Experimental investigations on electrical-insulation performance of Al2O3 coatings for high temperature PbLi liquid metal applications

Design, fabrication and validation of an electrical conductivity principle based two-phase detection sensor array for molten lead (Pb) based heavy metal coolants up to 600°C

“…In consideration to the IR values measured and IR performance ascertained in previous work [15] along with practical assumptions of negligible electrical resistivity for the molten metal and negligible electrical conductivity for a gas bubble, the voltage output from a conductivity probe circuit across a series connected 250 Ω sensing-cum-limiting resistor is expected to be a rectangular voltage wave with 𝑉 liquid ∼ 99.6% of 𝑉 Ex during molten metal immersion and 𝑉 gas ∼ 0.005% of 𝑉 Ex during gas encapsulation at 500 • C, where 𝑉 Ex is the excitation voltage for the conductivity probe circuit. Here, the complete circuit resistance (exclusive of the 250 Ω sensing resistor) is assumed to be 1 Ω for ease of calculations.…”

“…Nevertheless, a challenging and corrosive high temperature molten metal environment immensely strains the performance and thermal/chemical integrity of the electrical insulation layer necessary to realize electrical conductivity-based two-phase detection tools. In this study, taking the leverage of previously demonstrated electrical insulation integrity, thermal stability and chemical imperviousness of AlPO 4 -bonded 𝛼-Al 2 O 3 coatings in molten PbLi environment [15], an 8-probe sandwich-type flanged configuration sensor array is designed, fabricated and assembled at the Institute for Plasma Research (IPR) for future two-phase investigations in horizontal and vertical pipelines of high temperature molten Pb/PbLi loops within the operational temperature range of 400 • C-500 • C. Thermal analysis for the array corroborates the selection of functional materials while a manual dip/retrieval immersion cycle enables preliminary calibration and validation in molten PbLi static column at 400 • C. Further, detailed experiments in high temperature molten Pb column (500 • C-600 • C) substantiate the feasibility of individual sensor probes toward applications in molten metal environment of interest. electrical conductivity electrodes, made from needle-shaped SS-316L filler rods, are encapsulated in recrystallized Al 2 O 3 tubes spray-coated with aluminum monophosphate (AlPO 4 ) bonded high purity (99.8%) 𝛼-Al 2 O 3 suspension, which is heat cured to provide the necessary chemical compatibility, insulation integrity and ruggedness against gas bubbles impaction within the intended molten metal environment.…”

Effect of buffer on direct lithium extraction from Tibetan brine by formed titanium-based lithium ion sieves

“…Lithium, as the lightest alkali metal, is widely used in fields such as lithium batteries manufacturing, 1,2 atomic thermonuclear fusion (reaction), 3 the chemical industry, 4 pharmaceuticals. 5 However, recent interest in lithium batteries has stimulated a growth in lithium demand which has caused a shortage in supply.…”