102 MINERALS YEARBOOK, 1978-79 
 
 Lower output by both smelters and refineries was attributed to modernization
of facilities, at which time operations were reduced and production declined.
Production at MIM's refinery at Townsville, Queensland, was interrupted by
the modernization of the tankhouse, the first part of which began operating
in November 1978. The supply of concentrates to Electrolytic Refining and
Smelting's refinery at Port Kembla, New South Wales, was reduced, and the
smelter at Tennant Creek, Northern Territory, remained closed throughout
1978 and 1979. 
 At Mount Isa, the quantity of ore treated in 1978 was slightly above that
of 1977. Copper ore production was mainly from the No. 1190 ore body in 1978
and 1979. An important feature was the increased recovery of ore from pillars
left to maintain ground stability during initial mining. The success of the
pillar recovery operations was attributed to the standing ability of the
cement rock ifil that was placed in previously mined areas. Approximately
40% of the copper ore extracted was from pillars in 1978, and 60% in 1979.
The concentration on pillar mining in largely developed areas of the No.
1100 ore body resulted in a record level of productivity in the mine and
the containment of mining costs. A new ore body (No. 1900) was ready for
production at the end of 1979. 
 The Townsville copper refinery produced 139,950 tons of refined copper in
1978, compared with 139,140 in 1977. Output was marginally reduced in the
latter half of the year to enable work associated with the $15 million tankhouse
modernization program to proceed. Although from mid-1979 copper from Mount
Isa was supplied as anode instead of blister, an anode-casting facility was
still required at Townsville to enable anode scrap from the refining process
to be melted. 
 Work at the new MIM Hilton Mine in 1978 and 1979 was confined to a continuation
of the underground diamond drilling on the No. 10 level. The drilling completed
so far indicates that the geological structure of the deposit was considerably
more complicated than at Mount Isa. Primary ore reserves on June 30, 1979,
were reported at 37 million tons containing 7.7% lead, 9.6% zinc, and 6 troy
ounces of silver per ton. 
 Mount Lyell Mining & Railway Co. milled about 2.0 million tons of
ore
and produced 71,000 tons of copper concentrate at its Queenstown, Tasmania,
plant in 1978. Ore output increased slightly over that of 1977, 
as production from the two principal sources, Prince Lyell and Cape Horn,
increased. The company continued to operate at a loss and received financial
assistance from Government sources. During 1978, Government subsidies to
Mount Lyell totaled about $3.1 million. 
 Peko-Wallsend Ltd.'s copper operations at Tennant Creek, Northern Territory,
remained closed throughout 1978 and 1979, but plans were being prepared for
the recommissioning. The project was in a state of readiness and awaits firm
indications of an improved trend in copper prices. One year would be required
for recommissioning, as substantial changes were necessary to improve efficiency.
However, 10,568 tons of copper concentrate was produced in 1978 and 15,478
in 1979, as a byproduct of mining gold-bismuth ore at Peko-Wailsend's Warrego
Mine. The expanded gold ore treatment plant enabled a transfer of all milling
and concentrate production to Warrego with consequently greater efficiency
and lower cost per ton. 
 In 1978, Cobar Mines Pty. Ltd., in Cobar, New South Wales, owned by Broken
Hill South Ltd. (BH South), treated 517,300 tons of copper ore (1977, 609,600
tons) to yield 29,000 tons of copper concentrate assaying 
28.3% copper. The decrease in ore extracted in 1978 compared with 1977 was
largely owing to delays in bringing a new open stope into production because
of geological conditions that adversely influenced drilling and blasting.
The average grade of copper ore treated was 1.7% copper, compared with 1.2%
for 1977. The increased metallurgical recovery of copper from the previous
year reflected the higher ore grade. The copper concentrate produced in 1978
and 1979, continued to be sold to Electrolytic Refining and Smelting Co.

 Kanmantoo Mines Ltd., in Kanmantoo, South Australia, managed by BE South,
remained closed throughout 1978 and 1979. Facilities have been maintained
on a careand-maintenance basis since its closure in 1976. Revenue from hire
charges on equipment partly offset the cash costs of maintaining the mine
site and facilities. 
 Although several old mines could be reopened in the early 1980's, the most
significant copper production may involve new developments, in particular
the Olympic Dam project in South Australia and the Benambra deposit in Victoria.
Western Mining Corp. (WMC) continued diamond drilling at the Olympic Dam
project near Roxby Downs, where about 10 vertical holes