Update: World Coal Quality Inventory -- Argentina
Poster

By William E. Brooks and Jason C. Willett

U.S. Geological Survey, National Center, Reston, VA 20192 - wbrooks@usgs.gov

INTRODUCTION

Coal samples have been obtained from major and minor coal-producing regions around the world. Coal quality data derived from analyses of these samples will be included in the U.S. Geological Survey's World Coal Quality Inventory or WoCQI (Finkelman and others, 2001). Coal resources in South America are limited and this extensive region has only ~0.5% of the world's supply of coal (Alvarado, 1980). Occurrences of coal and other organic-enriched strata such as bituminous schists and lignite, are widely distributed in Argentina (fig. 1) (Borrello, 1956; Weaver and Wood, 1994; Lopes and Ferreira, 2000); however, Argentina ranks 34th worldwide in coal reserves (Agramonte and Diaz, 1983). Argentine coal is now used mainly for metallurgy and minor rural domestic use (fig. 2).

|  |  |  |  | <== Figure 1. Distribution of coal units in Argentina (Distribución de las facies carboníferous de la Argentina) (Borrello, 1956). [translation: Neógeno, Neogene; Eogeno, Eogene; Eogeno en el subsuelo, Eogene in the subsurface; Cretácico Superior, Upper Cretaceous; Neocomiano, Neocomian; Jurásico, Jurassic; Triássico, Triassic; Pérmico, Permian; Carbónico, Carboniferous] [VIEW a better quality PDF file] Figure 2. Rural use of coal at a ranch near Rio Turbio, Santa Cruz province.

REGIONAL HISTORY OF COAL USAGE

In South America, coal was used during pre-Inca times for metallurgy (Agramonte and Diaz, 1983) and decorative purposes, such as highly polished anthracite mirrors (Burger, 1992; Larco, 2001). Earliest recognition of coal-bearing units in Argentina was by Augustin del Castillo in 1887 (Borrello, 1956) near the present-day coal mining camp of Rio Turbio in the southern part of Santa Cruz province. Coal mines and occurrences in Argentina are reported to be as few as 41 (Weaver and Wood, 1994) to as many as 850 (Alvarado, 1980).

SITE VISITS

Coal reserves in Argentina are estimated to be 465 million metric tons, of which 460 million metric tons occur mainly in the Rio Turbio and Pico Quemado mines (Alvarado, 1980). Reserves for a number of other coal occurrences in Argentina are given by Weaver (1993). For this study, three samples were collected from Rio Turbio, and four samples were taken from Pico Quemado.

Pico Quemado, Rio Negro province

Coal in this area was first described in 1897-99; in the 1950s, five mines with 3,800 m of underground workings were mined by over a hundred workers (Borrello, 1956). Four seams that are 1.1 to 5.0 m in thickness are present in Miocene continental sediments that have been folded into a regional syncline (fig. 3) with minor faulting. Intermediate-composition volcanic rocks have intruded and overlie the coal-bearing sedimentary section. A drilling program carried out in the 1950s indicated reserves of 2,640,00 metric tons. Analytical data from Borrello (1956) indicates an ash yield of 10.1 to 25.4 percent, a sulfur yield of 0.5 to 0.6 percent, and 6,000 to 7,000 Btu/lb. Pico Quemado closed in the 1950s; the workings have since caved in, and the mine has been abandoned (fig. 4). However, Bergmann (1978) considers the coal to have valuable coking qualities, but reserves are unknown. Regional geology and mineral occurrences of the area have been compiled on a recent map by Glacosa and others (2000).

Figure 3. Regional syncline, looking south toward Pico Quemado, Rio Negro province.
Figure 4. Abandoned mining camp of Pico Quemado, Rio Negro province.

Rio Turbio, Santa Cruz province

This area was visited by Castillo in 1887 (Borrello, 1956) and is the only presently active coal mine in Argentina. The mine is operated by a government agency, Yacimientos Carboniferos Fisicales (YCF) (fig. 5). Production is presently considered low, and the YCF facility includes crushers, cyclones, and a washing apparatus that utilizes magnetite. Some of the coal is used in the plant forge to repair rail cars. Approximately 70 metric tons of coal are moved daily by rail from Rio Turbio to the port of Rio Gallegos for transport by ship to Buenos Aires for metallurgical uses.

Figure 5. East-dipping Tertiary section near entrance to Rio Turbio, Santa Cruz province.
Figure 6. Coal bed (manto Dorotea), Rio Turbio, Santa Cruz province.

Five coal-bearing units, locally referred to as "mantos," are present in gently (5° to 10°) east-dipping Tertiary marine and continental sediments (fig. 5). This area, also known as the Austral Basin, has a thick marine sequence without major tectonic disturbances (Malumian and Carames, 1997). Rio Turbio is an underground mine with five coal-bearing units (bottom to top): manto inferior, manto superior, manto B, manto A, and manto Dorotea. The uppermost of these units, manto Dorotea (fig. 6) is 1.92 m thick and is the only unit presently being mined. Borello (1956) estimated 370,500,000 tons of coal with ash yield of 11.0 to 24.2 percent, sulfur content of 0.35 to 1.1 percent, and 4,900-6,300 Btu/lb. Yacimientos Carboniferos Fisicales indicates an average sulfur content of 0.8 percent, an average ash yield of 13 percent, and an average of 6,500 Btu/lb. The Rio Turbio coal deposits are considered to be an extension of the Magallanes Basin to the west in Chile. Mineral occurrences and regional geology of the Rio Turbio area have been compiled by Malumian and others (2000).

ARGENTINE COAL PRODUCTION AND USAGE

Coal production and usage in Argentina is very modest. Of the 27 powerplants in Argentina that rely on fossil fuels, only one station -- San Nicolas -- relies on coal. All others rely on oil and gas.

| 1989 | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Production (millions of short tons) | 0.57 | 0.31 | 0.32 | 0.22 | 0.18 | 0.38 | 0.34 | 0.34 | 0.28 | 0.32 | 0.37
Consumption (millions of short tons) | 1.81 | 1.18 | 1.54 | 1.21 | 1.12 | 1.84 | 1.85 | 1.66 | 1.51 | 1.42 | 1.73

Total production in 1999 was 370,000 short tons of bituminous coal, and consumption was 1.73 million short tons, all of anthracite coal. Argentina imported 324,000 short tons of coal from the United States in 1998. Average calorific value of Argentine coal in 1996 was 10,600 Btu/lb. Recoverable coal reserves in 1999 were 143 million short tons (source, accessed 8/20/01: http://www.fe.doe.gov/international/argnover.html)

COAL CHEMISTRY

Aside from data given by Borrello (1956), there are no recent analytical data on Argentine coal. Similarly, data are not available on trace elements that might be of environmental concern. A review of internal YCF reports also yielded little recent data on coal chemistry. Regionally, however, Helle and others (2000) report trace-element data on coals to the west, in the Magellanes Basin in southern Chile. E. Hidalgo and others (written communication, 2000) have described the geology and chemistry of the Pecket coal in southern Chile.

Therefore, as part of the World Coal Quality Inventory, three samples from Rio Turbio and four samples from Pico Quemado were submitted to the U.S. Geological Survey Coal Laboratory for major-, minor-, and trace-element content. Proximate and ultimate analyses and sulfur-form data were obtained from commercial laboratories. These coal-quality parameters will be incorporated into the World Coal Quality Inventory database and are significant for economic byproduct recovery, technological behavior of the coal, and environmental impact (Finkelman and others, 2001; Davidson, 2000; Swaine and Goodarzi, 1995). Sampling methods and composite data for one sample from Rio Turbio and one sample from Pico Quemado are compiled in table 1 and table 2.

Table 1. Proximate and ultimate analytical data, Rio Turbio and Pico Quemado mines, Argentina [Analyses performed at Geochemical Testing, Somerset, Pa. n/a, not analyzed]
RIO TURBIO Santa Cruz Province S. 51° 32.388′/W. 072° 15.754′ Field number BA0301, underground, manto Dorotea, channel sample Lab number 01-035832 (Geochemical Testing)
AIR DRY LOSS | 5.35% |  |  |
RESIDUAL MOISTURE | 2.43% |  |  |
PROXIMATE ANALYSIS | As rec. | Dry | Dry ash-free |
Moisture | 7.65 |  |  |
Ash | 12.05 | 13.05 |  |
Volatile matter | 42.37 | 45.87 | 52.76 |
Fixed carbon | 37.93 | 41.08 | 47.24 |
ULTIMATE ANALYSIS | As rec. | Dry | Dry ash-free |
Hydrogen | 6.00 | 5.57 | 6.41 |
Carbon | 63.25 | 68.48 | 78.76 |
Nitrogen | 1.06 | 1.15 | 1.32 |
Sulfur | 1.60 | 1.7 | 1.99 |
Oxygen | 16.0 | 10.02 | 11.52 |
Ash | 12.05 | 13.05 |  |
| As rec. | Dry | Dry ash-free |
HEATING VALUE (BTU/lb) | 11588 | 12548 | 14431 |
FORMS OF SULFUR | As rec. | Dry | Dry ash-free |
Sulfate | 0.01 | 0.01 | 0.01 |
Pyritic | 0.77 | 0.83 | 0.95 |
Organic | 0.82 | 0.89 | 1.03 |
FREE SWELLING INDEX | 2.0 |  |  |
EQUILIBRATION MOISTURE | n/a |  |  |
ASH FUSION (reducing atmosphere) | Initial | Softening | Hemi | Fluid
T °F | 2090 | 2220 | 2350 | 2430
APPARENT specific gravity | n/a |  |  |
FLUORINE | n/a |  |  |
CHLORINE | n/a |  |  |
PICO QUEMADO Rio Negro Province S. 41° 34.766′/W. 071° 01.358′ Field number BA0401, from 50 cm in waste at abandoned underground mine Lab number 01-035833 (Geochemical Testing)
AIR DRY LOSS | 14.39% |  |  |
RESIDUAL MOISTURE | 3.76% |  |  |
PROXIMATE ANALYSIS | As rec. | Dry | Dry ash-free |
Moisture | 17.61 |  |  |
Ash | 47.03 | 57.09 |  |
Volatile matter | 18.91 | 22.95 | 53.49 |
Fixed carbon | 16.45 | 19.96 | 46.51 |
ULTIMATE ANALYSIS | As rec. | Dry | Dry ash-free |
Hydrogen | 3.78 | 2.20 | 5.13 |
Carbon | 22.64 | 28.69 | 66.85 |
Nitrogen | 0.72 | 0.87 | 2.03 |
Sulfur | 0.16 | 0.20 | 0.46 |
Oxygen | 24.67 | 10.95 | 25.53 |
Ash | 47.03 | 57.09 |  |
| As rec. | Dry | Dry ash-free |
HEATING VALUE (BTU/lb) | 3677 | 4705 | 10965 |
FORMS OF SULFUR | As rec. | Dry | Dry ash-free |
Sulfate | 0.01 | 0.01 | 0.02 |
Pyritic | 0.03 | 0.03 | 0.07 |
Organic | 0.12 | 0.16 | 0.37 |
FREE SWELLING INDEX | 0.0 |  |  |
EQUILIBRATION MOISTURE | n/a |  |  |
ASH FUSION (reducing atmosphere) | Initial | Softening | Hemi | Fluid
T °F | 2800 | 2800 | 2800 | 2800
APPARENT specific gravity | n/a |  |  |
FLUORINE | 0.009% |  |  |
CHLORINE | n/a |  |  |

Table 2.Oxide and trace element data (ash basis), Rio Turbio and Pico Quemado mines, Argentina (analyses performed at U.S. Geological Survey, Denver, Colo.) [wt %, weight percent; ppm, parts per million]
Oxides (wt %)
| % Ash | % Moisture | SiO2 | Al2O3 | Fe2O3 | MgO | CaO | Na2O | K2O | TiO2 | P2O5 | SO3
Rio Turbio-BA0301 | 12.8 | 2.9 | 42.2 | 22.4 | 10.8 | 1.3 | 8.0 | 0.54 | 0.24 | 1.3 | 0.05 | 7.2
Pico Quemado-BA0401 | 54.8 | 3.6 | 70.4 | 23.1 | 1.3 | 0.6 | 1.9 | 0.07 | 0.28 | 1.2 | 0.10 | 0.77
Trace elements (ppm)
| Be | Hg | Co | Cr | Cu | Li | Mn | Ni | Sc | Sr | Th | V
Rio Turbio-BA0301 | 2.5 | 0.17 | 26.3 | 32.2 | 130 | 58.6 | 1060 | 10.5 | 35.3 | 339 | 11.2 | 210
Pico Quemado-BA0401 | 3.6 | 0.03 | 21.2 | 57.8 | 39.9 | 36.1 | 50.6 | 79.8 | 18.2 | 135 | <8 | 241
| Y | Zn | B | Ba | Zr | Ag | As | Au | Bi | Cd | Cs | Ga
Rio Turbio-BA0301 | 35.4 | 63.5 | 1400 | 24.2 | 227 | <2 | 17.9 | <10 | 0.42 | 0.17 | 2.1 | 27.7
Pico Quemado-BA0401 | 29.7 | 53.4 | <20 | 374 | 505 | <2 | 1 | <10 | 0.17 | 0.17 | 1.4 | 21.8
| Ge | Mo | Nb | Pb | Rb | Sb | Sn | Te | Tl | U | Se | Cl (%)
Rio Turbio-BA0301 | 5.3 | 4.9 | 7.9 | 20.4 | 12 | 1 | 5 | 0.42 | 0.45 | 3.7 | 0.82 | <0.015
Pico Quemado-BA0401 | 9.5 | 1.6 | 8.1 | 10.9 | 11.1 | 0.89 | 3.8 | <0.1 | 0.16 | 1.7 | 0.24 | <0.015

SELECTED REFERENCES

Agramonte, J., and Diaz, A., 1983, Inventario preliminar del carbon mineral en el Peru: Instituto Geológico Minero y Metalúrgico, Lima, Perú, 77 p.

Alvarado, B., 1980, Recursos de carbon in Suramerica: Revue de L'Institut Francais du Petrole, v. 35, n. 2., p. 387-421.

Baruya, P.S., and Clarke, L.B., 1996, Coal prospects in Latin America to 2010: London, IEA Coal Research, 77 p.

Bergmann, F.A.J., 1978, Coal resources of the Argentine Republic, in Kottlowski, F.E., Cross, A.T., and Meyerhoff, A.A., eds., Coal Resources of the Americas Selected Papers: Boulder, CO, Geological Society of America, The Geology of North America Special Paper 179, p. 15-22.

_____, 1991, Calidad del carbon de los mantos Dorotea y A del yacimiento Rio Turbio: Yacimientos Carboniferos Fisicales Informe Interno 1195, 35 p.

_____, 1992, Calidad media del carbon de los mantos B superior y inferior del yacimiento Rio Turbio: Yacimientos Carboniferos Fisicales informe interno 1196, 37 p.

Bergmann, F.A.J., and Xicoy, A.N., 1990, Coal resources of Argentina, in Ericksen, G.E., Canas Pinochet, M.T., and Reinemund, J.A., eds., Geology of the Andes and its Relation to Hydrocarbon and Mineral Resources: Houston, Texas, Circum-Pacific Council for Energy and Mineral Resources Earth Science Series, v. 11, p. 131-137.

Borrello, A.V., 1953, La geologia del yacimiento carbonifero Rio Turbio, Santa Cruz: Yacimientos Carboniferos Fisicales informe interno 753, 45 p.

_____, 1956, Recursos minerales de la Republica Argentina, III Combustibles Solidos Minerales: Instituto Nacional de Investigacion de las Ciencias Naturales, Buenos Aires, 637 p.

Burger, R.L., 1992, Chavin and the origins of Andean civilization: Thames and Hudson, London, 248 p.

Cabrera, O., 1980, Mustreo del manto Dorotea apertura frente largo 53 mina 3: Yacimientos Carboniferos Fisicales informe interno 1142, 37 p.

Calliari, L., 1955, El yacimiento carbonifero de Pico Quemado, Rio Negro: Yacimientos Carboniferos Fisicales informe interno 788, 35 p.

Davidson, R.M., 2000, Modes of occurrence of trace elements in coal: IEA Coal Research, The Clean Coal Center, 36 p.

Finkelman, R.B., Warwick, P.D., and Pierce, B.S., 2001, The world coal quality inventory, U.S. Geological Survey Fact Sheet FS-155-10.

Glacosa, R., Heredia, N., Zubia, M., and Gonzalez, R., 2000, San Carlos de Bariloche: Instituto de Geologia y Recursos Minerales SEGEMAR (Argentina) Mapa 4172-IV, escala 1:250,000.

Helle, S., Alfaro, G., Kelm, U., and Tascon, J.M.D., 2000, Mineralogical and chemical characterization of coals from southern Chile: International Journal of Coal Geology, v. 44, p. 85-94.

Hidalgo, E., Helle, S., Alfaro, G., and Kelm, U., 2000, Geology and characterization of the Pecket coal deposit, Magellan Region, Chile: (Ms. in review), 30 p.

Larco, R., 2001, Los Mochicas: Museo Arquelógico Rafael Larco Herrera, Lima, Peru, 333 p.

Lopes, R., and Ferreira, J., 2000, An overview of the coal deposits of South America, in Cordani, U.G., Milani, E.J., Thomaz, A., and Campos, D.A., (eds.), Tectonic Evolution of South America, 31st International Geological Congress, Rio de Janeiro, 856 p.

Luengas, L.M., 1949, Estudio geologico de la mina de carbon Pico Quemado y alrededores de la provincia de Rio Negro: Yacimientos Carboniferos Fisicales informe interno 651, 35 p.

Malumian, N., and Carames, A., 1997, Upper Campanian-Paleogene from the Rio Turbio coal measures in southern Argentina -- Microbiology and the Paleocene/Eocene boundary: Journal of South American Earth Sciences, v. 10, n. 2, p. 189-201.

Malumian, N., Panza, J., and Parisi, C., 2000, Yacimiento Rio Turbio: Instituto de Geologia y Recursos Minerales SEGEMAR (Argentina) Mapa 5172-III, escala, 1:250,000.

Olive, W.W., 1978, Coal deposits of Latin America, in Kottlowski, F.E., Cross, A.T., and Meyerhoff, A.A., eds., Coal Resources of the Americas, Geological Society of America Special Paper 179, p. 49-56.

Piatnitzky, A., 1947, Sobre zona Chenqueniyeu (Pico Quemado), Rio Negro: Yacimientos Fisicales Carboniferos informe interno 492, 33 p.

_____, 1949, Sobre mina Quimey Mamil, Pico Quemado, Provincia Rio Negro: Yacimientos Carboniferos Fisicales informe interno 642, 35 p.

_____, 1953, Mina Quimey Mamil, Pico Quemado, Rio Negro: Yacimientos Carboniferos Fisicales informe interno 764, 28 p.

Petersen, C.R., 1978, Coal resources of Peru, in Kottlowski, F.E., Cress, A.T., and Meyerhoff, A.A., (eds.), Coal Resources of the Americas, Selected Papers: Boulder, Colorado, Geological Society of America: The Geology of North America Special Paper 179, p. 35-42.

Sarris, M., 1946, Trabajos de laboreo de destapes en la linea de afloramiento de los mantos en la mina de carbon Pico Quemado, Provincia Rio Negro: Yacimientos Carboniferos Fisicales informe interno 1024, 36 p.

Swain, D.J., and Goodarzi, F., eds., 1995, Environmental aspects of trace elements in coal: Kluwer Academic Publishers, Boston, 312 p.

Weaver, J.N., 1993, Coal in Latin America: U.S. Geological Survey Open File Report 93-239, 60 p.

Weaver, J.N., and Wood, G.H., 1994, Coal map of South America: U.S. Geological Survey Map C-145, scale 1:7,500,000

Return to Table of Contents