STUDY OF MATERIAL SYNTHESIS WITH DOLOMITE AND POTASSIUM DIHYDROGEN PHOSPHATE AS RAW MATERIALS FOR POTASSIUM DISSOLUTION TEST IN WATER

• Main Author: Nurbehaqi, Fajar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49102
• Institution: Institut Teknologi Bandung

The growth of the Indonesian population will make food demand increase. As condition of agriculture area is degrading over by time, fertilizer is used to give nutrition to soil so it can be absorbed by plants. However, intensive fertilizer use will impact the environment badly. High solubility of fertilizer causes the fertilizer elements to be improperly absorbed by the plants and pollute environment. One of the solutions for this problem is developing a material that can release potassium as soil nutrients for delayed and longer time. In this research work, this material is made from dolomite mineral and potassium dihydrogen phosphate mixture. Dolomite mineral was obtained from the region of Lamongan, East Java. A series of tests at atmospheric pressure have been carried out to study the effect of milling speed, milling time, and ball to powder ratio (BPR) on the potassium dissolution percentage in water. The product is milled and heated until 600°C. The effect of milling speed was studied at various speed of 150, 200, and 250 rotation per minute. The effect of milling time was studied at various times at 4, 6, 8, 12, 16, and 24 hours of milling. Meanwhile, the effect of ball to powder ratio was studied at BPR variation of 56:1, 28:1, and 14:1. The sample is dissolved in water for 5760 minutes. The percentages of dissolved K as a function of dissolution time were determined by Atomic Absorption Spectroscopy (AAS) analysis. XRD (XRay Diffraction) is used to analyse the compound change of the product. SEM (Scanning Electron Microscope) and FTIR (Fourier Transform Infrared Spectroscopy) were used for morphology and bonding change analysis. After milling and heating, the product obtained from the mixture is Potassium Calcium Pyrophosphate at mixture. SEM analysis result indicates presence of agglomerates after milling and larger size of agglomerates after heating. Based on FTIR analysis result, there is intensity peak change after milling and heating. Potassium dissolution percentage is 39,124% obtained from 24 hours, 250 rpm, and 56:1 BPR milling product.