Method and device for treating fluorine-containing water

Abstract

A high percentage of fluorine in fluorine-containing water is removed and high purity calcium fluoride is recovered when treating the fluorine-containing water by passing the same through calcium carbonate packed towers provided in series in a plurality of stages, preferably two stages. In a method including passing fluorine-containing water through calcium carbonate packed towers provided in series in a plurality of stages to remove the fluorine in the fluorine-containing water and recover calcium fluoride, the calcium carbonate towers are packed with calcium carbonate with a volume mean diameter of 30 to 150 μm. By the use of calcium carbonate granules with a volume mean diameter of 30 to 150 μm, an increase in the purity of the recovered calcium fluoride and an increase in the fluorine removal ratio can be realized with a relatively small device.

1 . A method for treating fluorine-containing water, comprising:
 passing fluorine-containing water through calcium carbonate packed towers arranged in series in a plurality of stages to remove fluorine in the fluorine-containing water and recover calcium fluoride,   wherein the calcium carbonate granules packed in each towers have a volume mean diameter of 30 to 150 μm.   
     
     
         2 . The method for treating fluorine-containing water according to  claim 1 , wherein the calcium carbonate packed towers are arranged in series in two stages. 
     
     
         3 . The method for treating fluorine-containing water according to  claim 1 , wherein the calcium carbonate granules contain granules with a particle diameter of lower than 20 μm at a ratio of 15% or lower. 
     
     
         4 . The method for treating fluorine-containing water according to  claim 1 , wherein a volume mean diameter of the calcium carbonate is 30 to 100 μm. 
     
     
         5 . The method for treating fluorine-containing water according to  claim 1 , wherein the fluorine-containing water is passed through the calcium carbonate packed towers at an SV of 0.1 to 5 hr −1 . 
     
     
         6 . A device for treating fluorine-containing water, comprising:
 a unit for treating the fluorine-containing water in which calcium carbonate packed towers are arranged in series in a plurality of stages;   a unit for passing the fluorine-containing water through the unit for treating the fluorine-containing water;   a unit for extracting treated water from the unit for treating the fluorine-containing water; and   a unit for recovering calcium fluoride from the calcium carbonate packed towers,   wherein a volume mean diameter of the calcium carbonate packed in the calcium carbonate packed towers is 30 to 150 μm.   
     
     
         7  The device for treating fluorine-containing water according to  claim 6 , wherein the calcium carbonate packed towers are arranged in series in two stages. 
     
     
         8  The device for treating fluorine-containing water according to  claim 6 , wherein the calcium carbonate granules contain granules with a diameter of lower than 20 μm at a ratio of 15% or lower. 
     
     
         9  The device for treating fluorine-containing water according to  claim 6 , wherein a volume mean diameter of the calcium carbonate is 30 to 100 μm. 
     
     
         10 . The device for treating fluorine-containing water according to  claim 6 , wherein an SV of the passage of the fluorine-containing water into the calcium carbonate packed towers is 0.1 to 5 hr −1 .