| 摘要 |
<p>PURPOSE:To prevent the accumulation of the silica content in absorbing liquid and improve the purity of recovered CaF2 by recovering calcium fluoride from the absorbing liquid after the treatment of waste gases contg. fluorine type components, then adding a magnesium component to settle and remove the silica content then recycling the same. CONSTITUTION:A treatment method which allows a waste gas 2 contg. fluorine components to contact absorbing liquid 4 of 4.4-5.5pH contg. CaCl2 to remove fluorines, conducts the liquid after the treatment to an absorbing liquid circulating tank 5, adds CaCO3 6, HCl 7 to control its pH to 4-5.5, and recycles the regenerated absorbing liquid regenerated of CaCl2 for treatment of the waste gas 2 contg. fluorine components. At this time, part thereof is fed to the 1st solid-liquid separating machine 10 where the CaF2 12 is recovered, next is is fed to a reaction tank 13, where it is added with an Mg compound 15 such as dolomite and is heated. The resultant MgO.nSiO2 18 is separated in the 2nd solid-liquid separating machine 16. The separated liquid is returned to the tank 5 and is reused.</p> |
