Depending on the operation it can vary, over a 5 ton load maybe about 200 to 300 pounds, the smaller sizes like rice will retain more water.
If you got it from Hudson and with rice coal it came from three possible places. Right from under the breaker and in that case the pile will have have a constant stream of wet coal going onto it. If the pile is high the outside of the pile will be well drained out. This is where I always wanted coal from because it was the cleanest it could possibly be and wasn't soaking wet. If they got it under the breaker where the pile was low you're going to have more water and more dust when it dries. Lastly off the stock pile in which case it will be drained out pretty good and your mileage will vary on the dust.
Look at it this way if there is no water then the price goes up.
As I've mentioned previously in other threads whenever I left there I was always a few hundred pound over so the water weight was mitigated by that.
Did you get it from Hudson? Looks nice?
Too bad they don't weigh it prior to hosing it down and then deliver it
Rice is always going to have some dampness, even dead summer in a stockpile that's been sitting there for weeks. The outside layer might be dry but once you start digging into it you'll find water. Truthfully you'd have to let it drain overnight in the truck to get most of the water out and even then it's going to be damp.