Análise da eficiência do peneiramento de calcário em uma mineradora no Ceará

Abstract

Limestone, with its composition rich in calcium carbonate, is a natural resource of great significance to society. It has applications in various sectors, such as the cement, paper, plastics, paints, glass, and ceramics industries, civil construction, environmental management, and even healthcare. In agriculture, it is an essential input used to neutralize soil acidity while providing calcium and magnesium, nutrients indispensable for plant growth. Additionally, limestone improves soil structure, increases nutrient availability, and reduces aluminum toxicity. The particle size distribution of limestone is a crucial factor in selecting the appropriate product for soil acidity correction. Choosing the proper granulometry ensures greater efficiency in the correction process, resulting in better crop development and higher productivity. Therefore, beneficiation processes must be efficient to ensure the quality of the final product. Among these processes, screening plays a fundamental role in separating particles according to the desired size. In this context, the objective of this study is to assess the efficiency of the screening process in a limestone mining operation located in the state of Ceará, Brazil. To this end, 547 limestone mining processes in the state were mapped, allowing for the identification of producing companies and the selection of representative samples for analysis. Physical characterization revealed a real density of 2.80 g/cm³ and an apparent density of 1.29 g/cm³, while the chemical composition analysis indicated a predominance of calcium oxide (32.407%) and magnesium oxide (18.298%), characterizing the material as dolomitic limestone. Mineralogical and petrographic analysis confirmed the predominant presence of dolomite (84.2%) and calcite (15.8%), along with a high content of calcium and magnesium carbonate (99.5%) The screening evaluation demonstrated that the 60 mm sieve exhibited 100% efficiency, indicating that all particles within the desired fraction passed through the opening. These results are crucial in determining whether the limestone will perform effectively in its intended applications.