LATIN AMERICA — BHP expands potential of Tintaya mine project

Australian-based major Broken Hill Proprietary (BHP-N) continues to outline significant mineralization near the Tintaya copper mine in southeastern Peru.

Since it gained control of Tintaya by merging with Magma Copper in 1996, BHP has delineated two deposits, southeast and southwest of the mine. Lately, the company has been focusing on the Antapaccay porphyry-skarn prospect, 10 km southwest of the mine, where, to date, 130 holes (45,000 metres) have been drilled. Results are highlighted in the accompanying table.

The most promising results include hole 135, which intersected 424 metres grading 1% copper plus 0.21 gram gold and 2.3 grams silver per tonne, and hole 158, which hit 372 metres of 1.17% copper, 0.28 gram gold and 2.6 grams silver.

BHP drilled the holes on 200-metre centres, partially delineating two mineralized bodies. So far, no resource has been calculated, though a geologic model is being prepared.

About 8 km northwest of Tintaya is the Coroccohuayco copper skarn deposit, where, over the past three years, BHP has drilled 186 holes totalling 71,329 metres. The measured, indicated and inferred resource is estimated to be 155 million tonnes grading 1.57% copper, 0.16 gram gold and 6.3 grams silver.

A resource was also calculated for the nearby Ccatun Pucara prospect. The estimate — 24 million tonnes grading 1.44% copper — is based on 76 holes totalling 24,639 metres.

Situated north of Arequipa, the Tintaya mine produces copper concentrates, which BHP trucks to a Peruvian smelter and to the port of Matarani. The concentrate is sold under long-term and spot market contracts, mostly in Peru, Brazil and the U.S.

For the fiscal year ended May 31, 1999, the mine produced 71,000 tonnes copper and 33,912 oz. gold, compared with 67,000 tonnes copper and 34,400 oz. gold in the prior year. Proven ore reserves stand at 49.4 million tonnes grading 1.5% copper and 0.22 gram gold, equivalent to 648,000 tonnes copper and 216,000 oz. gold.

In a announcement, Paul Anderson, BHP’s chief executive officer, described Tintaya as “fully cash positive,” while adding that the same is true of the company’s Escondida and OK Tedi copper mines in Chile and Papua New Guinea, respectively.

BHP is considering expanding Escondida, in which it owns a 57.5% interest. The major is also completing 15,000 metres of reverse-circulation and underground drilling at the nearby Escondida Norte project.

Hole	Depth	Intercept	Length	Copper	Gold	Silver
	(m)	(m)	(m)	(%)	(g/t)	(g/t)
51	430.35	75.95-159.5	83.55	1.33	0.29	2.53
		207-310.3	103.3	1.25	0.37	2.6
53	362.5	68.7-312.85	244.15	1.24	0.22	3.54
89	557.2	43.35-276.1	232.75	0.9	0.08	1.56
		309.25-557.2	247.95	1.1	0.36	2.47
127	430	75-171.75	96.75	0.94	0.2	2.22
		219.5-380.55	161.05	1.03	0.2	3.55
133	456.5	235.95-456.5	220.55	1.39	0.34	3.3
135	484.3	60.4-484.3	423.9	1.01	0.21	2.34
155	355.75	172.5-355.75	183.25	1.71	0.08	4.7
158	503	122.7-495.1	372.4	1.17	0.28	2.57
182	568.9	311.65-550.5	238.85	1.15	0.35	2.6
184	413.95	168-293.85	125.85	1.82	0.2	3.15