Right off the bat I would be concerned about finding a a recipe that would work. Your going to be dealing with a completey different desity compared to lead shot. If you know someone who loads rock salt that might be a place to start from for a recipe. But I sure wouldn't just pick a powder charge from listed data intended for a lead load. Just like loading for any other cartridge type, pressures are unpredictable when substituting with unintended components.
I knew a guy many years ago that was a regular in the gun store I worked in that was trying to develope a steel jacketed bullet. He used steel tubing and filled the inside with lead. His bullets, which looked really clean and functional, were loaded according to data for that weight and caliber, but when he fired the first round, the pressure was so extreme, it sheared the bolt lugs off of his 30-06. Our gun smith just laughed when the guy showed him the rifle. If your just wanting to reap some kind of monetary return or another use for those spent primers, I would just use them as scrap metal and put the money toward some reclaimed lead shot, or not?