Nowadays, due to using many rare metals in the most advanced technologies, the demand for these metals is increasing. Rare metals, however, mostly don’t show the property of creating their own mineral deposits, making their production more complicated. Some rare metals, e.g. gallium, germanium, indium and thallium usually accompany zinc ore. ...

By D. D. Stanojević, M. B. Rajković, D. V. Tošković, M. V. Tomić

Investigations, conducted in this study showed that waste phosphogypsum-dihydrate represents a burden which even must not be kept in deposits because of its large quantity in relation to the main product – phosphoric acid, as well as because of great impact of a phosphogypsum deposit on the environment. By the proposed procedure, calcium-sulp...

By M. B. Rajković, D. V. Tošković, D. D. Stanojević, Č. Lačnjevac

Today, rotary dryers are often use to dry sawdust prior to their further processing, palletizing and briquetting, into commercially voluble product. This paper present mathematical model for drying process of sawdust particles in a triple pass rotary dryer. As basis for this model, we used existing mathematical models for drying of sawdust and othe...

By S. Papuga, P. Petrović, M. Maksimović