An apparatus for countergravity casting a metallic has: a crucible for holding melted metallic material; a casting chamber for containing a mold; a fill tube capable of extending into the crucible to communicate melted metallic material to the casting chamber; and a gas source coupled to a headspace of the melting vessel to allow the gas source to pressurize said headspace to establish a pressure differential to force the melted metallic material upwardly through said fill tube into the mold. Added sulfur-gettering particles subsequently filtered or sulfur-gettering material removes sulfur from the melted metallic material.