| 摘要 |
PURPOSE:To perfectly remove the salt contained in sea sand for reinforced concrete, by a method wherein washing water is sprinkled over the sea sand during the transfer on a belt conveyor while the used washing water is degassed after filtering and receives the injection of a deoxigenating agent and desalting treatment according to a reverse osmosis method before repeated use. CONSTITUTION:Sea sand 3 collected by seawater is transferred by a washing belt conveyor 4 and washing water is sprinkled over sea sand 3 from the nozzles 5A of a water sprinkling head 5 to wash off the salt contained in sea sand 3 while washed sand is drained to be stored in a sand collection tank 9 and utilized as sand for concrete. Waste washing water is passed through a filter tank 11 from a water collection tank 10 to remove fine particulate sand and dust therein by filtering and a deoxidizing agent 12A is injected in the filtered water to remove dissolved oxygen to send said water to a degassing device 12 where oxygen and carbon dioxide dissolved therein are degassed under a vacuum degassing condition. A deoxidizing agent 12B is again injected in treated water and degassing is perfectly performed to prevent the embrittlement and destruction of a reverse osmosis membrane element. Subsequently, the treated water is sent to a reverse osmosis apparatus 15 under pressure by a high pressure water feed pump 7A to remove salts and purified water 19 is sent to a water storage tank 1 to be again used as washing water. |
