Natural radioactivity level of products and by-products of ilmenite processing industries in Perak, Malaysia

Abstract

Natural background radiation levels in the minerals collected from two tin tailing processing factories at Kinta Valley, Perak, Malaysia were measured. Nine samples were collected analyzed for the activity concentration of the naturally occurring radionuclides and gross alpha and gross beta activities. The activity concentrations of 238U, 232Th and 40K were analyzed by using a HPGe detector. The activity concentration of the samples were found in the range 374 - 13376 Bq kg-1for 238U, 842 - 147347 Bq kg-1 for 232Th and 96 - 1827 Bq kg-1 for 40K. Based on the activity concentration of 238U, 232Th and 40K, gamma absorbed dose rates in air at 1 meter above the ground were calculated using the procedure applied by UNSCEAR 2000. The range of absorbed dose rates calculated was 720 - 95253 nGy h-1and the range of annual effective dose rate was 883 - 116819 μSv y‒1. The calculated radium equivalent activities (R ) were in the range 1663 – 224223 Bq kg-1. The gross alpha activity of the soil samples were found in the range 5.79 - 220 Bq kg-1 and the range of the gross beta activity was 3.97 - 552 Bq kg-1. Finally, the range of the external radiation hazard index was calculated as 4 - 605.