DL-1a Uranium-Thorium Ore

Click to print PDF version of certificate.

DL-1a is intended as a replacement for reference ore DL-1, the supply of which is exhausted. DL-1 was part of a popular suite of seven uranium-thorium ores, the others being DH-1, BL-1, BL-2, BL-3, BL-4, and BL-5. DL-1a is waste-rock typical of the property of Denison Mines Limited in Elliot Lake, Ontario. It is a pale yellow, arkose sandstone containing uraninite and brannerite, and possibly traces of monazite and uranothorite.

Twenty and fourteen laboratories provided results for uranium and thorium, respectively. Preliminary data for iron, sulphur, and lead are also reported.

Certified Values and 95% Confidence Intervals
Constituent wt %
U 0.0116 ± 0.0003
Th 0.0076 ± 0.0004
Ra-226 1.40 ± 0.04 Bq g-1
Pb-210 1.40 ± 0.02 Bq g-1

Thirteen and eleven laboratories provided radioanalytical results for radium-226 and lead-210, respectively.

A certificate of analysis will be issued with each order of DL-1a. Copies of CANMET Reports 80-10E, "DL-1a: A certified uranium-thorium reference ore"; 83-9E, "Radium-226 in certified uranium reference ores DL-1a, BL-4a, DH-1a and BL-5"; and 84-11E, "Lead-210 in certified uranium reference ores DL-1a, BL-4a, DH-1a and BL-5", will be forwarded, free of charge, on request to the Coordinator, CCRMP.

Approximate Chemical Composition
Constituent wt %
SiO2 85.5
Al 5.3
Fe 0.9
S 0.4
Ca 0.3
K 0.2
Mg 0.2
Na 0.09
Ti 0.09
H2O (105/°C) 0.2
L.O.I. (900/°C) 1.4

CCRMP, CANMET Mining and
Mineral Sciences Laboratories

555 Booth Street, Ottawa
Ontario, Canada
K1A 0G1

Telephone: (613) 995-4738
Facsimile: (613) 943-0573
E-mail