The Technological Enhancement of Normally Occurring Radioactive Materials in Red Mud due to the Production of Alumina

Table 1

Technological enhancement factor (TEF) in red mud. The TEF in red mud in this study is determined by the ratio of the specific activity (Bq/kg) of the primordial in red mud to the specific activity in alumina. MDA refers to the “minimum detectable activity” of the detector used in this study.

Primordial/specific activity	Alumina (Bq/kg)	Red mud (Bq/kg)	Technological enhancement factor (TEF) in red mud
K-40	1130.9 ± 27.6	79.200 ± 3.336	0.07 (reduction)
U-238	69.46 ± 3.10	268.31 ± 4.71	3.86
Th-232	Below MDA	326.08 ± 5.33	High and undefined
U-235	10.075 ± 0.405	16.153 ± 1.006	1.60