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The utilization of sulfur acid residue is an urgent problem confronting sulfuric acid production enterprises, especially the application of sulfur acid residue (SAR) containing lead and zinc. A method combining chlorination roasting using CaCl2 with pelletizing for processing SAR containing lead and zinc was used in this study, and the effect of calcium chloride on pelletizing performance was studied; in addition, the removal behavior of lead and zinc was also studied by using polarized light microscopy (Zeiss double Axioskop 40A), X ray diffraction, SEM and EDS. The results showed that CaCl2 migrated to the surface of the pellets during drying, and this phenomenon resulted in a lower removal rate of lead and zinc inside the pellets than outside the pellets during the preheating phase. When the roasting temperature was 1220 °C, with an increase in the basicity of pellets, the silicate minerals in the pellets gradually decomposed, the hematite particles were gradually refined, and more lead or zinc minerals were exposed, which further increased the removal rate of lead and zinc in the pellets. Finally, the SAR pellets with Pb and Zn removal rates up to 91.33 and 97.88%, and a compressive strength of 2789 N, could be obtained, which is very beneficial to the sustainable development of sulfuric acid mills. [ABSTRACT FROM AUTHOR]

This study investigated the combustion characteristics of mixed straw char and coal powder when used in blast furnace injection. The experiments examined the effects of mixing ratios between biomass char types of wheat straw char, corn straw char as well as cotton straw char, and anthracite coal on combustion characteristics and the injection effect of blast furnace. The results show that a 1:1 mixing ratio of wheat straw char and anthracite coal yields the best combustion characteristics, followed by a 1:1 ratio of corn straw char and anthracite coal. A 2:1 mixture of cotton straw char and anthracite coal exhibits the highest combustion efficiency. The study on the grindability of the mixtures indicates that straw char is easier to grind due to its brittleness. Blast furnace coal injection experiments reveal that a 50:50 mixture of cotton straw char and anthracite coal achieves the highest combustion efficiency at 74%, which is a 20.2% improvement compared to mixtures of bituminous coal and anthracite coal, significantly outperforming the other ratios. The findings underscore the importance of integrating renewable biomass resources in industrial applications to enhance sustainability in the metallurgical industry. [ABSTRACT FROM AUTHOR]

While numerous studies have explored the mineralogical characteristics and purification techniques of high-purity quartz (HPQ), discussions on impurity control during various purification processes and their applications in photovoltaics, electronics, and optics remain limited. This review delves into the adverse effects of impurities such as aluminum, iron, and sodium in the manufacturing processes of these industries, emphasizing their critical role as these impurities can degrade material performance. This paper focuses on analyzing the types of impurities found in quartz and evaluates existing purification technologies such as acid washing, ultrasonic acid washing, chlorination roasting, and calcination quenching. It highlights the limitations of current technologies in processing quartz ore and discusses the advantages of different impurity types under various technological treatments. Moreover, it explores the environmental and economic impacts of these high-purity processes, underlining the necessity for more environmentally friendly and cost-effective purification techniques. The purpose of this review is to provide a comprehensive technical and strategic framework for the use of high-purity quartz in high-tech applications, supporting future research and industrial applications in this critical material field. [ABSTRACT FROM AUTHOR]