Better still: "When will you receive the coal?" (Note the singular of coal, which is still used even if receiving countless metric tonnes.
No English speaking person would say "When do you receive the coals?" Not in a million years ..... unless they were a badly programmed computer! They would say something like "When do you get the coal?" Or "When is the coal coming?"
Any English speaking lawyer asking about a contract or English speaking business person who dealt in coal or the equipment for using coal would ask "When do you receive the coal." The verb is certainly one English people who were asking about coal would use. The only problem here for me is the plural, which we do not use of "coal," because we think of it as a collective noun, like "rice."