The First Tin Smelter in Bolivia - May 1937

Who we Are?

“The First Tin Smelter in Bolivia” was founded by Mariano Peró Aramayo, with the introduction of rotary furnaces for the reduction of 50% tin concentrates. This was the first tin smelter in the world to use rotary furnaces for the reduction of tin. On May 30, 1937 the construction of the plant was initiated and by 1940 high grade metallic tin of 99.85% purity was being exported.

82 years later OMSA equipment and technology have been enhanced and modernized constantly and actually our production is exceeding today’s demanding levels of impurities for international markets. Nevertheless the rotary furnaces are still representing the heart of our operation.


OMSA is located east of the City of Oruro (3.730 m.a.s.l.), 3,5 Km. on the highway to Cochabamba, in the Huajara Industrial Park. The total gross area of the smelter installations extension is of 14 Hectares and developed surface of 10,000 m2.


Our main achievement is the production of premium tin metal (< 15 ppm Pb) from low grade concentrates (10 to 30% Sn content) or from highgrade concentrate ( 45% Sn and higher content), using for this intention its units of volatilization (Fuming Furnace) and reduction (Rotary Furnaces)


Due to stricter environmental laws passed on April of 1992 in Bolivia, OMSA was forced to leave the original site in the proximities of the city. For 6 months OMSA stopped production and rebuilt its plant in the current location. For almost two years until January 1994 only volatilization dusts were produced to maintain the cash flow and to complete the relocation. Year by year all environmental regulations have been implemented and currently new equipment is being installed to meet the legal levels of emissions and international regulations.

The quality control of metallic products is carried out in the laboratories of S. G. S. For the monitoring of our operations and the control of the tin contents and impurities in the raw material, we have our own chemical laboratory equipped with necessary analytical instruments. The purchase of concentrates is supervised and controlled by Alex Stewart Assayers.

The objective of the company, is to reach a capacity of 300 fine tonnes of metallic tin per month in one year without compromising the quality of its product, and even reduce current levels of impurities.


Plant view


Metallic TIN in Ingots (Sn)

99,99% of TIN

Content lower than:

30 ppm of lead

150 ppm of antimony

300 ppm of bismuth


If you have questions, please send an email to the following contact form.

Contact info

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Location: Higway to Cochabamba, Km 3,5 Industrial Zone Huajara

Phones: 591-25245054 - 55