Jo Jan 20, 2026
The viscosity of slag is a very important factor in understanding the rate of metal-slag chemical reactions and the mass transfer taking place in the pyrometallurgy process. It is also vital for ensuring stable operation of metallurgical furnaces. Therefore, accurate prediction of the viscosity of slag is of great importance not only for the operation stability and productivity in the pyrometallurgy process but also for high yield.
Up to now, many researchers have carried out various viscometric experiments of slag, and many models have been developed to estimate its viscosity. However, the previously developed slag viscosity prediction models are mostly for solid-free slag.
Since most metallurgical slag necessarily contains MgO, it is very important to develop a model for predicting the viscosity of CaO–SiO2–Al2O3–MgO system slag.
Ro Tae Song, a researcher at the Faculty of Metallic Engineering, has proposed a viscosity prediction model of CaO–SiO2–Al2O3–MgO system slag using the multi-gene genetic programming (MGGP).
The proposed viscosity model is a simple algebraic equation with varying basicity, Al2O3 content, MgO content and temperature of slag. Furthermore, the average relative error between experimental data and the calculated values using the model is 25.10%, which is comparatively small.
For more information, please refer to his paper “Viscosity Prediction of CaO–SiO2–Al2O3–MgO System Slag Using MGGP” in “Transactions of the indian institute of metals” (SCI).
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Jo Jan 18, 2026
Now cyanidation is the main method for producing gold from gold ore/concentrate.
It is well-known that gold in ore/concentrate is dissolved in the form of gold-cyanide complex by the action of cyanide and oxygen. During cyanidation, copper in the ore/concentrate readily reacts with cyanide to form stable cyanide complexes and under ordinary cyanidation conditions Cu(CN)32- is the dominant species in leach solution. Thus, the recovery of copper as well as cyanide from gold-plant wastewater will offer economic benefit.
AVR (acidification-volatilization-regeneration) technology, SART (sulfidization-acidification-recycling-thickening) process, electrowinning, membrane technologies, etc. have been developed to recover cyanide and/or copper, but each of these technologies has advantages and limitations and there is no universal method. Among these, AVR process has been used in industry owing to its simple principle and high effectiveness and robustness.
Kim Yong Il, a researcher at the Faculty of Metallic Engineering, evaluated sulfuric acid baking-leaching process to recover copper from precipitate containing Cu of 44.53 wt %, Fe of 5.56 wt % and S of 16.81 wt %, which comes from cyanidation wastewater treatment process by AVR (acidification-volatilization-regeneration) technology in a gold plant.
The experimental results showed that by acid baking under following conditions of 250℃, 60 min and the ratio of H2SO4 to copper precipitate 2.4:1, ~98.5 wt % copper was released to the leach solution, and that the leachate containing Cu and Fe can be sent to the conventional SX-EW process to produce electrolytic copper.
You can find the details in his paper “Acid Baking-Leaching Process for Treatment of Copper Precipitate from AVR Process” in “Russian Journal of Non-Ferrous Metals” (SCI).
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Jo Jan 16, 2026
Point-type smoke sensors detect fire through sensor signals that are changed by smoke, which occurs early from the fire. However, the drawback of these smoke sensors is the drift of sensor signals due to the sensitivity to environmental changes. This can be the cause of occasional false alarms.
The first reason for sensor signal change in smoke sensors is seasonal changes in temperature and humidity. Secondly, in the case of an ionic smoke sensor, the accumulation of dust layers on the surface of radiation source decreases the ion current and the leakage of current between the electrodes causes the sensor signal to change. Inherent noise caused by the uncertainty of the radioactive decay for ionization is another reason, which is inversely proportional to the square root of the radioactivity. Lastly, the radiation sources used for the ionic smoke sensor are not uniform, so the sensitivities and signals of the sensors are also different, which also degrades the accuracy of fire alarm in a fire monitor based on a fixed threshold.
By these factors, sensor signals tend to increase or decrease slowly with time. If these signals are higher than a fixed threshold already set, the false alarm can be heard in the absence of fire, and if they are lower, they may generate the alarm late for real fires or may not generate the alarm at all. Therefore, smoke sensors or fire monitors need to adjust the threshold actively according to the sensor signals.
Jo Jin Song, a researcher at the Institute of Analysis, designed and verified a compensation algorithm that can automatically adjust the threshold for point-type smoke sensors or fire monitors.
The algorithm does not fix the threshold that is the criterion for identifying fire presence, but it can adjust it gradually to the change of sensor signals to improve the accuracy of alarm.
This algorithm can be applied to almost all point-type smoke sensors or fire monitors for active fire detection.
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Jo Jan 13, 2026
When the hull roof frame with a large bending radius is made with L-shaped steel instead of a square pipe by a press, the die must be designed correctly considering the spring-back in order to ensure high accuracy.
Ri Song Min, a researcher at the Faculty of Mechanical Science and Technology, proposed a method of selecting a reasonable bending radius of the die by considering the stress, strain characteristics and spring-back of work-pieces in the process of bending the L-shaped steel that is used in the manufacture of the roof frames of vehicles including underground trains by means of a press, and conducted a simulation analysis. In addition, by measuring the amount of spring-back at the time of bending with constant force using a press to compare the experimental values with simulation values, he evaluated the accuracy of the simulation analysis, and compared the bending radii of the die to form an L-shaped steel product for roof frames.
He performed a finite element analysis at the ceiling and the corner sections, respectively. The finite element simulation analysis result of the process of bending the L-shaped steel shows that the bending radius of the die must be designed to be 7 782mm and 426mm for the ceiling and the corner sections, respectively.
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Jo Jan 9, 2026
PTN (Packet Transport Network) based on MPLS-TP (Multi-Protocol Label Switching-Transport Profile) does not rely on subscriber service signals. It provides real-time transmission and robust OAM (Operation, Administration and Maintenance) functions thanks to VPN (Virtual Private Network) technique using LSP (Label Switch Path) and PW (Pseudo-Wire) for transparent transport, thus being widely used in transport systems for mobile communication.
The PTN for 3rd generation mobile communication is operated in the centralized way, and it is difficult to apply to the next generation mobile communication.
Kim Myong Jun, a researcher at the Faculty of Communication, has proposed a method of how to apply MPLS-TP based PTN device using dedicated network processor WINPATH to the next generation systems, and verified its application possibility.
The experimental results show that transport network for next generation can adopt MPLS-TP based PTN device by the proposed method.
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Jo Jan 9, 2026
Radiation leaking into the surrounding environment has a detrimental effect on the human body, so it should be evaluated first to prevent it.
The most considerable radiation affecting the human body is gamma rays. This is because the penetrability of gamma rays is the strongest of all other kinds of radiation. Therefore, gamma dose measurement is of paramount importance for its dosimetry.
Radiation detectors for environmental radiation monitoring usually include scintillation detectors, ionization chambers, and automatic discharge counters. Among them, automatic discharge counter tubes are widely used for environmental radiation monitor fabrication because of their low cost and simple measurement circuitry. However, the automatic discharge counter tubes manufactured at home and abroad have the disadvantage of narrow energy band for dose estimation and low counting rate.
Pak Yong, a researcher at the Institute of Analysis, has designed a new environmental radiation monitor to measure radioactive contamination and environmental radiation.
By applying the time-count conversion method, he eliminated the effect of dead time in the GM counter tube and extended the counting rate measurement range from 2×103 to 105cells/s.
The proposed monitor enables measurement from 10nSv/h to 200mSv/h using two GM counters with improved properties.
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