Calcium Extraction from Brine Water and Seawater Using Oxalic Acid

Calcium can be extracted not only from rocks but also from natural liquor such as seawater and brine water. In order to extract the calcium from seawater and brine water, oxalic acid was used in this research. Effect of variations of the volume of the oxalic acid at a constant concentrationin seawater and brine water to produce calciumwas investigated. The concentration of oxalic acid was100 g/l and the variations of itsvolume were 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml,and 50 ml. The used seawaterand brine water were firstly evaporated from 100 ml into 50 ml and then the oxalic acid was added into them with mixing to produce the calcium precipitates. The precipitateswereanalyzed by X-ray diffraction (XRD) and scanning electron microscope(SEM) and the filtrateswereanalyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES). The SEM analysis showedthat the precipitatesfrom brine water were consisted of only calciumcompoundwhile from seawater sodiumone was also found along with calcium compound. The XRD analysis showedthat the calcium was presentin the form of calcium oxalate for both seawater and brine water. The ICP-OESanalysis of the filtratefrom seawater precipitation showedthat the its calcium content was decreased from 826.20 ppm to 0.04 ppm whilefrombrine water, itdecreased from 170.06 ppm to 1.96 ppm. Theseresults showedthat both seawater and brine water havethepotential to be araw material for calcium production. AIP Conference Proceedings 1805 , 070002 (2017)