In this paper, mullite was adopted in order to absorb Palmitic Acid (PA) via a direct impregnation method. The prepared PA/mullite form-stable phase change materials (FSPCM) were systematically characterized by the Leakage Test (LT), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Differential Scanning Calorimeter (DSC), Thermogravimetry (TG) and Cooling Curve Method (CCM). The results indicated that, among these composites with different mass fractions of PA, the sample with the 32 wt % Palmitic Acid has the best properties without any leakage. The enthalpy of 32%PA/68%mullite FSPCM is 50.8 J/g for melting process, and 58.3 J/g for solidifying process. The phase change point of 32%PA/68%mullite FSPCM is 64.1 °C for melting and 58.7 °C for solidifying. The heat storage efficiency of the PA/mullite FSPCM was enhanced considerably by adding mullite. The leakage and thermal properties of PA/mullite FSPCM were discussed and the performance of the FSPCM has been apparently improved.

Porcelain tiles are a building material that has been widely used in recent years and that consumes substantial resources during the sintering process. This study reports on the production of low-temperature porcelain tiles by using low-grade lithium ore (LO) and silica crucible waste (SCW) in a new SiO₂–Al₂O₃–Na₂O–K₂O–Li₂O system. The firing temperature of the porcelain tiles was reduced from 1260 °C to 1070 °C by adding 30% LO instead of feldspar in a modified triaxial ceramic body, and SCW was recycled and used as a raw material. These actions help to reduce the carbon emissions produced during sintering and achieve sustainable development. The effect of phase transitions on the sintering and technological properties of the porcelain tiles was studied by quantitative phase analysis, using X-ray diffraction (XRD). Secondary mullite (0–19%) can be formed at 1040–1100 °C, where more quartz and cristobalite will be retained, which increases the rupture modulus of the porcelain tiles. While the vitreous phase increases rapidly at 1100–1160 °C, the closed pores (0.1–33.1%) will simultaneously expand, causing a decrease in compactness. The results show that low-grade LO (with a cost similar to that of feldspar) allows for the production of porcelain tiles with better process performance at lower temperatures (≤1100 °C).

In photovoltaic industry, silica crucible has an important influence on the quality of single crystal silicon. To obtain a silica glass crucible with large diameter, high uniformity, and low bubble content, two series of crucibles were prepared by the arc melting method, one with various melting parameters (initial power, melting power, and melting time) and crucible sizes, and the other with various quartz purities. The bubbles inside the crucible wall and pores on the inner surface were all measured using a polarised optical microscope and a portable microscope. The results show that all crucibles have a bubble aggregation area in their inner surface (0–0.4 mm), in which the density and size of bubbles are affected by melting time, melting power, and the distance between the crucible and the graphite electrode. The uniformity of the crucible decreases as the crucible diameter increases (16–28 inches), and the crucible is relatively stable when the initial power is below 400 kW. In final, a silica crucible with large size (diameter of 28 inches) and low bubble content on inner surface (∼50% reduction than that of traditional crucibles) was successfully prepared, which is of great value to the photovoltaic industry.