Present State of Mineral Resources in Argentina 講 演
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198 特 別 Present state of mineral resources in Argentina 講 演 Jorge R. Palmes INTRODUCTION In chronological order, the development of Argentina's mining industry can be placed under three periods of time, the first is in relation with the pre-colonization period, the second from the colonization period to the end of the 19th century and the third is from 1900 up to date. We have very little information about the first period, and it was assumed to be connected with the activity of aborigines in relation to the extraction of alluvial gold in the western part of Argentina and may be, in other parts of the country as well. With respect to the exploitation of gold and silver ore in the form of vein by "Incas" aborigines and accustomed miners, there are no references. During the colonization period and the later part of it, the search for silver minerals for manufacture of coins had a big impulse. Early in the past century deposits were discovered due to the activity of prospectors and muleteers. In the second part of the last century the mining industry acquired a very important evolution, with the pronoucement of minerals deposits and investment of foreign capitals, mostly from England, for the exploitation and processing of ores. The third period is from the begining of the past century up to date, during which time the miningindustry went through different stages. Large and small mineral deposits were intermittently discovered and the industry grew sharply due to the presence of minable deposits of Sn, Ag, Fe ores in the deposits. Besides, the exploitation of other mineral deposits such as Pb, Zn, Cu, etc., on order to satisfy the demand of industrial development also promoted the mining industry. The production of metallic minerals suffered important distortion due to low internal and international prices. In specific cases i.e.: tungsten and tin, the unfavourable market situ- ationhad a severe impact in the operation of enterprises, due to the high cost of exploitation of the mineral deposits, the complexity of the ore and the content of metals in the mineral ex- tracted. In other cases the situation was overcame by the better utilization of obsolete equipment. The production of metal contained in the minerals had experienced significant increases, espe- cially those for the iron and steel industry. With respect to non-metallic minerals, (which included those minerals known by international classification as industrial minerals) we can see a sharp growth in the relation to the international market despite the still suspended internal market. The growth of production of rockfor construction purposes i.e.: sand for construction, basalt, marble, etc. depend on the evolution of the private and public investment in the construction of houses, roads and public works. The production of marble, granite and their application in structural facing and decorationis sensitive to the demand of the external markets. 昭 和63年11月16日 本 会 第81回 例 会 に お い て 発 表 Researcher,National Institute of Industrial Technology,Argentina. 昭 和63年10月5日 受 理 (8) 資源処理技術 Present state of mineral resources in Argentina199 Below is the production figures in tons for various years and mineral types . Year Metallic Mineral Non-Metallic Mineral Building Stones Total 1982 843,273 4,072,627 45, 875, 490 51, 206, 821 1983 1,433,331 5,351,548 51, 728, 043 58, 512, 903 1984 1,309, 148 5,387,725 55 , 609, 900 62, 666,841 1985 1,079,568 5,481,624 58, 631, 876 65,193, 068 1986 975,934 5,941,211 58, 515, 840 65, 422, 985 1987 822,532 5,017,023 55, 371, 875 61, 211, 431 It can be seen from the above figures that the ratio of metallic minerals to non-metallic mineral is 1:5 and that of metallic mineral to Builing Stones is 1:50 The obvious growth in the volume of metallic minerals during 1983, 1984, and 1985 is mostly due to the exploitation of mineral deposits of Fe at Sierra Grande and the intensification of the exploitation of uranium ore in the case of Sierra Pintada. Both of them are state owned. Below is the discussion of the main mineral deposits in Argentina. METALLIC MINERALS 1. Copper With the discovery of new deposits of disseminated copper, geological and mineralogical data of the copper reserves have changed considerably. Presently, the reserves contain about 10,190,000 tons of metal and the main deposits are those of Pachon at San Juan province, Capillitas and Bajo de la Alumbrera at Catamarca province (see Fig, 1). The total reserves in these deposits had been assessed to completely satisfy the demand of local copper industries. In the production of minerals in Argentina, copper is low in priority and the average for the period 1970-1986 was only 362.6 tons of fine Cu metal per year. These rather low production of copper minerals came from the province of Mendoza, Jujuy and Chubut. The polymetallic ores which are mined in the province of Chubut are not treated in Argentina, and they are exported untreated because of inadequate facilities to treat the tonnages mined. However, the copper minerals mined are used to produce primary copper metal mostly in Jujuy province. The chemical industries produce copper salt and copper compound from small quantities ofcopper minerals and copper concentrates. However, the largest raw materials are scrap copper or imported copper. Argentina's requirement of copper are satisfied mainly by imported refined copper. The Secretariate of Mining initiated plans to develop the Bajo de la Alumbrera deposit in Catamarca province but was interested in attracting foreign companies to undertake both gold and copper extraction. The deposit estimated at 430, 000, 000 tons and assays 0.6 to 1.3% Cu and 0.3 gm/ton Au is owned by a state agency formed by the Federal Government and the pro- vince of Catamarc There have been several studies carried out by companies to develop small copper mines to produce copper sulphate, but none of them has been able to reach commercial quantities. Minera Aguilar company has announced the testing of thin layer (TL) leaching of oxides from the Pachon deposits in the province of San Juan, but the project has not reached the engineering stage yet. 2. Tin This metal became very important in 1933 owing to the discovery of alluvial deposits at Vol.35,No.4('88-冬) (9) 200 Jorge R. Palmes Fig.1: Location of the main mineral deposits of copper and iron minerals. Pirquitas (province of Jujuy), and its treatment started one year later. By 1949 15, 224 tons with an average of 60% metal content had been mined. Out of this, ore concentrate of tin as well as a combination of Sn-Ag were obtained. The Sn concentrates contain 3-5% Sn and the Sn-Ag concentratescontain 50-60 kg/ton Ag and 40% of Sn between 1936 and 1939. Presently there are two main deposits in the country. These deposits have different charac- teristic: a) mineral of tin and silver (with sulphur) in the province of Jujuy b) mineral of tin (casiterite) in the province of Catamarca. From 1982 production of metallic tin from concentrate imported from Bolivia, and production from recycled tin plates and bronzes scrap started. The present reserves of the main mineral deposit totals 22, 663 and this represent 0.230 of the world total reserves. The nation's production (10) 資源処理技術 Present state of mineral resources in Argentina201 of the mineral concentrates was 3,831 tons, 4,551 tons, 3,505 tons for the years 1984, 1985 and 1986 respectively. Their metal contents were also 274 tons, 451 tons, and 379 tons respectively . 3. Iron and Steel The iron ore reserves of Argentina is estimated to contain 492, 330, 000 tons . The main deposits can be found at Sierra Grande (province of Rio Negro) Zapla-Puesto Viejo (Province of Jujuy), Agua Negra (province of San Juan) etc. (see Fig. 1). The ore mineral extracted in Zapla is used to feed Altos Hornos de Zapla smelter, mean- while thosemined at Sierra Grande is consumed in the SOMISA smelter and part of this primary iron is used forthe production of heavy drilling slurries and cement of high density. The production of iron concentrate in tons for the year 1986 was 514, 259 tons while the quantity of pellets (with grade up to 68% iron) produced was 706, 863 tons. The Altos Hornos de Zapla smelter commenced operationsin 1945 with its mineral raw material supplied by 9 de Octubre mine situated in the same province (Jujuy). Fifteen years prior to 1945, the smelter's main raw material was ferro-titanium sand and the iron mineral mined on small scale from vein deposits. The mining group of Zapla-Puesto Viejo had announced possible ore reserves of several millions of tons with a grade of 20-30% Fe. The deposits in Sierra Grande mined in the province of Rio Negro have a higher metal grade than those of Zapla which have a grade up to 55-57% Fe. This ore is concentrated and its phosphorous content is reduced for the production of blast furnace pellets. Crude steel production was only 2, 620, 000 tons while the volume of rolled steel products was 2,700, 000 tons. For 1986 this figure represents the utilization of half the annual plant capacityof Argentina, which has been estimated to be 5, 200, 000 tons. 4. Aluminium The production of aluminium at Aluar's Plant in the city of Puerto Madryn (province of Chubut) wasup to 138, 000 tons in 1987, and represented the utilization of 960 of the plant capacity.