RADIUM CONTROL IN RADIUM CONTROL IN URANIUM MINING WITH A URANIUM MINING WITH A SELECTIVE COMPLEXERSELECTIVE COMPLEXER

Wayne LaughlinBob GoltzThe Dow Chemical Company

Historical Approaches to RadiumRa is a divalent cation; removed by water softener

+ Effective in removing Ra

- Cost of salt, disposal of Ra brine

Precipitation with BaSO4

+ Effective in removing Ra

- Requires sedimentation time and volume

- Unknown cost at the end of the project

Selective Radium Complexer

Precipitate of BaSO4 crystals inside of IX beads >8% wt/wt BaSO4 content Excellent Ra removalHigh capacity - Hundreds of nCi Ra/gram mediaExcellent flow propertiesMinimized volume of wasteConfined and controlled

Photo of the beads

TEM of BaSO4 in beads

Radium Removal

• Typical flow rate of 10 gpm/ft2• Used to remove Ra from drinking water

Typical Ra Loading Profile w/ Cleaning

0

5

10

15

20

0 5 10 15 20 25

Rad

ium

Co

nce

ntr

atio

n

Cleaning

Excellent Flow Properties

• Beads are easily confined by screens in a column

Pressure Drop for DOWEX RSC Na

0

1

2

3

4

0 4 8 12 16

Flow Rate gpm/ft2

Pre

ssu

re D

rop

(P

SI/f

t b

ed d

epth

)

Loading Capacity

• Hundreds of nCi/gram of media

• Since this is a precipitation mechanism, the loading capacity can be weight % levels

• Translates into millions of volumes of water treated per volume of media

• Need to run a projection to size a treatment system

Selective Radium Removal Media

Excellent Ra removal

High capacity

Easy to use

Minimized volume of waste

Confined and controlled

Known cost of use

ReferencesSee our web site at www.TraceContaminants.com

“Radium removal form Canadian uranium mining effluents by a radium-selective ion exchange complexer” L.A. Melis, Melis Consulting Engineers Ltd., Metallurgical Society of CIM, Vol 78, No. 883, pp 82-90 1985.

“Removing and disposing of radium from well water” K.A. Mangelson and R. P. Lauch, Journal AWWA, June 1990, p 72-76.