Kinetics of Carbothermal Reduction Process of Different Size Phosphate Rocks

Abstract The effects of particle size on the apparent kinetics carbothermal reduction process phosphate rock were studied by non-isothermal thermogravimetric analyses. Phosphate various was reacted with coke and silica under high purity argon atmosphere. kinetic model parameters reaction different sizes derived combination model-free (Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, Tang, Starink) model-fitting (Coats-Redfern, Master-plots) methods. results showed that obtained activation energy reduces from 371.74 kJ/mol to 321.11 as decreasing 100–150 μm 38–48 μm. found follow shrinking-core conversion degree function equation is G ( α ) = 1 − 2 G\left( \alpha \right) = 1 - {\left( {1 } \right)^{{1 \over 2}}} ( α G ) integral form function).