Extracting the salt from the earth
Since 1989, KBB has been providing engineering support to Thai company Pimai Salt Co. Ltd. (PSC) for their underground cavern operations. In 2005, KBB Underground Technologies GmbH took over.
PSC extracts sodium chloride from a shallow salt deposit in central Thailand using solution mining. The caverns are located at depths ranging from 200 to 250 metres, with volumes of about 150,000 m³. About 60 of the approximate 90 caverns of the production field are in operation, 30 caverns have been depleted and decommissioned.
Salt production capacity increased from an initial 150,000 tons per year to 1.3 million tons per year. PSC extracts the salt from the brine using a highly energy-efficient thermocompression method.
With 99.9% of NaCl, the salt has a high degree of purity. Most of it is used by the chemical industry, but some is also used as table salt. While most of the salt is sold in Asia, some is even shipped to Australia.
KBB UT is responsible for planning and ongoing backup of the cavern construction process as well as supervising and evaluating the regular sonar cavern surveys.
The PSC salt plant meets stringent environmental standards. It produces no waste that needs to be disposed of externally. The gypsum mud produced as a result of brine purification is deposited in solution-mined caverns. The area between the caverns is covered with vegetation or used for agricultural purposes.
At the moment, PSC expands the existing cavern field eastward with the help of KBB UT.