Production of slow release nitrogen fertilizers by improved method of coating urea with sulfur

摘要: A process for applying a precisely uniform solid coating of fluid material onto substrate particles where in one embodiment the surface is smoothed by superficial fusion and rolling rotary drum, multiple, thin, concentrically formed layers are applied cascading beneath plurality sequentially applied, closely controlled pneumatic sprays drum. In second embodiment, hydraulic spray nozzles utilized manner wherein requisite preheating not required. Special operating conditions specified which allow production slowrelease fertilizer coated only with sulfur. Proper temperature control maintained during to assure that sulfur solidifies proper crystalline structure impart significantly improved tensile strength characteristics coating. Each has characteristically different conditions, specifically temperatures, result decisively characteristics.