Investigation of dissolution kinetics of colemanite in propionic acid solutions

Abstract

Colemanite is one of the raw materials used to produce boron compounds which have a constituent of the richest composition ratio boron trioxide $\lpar B_2O_3\rpar$(B2O3). The main purpose of this study is to investigate the dissolution kinetics of colemanite in a propionic acid solution. Reaction temperature, solid-liquid ratio, propionic acid concentration, stirring speed, and particle size were chosen as relevant parameters in the dissolution. According to the results of the study, the dissolution rate was directly proportional to the rise in the reaction temperature and inversely proportional to the increase in the solid-liquid ratio, acid concentration, and particle size. Additionally, it was observed that stirring speed did not significantly effect. Experiment results were correlated with the use of the Statistica10 software programme for linear regression. For the dissolution kinetics of colemanite, a model that can control the reaction was obtained by using homogeneous and heterogeneous reaction models. It was determined that the dissolution rate of the process was controlled by diffusion through the product film (ash) and the Activation energy was calculated as 37.51 $kJ.mol<^>{-1}$kJ.mol-1. Experimental data were analyzed with graphical and statistical methods, and a semi-empirical mathematical model was determined, which included the parameters of the study. La col & eacute;manite est l'une des mati & egrave;res premi & egrave;res utilis & eacute;es pour la production de compos & eacute;s de bore qui ont un constituant du rapport de composition le plus riche en trioxyde de bore (B2O3). Le principal objectif de cette & eacute;tude est d'examiner la cin & eacute;tique de dissolution de la col & eacute;manite dans une solution d'acide propionique. On a choisi la temp & eacute;rature de r & eacute;action, le rapport solide-liquide, la concentration en acide propionique, la vitesse d'agitation et la taille des particules comme param & egrave;tres pertinents dans la dissolution. D'apr & egrave;s les r & eacute;sultats de l'& eacute;tude, le taux de dissolution & eacute;tait directement proportionnel & agrave; l'& eacute;l & eacute;vation de la temp & eacute;rature de r & eacute;action et inversement proportionnel & agrave; l'augmentation du rapport solide-liquide, de la concentration en acide et de la taille des particules. De plus, on a observ & eacute; que la vitesse d'agitation n'avait pas d'effet significatif. Dans la production d'acide borique en utilisant l'acide propionique & agrave; partir de la col & eacute;manite, le propionate de calcium, un sous-produit, est utilis & eacute; comme agent de conservation dans l'industrie alimentaire, rendant ce proc & eacute;d & eacute; plus avantageux. On a corr & eacute;l & eacute; les r & eacute;sultats exp & eacute;rimentaux gr & acirc;ce & agrave; l'utilisation du logiciel Statistica10 pour la r & eacute;gression lin & eacute;aire. Pour la cin & eacute;tique de dissolution de la col & eacute;manite, on a obtenu un mod & egrave;le qui peut contr & ocirc;ler la r & eacute;action en utilisant des mod & egrave;les de r & eacute;action homog & egrave;nes et h & eacute;t & eacute;rog & egrave;nes. On a d & eacute;termin & eacute; que le taux de dissolution du proc & eacute;d & eacute; & eacute;tait contr & ocirc;l & eacute; par la diffusion & agrave; travers le film de produit (cendres) et l'on a calcul & eacute; l'& eacute;nergie d'activation & agrave; 37.51 kJmol-1. On a analys & eacute; les donn & eacute;es exp & eacute;rimentales & agrave; l'aide de m & eacute;thodes graphiques et statistiques, et l'on a d & eacute;termin & eacute; un mod & egrave;le math & eacute;matique semi-empirique, qui incluait les param & egrave;tres de l'& eacute;tude.