Ramona Flavia CAMPEAN¹, Ioan PETEAN², Marius BĂRĂIAN², Alexandra Gertrud HOSU - PRACK³, Dumitru RISTOIU¹ & George ARGHIR^2*
1Babeş-Bolyai University, Faculty of Environmental Science and Engineering, Fântânele Str., No. 4
400294 Cluj-Napoca, Romania.
²Technical University of Cluj – Napoca, Faculty of Materials Science and Engineering,
Muncii Ave. No., 103-105, Cluj - Napoca, Romania. * Corresponding author: georgearghir@hotmail.com
³Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, Arany Janos Str, No 11
400028 Cluj-Napoca, Romania.

MINERAL PARTICULATE MATTER FROM THE ST. ANA LAKE SAND RELATED TO THE WATER SUSPENSIONS

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The St. Ana Lake is the unique Crater Lake in the Eastern Europe formed by water accumulation in the Ciomadu Mare volcano cone. The shore sand contains a wide range of mineral particulate matter containing andesite with: potassic feldspar, biotite, hornblende, muscovite, hydrated potassium silicate. The dimensional measurement reveals very fine fraction of minerals having an average diameter of 1 – 10 μm mixed with some of larger microscaled particles (e.g. 100 - 300 μm average diameter) to the larger particles such gravel having an average diameter of 5 mm. The greater particles are subjected to an almost sedimentation in contact with water. The smaller particles act somehow different. We design an algorithm based on the spherical and tabular approach of mineral shape to establish a function of weight and the ascension force depending on the measured average diameter of particles. The model reveals that the tabular minerals with measured average dimension of 10 μm and beneath are subjected to the colloidal and superficial interactions remaining suspended in different water strata, meanwhile the spherical ones needs submicron dimensions to remain suspended. The measurement performed at several water strata reveals the increasing of average diameter and number of suspended explaining the variation of water properties. The suspended particle diameter and their number increase progressively with the water depth. The electrical conductivity and turbidity increase along with water depth mainly in the proximity of mud layer. The suspended biotite and hornblende presence in the water strata causes an increasing of Fe content along with water depth. Also the presence of feldspar and hydrated silicates causes a decreasing of pH value along the water depth.