In situ observation of crystallization of mold slag using a digital optical microscope in an infrared furnace

Abstract

The complete crystallization process of mold slag in the crucible (inner diameter: 6.2 mm) was successfully recorded in situ using a digital optical microscope and image processing software in an infrared furnace (IR-MOP). The crystallization behavior of non-volatile mold slag tested with the new method is consistent with the findings of differential scanning calorimetry (DSC) analysis. Although the volatilization ratios of volatile mold slag during both DSC and SHTT experiments are greater than 8%, it is less than 1.2% during IR-MOP experiments equipped with an isolated observation system, which explains why the difference in the initial crystallization temperature measured by the three methods was very large.Therefore, IR-MOP equipped with an isolated observation system can record and accurately measure the crystallization behavior of volatile mold slag. K E Y W O R D Scrystal morphology, crystallization process, digital optical microscope, volatilization

Influence of Al₂O₃/SiO₂ and BaO/Al₂O₃ Ratios on Rheological and Crystallization Behavior of CaO–BaO–Al₂O₃-Based Mold Slags

“…To accurately test the crystallization behavior of CaO-Al 2 O 3 -based mold slag, a modified confocal scanning laser microscopy was employed in this study. The confocal scanning laser microscopy was replaced with a digital optical microscope in an infrared furnace (IR-MOP), 31) which can observe the entire crystallization process of the mold slag. IR-MOP equipped with an in-house observation system has been proved to have a lower volatilization ratio of the slag than other methods and could accurately measure the crystallization of the volatile mold slag.…”

“…IR-MOP equipped with an in-house observation system has been proved to have a lower volatilization ratio of the slag than other methods and could accurately measure the crystallization of the volatile mold slag. 31) The effect of Al 2 O 3 /SiO 2 and BaO/Al 2 O 3 ratios on the rheological and crystallization behavior of CaO-Al 2 O 3 -based mold slag was investigated at different cooling rates applying this method. The crystallization phases at different cooling rates were analyzed by X-ray diffraction (XRD).…”

“…In the current study, the crystallization behavior of mold slags in Table 1 was fully observed and recorded in the wide field of view by a digital optical microscope of the infrared furnace (IR-MOP), 31) as shown in Fig. 1.…”

“…In the current study, the initial crystallization temperature (T c ) of the slag was defined as the temperature at which the ratio of the crystalline area to the total area of the observed field was 5.0%, i.e. the crystalline fraction X was equal to 0.05, 31) and the image processing software Photoshop was used to analyze the images and determine the crystallization fraction, as shown in Fig. 2.…”