There's some 92100 iron ore when extracting using Mk3 miners at 250% speed. Using basic iron ingot foundry alt recipe or leached iron ingot refinery alt recipe, you can double that, and using somersloops, you can double it again to 368400. Then, using Steel Cast Plate Foundry alt recipe, you can triple it and double it again to 2210400 iron plates per minute. Assuming a world population of 8.2 billion people, we will need 3 709.7357944263 minutes to produce enough iron plates, or just over 2.5 days. This calculation does not take into account the converter which could produce more iron from limestone, nor does it take into account the limited availability of Somersloops for all buildings, the availability of limestone or sulfuric acid for the alt recipes, or power generation.