Vikings didn't make steel with sand. No one did excepting black 'iron sand', and that was used primarily in Eastern Cultures where other, more pure/steady and reliable sources of iron like mountainous/meteoric and bog iron were unavailable. It wouldn't be any more or less superior that regular old carbon steel and likely inferior to durasteel in the way you are talking about, unless tatooine sand has some magical mineral or metallurigcal properties, which it doesn't.
Alloys and new metals are possible, but the way you describe yours wouldn't give you the end result you're wanting.
EDIT: Also, resmelting would SEVERELY alter the make up of durasteel to the point you likely wouldn't get the right properties. If you want a new alloy (because at this point it's an alloy, not a new metal) you're better off using the same components as durasteel with your new ingredients added in and smelting from there.
EDIT X2: Also, Vikings used bog ore, which often had a stupendously high phosphorus content, so they tended to fold their steel to drive out the impurities and forge weld several metals together (just like japanese panel steel in katanas) to get a sword that was even usuable and not full of impurities and flaws and such. It wasn't until the tail end of the viking age they could reliably produce monosteel, and even then it wasn't via the process you mention, though I am willing to help explain said process and see if I can help guide you to understand it well enough to make a workable sub. Just understand, sand won't do much.
[member="Darth Ferus"]