Naslov
Comparison of semicontinuous and batch precipitation of calcium carbonate

Autori
Kralj, Damir ; Ukrainczyk, Marko ; Kontrec, Jasminka ; Brečević, Ljerka

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
17th International Symposium on Industrial Crystallization / Ulrich, Joachim - Maastricht : European Federation of Chemical Engineers, 2008, 1059-1066

Skup
17th International Symposium on Industrial Crystallization

Mjesto i datum
Maastricht, Nizozemska, 14.09.2008. - 17.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Precipitated calcium carbonate; carbonation; batch and semicontinuous process; morphology

Sažetak
A comparison of semicontinuous and batch precipitation of calcium carbonate is presented. In both processes, precipitated calcium carbonate (PCC) was synthesized by carbonation of slaked lime. The experiments in the batch process were performed by varying the initial mass concentration and temperature, and in the semicontinuous process by varying the supersaturation and temperature. It was found, that in the batch experiments the specific surface area and the average size of calcite particles decreased with increase of temperature. PCC nanoparticles can be produced at 25 °C, whereas the increase of the initial mass concentration of slaked lime enhances the degree of their aggregation. At higher temperatures (35 and 45 °C), scalenohedral micrometric calcite precipitates. By careful tuning of the semicontinuous process parameters, calcite in the form of rhombohedral, truncated prismatic, scalenohedral or nanosized particles can be produced. Specific surface area increases with increasing supersaturation and decreasing temperature. The excess of suspended Ca(OH)2 has a decisive role in the formation of the calcite nanoparticles.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA