Automating a GregTech industrial grinder:
You need to supply water cells to the grinder along with the ore. Filling those water cells in a Deployer-less age isn't technically an issue but most replacement methods require power (liquid transposer, electric craftingtable etc). Not so the big railcraft tanks: just pump in empty cells and they'll automatically be filled.
In my world I have set up an AE system that knows all the important industrial grinder recipes, and I have three railcraft tanks - one with water, one with sodium persulfate, and one with mercury. Whenever an ore arrives that needs to be processed, the AE system automatically inserts an empty cell into the appropriate tank via a ME interface with an external crafting pattern, thus creating the proper cell, which it then imports back into the system to supply the grinder. For example, copper will be processed with persulfate, gold with mercury, and iron with water.
Since that generally doesn't require nearly as much water as the single accumulator feeding the tank generates, the tank is also supplying other things with intermittent water needs, such as one of my three carpenters (the other two are running on seed oil and honey, respectively) and, in the future, the backup fermenter (the main one will run on juice).