Ingots obtained by using super-heated options on ore block are not possible to gather. They appear on the ground and one of them is appearing in backpack but rest of them just lays on ground. If you mess around with items in backpack sometimes another ingot shows up... but it doesn't stack with the rest appearing in the same way, it just disappears after moving or using it in hand. First obtained ingot stacks well with normally obtained (refined or melted ingots). This things happens to iron, tin, copper and gold ore. Very same thing happens with charcoal from trees created by super-heated mode.