For my range lead smelting i run 2 14" dutch ovens over 225k burners. I start with an inch or 2 of solid lead in the bottom of each pot and put a dose of material in. The stuff i have seems to be very heavy on jackets so i don't fill the pot all the way. Once i bring it up to temp i skim the jackets and then turn the pot off and let it slush up. Add another batch of material and repeat. I keep doing these smaller batches until i have a good pot full of molten then i flux and cast out my ingots. I use an ingot mold that holds about 70 lbs(4 bricks) so it empties the pot quick. I found that even with the cool down time i can go faster than over filling the pot where i cant get a good stir. Getting the jackets and other scrap stirred down into the hot molten seems to be the most effective way to melt everything down.