuable structural fill was investigated. Structure fills were prepared under various formula and curing conditions. Modulus of elasticity was detemined at 7 days, 14 days and 28 days with different types of load application. Atterberg limit, compactibility and CBR values are reported. The relationship between the microstructure and engineering properties of treated sludge are examined. The results clearly show the technical benefits by stabilizing soft soils with Hydraulic ash-slag cementitious materials. XRD and DTA-TG tests were carried out on certain samples to characterize the hydraulic compounds formed.

Particles o f a nonmagnetic material are rendered mag netic by contacting their surfaces with a m... more Particles o f a nonmagnetic material are rendered mag netic by contacting their surfaces with a magnetizing reagent comprising water containing particles of a mag netic material, each o f which has a two layer surfactant coating including an inner layer and an outer layer. The inner layer covers the magnetic particle and is a monomolecular layer of a first water soluble, organic, heteropolar surfactant containing at least 3 carbon atoms and having a functional group on one end which bonds with the magnetic particle. The outer layer coats the inner layer and is a monomolecular layer of a second water soluble, organic heteropolar surfactant containing at least three carbon atoms and having a hydrophobic end bonded to the hydrophobic end o f the first surfactant and a functional group on the other end capable of bonding with the particles to be magnetized.

Metallurgical and Materials Transactions B, 2015

A (Cu,Ni)/(10NiO-NiFe 2 O 4) cermet was tested as an inert anode for aluminum electrolysis in Na ... more A (Cu,Ni)/(10NiO-NiFe 2 O 4) cermet was tested as an inert anode for aluminum electrolysis in Na 3 AlF 6-K 3 AlF 6-AlF 3 melt at 1173 K (900°C), and its corrosion behavior was studied. The results show that the low-temperature Na 3 AlF 6-K 3 AlF 6-AlF 3 bath is beneficial, improving the service conditions. With the combined effects of the electrolyte composition and the nascent oxygen during electrolysis, the metal phase (Cu,Ni) at the surface of anode will not be leached preferentially, but be transferred into the aluminates including FeAl 2 O 4 , NiAl 2 O 4 and CuAl 2 O 4. This is helpful for the anode to improve its corrosion resistance.

Hwang/Characterization, 2012

Nickel oxide nanoparticles were synthesized using sodium dodecyl sulfate as the surfactant and ur... more Nickel oxide nanoparticles were synthesized using sodium dodecyl sulfate as the surfactant and urea as the hydrolyzing agent and different calcination temperatures and time were selected for preparation. Nitrogen adsorption (BET), X-ray diffraction (XRD) and scanning electron microscope (SEM) were subsequently used to characterize the prepared samples. The effect of an external electric field on hydrogen adsorption over a prepared nickel oxide was carried out. The electric filed was introduced by a piezoelectric element, which is capable of autogenously generating charges under hydrogen pressure. Increased hydrogen adsorption was obtained from this study, which indicated a stronger interaction between the adsorbent surface and hydrogen

Journal of Minerals and Materials Characterization and Engineering, 2011

The morphology and elemental characteristics of Kuru Cassiterite ore deposit was performed by the... more The morphology and elemental characteristics of Kuru Cassiterite ore deposit was performed by the combination of different instruments. This is vital to obtain accurate mineralogical, surface properties and compositions of the ore. Mineral particles were prepared on epoxy resin, polished and analyzed by a SEM coupled with an EDS. X-ray diffraction showed that the ore contained different minerals of cassiterite, coffinite, siderophyllite,ilmenite, qartz, rutile, manganocolumbite, zircon, tilleyite and monazite. Further quantitative analysis using inductive coupled plasma-optical emission spectrometry gave the elemental analysis as follows;

Journal of Minerals and Materials Characterization and Engineering, 2005

Different metals were tested to determine if microwave irradiation can heat liquid metals. Temper... more Different metals were tested to determine if microwave irradiation can heat liquid metals. Temperature profiles of different molten metals under microwave radiation revealed that molten metals are primarily microwave reflectors. To explain this phenomenon, microwave heating mechanisms and skin depths of conductors have been introduced. The influences of resistivities on metal skin depths are also discussed.

Journal of Minerals and Materials Characterization and Engineering, 2012

Model for prediction of the concentration of tin extracted during potassium hydroxide leaching of... more Model for prediction of the concentration of tin extracted during potassium hydroxide leaching of cassiterite has been derived. The model: A = Nt 1.53 , indicates that the concentration of tin extracted is dependent on the residence time. It was found that the validity of the model is rooted in the expression LogA = Log(Nt 1.53). Tin extraction per unit time as obtained from experiment and derived model are 2.6666 and 2.6268 mg/min respectively. The maximum deviation of the model-predicted concentration of dissolved tin from the corresponding concentration obtained from the experiment was found to be less than 8%, which is quite within the acceptable deviation limit of experimental results and hence, impacting about 92% confidence coefficient on the model.

Hwang/2nd International, 2011

2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hw... more 2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hwang, Jaroslav/ Drelich, Jerome Downey, Tao Jiang, and Mark Cooksey TMS (The Minerais, Metals & Materials Society), 2011 ... MICROWAVE ASSISTED ...

Hwang/2nd International, 2011

Peng, Z., Hwang, J.-Y., Huang, X., Andriese, M. and Bell, W.(2011) Microwave Field Attenuation Le... more Peng, Z., Hwang, J.-Y., Huang, X., Andriese, M. and Bell, W.(2011) Microwave Field Attenuation Length and Half-Power Depth in Magnetic Materials, in 2nd International Symposium on High-Temperature Metallurgical Processing (eds J.-Y. Hwang, J. Drelich, J ...

Hwang/2nd International, 2011

2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hw... more 2nd International Symposium on High-Temperature Metallurgical Processing Edited by: Jiann-Yang Hwang, Jaroslaw Drelich, Jerome Downey, Tao Jiang, and Mark Cooksey TMS (The Minerals, Metals & Materials Society), 2011 ... Zhiwei Peng1, Jiann-Yang Hwang1, ...

Jiang/4th International, 2013

The microwave reflection loss (RL) of ferric oxide is studied in the temperature range from 297 t... more The microwave reflection loss (RL) of ferric oxide is studied in the temperature range from 297 to approximately 1400 K at frequencies of 915 and 2450 MHz. It is shown that the maximum microwave absorption with RL of -38.46 and -35.97 dB can be obtained for ferric oxide having thicknesses of 0.03 and 0.01 m at 915 and 2450 MHz, respectively. The maximum absorption peak with RL below -10 dB is in a 250 K temperature range from 723 to 973 K at 915 MHz, which shifts to the range between 823 and 1073 K at 2450 MHz. This migration is in good agreement with the variation of the dielectric loss tangent of ferric oxide

Steel is a basic material broadly used by perhaps every industry and individual. It is critical t... more Steel is a basic material broadly used by perhaps every industry and individual. It is critical to our nation's economy and national security. Unfortunately, the American steel industry is losing competitiveness in the world steel production field. There is an urgent need to develop the next generation of steelmaking technology for the American steel industry.

This research addresses the high priority research need for developing inert anode and wetted cat... more This research addresses the high priority research need for developing inert anode and wetted cathode technology, as defined in the Aluminum Industry Technology Roadmap and Inert Anode Roadmap, with the performance targets: a) significantly reducing the energy intensity of aluminum production, b) ultimately eliminating anode-related CO 2 emissions, and c) reducing aluminum production costs. This research intended to develop a new electrometallurgical extraction technology by introducing microwave irradiation into the current electrolytic cells for primary aluminum production. This technology aimed at accelerating the alumina electrolysis reduction rate and lowering the aluminum production temperature, coupled with the uses of nickel based superalloy inert anode, nickel based superalloy wetted cathode, and modified salt electrolyte. Michigan Technological University, collaborating with Cober Electronic and Century Aluminum, conducted bench-scale research for evaluation of this technology. This research included three sub-topics: a) fluoride microwave absorption; b) microwave assisted electrolytic cell design and fabrication; and c) aluminum electrowinning tests using the microwave assisted electrolytic cell. This research concludes that the typically used fluoride compound for aluminum electrowinning is not a good microwave absorbing material at room temperature. However, it becomes an excellent microwave absorbing material above 550°C. The electrowinning tests did not show benefit to introduce microwave irradiation into the electrolytic cell. The experiments revealed that the nickel-based superalloy is not suitable for use as a cathode material; although it wets with molten aluminum, it causes severe reaction with molten aluminum. In the anode experiments, the chosen superalloy did not meet corrosion resistance requirements. A nicked based alloy without iron content could be further investigated.

Jiang/4th International, 2013

Magnetic iron sulfide ore particles heat rapidly by microwave (MW) irradiation generating plasma ... more Magnetic iron sulfide ore particles heat rapidly by microwave (MW) irradiation generating plasma during oxidation of surfaces. The high temperatures produced by the exothermic event decompose local portions of samples forming a differentiated flux of partially melted silicate (si-mt) with entrained metal-sulfide (sul-mt) droplets. The si-mt forms crystals of olivine (Ol) in Ca-rich pyroxene (Cpx) melt that resorbs a portion of iron sulfide (Po). The immiscible sul-mt droplets of (Fe,Ni,Cu)1-xS contain magnetic subsolidus Ni-pyrrhotite (Ni-Po) with Cr-bearing ferrospinel (Mag). Sub-micron sized flecks of Au are found on the surface of a sul-mt droplet with scanning electron microscope (SEM)