Method recovering useful metal in concentrated water according to seawater-desalination

• Main Authors: LEE SUNG JAE, LEE GANG YEON, YU SEUNG UK, KIM OK, SHIN MI RAE, JEONG DA EUN
• Format: Patent
• Language: English; Korean
• Published: 01.07.2022
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRETREATMENT OF RAW MATERIALS; PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY ORREFINING OF METALS; PRODUCTION AND REFINING OF METALS; SEPARATION; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A method for recovering useful metal in concentrated water from seawater desalination according to the present invention comprises the following steps of: receiving seawater and then removing impurities included in the seawater; separating drinking water and concentrated water by reverse osmosis method for salt concentration of the seawater from which impurities are removed by seawater pretreatment; removing impurities of cations and anions from the concentrated water separated through the reverse osmosis method by using cation exchange resin and anion exchange resin mixed and filled in a mixed ion resin column; electrolyzing lithium ions from the concentrated water with impurities removed; and supplying at least one of phosphoric acid and phosphoric acid compound to the lithium ions recovered by the electrolysis to extract lithium phosphate with low solubility. 본 발명에 따른 해수 담수화에 따른 농축수내 유용금속 회수 방법은, 해수를 공급받은 후 해수에 포함되는 불순물을 제거하는 단계; 해수 전처리에 따라 불순물이 제거된 해수의 염분 농도를 역삼투 공정으로 식수원과 농축수를 분리시키는 단계; 혼상 이온수지탑에 혼합 충진되는 양이온 교환수지 및 음이온 교환수지를 이용하여, 상기 역삼투 공정을 통해 분리된 농축수에서 양이온과 음이온의 불순물을 제거하는 단계; 분순물이 제거된 농축수로부터 리퓸 이온을 전기분해하는 단계; 및 상기 전기분해에 의해 회수된 리튬이온에 인산 및 인산화합물 중 적어도 하나를 공급하여, 용해도가 낮은 인산리튬을 추출하는 단계를 포함하는 것을 특징으로 한다.