Abstract
	Contribution presents study of steel scrap quality and quantity influence on some parameters of oxygen converter process, represented by contents of sulphur and phosphorus in slag and nitrogen contents in steel, in two types of  oxygen converters : top blowed converter, and converter with combined blowing. Quality of steel scrap is characterized by three kinds of scrap charges : selectivity 1, 2  and 3.
	Study was realized by statistic evaluation of above mentioned parameters in extensive set of heats. The results are as follows :


Quantity of steel scrap charged into top blowed oxygen converter has little influence on sulphur and phosphorus contents in slag from refining process. With increased quantity of charged scrap sulphur content in slag increased and phosphorus content in slag decreased. Increase of charged scrap quantity decreased upper limit of nitrogen contents in steel.
Quantity of charged steel scrap didnīt influence the refining process parameters in converter with combined blowing.
Selectivity of scrap charge influenced  sulphur contents in refining process in top blowed converter. Sulphur content in slag decreased from selectivity 1 to selectivity 3, content of phosphorus wasnīt influenced. When selectivity 3 was used, nitrogen content in steel was higher then ones connected with selectivities 1 and 2.
Refining in converter with combined blowing was influenced by quality of scrap charge by similar way as refining in top blowed  converter. Moreover, selectivity of  scrap charge influenced  also the phosphorus contents in slag.