Vjačeslavs Lapkovskis

Ferromagnetic Sorbents for Collection and Utilization of Oil Products

This Current paper reports the research conducted at Riga Technical University and Rezekne Higher Education Institution on the development of sorbent material, which is made of closed hollow microspheres possesses ferromagnetic properties, with a large specific surface. A review and comparison of existing sorbents for oil products collection are presented. The manufacturing process of proposed sorbent are described. The structure and morphology of obtained composite sorbent are discussed. It was found that proposed sorbent allows an efficient and safe way for surface water cleaning contaminated by spilled oil products. In particular, it shows a storing effect on a thin oil film (1-2 mm). Adsorption capacity to motor oil is investigated and compared with other magnetic sorbents on metal powders base. Newly proposed sorbent demonstrates a significantly higher adsorption capacity comparing to iron powders. Sorbent saturated by spilled oil can be evacuated by means of magnetic (or electromagnetic) captures.

SUPPLY AND SUBSTITUTION OPTIONS FOR SELECTED CRITICAL RAW MATERIALS: COBALT, NIOBIUM, TUNGSTEN, YTTRIUM AND RARE EARTHS ELEMENTS

European industry is dependent on the import of raw materials. The European Commission has recognized that some raw materials are crucial for the function of the European economy and show a high risk of supply shortage. This communication addresses supply and substitution options for selected critical raw materials: cobalt, niobium, tungsten, yttrium, and the rare earth elements. For each element, the most relevant data concerning mining, abundance, recycling rates and possible substitutes are summarized and discussed.​

Application of Pulse Electromagnetic Field for Metal Coatings Manufacturing

In current article, applications of pulsed electromagnetic fields (PEMF) for processing of powder parts obtaining bronze coating on a steel rod are presented. Experiments were carried out in Laboratory of Metal Forming Technology (University of Applied Sciences of Zwickau, Germany) and in Laboratory of Powder Materials (Riga Technical University, Latvia). An adhesion strength between steel and bronze parts was measured by means of a shearing test.