Kinetic Study on the Preparation of Aluminum Fluoride Based on Fluosilicic Acid

Reasonable mathematical derivation and mechanism model in the process of producing aluminum fluoride by fluosilicic acid is the key to the industrial treatment of fluorine resources in the tail gas of phosphate ore. In this work, aluminum fluoride was generated directly by fluosilicic acid to extract fluorine from the tail gas of phosphate rock. The uncreated-core model dominated by interfacial reaction and the uncreated-core model dominated by internal diffusion-reaction were then respectively utilized to describe the reaction kinetics of the generation of aluminum fluoride. The result showed that the uncreated-core model was dominated by interface reaction and internal diffusion, the apparent reaction order n = 1, and the activation energy Ea = 30.8632 kJ . mol–1. Product characterization and kinetic analysis were employed to deduce the reaction mechanism of preparing aluminum fluoride. The theoretical basis for the low-cost recycling of fluorine resources in the tail gas of industrial phosphate ore was provided in this work.

Increasing the efficiency of phosphate ore processing using flotation method

The paper presents flotation of two phosphate ore samples of different origin. Statistical analysis was used to study the effect of operating parameters on flotation efficiency. The paper proposes to increase the efficiency of flotation processing of magmatic phosphate ore with a low grade of the valuable component (P2O5 = 10.88 %), containing nepheline and feldspars, by means of direct anionic flotation. Authors present an optimization of anionic flotation using tall oil fatty acids mixed with anionic phospholane as an anionic collector. The effect of adding soda ash to compensate for the influence of calcium cations on technological parameters of P2O5 flotation was examined. The results of studying the flotation of nepheline ore (flotation tailings of magmatic phosphate ore) showed that replacement of phospholane with oxyethylated isotridecanol allowed to obtain a high-quality concentrate. It was estimated that with the addition of Na2CO3 in the amount of 2,000 g/t, a concentrate was obtained with the grade and recovery of phosphorus pentoxide equal to 39.15 and 94.19 %, respectively. The paper proposes to increase the efficiency of flotation processing of sedimentary phosphate ore with a low grade of the valuable component (P2O5 = 22.5 %), containing gypsum and quartz, by means of desliming followed by anionic or cationic reverse flotation. Tall oil fatty acid with anionic phospholane was used as a collector in anionic reverse flotation, and amine was used in cationic reverse flotation. Sodium tripolyphosphate was used as a P2O5 depressant. It was found to be an effective depressant in both anionic and cationic flotation. When analyzing the statistical plan, it was estimated that the maximum grade of the valuable component in the concentrate (P2O5 = 31.23 %) and the recovery to concentrate of 95.22 % were obtained in the chamber product at amine consumption of 950.88 g/t and sodium tripolyphosphate consumption of 500 g/t.