Research of kinetics of zinc leaching with sulfuric acid from smithsonite

The study investigates the kinetics of zinc leaching from smithsonite with sulfuric acid in order to expand the zinc production feedstocks. The recovery rate of zinc from smithsonite into water-soluble zinc sulfate was found at different leaching time and temperature. Sulfuric acid concentration, its consumption and smithsonite particles size selected in this work for leaching of zinc from this mineral using the indicated solution allowed to determine the magnitude of “apparent” activation energy of the smithsonite reaction with the indicated acid, equal to 2,633 kJ / mol. The calculated value of E, shows that the process investigated is accompanied by diffusion phenomena

Investigation of the kinetics of sulphuric acid leaching of zinc from calamine

This article aims at the research of kinetics of the sulphuric acid leaching of zinc from calamine (hemimorphite) of Shaimerden deposits. The ratio of zinc extraction from calamine to water-soluble zinc sulphate was determined at various leaching durations and its temperatures. The concentration of the sulfuric acid solution, the flow rate of this solution and the size of the calamine particles, selected in the course of this work for leaching zinc from this mineral with the specified solution, made it possible to establish the value of the “apparent” activation energy of the reaction of calamine with sulfuric acid, amounting to 3,075 kJ / mol

Luminescence of sapphire single crystals irradiated with high-power ion beams

Optical absorption, photo- and cathodoluminescence of a sapphire single crystal (α-Al 2 O 3 ) exposed to pulsed nanosecond radiation with high-power ion beams C + /H + with an energy of 300 keV and energy density 0.5-1.5 J/cm 2 were first investigated in this work. It was found that under ion irradiation accompanied by heating of sapphire up to melting, the formation of F-type centers and their aggregates associated with oxygen vacancies was observed in the crystals under study. These centers have luminescence bands at 330, 410 and 500 nm which depend on the type and wavelength of the optical excitation. The appearance of a new PL emission at 435 nm, presumably associated with a complex vacancy-impurity defect, was also observed in the photoluminescence spectra. © Published under licence by IOP Publishing Ltd.The work was supported by the initiative scientific project № 16.5186.2017/8.9 of the Ministry of Education and Science of the Russian Federation. Experiments on ion irradiation of sapphire was done at the KIPT as a part of the state task

Research of component composition and catalitic reactivity of metallurgical industry slag

The article deals with the research of component composition and catalitic reactivity of metallurgical waste products. The slags component composition was investigated by X-ray fluorescence analysis. The slag stuff has been modified with alkali (NaOH) and mineral acids (HNO3, H2SO4, HCI and H3PO4), and their catalytic reactivity in the catalytic decomposition of ethyl alcohol and hydrogen peroxide has been determined for the first time. The revealed catalytic reactivity of the slag staff for the decomposition of ethyl alcohol and hydrogen peroxide indicates the need for a more detailed research and development of an industrial non-ferrous waste treatment technology

Mucosite Associada a Mycoplasma Pneumoniae

A Síndrome de Stevens-Johnson (SSJ) e a Necrólise Epidérmica Tóxica pertencem a um espetro de doenças raras, potencialmente fatais, distinguindo-se pela área corporal afetada. A mucosite é comum aos dois quadros, frequentemente inaugural e pode ocorrer isoladamente. É o caso da mucosite associada a Mycoplasma pnemoniae, também designada SSJ atípica, que se caracteriza por pródromo respiratório seguido de mucosite oral e ocular extensa, sem manifestações cutâneas. Descreve-se o caso de uma criança de 4 anos, do sexo masculino, com apresentação de mucosite severa associada ao Mycoplasma pneumoniae, na sequência de infeção respiratória baixa, medicada com azitromicina. Após dois dias, recorreu à urgência do Hospital Dona Estefânia por edema e lesões na mucosa labial com agravamento progressivo. No internamento, apresentava estomatite com lesões erosivas em diferentes fases evolutivas e extenso compromisso do vermelhão. Predominavam erosões, crostas e hemorragia, existindo também áreas com exsudado purulento e coalescência de “placas de descamação”. Estas alterações coexistiam com olho vermelho. Sem compromisso das restantes mucosas ou exantema. Durante o internamento, privilegiaram-se medidas de suporte associadas a limpeza cirúrgica da cavidade oral, interposição labial de “boneca” embebida em soro fisiológico e lubrificação do vermelhão com vaselina. As pesquisas de IgG e IgM para Mycoplasma pnemoniae foram positivas. Após 13 dias de internamento, teve alta com retitutio ad integrum.info:eu-repo/semantics/publishedVersio

Conversion processes for high-viscosity heavy crude oil in catalytic and noncatalytic aquathermolysis

© 2014 Springer Science+Business Media. We have conducted experiments on noncatalytic and catalytic aquathermolysis of high-viscosity heavy crude oil from the Ashal'cha field (Tatarstan) in the presence of a crude oil-soluble nickel- and cobalt-containing catalyst, a proton donor, and a rock-forming mineral. We have identified the characteristic features of the change in the constituent composition, the hydrocarbon composition, and the fractional composition, the rheological properties of the crude oils, the average molecular weight of the asphaltenes for catalytic and noncatalytic conversion processes. For catalytic aquathermolysis, we established significant de novo formation of light 70°C-250°C fractions (by 23 wt.%), n-alkylbenzenes, an increase in the oil content by a factor of 1.3, a decrease in the resin content by a factor of 1.7, and a decrease in the viscosity by 98 rel.%. The major difference between the conversion of crude oil in the presence of the catalyst and the proton donor involves activation of degradation reactions at C-C, C-N, C-O, C-S bonds and blocking of polymerization reactions and accordingly less coke formation. We observed sorption of the catalyst components on rock