Woo, That is completely incorrect. A basic understanding of mineral processing will tell you oxide and sulphide processing is completely different. And Cobalt presents as both.
Laterite (Oxides) require leaching of every cubic metre of ore mined so if the co-present Ni, Cu or Co low grades it is expensive and potentially uneconomical for low grades especially if Nickel price is low. Leaching is very established tech and has many different processes for different ore types and grades.
Sulphides are generally crushed, milled and floated at significantly less cost and reagent input!
Maybe check Perry's for a series of details on basic processing fundamentals before making uninformed & misleading statements like this. Even wikipedia will probably provide you better information than your last statement.
