Open AccessRecovery of silica and carbon black from rice husk ash disposed from a biomass power plant by precipitation method
Author(s) -
B. Thongma,
Siriluk Chiarakorn
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/373/1/012026
Subject(s) - sodium silicate , fly ash , husk , sodium hydroxide , carbon black , dissolution , bottom ash , precipitation , sulfuric acid , bet theory , carbon fibers , raw material , nuclear chemistry , materials science , chemistry , metallurgy , adsorption , composite material , botany , natural rubber , meteorology , composite number , biology , physics , organic chemistry
In Thailand, air pollution caused by rice husk ash (RHA) disposed of biomass power plants has become more serious concerns. Recovery of silica and carbon black from RHA is an attractive solution to solve this problem. This study aims to extract silica and carbon black from RHA, which was burnt in a stoker firing at 800-850 ºC, by a precipitation method. RHA was dissolved in 2M sodium hydroxide at 105 ºC for 2-5 h. After that, carbon black was filtered out from sodium silicate solution. The solution was then precipitated by sulfuric acid to produce precipitated powder. The extraction parameters such as types of RHA (fly ash and bottom ash), dissolution time and precipitation time were studied. The precipitated powder was characterized by XRF for elemental analysis, XRD for crystallinity and BET for porosity analysis. The results showed that dissolution for 4 h and precipitation for 1 h could produce precipitated amorphous silica with the purity of 95-99 % SiO 2 . The yields of silica extracted from bottom ash and fly ash were 85.66 wt% and 72.33 wt%, respectively. The yields of carbon black extracted from bottom ash and fly ash were 14.34 wt% and 27.67 wt%, respectively. The surface area of silica extracted from fly ash (410.72 m 2 /g) was higher than that of the silica extracted from bottom ash (296.98 m 2 /g).