Avaliação qualitativa das diferentes variedades de mármore da região de Caçapava do Sul como matéria-prima para a produção de corretivos de acidez dos solos e cal

Abstract

The carbonate rocks occupy an expressive volume throughout the Earth’s surface. They are found in many litostratigraphic units, deposited by chemical and biological processes since the Archean (>2.5 GA) until the Quaternary (<1,75 Ma). Limestones and marbles are examples of this type of rock, which represent 10 to 15% of all the metasedimentary and sedimentary rocks in the world. The region of Caçapava do Sul – RS is an example of this occurrence, with marbles that are explored by many mining companies, which represents a large income source and jobs for the city. The rocks of the area are predominantly white and, due to their chemical features, are classified as dolomite marbles that after extraction and beneficiation are commercialized as agricultural limestones, being used as acidity soil corrective and a small percentage as lime. However, besides the white marbles, in some areas, it is possible to find black, pink and cream rocks. Therefore, this research aims to evaluate the quality of the different types of limestones (dark, pink, white and cream) found in Caçapava do Sul - RS as raw material for the production of soil correctors and lime. Through the analysis of the parameters required by the Ministério da Agricultura, Pecuária e Abastecimento for the production of soil correctors and for the ABNT norm NBR-6473 for the production of lime. It was possible to conclude that all the varieties of marbles analyzed present the minimal chemical features required by the legislation for the production of acidity soil corrective. For the production of lime, only the dark, white and pink varieties presented the expected result.