Open AccessRemoval of iron in rice husk via oxalic acid leaching process
Author(s) -
Faizul Che Pa,
Wong Kok Kein
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/701/1/012021
Subject(s) - oxalic acid , leaching (pedology) , husk , calcination , amorphous solid , selective leaching , impurity , metal , chemistry , materials science , nuclear chemistry , metallurgy , inorganic chemistry , sulfuric acid , catalysis , organic chemistry , botany , environmental science , biology , soil science , soil water
Rice husk (RH), an agricultural waste which has been used as an alternative source for silica (SiO 2 ). In order to produce high purity amorphous SiO 2 from RH, acid leaching pre-treatment was required to remove the metallic impurities, followed by calcination at 800 °C to obtain the ashes. This research was studied about using oxalic acid as the leaching agent to remove iron (Fe) content in RH. The experimental parameters used in this study were acid concentration, reaction temperature, and leaching time. Based on the chemical composition analysis, the highest SiO 2 content of 99.30% and the lowest Fe 2 O 3 content of 0.43% were to be found in RHA which had treated under optimum parameters of 1.0 M of oxalic acid concentration, 90 °C of reaction temperature and 3 hours of leaching time. In addition, the particles of TRHA were observed with a tubular porous structure and irregular shape due to the leaching effect. Phase analysis by x-ray diffraction show that the amorphous SiO 2 was confirmed as a broad diffused peak. It’s been found in the 2θ angle range of 18° to 30° with no crystalline peak observed.