A primary test analysis on metallurgical functions of an 80-t single snorkel vacuum refining furnace has been carried out. Results show that the single snorkel vacuum refining furnace has the metallurgical functions including dehydrogenation

denitriding

decarburizing

deoxidation

desulphurization

liquid heating by chemical reaction

removing inclusions in liquid and adjusting alloy component. By using the 80-t single snorkel vacuum refining furnace to refine liquid

the hydrogen and oxygen content in alloy constructional steels are respectively reduced to (0. 9~1.2) x 10

-6

and (9 - 12) x 1O

-6

in ultra-low carbon steels

the carbon content is (10 ~ 20) x 10

-6

the nitrogen content is (29 ~ 37) x 10

-6

and the sulphur content is (10-30) x 10

-6

the single snorkel refining furnace has better heating function by chemical exothermic reaction and its inclusions removing effect is equal to that of RH refining unit ； the results of 20 heats ultralow carbon steel alloy-compound-adjusting in single snorkel refining furnace show that the yield of alloy elements is high

the yields of silicon

manganese and aluminum are respectively 93% ~96%

93% ~95% and 64% ~67%.