Thermodynamics and Kinetics Research of the Fluorination Process of the Concentrate Rutile

Abstract

The growth in the production of titanium metal and its compounds leads to an increase in the amount of toxic waste. As a result, at the legislative level, emissions of such wastes are limited, which leads to a drop in the production of titanium-containing products and a shortage of titanium in the international market. This paper presents the results of the process of fluorination of rutile concentrate from the Tarsky deposit (Russia, Omsk region) with elemental fluorine using a laboratory setup of a special design. For fluorination, samples of rutile concentrate weighing 0.1–1.0 g were used. The particle size distribution of particles varied from 2 × 10−6 to 2 × 10−5 m. To determine the possibility of carrying out the process, the calculation of the change in the logarithm of the equilibrium constant versus temperature was performed. The influence of the following operating parameters on the fluorination process has been studied: various concentrations of F2 in a fluorinating mixture of fluorine with nitrogen; process time from 0 to 9 min; different ratios of the initial solid phase to fluorine (10 and 50% excess of fluorine and 10 and 50% of its deficiency); fluorination temperature in the range of 300–1800 K. A kinetic equation is selected that most accurately describes the fluorination process. The values of the activation energy and the preexponential factor in the kinetic equation are determined. The obtained results show that with an increase in the fluorine content in the fluorinating gas mixture and the temperature of the process, the fluorination rate increases. Optimal conditions for fluorination: temperature—680 K; time—5 min excess fluorine in the fluorinating mixture—20–25%. The obtained results allow to propose and consider the conditions of process execution on industrial equipment.

Kinetic Modeling of Homogenous Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

“…One such example involves the dehydration of biomass sugars into 5-hydroxymethylfurfural (HMF) − and its subsequent selective oxidation to 2,5-furandicarboxylic acid (FDCA) . FDCA has the same functional group and similar aromatic property as the traditional petroleum-based purified terephthalic acid (PTA), making it a potential replacement for PTA in the production of polyester and metal–organic backbone materials. − The copolymerization of FDCA with ethylene glycol (EG) is also used to produce a new environmentally friendly and renewable polymer, polyethylene furanoate (PEF), , which outperforms polyethylene terephthalate (PET) in many aspects such as improved barrier properties for CO 2 , O 2 , and H 2 O as well as enhanced thermal stability and mechanical properties. This makes PEF a versatile and promising polymer that could contribute to less dependence on fossil resources and environmental pollution in the future. , As a result, in 2004 FDCA was recognized as one of the top 12 biobased compounds by U.S. Department of Energy.…”