Comment by jandrewrogers

The cost of refining ore varies widely based on electricity, regulatory, and other costs. Proximity to the end user of the refined product also figures into it. Shipping bulk materials is very inexpensive. Buyers in other countries with low refining costs can pay prices that would bankrupt a local refiner and still make a profit.

This is common for bulk industrial materials. For example, it is cheaper for many countries to send their crude oil to the US to be refined than for them to refine it themselves.