Coal Bin

building a coal bin in my basement saw a few pics of bins with what looks like a baffel board near the bottom of the opening at the floor to I assume keep the coal from rushing out ,,do I need this for rice coal?

The baffle board as you call it is so you can get the rice coal out of the bin without having to crawl into it. The coal won't come rushing out through that opening.

The higher you fill the bin, the higher you add boards. As coal is used up, take boards back out.

Presumably you are talking about a doghouse? However high the opening is on the bottom is how much the coal will come out onto the floor. If you have a four inch opening you can expect the coal to come out 4 inches. If you build the bottom board like a doghouse it will keep things a little tidier...

Slanted slats is how I keep rice coal in my bin,i can remove a board from the bottom for gravity flow to shovel from.it will only flow out when a shovel full is taken away.