Even thoug I have a pretty good grasp on the workings of this blast furnace, the function of some buildings isn't immediately clear. This building, which I'd simply walked past on the previous 12 visits, was one I wanted to take a look at during my thirteenth (hence "Charbon13") visit to HFB.

Given its location—the closest to the train tracks where the coal was delivered—and the remaining machinery in the building and the conveyor belts leaving the building, it seems to have something to do with coal processing. Perhaps it was used for initial sorting of the coal, before being distributed throughout the site? If anyone knows its exact function, I'd be happy to hear from you.