Characteristics and utilization of clay minerals in Kuwu Mud Volcano, Kradenan District, Grobogan Regency, Central Java Province

Abstract

The benefits of clay minerals are currently numerous. Therefore, this study aims to determine clay minerals’ characteristics in the mud material recommended for use, especially in the ceramic and cosmetic industry. This research is located in Bledug Kuwu, in Kuwu Village, Kradenan District, Grobogan Regency, Central Java Province. Bledug Kuwu produces mudflows composed of gravel, sand, silt, plastic clay, and water. Field observations and sampling were carried out on any differences in the morphology of the existing mud volcanoes, namely inactive craters and active griffins, with an average area of about 0.8–5 meters of mud material distribution. Samples were prepared to analyze X-ray diffraction (XRD), cation exchange capacity (CEC), pH, grain size distribution, plasticity test, swelling test, shrinkage limit test, and specific gravity. The results of the analysis show that the dominant clay minerals were smectite, followed by kaolinite and illite minerals, with dominant clay to silt grain sizes, plasticity levels of 24.78% to 55.48%, swelling percentage of 7.8%. up to 12.5%, with shrinkage limits of 9.36% to 14.83%, specific gravity values of 2.50–2.84, cation exchange capacity (CEC) values of 9.96–20.47 meq/100g, and the pH value shows the numbers 8.01– 8.40. These characteristics can be recommended to use clay minerals as raw material for cosmetics and ceramics.