This involved developing a process for producing high-quality KCl products from potash salt ore in Thakhaek and Saybouathong counties of Khammouane province, and Sepone county of Savannakhet province, in Laos, and research on underground backfilling with solid and liquid waste from the production of KCl. The goal was to get KCl ≥ 95 percent and K+ ≥ 90 percent, with the solid and liquid waste left from the process being used to fill in the shafts for zero discharge of solid waste.