No more striking example of the rise and fall of a copper mining centre is to be seen in Chile than at the deserted city of La Higuera. It lies just off the road leading from La Serena (Coquimbo) to the iron mountain of El Tofo, upon a tiny thread of a stream trickling from the steep and tumbled mountains. The city lies in the shallow cup of an immense hillside, a patch upon the sandy and orange waste; numbers of black dumps mark the sites of old copper mines, a score of chimneys stand among the silent machinery of abandoned mines. At least a thousand houses make, from a distance, a brave showing.
But at the approach of the infrequent visitor in automobile or on horseback, the houses are seen to be windowless, empty; nothing moves in the sun but a stray cur or two, until presently an old woman with a child at her skirts peeps from a makeshift shelter. The whole place is dead; not an engine is working, not a gang of workers moves upon the great spread of properties. The exhaustion of rich veins, difficulty of competition with metal produced at less expense in a fallen market, coupled with tangled litigation, has brought back silence to this strange spot in the mineral-strewn mountain spurs that here crowd down almost to the sea.
The day of La Higuera is not long past; the mines of this extraordinarily rich region were actively productive during the present century. But a similar fate has already closed down very many smaller groups of mines, as it closed down smelters from Arauco to Antofagasta. In the prosperous days of the industry last century, when Chile was the greatest copper-producing country in the world, a big fleet of sailing ships, copper-bottomed, fast, with a famous list of captains, voyaged constantly between Swansea and the Chilean coast by way of Cape Horn, bringing British coal and merchandise and returning with bar copper or rich ores. A whole colony of Welsh set up the first scientific furnaces in Herradura Bay, just outside Coquimbo Town, and at a dozen points the little smelters of Copiapó and Coquimbo were busy; simple methods were used with profit, and many Chilean residents recall the time when the stem and stalk of the cardón were always used to obtain a fine clear fire when annealing copper.
El Teniente and Chuquicamata
The most spectacular of the large copper mines in operation today in Chile is that of El Teniente, situated on the rim of an ancient crater of the Andes east of Rancagua, the nearest main line railway station. Sewell, the little town of mining employés, is connected with Rancagua by the private line of the Braden Copper Company, 72 kilometres in length, climbing from Rancagua’s altitude of 513 metres, or about 1600 feet, to the mining camp’s height above sea level of 2140 metres, or some 7000 feet, on the side of a terrific gorge in a tangle of rocky mountain shoulders and peaks. The main ore bodies lie above the site of the town and plant at altitudes ranging from 9000 to 11,000 feet, one peak, El Diablo, on the crater’s edge, rising to 13,000 feet.
Sewell Camp at Night.
Sewell (El Teniente Copper Mines) near Rancagua.
The amount of copper ore found in masses on the circular rim was calculated at the beginning of 1920 as 174,500,000 tons of 2.45 per cent, with (probably) 92,000,000 tons of 1.91 per cent ore in sight, with, in all probability, other large deposits in the vicinity. The main body now under exploitation yields a low-grade ore containing an average of 2½ per cent of copper in the form of sulphides. The ore is brought down to the plant by a railway line protected by sheds from the deep snow falling and standing for six months of the year; is crushed very fine, treated by the oil flotation system about which so much litigation has raged, and smelted by three processes during which the copper is freed from sulphur and iron. A small quantity of gold and silver remains in the bars shipped to market. Crushing 5000 tons of ore per day, a production of 100 tons of bar copper is at present possible; plans are also under way for new mills at a snow-free site on the railway line to Rancagua, at a spot where the junction of the Coya and a canal from the Cachapoal River forms a waterfall of 422 feet, yielding hydraulic power sufficient for the generation of 40,000 H.P. A new power house recently completed, on the Pangal River, another nearby Andean torrent joining the Cachapoal and Coya, adds to the equipment by which the Braden Company contemplates 10,000 tons of daily crushing, operations which should result in the production of over 70,000 tons of bar copper each year. Paralyzation of international markets has so far checked the materialisation of these plans, and during 1921 the plant was operated at no more than half its capacity. The most prosperous year which the mine has had so far was that of 1918, when El Teniente produced nearly 35,000 metric tons of bar copper, out of the Chilean total production of rather more than 102,200 tons: a year later, 1919, the Braden Company sold and shipped only 10,000 tons of bar copper.