Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

The specific activities of 238U, 226Ra, 232Th and 40K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P2O5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P2O5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238U, 226Ra, 232Th and 40K were found to be up to 557, 625, 26 and 297 Bq x kg-1, respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P2O5 and F concentrations. (author)