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The effect of mannitol and pH of the solution on the properties of sintered magnesium oxide obtained from sea water
Author(s) -
Petric Nedjeljka,
Martinac Vanja,
Labor Miroslav
Publication year - 1997
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.270200107
Subject(s) - magnesium , sintering , dolomite , precipitation , mannitol , distilled water , stoichiometry , chemistry , oxide , seawater , porosity , inorganic chemistry , lime , nuclear chemistry , materials science , metallurgy , mineralogy , chromatography , geology , organic chemistry , physics , oceanography , meteorology
In order to reduce the B 2 O 3 content in sintered magnesium oxide as much as possible, in precipitation with 80% of the stoichiometric quantity of dolomite lime, the effect of the pH of the agent used for rinsing the magnesium hydroxide precipitate was examined, as well as the effect of mannitol in sea water before precipitation. Mannitol binds orthoboric acid present in sea water into a weakly dissociated complex acid HB(OC) 4 . Experiments have shown that the B 2 O 3 content in the sintered magnesium oxide samples is satisfactorily low. The lowest B 2 O 3 content is obtained when mannitol is added; no B 2 O 3 was found in these samples after sintering. Magnesium oxide samples were sintered at 1500°C; duration of isothemal sintering was one hour. Values for density and porosity of individually sintered samples are listed. The ratio CaO/SiO 2 indicates that forsterite (Mg 2 SiO 4 ), monticellite (CaMgSiO 4 ) and mervinite (Ca 3 MgSi 2 O 8 ) are formed during sintering of the samples.