When you smelt using a coal block, you can smelt at lest 64 + 16 items (for example iron ores), but when you smelt using 9 pieces of coal, you can smelt at lest 64 + 8 items (for example iron ores).
Comments 12
Why is this work as intended? If coal blocks are made with 9 pieces of coal, it should have the same smelting duration as 9 pieces of coal.
Probably to incentivize creating blocks of coal, which are more difficult to use efficiently, because a single block will smelt more than one stack. Unless there's some advantage to converting coal into a block, people would be more likely to stick with 8 coal for a stack, because they can leave it unattended. Automating the process with hoppers works, but eliminates the opportunity to receive experience for smelting. In short, it's about making the choices more interesting, and games are fundamentally about interesting, meaningful choice.
From a perspective of realism, a block of coal may be more dense, and have less surface area, than 9 individual pieces. Thus, it may burn for longer because it releases combustible gasses more slowly. Not sure if that really applies, considering that the coal is burned one piece at a time, rather than all at once, but it may be part of the logic behind it, if any.
Coal blocks should have the same smelt duration as 9 pieces of coal though.