Supervising Scientist Division

Supervising Scientist Annual Report 2003 - 2004: Ranger

Supervising Scientist, Darwin, 2004
ISBN 0 642 24391 3
ISSN 0 158-4030

2 - Environmental assessments of uranium mines (continued)

2.2 Ranger

2.2.1 Developments

Mining and milling at Ranger occurred throughout 2003-04 but was disrupted as a result of production ceasing between 24 March 2004 and 6 April 2004 due to the potable water contamination incident (described in Section 2.2.4 of this Annual Report). Production was also affected by a planned closure of the mill in May 2004 for maintenance operations.

The development of Orebody 3 continued during the year with expansion mainly to the east, consuming Djalkmara Billabong by early July 2004. The remaining water within Djalkmara Billabong was pumped to Retention Pond 2 prior to excavation. Excavation of Djalkmara Billabong commenced in June 2004. Ranger minesite is shown in Figure 2.1.

Exploration drilling has been proposed further to the east of Pit 3 to further delineate the extent of Orebody 3.

The Ranger mill produced some 4666 t of uranium oxide (U3O8) during 2003-04 from some 1 916 362 t of treated ore (Table 2.1). This represented some 48.95% of total Australia's total U3O8 production of 9533 t for 2003-04. Production statistics for the milling of ore and the production of U3O8 at Ranger for the years 1999-2000 to 2003-04 are at Table 2.2.

Table 2.1: Ranger production activity for 2003-04 by quarter
  1/07/2003 to
30/09/2003
1/10/2003 to
31/12/2003
1/01/2004 to
31/03/2004
1/04/2004 to
30/06/2004
Total
Production (drummed tonnes of U3O8 ) 1 086 1 274 1 210 1 096 4 666
Ore Treated (tonnes) 454 816 480 554 513 326 467 666 1 916 362
Table 2.2: Ranger production activity for 1999-2000 to 2003-04
  1999-2000 2000-2001 2001-2002 2002-2003 2003-2004
Production (drummed tonnes of U3O8 ) 4 144 4 612 3 815 5 312 4 666
Ore Treated (tonnes) 1 468 000 1 840 000 1 429 000 2 153 000 1 916 362

Figure 2.1: Ranger minesite

Figure 2.1: Ranger minesite

Although Australia's annual production of U3O8 varies on a year-by-year basis, Ranger's contribution continues to constitute a significant proportion of Australia's total U3O8 production. Figure 2.2 shows Ranger's contribution to Australia's total production for the period 1983-2003.

Figure 2.2: Ranger uranium production as a proportion of Australian total (1983-2003 calendar years)

Figure 2.2: Ranger uranium production as a proportion of Australian total (1983-2003 calendar years)
On-site activities
Figure 2.3: Drainage works on the Ranger southern stockpile

Figure 2.3: Drainage works on the Ranger southern stockpile

Sheeting works on the southern 2s stockpile, and drainage works on the active northern and western stockpiles were completed in preparation for the 2003-04 wet season. The sheeting works on both the southern stockpiles were undertaken to direct surface runoff towards the corridor creek catchment as in previous seasons. These works held up well throughout the wet season with no evidence of the same runoff contamination encountered in previous seasons. Drainage works on the northern and western stockpiles were undertaken to direct water inwards towards the base of the southern stockpile and into the Retention Pond 2/Pit 3 catchment. The southern stockpile seepage sump, which had undergone remedial works during the 2003 dry season to prevent the large loss of water seen in previous wet season, collected and held water well throughout the 2003-04 wet season (Figure 2.3).

The reporting of minor leaks in the process line within the mill area continued to be a regular item on the unplanned events register during the later part of 2003. As a result ERA undertook to replace the old steel lines with new HDPE lines and install spray covers at appropriate points near the pumps in these lines. This has reduced the number of process leaks recorded in the area. ERA also committed to replacing the corridor road line with HDPE towards the end of 2003. This was undertaken during December 2003 and subsequently there have been no further reported leaks from this area other than one incident in January 2004. On 11 January 2004, the HDPE return line fell off a supporting bracket severing the A/E tails line resulting in approximately 100-200 m3 of tailings spilling into the Corridor Road drain. The spill was contained within the drain and remediated appropriately.