is this the first batch out of the bucket?

One thing I do when I get a new bucket of salt, before i open it, is shake it up, roll it around, and generally treat it like a can of soda I intend to give to someone I want to play a trick on. It only makes sense that different components of the salt mix are different sizes, and settle slightly during shipping.

a word of advice though, let it sit for a few minutes before you open it after you have gone 'a shakin' as when you peel that top off, there will be a fine salt dust plume... probably don't want to inhale that.