Not with any accuracy.
Malt will always supply significant quantities of potassium, magnesium and phosphates as barley needs those to grow and even more to be suitable for malting. Barley also provides chloride and sulfate, but in relatively smaller amounts and calcium lesser again.
Obviously, the more malt, the stronger the beer, the lesser proportion of liquor to malt, the more minerals that malt supplies. Different beers have different proportions of barley malt to other ingredients, meaning recipes would also need to be known before any potential calculation could begin.
The brewing process can have a greater influence than the ingredients and mineral additions. Some very large breweries use mash presses (a system dating back to the early 20th century) to produce higher gravity worts that are liquored back at later stages. If done using RO water, the mineral presence during critical parts of the brewing process could be assumed to be vastly less than actually was.
On the other side, calcium is lost at every stage in the brewing process and magnesium during the boil and fermentation. Those losses are not a simple proportion of the amount added, but are quite complex and depend upon many factors, in particular the time, rate and type of those additions.
At best, you can get a rough idea, but certainly not readily be able to tell what was added and when.
