Anhydrous calcium chloride (CaCl2) is white or off-white solid ( granular, massive or powder ) , slightly bitter taste , odorless , soluble in water , emit a lot of heat when dissolved in water. With a strong hygroscopic , easily deliquescence in the air, should be sealed storage.
CaCl2 used as a desiccant, dehydrating agent, refrigerant , aerospace and automotive engine antifreeze , antifreeze coagulation , fire retardant fabric , food preservatives and the like . 0 P0 r9 L! P7 r
First, the production principle (z & {/ X-V) J1 w
The reaction of limestone and hydrochloric acid used in the system. The main chemical reaction is as follows :; P J% @ 6 K g, y6 z!
CaCO3 +2 HCl → CaCl2 + H2O + CO2 ↑ 7 C7 B) t $ s "S4 o5 t7 s0 X7 u: N
Second, during the operation 'h O: y L3 V2 n: @ 5 Z; Z.
A system of calcium chloride dihydrate (CaCl2 · 2H2O):. Hydrochloric acid ( 31% ) and limestone powder , according to the ratio of 2.2:1 cylinder into the reaction , the reaction under stirring , an acidic solution of calcium chloride , shifted clarifying tank. Lime added to adjust the solution to pH of 8.9 to 9 , when ferric hydroxide precipitates . The clarified , filtered and the filtrate evaporated in the shift dish was heated to 172 ~ 174 ℃ evaporation , crystallization, separation of 200 ~ 240 ℃ after the dehydration , i.e., a calcium chloride dihydrate .
2 Anhydrous calcium chloride : calcium chloride dihydrate and then heated to 260 ~ 300 ℃, dehydration , which becomes white anhydrous calcium chloride.
