7.2　Material Preparation and Supply

7.2.1　The composition of ferroalloy for refining shall be in accordance with the current relevant national standard and also shall be in accordance with the following provisions:

1　High-grade ferroalloy shall be used and in special case 90% ferrosilicon and manganese alloy shall be provided.

2　For refining of ultra-low carbon steel，the carbon content of ferroalloy for final composition adjustment shall be strictly controlled.

3　The particle size of ferroalloy shall be 5mm-50mm for non-vacuum refining and 5mm-30mm for vacuum refining.

4　The ferroalloy shall be protected from mixing with other material，rain and moisture during storage and transport.

7.2.2　The lime for slagging shall be the fresh metallurgical active lime.The particle size of lime shall be 5mm-50mm for non-vacuum refining and 5mm-30mm for vacuum refining.The composition of lime shall be in accordance with the current industrial standard Lime for Metallurgical Industry（YB/T 042）.