Eschka’s mixture is primarily used in the determination of sulfur content in coal and other carbonaceous materials. It is a key reagent in analytical chemistry for the gravimetric analysis of sulfur. The mixture is employed to convert sulfur compounds into sulfate during the combustion process, which can then be precipitated as barium sulfate for accurate measurement. This application is crucial in industries such as coal mining, energy production, and environmental testing, where monitoring sulfur levels is essential for compliance with regulations and assessing fuel quality. Additionally, it is used in laboratories for research and quality control purposes to ensure the accuracy of sulfur content data in various materials.