The study of the selective rhenium solvent extraction possibility with the mixture of aliphatic alcohol and ketone from acid solutions of rhenium-containing wastes processing

The results of rhenium (VII) solvent extraction with synergistic mixtures of octyl alcohol and ketone from the high acid chloride and sulphate solutions with high accompanying metals (platinum and molybdenum) content, obtained from leaching of rhenium-containing wastes, were presented. It is shown that synergistic coefficients at rhenium solvent extraction by mixtures of 30–50 % v/v 2-octanol in 2-octanone were not exceeded 1.2–1.3. However, such mixtures recovered fewer impurities of Pt (IV) and Mo (VI), and the separation factors reached 16.0 and 573.2. Besides, mixtures of alcohol and ketone are characterized by higher rhenium (VII) capacity than the alcohol alone.

Preparation of a Cellulase-imitated Solid Acid Catalyst With High Acid Density and Its Evaluation for Hydrolysis of Cellulose

In this paper, tannic acid, a polyphenolic substance rich in plants, is modified by the glutamic acid and cross-linked with formaldehyde to prepare a high acid density tannin-glutamate acid resin-based imitation enzyme solid acid catalyst (T-Glu-R), which is completely different from traditionally carbon-based solid acid synthesized by concentrated sulfuric acid and carbonized matter. The solid acid catalyst was characterized by Fourier transform infrared spectroscopy, scanning electron microscope, thermogravimetry, and X-ray photoelectron spectroscopy. The catalytic activity and cycle performance of T-Glu-R in the cellulose hydrolysis reaction were evaluated. The results show that the acid density of T-Glu-R reached 7.28 mmol/g, which is much higher than that of the highest acid density of carbon-based solid acid. Microcrystalline cellulose was hydrolyzed in distilled water at 180 °C for 2 h, the yield of total reducing sugars reached 72.15%. After four cycles of hydrolysis, the yield was only reduced by 4.32%, showing excellent cycle performance and stability. The study provides a new strategy with the synthesis of solid acid catalyst for hydrolysis of cellulose converted into platform compounds without concentrated sulfuric acid.

Felsite in Ceramic Materials Production

This project is devoted to the study of the felsite properties for the purpose of its application in the production of various types of fine ceramics: ceramic tiles, acid-resistant tiles, aluminosilicate proppants, etc. Felsite is a mixture of quartz (about 40%) and feldspars. In the compositions of ceramic masses, felsite can play the role of both nonplastic due to the quartz content, and flux due to the content of feldspars, that reduces the amount of mixture components. When felsite is fired, the melt appears at a temperature above 950°C. The felsite has a sintering effect when fired at a temperature of 1000°C. Glass phase enriched with SiO2 ensures the absence of material deformation after firing. Also, glassy phase provides high-acid and chemical resistance of materials based on it. In addition, after firing above 1150°C, felsite has a light color, which is a great advantage in comparing it as a melt with other iron-alkali-containing materials. Ceramics based on felsite does not require the use of opacified glazes.