There is a particular kind of frustration that shows up whenever African trade officials sit down to talk numbers. The continent holds roughly 48 percent of the world's cobalt reserves, close to 48 percent of its manganese and over a fifth of its graphite. Ghana alone is the fourth-largest cocoa exporter among 137 countries tracked globally. And yet very little of the profit generated by turning any of that into a battery, a stainless steel panel or a chocolate bar is captured on African soil.