Abstract
Colemanite is one of the most important boron minerals used for production of boric acid. Boric acid (H3BO3) is produced by the reaction of colemanite (2CaO · 3B2O3 · 5H2O) with sulfuric acid in a heterogeneous solid-liquid reaction leading to crystallization of gypsum as a byproduct.The influence of ultrasound on the dissolution of colemanite in H2SO4 solution and on the precipitation of the gypsum during the reaction was investigated. Experiments have been carried out in a batch stirred vessel at 85 °C in the absence and presence of ultrasound. The stirring rates were chosen as 600 rpm (for 500-600 μm) and 800 rpm (for 1000-1180 μm) to provide a homogeneous suspension during the reaction. The boric acid and calcium ion concentrations in the solution were determined as a function of time. The results showed that ultrasound enhances the dissolution of colemanite and precipitation rate of the gypsum in the solution after 1 h. It has been shown that the use of ultrasound decreases the size of gypsum crystals.
Original language | English |
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Pages (from-to) | 633-638 |
Number of pages | 6 |
Journal | Ultrasonics Sonochemistry |
Volume | 14 |
Issue number | 5 |
DOIs | |
Publication status | Published - Jul 2007 |
Keywords
- Boric acid
- Colemanite
- Gypsum
- Precipitation
- Ultrasound