Nessmuck,.... when I process scrape lead into ingots, I use an old dutch oven for a melting pot (most any kind of metal pot will work though) and a propane burner.
If you put wet lead in the pot
before turning on the heat, you won't get the "explosion" caused by steam that you get by dropping wet lead into
molten lead.
NEVER introduce ANY amount of water (even sweat) into already molten lead!!!!As lead slowly heats up the water has a chance to safely evaporate.
After the scrap lead has turned molten, I simply skim the dross and dirt off the top of the melt, even the metal off old wheel weights will float to the top of molten lead.
To "flux" the melt, I drop in a pea sized piece of beeswax and stir the melt, then skim again when casting round balls (unless I'm casting "hardened" round balls, then I just stir and cast).
I'm not sure this is the way expert casters cast round balls, but it works for me.
Old muffin tins work great for ingot molds.