Tellurium 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 tellurium at its Amarillo Copper Refinery in Texas. Stringent quality control procedures assure that Asarco’s tellurium 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 largest use of tellurium is as a trace additive in steel to improve machinability. Tellurium also helps control the depth of chill in cast iron and is added to lead to increase resistance to vibration and fatigue. Electronic applications for tellurium include thermoelectric materials, infrared sensors, photoconductors, and photovoltaic cells. Tellurium is used in the rubber industry as an accelerator and curing agent to improve high temperature properties and in the chemical industry as a catalyst.

Commercial Grade

Commercial grade tellurium is produced by Asarco to a minimum purity of 99.7% and can be ordered in several different shapes. Tablets come in 1- and 3-gram weights and are packed in 15-pound boxes. (Tablets contain approximately 4% carnauba wax as a binder.) Slabs weighing 5 pounds and sticks weighing 1 and 2 pounds are shipped in 50-pound pails. Tellurium powder is available as minus 100 and minus 200 mesh (99% through the mesh) and minus 325 mesh (minimum 90% through 325 mesh), all shipped in 50-pound pails. A typical chemical analysis of Asarco’s commercial grade tellurium is shown on the next page.

PHYSICAL CONSTANT

Atomic number 52
Atomic weight 127.60
Boiling point 990 °C(1814 °F)
Meltin point 449.8 °C (841.6 °F)
Crystal structure Hexagonal
Density
g/cc 20°C 6.25
lb/cu. in. 0.225
Mechanical properties
Hardness,Mohs 2.3
Modulus of elasticity, psi 6.0 ¤ 10

TYPICAL ANALYSIS

Tellurium 99.7% minimum
Copper 0.01% maximum
Lead 0.003% maximum
Selenium 0.01% maximum

Handling Recommendations

Elemental tellurium is not generally considered to be a hazardous material in typical commercial applications. Under certain conditions, however, tellurium 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 tellurium and its compounds should be stored in a cool dry area. 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 tellurium 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 tellurium 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.

ASARCO Contact:

ASARCO LLC • Commercial Department
5285 E. Williams Circle, Suite 2000
Tucson, AZ 85711-7711 USA
Contact: Rene Bustamante
phone: 520-798-7791 • fax: 520-798-7584
e-mail: RBustamante@asarco.com