| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing salt by which the sticking of scale to an evaporation can can be suppressed and prevented, and natural salt containing components contained in seawater almost as they are can efficiently be manufactured. SOLUTION: Seawater is continuously evaporated and concentrated at≤50°C so that hemihydrate or anhydrous salt of gypsum (CaSO<SB>4</SB>) are not precipitated, and natural salt containing the precipitated crystals of CaSO<SB>4</SB>-2H<SB>2</SB>O is separated and recovered. Alternatively, a concentrated liquid evaporated and concentrated at≤50°C and containing the crystals of natural salt ( crystals of CaSO<SB>4</SB>-2H<SB>2</SB>O) and seawater as the raw material are mixed at≤50°C in a mixed tank 2. The mixture is retained while it is stirred for≥30 min. Thereafter, the mixed liquid is fed to an evaporation crystallization can 1, and is continuously evaporated and concentrated at≤50°C. COPYRIGHT: (C)2004,JPO
|
