R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

[R2-04] Synthesis of potassium silicate fertilizer from drifted pumice stones from Fukutoku-Okanoba -a preliminary report-

*Hiroaki Ohfuji¹, Haruki Urazoe¹ (1. Tohoku Univ. Sci.)

Keywords:pumice stone, potassium silicate fertilizer, kaliophilite

We present a preliminary report on the synthesis of potassium silicate fertilizer, which is highly effective in improving the growth and yield of rice plants, from drifted pumice stones originated from Fukutoku-Okanoba, Ogasawara Island. The heating of a mixture of powdered pumice and KOH solution at 800 ºC gave a product composed of kaliophilite (KAlSiO₄), similar to the commercial “Keisankari” fertilizer synthesized from coal fly ash.