Abstract
	The aim of the presented study is to solve the problems of physical – chemical properties of the melted metallurgical slags, especially from the surface phenomena point of view. The experimental method for the surface tension measurement of melts  has been practised, using the method of the lying drop, inovated by including the CCD – camera and consequent data transfer into PC. There are presented continual changes of physical – chemical properties using the examples of chosen systems , with dependance on the temperature and chemical structure. Concurrently with the influence research of the content of chosen components on the surface properties of melts, there were compared the courses of their temperature dependances to the values of laboratorary prepared slag systems on the same basis. The changes of percentages by weight of CaO in the samples proved the differences in the course trends of the surface tension temperature dependences. Consequently, considering the laboratorary and real systems, there were also proved considerable divergences in  absolute values and in total reactions of the analysed quantities. The measurements are completed with the temperature density dependences of the examined systems.