Dampier Salt (DSL), now the world's largest salt exporter, produces industrial salt by solar evaporation of sea water at Dampier, a coastal iron ore port that serves Rio Tinto's iron mines, and from underground brine at Lake MacLeod, both in Western Australia. Dampier also mines gypsum with the use of dredges at Lake MacLeod. In August 2001 Dampier Salt acquired a three million tonne per year salt operation at Port Hedland, Western Australia. Dampier's production capacity was increased in stages during the 1990s to more than five million tonnes of salt per year. Salt is sold principally to established chemical industry markets in Asia. Gypsum is sold to the wallboard and cement