Since 1963 he had been working at the Institute of Inorganic Chemistry, Slovak Academy of Sciences and had become one of the most renowned experts in the field of physical chemistry of molten systems. In his research, Dr. Daněk concentrated on the establishment of relationships between the composition, properties, and structure of the inorganic melts that are suitable for electrochemical deposition of light and transition metals and binary compounds. He developed methodology for the determination of electrical conductivity of molten fluorides and studied the effect of addition of lithium fluoride and lithium hexafluoroaluminate on the electrical conductivity of the aluminium electrolytes. Later, he participated in the study of the metal deposition and of the surface modification of metal substrates in the molten salt media, especially at the processes of titanation and boridation of steel, as well as in the investigation of high-temperature sulfate and vanadium corrosion of the construction parts of thermal power plants.
During the years 1977-1985 Dr. Daněk focused on the study of the structure and physicochemical properties of the molten oxide systems, which are of importance in steel and iron metallurgy. He suggested a thermodynamic model of the silicate melts and applied it to a series of binary and ternary systems. Dr. Daněk also studied corrosion of basic thermostable refractory materials by steelmaking cinders. He developed a dissociation model of the molten salts mixtures and applied it to various types of inorganic systems.