It was strange to see this when I was going at an Iron ore block (which is bizarre in itself coming out of the ground like a hemorrhoid) and getting scrap iron for the usual use of crafting previously, but not as great for smelting. The only thing that this affects is smelting, but I really liked to get massive amounts raw iron ore from mining, so I will miss it a bit.
There was a ratio of scrap iron smelting compared to raw iron smelting in speed to smelt and quantity of ore gained from smelting, but I guess this is all that is really changed, the raw iron was useless for anything other than scrapping to scrap iron and smelting so its not a terrible change.
I have to say that A18 has a massive amount of changes in so many things that I was really wondering what I should actually do next strategical in the game at only day 4 before day 7 comes around.