the surface regions comprise a plurality of fin regions configured to cause a substantial portion of a phosphorus species to be exhausted while returning a substantial portion of silicon species into the melted material of course there can be other variations modifications and alternatives in addition in order to prevent oxidation of the silicon at high temperature and superheating of the silicon melt the degree of vacuum inside vessel 10 is changed to accommodate evaporating conditions for various impurities contained in the raw silicon so as to ensure a safe metallurgical silicon purification process specifically a vacuum pump not shown and a gas flow valve not shown can be used to control the gas and gas flow in vessel 10 wherein the pump regulates pressure via decompression tube 12 which avoids any danger caused by pressure rising due to a constant supply of water steam purifying material thereby providing safe and stable metallurgical silicon purification process conditions fig3 and 4 are diagrams depicting a second embodiment of the metallurgical silicon purification apparatus modified from the conventional puller in the diagram reference numeral 10 indicates a vessel 11 a heater 12 a decompression tube 13 a set of valves and or port or load locks 14 a set of valve operating arms 15 an exhaustion passage controlling cap 20 a crucible 30 a crucible manipulating device 31 a crucible manipulating device base 32 a crucible manipulating device shifting shaft 33 a crucible manipulating device motor 40 a crucible transporting device 41 a crucible conveyer belt 50 a plasma arc heater 60 a purifying.