Kinetics of leaching of tunisian phosphate ore particles in dilute phosphoric acid solutions

Canadian Journal of Chemical Engineering - Tập 77 Số 1 - Trang 136-142 - 1999
F. Ben Brahim1, Arbi Mgaidi1, Mohamed Elmaaoui1
1Industrial Inorganic Chemistry Laboratory, Chemistry Department, Faculty of Sciences,Tunis 1060, Tunisia

Tóm tắt

AbstractVan der Sluis et al.'s model was used to determine the rate of the partial dissolution of a Tunisian phosphate rock with dilute phosphoric acid (1.5 mass% P2O5). When the temperature rises from 25 to 90°C, for a given particle size, the mass‐transfer coefficients, kL°, vary from 3 × 10−3 to 8 × 10−3 m ·s−1. The corresponding diffusion coefficients, D, lies between 6 × 10−7 and 27 × 10−7 m2·s−1. Activation energy is equal to 14 kJ·mol−1 and values of kL°, at 25°C, are in the range of 0.28 × 10−3 and 4 × 10−3 m·s−1 when the agitation speed goes from 220 to 1030 rpm, showing that the leaching process is controlled by diffusion rather than by chemical reaction.

Từ khóa


Tài liệu tham khảo

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Thông tin
Thông tin xuất bản

Canadian Journal of Chemical Engineering

Tập 77 Số 1

136-142

Thông tin tác giả