Thesis Type: Postgraduate
Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Chemical Engineering, Turkey
Approval Date: 2003
Student: ELİF ÖZTİN
Supervisor: GÜRKAN KARAKAŞ
Abstract:Phosphate is one of the essential minerals for all living organisms. It has to be supplied to the soil in order for plant growth. In Turkey, most of the soils lack phosphate mineral. Although this can be overcome by the use of phosphate fertilizers, in Turkey there are no phosphate mines being utilized; and this brings about the need to import phosphate rock and phosphate fertilizers. The estimated phosphate rock reserve of Turkey is around 300 million tons, but it cannot be utilized since no economical method of upgrading has been proved to work yet. The aim of this study has been two-fold; to determine the effects of several parameters on the cell flotation of Mardin-Mazidagi phosphate rock and to increase the grade of the product above 30% P2O5 content with a reasonable recovery rate, so that it could be used commercially. Phosphate rock upgrading was made by using flotation in a cell. There are many factors affecting the recovery and grade of the product such as, particle size, pulp pH, collector volume, acid and collector conditioning times and temperature. Phosphate rock samples used contained 14% P2O5, 43% CaCO3 and 1% SiO2 with a CaO/P2O5 ratio of 3.1. Due to the low silica content, one-stage flotation was made. In the experiments, effects of the important parameters were tested at constant pulp density (10% solids by weight). Particle sizes were between 53 m and 150 m, while the pH values were kept between 5,0 - 6,5 using amounts of acid within the range of 6 - 19 kg H3PO4/ton of rock. The collector (mixture of kerosene and oleic acid in 1:3 volumetric ratio) was used in the range of 0,6 ml (0,96 kg collector/ton rock) and 5,4 ml (8,64 kg collector/ton rock). Acid and collector conditioning times were changed between 10-110 s and 10-80 s, respectively. The temperature range was between 15-35 °C. At the end of the parametric studies a grade of 36% P2O5 with a