Open AccessA STUDY OF UNCOATED AND COATED UREA CRYSTALS DISSOLUTION IN STIRRED VESSEL
Author(s) -
Muhammad Husin Ismayanda,
Myrurlatifah Zakaria
Publication year - 2017
Publication title -
reaktor
Language(s) - English
Resource type - Journals
eISSN - 2407-5973
pISSN - 0852-0798
DOI - 10.14710/reaktor.8.2.81-84
Subject(s) - dissolution , urea , coating , coated urea , materials science , starch , chemical engineering , mass transfer coefficient , nuclear chemistry , mass transfer , chemistry , chromatography , composite material , organic chemistry , engineering
An immersing and spray coating process has been developed for the continous production of tapioca starch and silica coated urea. The coating thicness and quality of coated urea was produced in a laboratory-scale unit. The dissolution rates of urea uncoated and coated urea crystals were studied in a stirred vessel. Coated urea crystals genarally shows low dissolution rates compared to uncoated for all coating materials. The effect of coating was best with tapoca starch and silica combination baked at 70oC. This cating material of tapioca starch coating urea the dissolution time was in the range of 300 to 360 second mass transfer coefficient in the range of between 3.63 x 10-6 to 2.91 x 10-3 cm 2/s. And for the silica coated urea coating material, the dissolution time was in the range of 300 to 380 second. mass coefficient in the ranger of 1.65 x 10-2 to 3.30 x 10-2 cm/s.and diffusion coefficient in the ranger of 3.57 x 10-6 to 3.30 x30 x 10-3 cm 2/s. The dissolution rangers from about 87% for a product containing 10.5 % tapioca starch to the dissolution range of about 85% for a product containing 9.5% silicaKeywords : urea crystals, Coating, dissolution, stirred vessel