Workers walk along a pathway at the nickel smelter of PT Vale Tbk, near Sorowako, Indonesia's Sulawesi island, January 8, 2014. Indonesia's ban on exports of key mineral ores - unless they are processed in the country - risks backfiring as weaker commodity prices mean it is not cost-effective to invest in expensive smelters and refineries. Picture taken January 8, 2014. REUTERS/Yusuf Ahmad (INDONESIA - Tags: ENERGY BUSINESS EMPLOYMENT)