SELENIUM (Se)

Selenium is a non-metallic element recovered as a by-product of electrolytic copper refining. It is a member of the sulfur family and exhibits a number of unique chemical and physical properties.

Asarco produces selenium at its Amarillo Copper Refinery in Texas. Stringent quality control procedures assure that Asarco's selenium is uniformly high in quality.


This sheet describes Asarco's standard products. Asarco is ready to work with individual customers to provide products that meet special requirements.

The most important uses for selenium are in the production of a light-sensitive surface on photocopier machine drums, decolorizing of container glass, and tinting of architectural glass. Selenium is also used in pigments for plastics, glass, ceramics, and paint, where in combination with other elements it provides durable colors ranging from orange to deep red. In metallurgy, selenium is a trace additive that improves the free-machining characteristics of stainless steel. The electronics industry uses selenium to manufacture semiconductors and rectifiers. Selenium is an essential trace element in human nutrition. It is also valued as a dietary supplement in animal feed and is added to pharmaceutical preparations for controlling dandruff and dermatitis.

Commercial Grade

Asarco's commercial grade selenium is normally produced in powder form to purities of 99.5% and 99.9%. Selenium powder can be ordered as minus 200 mesh (minimum 99% purity through 200 mesh) and minus 325 mesh (minimum 90% purity through 325 mesh). Powder is shipped in 50-pound polyethylene-lined pails. A typical chemical analysis of Asarco's commercial grade selenium is shown on the next page.

Selenium Alloys

Asarco produces ferroselenium in random-sized chunks averaging 3" to 4" across and granules (minus 20 mesh). Ferroselenium contains 50% to 60% selenium and is shipped in 500-pound steel drums. Special packaging is available for smaller orders.



Handling Recommendations

Elemental selenium is not generally considered to be a hazardous material in typical commercial applications. Under certain conditions, however, selenium and its compounds can react to form toxic fumes or gases. Contact with mineral acids under reducing conditions can produce toxic gases unless proper precautions are taken.

Containers of selenium and its compounds should be stored in a cool dry area. Selenium should be stored and handled at an ambient temperature not exceeding 75°F in order to minimize lumping and crystallization. Any accidental spillage should be cleaned up immediately in a manner that does not create dust. Powders should be vacuumed.

Fully effective dust control systems should be operated at all stages of in-plant handling where selenium powder may become airborne. When melted, temperature should be kept as low as is practical. Protective clothing and NIOSH-certified respiratory equipment should be worn at all stages where airborne selenium concentrations cannot be kept within government-established limits by mechanical ventilation equipment.

Good sanitary procedures should be followed. Eating, drinking, and smoking should not be allowed in work areas. Hands and face should be washed before eating, drinking, and smoking. Workers should shower and change clothes before leaving the plant. Work clothes should not be worn home.

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ASARCO LLC. • Commercial Department
Contact: Chris Strand
phone: 520-798-7558 • fax: 520-798-7584
email: cstrand@asarco.com