Red mud is a hazardous waste of the alumina industry that contains high amounts of iron, aluminum, titanium and rare-earth elements (REEs). One of the promising methods for the extraction of iron from red mud is carbothermic reduction with the addition of sodium salts. This research focuses on the process of hydrochloric high-pressure acid leaching using 10 to 20% HCl of two samples of non-magnetic tailings obtained by 60 min carbothermic roasting of red mud at 1300 °C and the mixture of 84.6 wt.% of red mud and 15.4 wt.% Na2SO4 at 1150 °C, respectively, with subsequent magnetic separation of metallic iron. The influence of temperature, leaching duration, solid-to-liquid-ratio and acid concentration on the dissolution behavior of Al, Ti, Mg, Ca, Si, Fe, Na, La, Ce, Pr, Nd, Sc, Zr was studied. Based on the investigation of the obtained residues, a mechanism for passing valuable elements into the solution was proposed. It has shown that 90% Al, 91% Sc and above 80% of other REEs can be dissolved under optimal conditions; Ti can be extracted into the solution or the residue depending on the leaching temperature and acid concentration. Based on the research results, novel flowsheets for red mud treatment were developed.

The goal of this article is to investigate the impact of corporate social media on the perception of employer brand image and employer attractiveness which, in turn, could lead to application intention of Millennials in FMCG industry in Russia. The research model was tested through questionnaire from 119 bachelors, masters, and graduates in the Russian leading business school. The empirical data was analyzed with regression analysis. At the second stage, six semi-structured interviews in two Russian business schools were conducted to receive deeper insights. As hypothesized, both high level of information availability and employees' engagement in social media led to the positive perception of the employer brand image as well as to attractiveness perception. The latter, in turn, increased the application intentions of Russian Millennials. The qualitative research provided additional evidence about the advantages of using social media for recruitment and employer branding needs, expected content, and the role of particular social media tools in enhancing the employer branding programs in FMCG industry in Russia. Limitations of the study relate to inability of generalization (the research was undertaken for FMCG industry), noninclusion of some demographic characteristics, and opportunity to include the intermediate mechanisms into the model. The study enhances current knowledge about the role of social media in enhancing employer branding and recruitment initiatives. It contains a set of particular recommendations for FMCG employers.

The present study focuses on the experimental investigation of sulphatizing roasting of flotation tailings from copper slag processing using iron (II) and (III) sulfates followed by water leaching. The effect of temperature, duration of sulphatizing roasting, as well as the amount of iron sulfates on the conversion of zinc, copper, iron and other components in the tailings into water-soluble sulfate compounds were studied. The experiments have shown that there is no significant difference between using of both iron sulfates. The extraction degree after more than 20 min of the roasting varied in the approximate ranges of 50-70% for Zn, 45-70% for Cu and 0.01-10% for Fe. The best results were the extraction of 69.2% Cu, 62.8% Zn and 1.2% Fe obtained by 180 min of the roasting at 625°C with addition of 150% FeSO4⋅7H2O to 100% of the tailings. Based on the mineralogic and microstructure investigations of the samples, the assumptions were made for the reasons of the deficient extraction degrees of copper and zinc, as well as high sulphatizing agent consumption.