Technetium

Close-packed hexagonal structure; isomorphous with rhodium, ruthenium, and osmium

Technetium obtained by hydrogen reduction of ammonium pertechnate is a silver-gray spongy mass which tarnishes slowly in moist air

2157 °C

Molar enthalpy of fusion at melting point: 33.29 kJ/mol

Most Important Radionuclide: Tc-99m Source: Decay of molybdenum-99 Half-Life: 6 hours Decay Mode: Isomeric Transition (gamma) Decay GI Absorption: 50-80% of technetium pertechnetate (TcO4) Lung Clearance Half-Time: Weeks for oxides, hydroxides, halides, and nitrates; Days for all other compounds; Critical Organ: Total body Internal Toxicity: Low Annual Limit on Intake: 80 mCi Gamma Ray Constant: 0.6 R/h @ 1 cm per mCi Tenth-Value Layer: 0.9 mm Pb Radiation Energy (MeV): Gamma 0.141 (88%) [See Glossary for references.] See Radiation, ionizing.

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

Technetium is the first man-made element, produced in 1937 by deuteron bombardment of molybdenum. All isotopes are radioactive. Six atoms of technetium are created for every 100 fissions of uranium. Technetium is a waste product in spent nuclear fuel. Of the ten major isotopes, Tc-99 is the one of most concern as an environmental contaminant. The half-life of Tc-99 is 210,000 years. Used in steel as a corrosion inhibitor, but this use is limited by the radioactivity of technetium; Tc-99m is used in nuclear medicine; [Argonne]

Steel Producing [Category: Industry]

Technetium and its alloys are superconductors and can be used to create high-strength magnetic fields at low temperature. ...

... cryochemistry, corrosion resistance

Technetium is a very good corrosion inhibitor for steel, and protection can be achieved by adding only very small amounts during production. However, this use is limited by the radioactive nature of technetium.

The free metal is obtained from reactor fission products by solvent extraction followed by crystallization as ammonium pertechnetate, which is reduced with hydrogen.

Technetium was first obtained by deuteron bombardment of molybdenum, but since has been found in the fission products of uranium and plutonium.