feature stories | mining the dead sea The Arab Potash Company (APC) has been producing potash from the Dead Sea for over 30 years. The refineries and solar pond evaporation system extract the KCl rich Dead Sea Brine (DBS) and process the potash - a highly effective fertilizer - into its three most common forms KCl (Potassium Chloride), K2SO4 (Potassium Sulfate) and KNO3 (Potassium Nitrate). Since 1982, APC’s two intake stations pumped the DSB to the solar ponds where salt deposition occurs. The pumped brine flows into the solar ponds to begin a two-phase evaporation and crystallization process. In the evaporation phase the solid concentration rises, NaCl (free salt) in the DSB precipitates onto the ponds’ floor. The remaining DSB is directed to the carnallite ponds for an extended second phase sun exposure ending with the deposition of carnallite crystals - a mixture of KCl and MgCl2 (Magnesium Chloride) and other compounds. The carnallite crystals are then harvested as slurry and pumped to the refineries where the potash is recovered. At the end of the process, the remaining DSB is returned to the Dead Sea. The first pumping station (PS1) became operational in 1982; it relied on four vertical type pumps atop a steel and wood deck resting on vertical steel piles embedded in the Dead Sea floor. In 1989, PS1 was modified as a result of the Dead Sea’s receding water level and was kept operational for an additional five years. It was finally retired in 1997. Plans and construction of a second identical pumping station (PS2) - still operational - were put into motion to coincide with the retirement of PS1. It was forecasted based on the previous Dead Sea’s receding rate trend figures that PS2 will be operational up to 2012. The receding rate for the last 10 years at an almost constant rate of 1 to 1.2 m per year - has shortened PS2’s life; its operation is now critical and expected to be phased out of service by 2010. 34