Update: World Coal Quality Inventory—Perú
Poster

By William E. Brooks and Jason C. Willett

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

INTRODUCTION

The U.S. Geological Survey's (USGS) World Coal Quality Inventory (WoCQI) will contain coal-quality information on samples obtained from major and minor coal-producing regions throughout the world (U.S. Geological Survey, 2001). In South America, coal resources are limited, and this extensive region has only 0.5 percent of the world's supply of coal (Alvarado, 1980). Although coal is widely distributed in Perú (fig. 1), Perú ranks thirty-ninth worldwide in coal reserves (Agramonte and Diaz, 1983). Peruvian coal is used mainly for rural domestic use (fig. 2) and minor industrial applications that include brickmaking, coal briquettes, metallurgy, cement production, and filters.

|  |  |  |  | <== Figure 1. Coal basins in Perú (Cuencas con carbón en el Perú). Cenozoico, Cenozoic; Eoceno, Eocene; Mioceno, Miocene; Mesozoico, Mesozoic; Paleozoico, Paleozoic; Mississipiano, Mississippian; Cretáceo inferior, Lower Cretaceous; Jurásico superior, Upper Jurassic. Carreteras de primer orden, Main roads; Carreteras de segundo orden, Secondary roads; Rios, Rivers; Puertos, Ports; Ciudades principales, Main cities; Poblados, Towns (from Carrascal and others, 2000). [VIEW a better quality PDF file]

REGIONAL HISTORY OF COAL USAGE

In Perú, coal was used during pre-Inca times for metallurgy (Agramonte and Diaz, 1983) and decorative items such as highly polished anthracite mirrors (Burger, 1992; Larco Hoyle, 2001). In northern Perú, Lechtman (1976) indicates that "use of coal [as a fuel during pre-Inca time] is not at all improbable because there is a large source of coal in the Quebrada de Cupisnique."

However, the first large-scale industrial application of coal in Perú began around 1816 for steam generation at the copper mines near Cerro de Pasco (fig. 1) (Agramonte and Diaz, 1983). By 1880, coal was used extensively in the copper and silver smelters in the region (Bargellini, 1992). Exploitation of coal intensified from 1880 to 1931; in 1931, an 8-km-long cable system with a hauling capacity of 225 tons of coal per day was set up to transport coal from the mines at Callacuyan to the silver smelter at Shorey (Minero Perú, 1986), which is near Santiago de Chuco (fig. 1). Between 1943 and 1956, anthracite from northern Perú was exported to Argentina and France (Carrascal and others, 2000). Electricity in Perú is produced mainly from hydroelectric power; however, because of the high sulfur content of most coal in Perú, coal for power generation for copper mining operations in southern Perú is imported from Indonesia, Colombia, and Venezuela (Bowen, 2001).

COAL-PRODUCING REGIONS

The number of coal-producing basins in Perú varies by author. For example, Carrascal and others (2000) list 13 (fig. 1); Lopes and Ferreira (2000) show 3; Dunin-Borkowski (1996) lists 5; Weaver and Wood (1994) and Yanque (1989) list 8; Agramonte and Diaz (1983) list 12; Alvarado (1980) lists 15; Olive (1978) lists 7; and Petersen (1978) lists 4. Weaver (1993) also compiled data on Peruvian coalfields, reserves, and usage. Similarly, the number of coal occurrences varies by author. For example, Carrascal and others (2000) provide information on 230 occurrences; INGEMMET (undated) lists 51 occurrences; Weaver and Wood (1994) list 89.

Coal is present in Paleozoic, Mesozoic, and Cenozoic basins (fig. 1) and ranges in rank from bituminous to meta-anthracite (in proximity to and affected by intrusive rocks such as the Coastal Batholith) in the Paleozoic-Mesozoic basins and from lignite to sub-bituminous in the Cenozoic basins. Coal reserves are estimated to be 1,054,613, 559 metric tons (Carrascal, 2000, table 4.1.8), 78.3 percent of which is from Mesozoic basins, 21.4 percent of which is from Cenozoic basins, and 0.3 percent of which is from Paleozoic occurrences (Carrascal and others, 2000).

Historically, the best-known coal-producing area is the Goyllarisquizga coalfield in central Perú, which supplied coking coal to the copper smelters near Cerro de Pasco. From 1903 to 1971, this mine yielded 8,800,000 metric tons of coal. The mine closed in 1971 for economic reasons (Petersen, 1978).

The most extensive — and potentially the most productive — coal-producing area in Perú is in northern Perú, an area referred to as the Northern Anthracite Field by Petersen (1978) or, more commonly, the Alto Chicama (Escudero, 1979). Carrascal and others (2000) subdivided this area into four sectors, each having numerous coal occurrences. The Alto Chicama is 1,520 km2; reserves are estimated to be 223,700,000 metric tons (Escudero, 1979). Coal is hosted in folded and faulted rocks of the Cretaceous Goyllarisquizga Group, which includes the sandstones of the Santa and Chimu Formations (Petersen, 1978). The coal beds are 1.0 to 2.5 m in thickness (Carrascal and others, 2000). Average sulfur content and ash yield of Alto Chicama coal are 0.6 and 11.1 percent (as received), respectively. These averages are for 37 analyses. Analytical data from the anomalously high-sulfur coal (to 23 percent) from Callacuyan are excluded (Carrascal and others, 2000).

Figure 2. Rural use of a coal briquette burner, town of Chao, northern Perú. |

Another important coal region in northern Perú included in the Alto Chicama, is the Santa Basin. Several mines such as La Galgada, Cocobal, and La Limeña, have been active in this area, which is near the steel works at Chimbote. Carrascal and others (2000) also subdivide the Santa Basin into several sectors. Steeply dipping anticlines and synclines are the dominant structures, and coal beds range from 0.3 to 3.5 m in thickness. Average sulfur content and ash yield of Santa coal (17 analyses) are 0.48 and 15.2 percent (as received), respectively (Carrascal and others, 2000).

According to Burgess (1985), the level of credibility for reserve figures in Perú is low. However, they are reliable enough to indicate that coal is present in large quantities, such as Carrascal's (2000) estimate of 1,054,613,559 metric tons. However, no estimate can be made of the total resources on a countrywide basis or of those reserves in the many small coalfields (Burgess, 1985).

SITE VISITS

The author obtained coal from several locations in Perú during site visits in the Alto Chicama.

Mina San Juan (Baños de Chimu).—Channel samples were taken from conchoidally fractured, shiny, anthracite (locally called "cisco") at Mina San Juan (fig. 3) — which is also referred to as Baños de Chimu — from a steeply dipping, 3-m seam in the Cretaceous Chimu Formation. This coal is used locally for cooking and is transported 110 km south to Trujillo for processing into briquettes (coal, clay, calcium, and water) for domestic use, for brickmaking, and as a heat source for the poultry industry. Two nearby hot springs described by Marquez (1992) contribute a strong sulfur smell and elevated temperatures in the adit.

Figure 3. Mina San Juan at Baños de Chimu, northern Perú. |  | Figure 4. Coal from Mina La Victoria brought to market in Quiruvilca, northern Perú. |  | Figure 5. Domestic use of coal in Quiruvilca, northern Perú.

La Victoria.—Channel samples were taken from cisco at Mina La Victoria from an 800-m adit that follows a 2-m coal bed, offset by faults, in steeply dipping massive sandstones of the Cretaceous Chimu Formation. One or two trucks leave the mine two to three times a week and drop the coal near the public market (fig. 4) for domestic use (fig. 5) in the silver-mining town of Quiruvilca. Coal from La Victoria is used for cooking and heating in Quiruvilca and in the nearby mining town of Shorey. At nearby Mina Callacuyan (Jessen, 1989), the high sulfur content of the coal combined with terrorist activity shut down mining in 1992. Both Mina La Victoria and Mina Callacuyan are hosted in a northwest-trending breached anticline that is several kilometers long. Sulfur (0.61 percent average for nine analyses, as received) (Carrascal and others, 2000) has not been a problem at La Victoria.

PERU PRODUCTION DATA

Recoverable coal reserves (1996): | 1.17 billion short tons
Coal production (1999): | 23,000 short tons
Coal consumption (1999): | 680,000 short tons

Source (accessed 8/03/01): http://www.eia.doe.gov/emeu/cabs/peru.html

COAL CHEMISTRY

A review of the literature indicates that abundant proximate and ultimate coal data are available for Peruvian coal (for example, Carrascal and others, 2000; Dunin-Borkowski, 1996; Agramonte and Diaz, 1983), and some trace-element data are also available (for example, Carrascal and others, 2000; and Ojeda and Mendoza, 1996). However, data on some elements of environmental concern such as As and Hg are not available. Therefore, as part of the WoCQI, coal samples were submitted to the USGS 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, which are significant for economic byproduct recovery, technological behavior of the coal, and environmental impact (U.S. Geological Survey, 2001), will be incorporated into the WoCQI database. A part of this initial database for Perú is compiled in tables 1 and 2.

Table 1. Proximate and ultimate analytical data, Alto Chicama, northern Perú [Analyses performed at Geochemical Testing, Somerset, Pa.]
LA VICTORIA Alto Chicama, northern Perú UTM 0799817/9126464 Sample number BP2500, channel sample, working seam in mine Lab number 00-031796 (Geochemical Testing)
AIR DRY LOSS | 4.35% |  |  |
RESIDUAL MOISTURE | 1.48% |  |  |
PROXIMATE ANALYSIS | As recorded | Dry | Dry ash-free |
Moisture | 5.77 |  |  |
Ash | 2.17 | 2.30 |  |
Volatile matter | 1.65 | 1.76 | 1.80 |
Fixed carbon | 90.41 | 95.94 | 98.20 |
ULTIMATE ANALYSIS | As recorded | Dry | Dry ash-free |
Hydrogen | 1.68 | 1.10 | 1.13 |
Carbon | 88.18 | 93.57 | 95.78 |
Nitrogen | 0.54 | 0.57 | 0.58 |
Sulfur | 0.28 | 0.29 | 0.30 |
Oxygen | 7.15 | 2.17 | 2.21 |
Ash | 2.17 | 2.30 |  |
| As recorded | Dry | Dry ash-free |
HEATING VALUE (BTU/lb) | 13547 | 14377 | 14716 |
FORMS OF SULFUR | As recorded | Dry | Dry ash-free |
Sulfate | 0.01 | 0.01 | 0.01 |
Pyritic | 0.02 | 0.02 | 0.02 |
Organic | 0.25 | 0.26 | 0.27 |
FREE SWELLING INDEX | 0.0 |  |  |
EQUILIBRATION MOISTURE | 2.88 |  |  |
ASH FUSION (reducing atmosphere) | Initial | Softening | Hemi | Fluid
T °F | 2410 | 2450 | 2480 | 2790
APPARENT SPECIFIC GRAVITY | 1.56 |  |  |
FLUORINE | 0.004% |  |  |
CHLORINE | 0.01% |  |  |
SAN JUAN Baños de Chimu, Alto Chicama, northern Perú UTM 0761393/9168123 Sample number BP2900, working seam in mine, channel sample Lab number 00-031797 (Geochemical Testing)
AIR DRY LOSS | 1.09% |  |  |
RESIDUAL MOISTURE | 2.15% |  |  |
PROXIMATE ANALYSIS | As recorded | Dry | Dry ash-free |
Moisture | 3.22 |  |  |
Ash | 8.73 | 9.02 |  |
Volatile matter | 4.12 | 4.26 | 4.68 |
Fixed carbon | 83.93 | 86.72 | 95.32 |
ULTIMATE ANALYSIS | As recorded | Dry | Dry ash-free |
Hydrogen | 1.15 | 0.82 | 0.90 |
Carbon | 82.90 | 85.66 | 94.16 |
Nitrogen | 0.32 | 0.33 | 0.36 |
Sulfur | 0.44 | 0.45 | 0.49 |
Oxygen | 6.46 | 3.72 | 4.09 |
Ash | 8.73 | 9.02 |  |
| As recorded | Dry | Dry ash-free |
HEATING VALUE (BTU/lb) | 12176 | 12581 | 13829 |
FORMS OF SULFUR | As recorded | Dry | Dry ash-free |
Sulfate | 0.15 | 0.15 | 0.17 |
Pyritic | 0.03 | 0.03 | 0.03 |
Organic | 0.26 | 0.27 | 0.29 |
FREE SWELLING INDEX | 0.0 |  |  |
EQUILIBRATION MOISTURE | 1.11 |  |  |
ASH FUSION (reducing atmosphere) | Initial | Softening | Hemi | Fluid
T °F | 2420 | 2590 | 2750 | 2790
APPARENT SPECIFIC GRAVITY | 1.98 |  |  |
FLUORINE | 0.009% |  |  |
CHLORINE | 0.02% |  |  |

Table 2. Oxide and trace element data (ash basis), Alto Chicama, northern Perú (analyses performed at U.S. Geological Survey, Denver, CO) [wt %, weight percent; ppm, parts per million; n/a, not analyzed]
Oxides (wt %)
| % Ash | % Moisture | SiO2 | Al2O3 | Fe2O3 | MgO | CaO | Na2O | K2O | TiO2 | P2O5 | SO3
BP2500, La Victoria | 2.4 | 1.3 | 30.1 | 33.0 | 5.6 | 5.4 | 7.5 | 1.3 | 0.81 | 1.6 | 0.58 | n/a
BP2900, San Juan | 8.9 | 2.2 | 38.2 | 32.8 | 1.8 | 1.4 | 2.2 | 2.3 | 1.6 | 1.7 | 0.54 | n/a
Trace elements (ppm)
| Be | Hg | Co | Cr | Cu | Li | Mn | Ni | Sc | Sr | Th | V
BP2500, La Victoria | 9 | 0.04 | 73.4 | 118 | 258 | 197 | 753 | 113 | 48.4 | 771 | 32.5 | 406
BP2900, San Juan | 21.9 | 0.31 | 121 | 280 | 631 | 463 | 866 | 162 | 122 | 2020 | 69.1 | 1070
| Y | Zn | B | Ba | Zr | Ag | As | Au | Bi | Cd | Cs | Ga
BP2500, La Victoria | 84.8 | 326 | 198 | 706 | 346 | <1 | 24.2 | <10 | 1.6 | 1.9 | 2.8 | 39.7
BP2900, San Juan | 93.1 | 567 | 124 | 620 | 311 | <1 | 84.3 | <10 | 2.5 | 1.4 | 60.5 | 104
| Ge | Mo | Nb | Pb | Rb | Sb | Sn | Te | Tl | U | Se | Cl (%)
BP2500, La Victoria | 5.7 | 6.9 | 27.7 | 53.8 | 27 | 6.6 | 106 | 2.5 | 0.36 | 10.1 | <0.10 | <0.015
BP2900, San Juan | 7.8 | 14 | 51.7 | 104 | 144 | 21.9 | 33.7 | 3.1 | 1.3 | 17.7 | 0.41 | 0.018

SELECTED REFERENCES

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

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

Bargellini, F., 1992, El uso del carbon en la industria del cobre: Minerales, vol. 47, no. 197, p. 64-74.

Bowen, S., 2001, Cheap energy — Belgian company opens Perú's first coal utility plant: Latin Trade, 2/2001, p. 29-30.

Brooks, W.E., and Kent, J.D., 2000, Mineral, energy, and fertilizer resources of the northcoast of Perú — Perspective from the Santa Rita B archaeological site: Geological Society of America Abstracts with Programs, vol. 32, no. 7, p. A423.

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

Burgess, I.C., 1985, Peruvian coal studies: Nottingham, British Geological Survey-Technical Report, Overseas Geology Series, no. 85/1, 25 p.

Carrascal, R., Matos, C., and Silva, O., 2000, Carbón en El Perú: Instituto Geológico Minero y Metalúrgico, Boletin no. 7, serie B, Geología Económica, Lima, Perú, 150 p.

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

Dunin-Borkowski, E., 1996, Minerales industriales del Perú: Instituto Geológico Minero y Metalúrgico, Publicación Especial, Lima, Perú, 166 p.

Escudero, J., 1979, El carbon del Alto Chicama: Instituto Geológico Minero y Metalúrgico, Lima, Perú, 77 p.

INGEMMET, undated, Yacimientos no metalicos del Perú: Instituto Geológico Minero y Metalúrgico, Lima, Perú, 13 p.

Jessen, A., 1989, Projecto carbonifero Callacuyan: Carbon Energetico Electrico Siderugico Industrial-El Primer Simposio, Empresa Siderugica del Perú, p. 26-36.

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

Lechtman, H., 1976, A metallurgical site survey in the Peruvian Andes: Journal of Field Archaeology, vol. 3, no. 1, p. 1-42.

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.

Marquez, E.J., 1992, Geologia y potencial carbonifero de la parte central de la sub-cuenca Chavin-Cuenca del Santa: Tesis, Univ. Nacional Mayor de San Marcos, Escuela de Ingenieria Geologica, Lima, Perú, 95 p.

Minero Perú, 1986, Coal — Alto Chicama, in Samame Boggio, M. (ed.), Perú — A Mining Country, vol. IV, pt. 3, Ore Deposits, Instituto Geológico Minero y Metalúrgico, p. 1265-1272.

Ojeda, M.J., and Mendoza, A., 1996, Distribucion de elementos trazas en carbones Perúanos, en VI Simposium, Potencial y Desarrollo Minero, Univ. Nacional San Antonio de Abad de Cuzco, p. 17-22.

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.

Petersen, C.R., 1978, Coal resources of Perú, 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. 35-42.

Petersen, G., 1970, Mineria y metalurgia en el antiguo Perú: Arqueologicas 12, Museo Nacional de Antropologia y Arqueologia, Lima, Perú, 40 p..

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

U.S. Geological Survey, 2001, The world coal quality inventory, U.S. Geological Survey Fact Sheet FS-155-10.

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.

Yanque, J., 1989, El programa carboelectrico de ElectroPerú y el proyecto carboelectrico Rio Santa: Carbon Energetico Electrico Siderugico Industrial-El Primer Simposio, Empresa Siderugica del Perú, p. 23-33.

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