Determination of crystalline structure of calcium carbonate obtained from drinking water

Abstract

Sample of scale which taken from house boiler is examined. This scale is made by warming drinking water from water-supply system of the -city of Belgrade - New Belgrade. Examinations on atomic absorption spectrophotometer (AAS) showed that there was mostly calcium, like CaO, for 48.90 % of mass which means calculated on contents CaCO3 takes 87.32 % of mass. Research on diffraction meter showed that scale is composed of CaCO3 (in % of mass) (85.25%), MgCO3 (11.05%), FeCO3 (1.90%) and MnCO3 (1.80%). It was also proved that scale is mixture of 66.92 % Mg calcite and 33.07 % aragonite. This structure is result of fact that Mg calcite and aragonite are become in quiet conditions of sedimentation of half shut skin-deep water surrounding on temperature between 60 and 100°C (nearest about 80°C) and low pressure.

Ispitivan je uzorak kamenca koji je uzet sa kućnog bojlera nastao zagrevanjem vode za piće koja se nalazi u vodovodnoj mreži grada Beograda - Novi Beograd (blokovi). Ispitivanja na atomskom apsorpcionom spektrofotometru ukazala su da se nalazi dominantno kalcijum, kao CaO i to 48,90%, što preračunato na sadržaj CaCO3 iznosi 87,32%. Snimanja na difraktometru ukazala su da se kamenac sastoji od CaCO3 (85,25%), MgCO3 (11,05%), FeCO3 (1,90%) i MnCO3 (1,80%). Takođe je dokazano da je kamenac mešavina koja se sastoji od 66,92 % kalcita i 33,07% aragonita. Ovakav sastav posledica je činjenice da su kalcit i aragonit nastali u mirnijim uslovima sedimentacije u poluzatvorenoj plitkovodnoj sredini na temperaturi između 60 i 100°C (najbliže oko 80°C) i pri niskom pritisku.