Application of high intensity ultrasound for obataining magnesium hydroxide from seawater : bachelor thesis

Talog magnezijeva hidroksida koji se dobiva iz morske vode uz dodatak 80% od stehiometrijski potrebne količine dolomitnog vapna kao taložnog sredstva je velike čistoće, te se kao takav može koristiti u različiti svrhe. Primjenjuje se u raznim tehnologijama kao i u nanotehnologiji. Svrha rada je dobiti magnezijev hidroksid veličine čestica nanometara uz primjenu ultrazvuka visokog intenziteta. Istaloženi magnezijev hidroksid karakteriziran je s TG/DTG i SEM analizom. TG/DTG krivulje izvedene su radi ispitivanja toplinske stabilnosti pripremljenih čestica magnezijeva hidroksida. Gubitak mase uzoraka započinje pri 244,94 o C i završava pri 481,31 o C, s gubitkom mase od 27,090%, što je neznatno niže od teorijskog gubitka mase od 30,89%. Rezultati ukazuju na nastanak aglomerata (veličine µm) u kojima se nalaze čestice magnezijeva hidroksida veličine od 130-250 nm.The magnesium hydroxide precipitate obtained from seawater by substoichiometric precipitation, with the addition of 80% of the stoichiometrically required quantity of dolomite lime as the precipitation agent, has high purity and therefore it can be used for various purposes. There are numerous applications in different technologies as well as in nanotechnology. The purpose of the paper is to obtain magnesium hydroxide, with nm particle size, by using the high intensity ultrasound. The precipitated magnesium hydroxide was characterized by TG/DTG and SEM analysis. TG/DTG curves are performed to investigate the thermal stability of the prepared magnesium hydroxide particles. A weight loss stage of samples begins at 244.94 o C and ends at 481.31 o C, with 27.090% weight loss, which is slight lower than the theoretical weight loss of 30.89%. The results indicate the formation of agglomerates (size µm) in which particles of magnesium hydroxide are in the range of 130-250 nm