The technical and economic indexes of sea salt, lake salt and well salt in China are quite different due to different raw material sources and processing technologies, such as production cost, raw material consumption and product quality. According to 1995 salt industry statistical annual report, in terms of product quality, it is required that well salt contains 99.03% sodium chloride, lake salt contains 96.7% sodium chloride and sea salt contains 94.67% sodium chloride (bounded by the Yangtze River estuary, sea salt in the north contains 96.06% sodium chloride and sea salt in the south contains 92.99% sodium chloride).

Salt production from well salt:

(1) Techno-economic index of artificial brine flotation separation salt making process: salt content of finished product: NaCl ≥ 99.3%; Salt water consumption:10.5 ~11.0m3/t salt; Vaporization heat economy: 2.6~3.0 kg water/kg steam.

(2) Technical and economic indexes of mechanical hot-pressing salt-making process of gypsum-type rock salt artificial brine: NaCl content ≥ 99.3%; Salt water consumption: 10.5 m3/t salt; Power consumption: ≤170 kw h/t salt; Steam consumption (including dry steam): 60 ~ 80 kg/ton of salt.

(3) Technical and economic indexes of salt production process by separating artificial brine from frozen mirabilite: NaCl content ≥ 99.1%; Salt water consumption: 12 ~ 14 m3/t salt; Heat of vaporization economy: 2.6~3.0 kg water/kg steam; Sodium sulfate: Na2SO4 ≥ 99%; Power consumption of sodium sulfate: 450 kW h/t; The steam consumption of sodium sulfate is1.8 ~ 2.0 t/t.

(4) The technical and economic indexes of salt-making process with artificial brine mixed with mirabilite are: NaCl content ≥ 99.1%; Salt water consumption: 12 ~ 14 m3/t salt; Heat of vaporization economy: 2.6~3.0 kg water/kg steam; Mass of intermediate nitrate: Na2SO4 85% ~ 95%.

(5) Technical and economic indicators of "mother liquor recovery method" for denitration of mirabilite artificial brine: salt content ≥ 99.3%; Quality of anhydrous sodium sulfate: Na2SO4 ≥ 99%; Salt water consumption: 4.4 m3/t salt; By-product anhydrous sodium sulfate: 75 kg/ton salt; Steam consumption (including anhydrous sodium sulfate): 1.05 t/t salt; Power consumption: 22 kWh/ton of salt.

(6) Technical and economic indicators of underground brine staged evaporation salt production process: salt content: NaCl ≥ 98.5%; Salt water consumption:11.0 ~12.5m3/t salt; Salt water content: 50 ~ 60 kg/t salt, in which the recovery rate of useful chemical raw materials is ≥ 85%; Vaporization heat economy: 2.6 ~ 2.8 kg water/kg steam.

(7) Technical and economic indicators of solid crude salt flash recrystallization salt making process: salt content ≥ 99.3%; Steam consumption: 0.9 tons/ton of salt.