Synthesis of Silica-Potassium-Nitrogen from Carbamide and Potassium Silicate by CO_2 Precipitator

摘要

Potassium silicate is well known as a fertilizer and source of silica for plants growth. This study aims to infiltrate nitrogen from carbamide (urea) into potassium silicate solution to produced silica potassium nitrogen (Si-K-N) matrix by precipitation method using CO_2 as precipitator. Potassium silicate in the range of 3-8% SiO_2 was obtained by extracting silica from geothermal sludge using potassium hydroxide solution. Carbamide is added to the potassium silicate solution allowed by mixing and flowing of CO_2 gas in reactor glass. The result of IR spectra indicated the presence of N-H groups, potassium and silica in the gel matrix produced from precipitation process while no N-H group appears in the gel matrix produced from precipitation in the absence of carbamide. X-ray fluorescence showed the composition of the product Si-K-N in the range of 40 to 50 %SiO_2 and in the range of 50 to 60 %K_2O.