I currently have four gold ores and a few others in my cart, and my furnace is stoked twice. It only says "Just chilling" after smelting other ores, but it doesn't touch my gold ore. I've refreshed several times, but it doesn't continue smelting the gold ore into a bar. Only after heading to the Lucid Lagoon and immediately heading back to the furnace does it continue smelting the gold ore. It is a bit of a waste of the wheel though, and the furnace should just continue smelting ores as long as there's enough ore left.