TELLURIUM (Tellurium, Those) — chemical element VI of group of a periodic system of D. I. Mendeleyev, is applied to production of semiconductors, serves as the alloying additive of hl. obr. to lead, it is used as dye in glass and ceramic industry, and also during the curing of rubber on the corresponding productions; represents professional harm. All connections T. are poisonous.
T. it is open in 1782, in 1798 received the name in honor of Earth (Latin of Tellus). Maintenance of T. in crust makes 1 • 10 - 6 weight. %.
Sequence number of tellurium 52, atomic weight (weight) 127,60. There are 8 stable isotopes of T., from them 127 Those are most known and 130 Those, and also artificially received radioisotopes, from to-rykh in the equipment as marked atoms apply 122 Those and 129 Those.
T. represents the crystals of silver-gray color with metallic luster reminding crystals of antimony (see), g°pl 449,8 + 0,1 °, * °shsh 990 + 1 °. Warmth of melting of 32,8 kcal!. Tellurium — the semiconductor. The most characteristic valence states — 2, +4, +6. The most known connections T.: N2te hydrogen telluride — colorless poisonous gas with a disgusting smell, in solutions shows properties to - you, salt a cut call tellurides, e.g. K2te, etc.; Te02 tellurium dioxide is formed during the burning of T. on air or in oxygen, reacts with alkalis with formation of salts telluride to - you, called by tellurites (Te02 + 2KOH —> K2te203 + + H20). With to-tami T. forms salts Those (IV). At oxidation telluride to - you are formed telluric to - that N6teoye, salt a cut call tellurates.
Got into a human body of T. (especially at inhalation of the air contaminated by connections T.) it is long circulates in blood, partially communicating (3 globulins, collects in a skeleton, a liver, muscles, skin, lungs and kidneys. All its connections are exposed to recovery to elementary Those. The T is removed. from an organism with expired air, urine and a stake.
In air T. determine colorimetric by intensity of the coloring developing as a result of interaction of T. with muriatic butylrhodamine or rhodamine. For determination of T. in an organism it is transferred from connections to an elementary state and measure intensity of coloring of the complex received at reaction with thiourea, butyl rhodamine B, etc.
Tellurium x as professional harm. In air of a working zone T. and its connections can get in the form of dust, an aerosol and in gaseous state (hydrogen telluride). In a human body of T. can come with inhaled air, through a mouth and to a nek-swarm of degree through skin.
T. and its connections have on a human body effect, in many respects similar to effect of arsenic (see) and selenium (see). Water soluble salts telluric and telluride to - t, tellurium dioxide and hydrogen telluride are most toxic, is less toxic elementary Those. Preferential the nervous system, a liver, respiratory system and a digestive tract are surprised.
Hron. poisoning of T. and its connections it is characterized by instability of a chair, nausea, emaciation, drowsiness, metal taste in a mouth. From a mouth, from sweat and urine the specific garlick smell is felt. Disturbances of a trophicity of a hypodermic fatty tissue, oppression of function of sweat and sebaceous glands come to light, the epilation of indumentum, dermatitis, bronchitis, pneumonia, a pneumosclerosis are possible. Symptomatic treatment.
Acute poisoning is followed by irritation of mucous membranes of upper respiratory tracts, dizziness, nausea, vomiting, a fever. In hard cases note a tremor, spasms, renal pains, a hamaturia, the phenomena of cystitis, cyanosis, increase of pulmonary insufficiency. Coma can develop and come death.
On opening at the dead from poisoning with tellurium note coloring of a mucous membrane of upper respiratory tracts in dark green color, and a mucous membrane went. - kish. a path — in black color; hypodermic cellulose has yellow coloring, internals are full-blooded, from them the specific garlick smell proceeds. At a histologic research in a liver hypostasis and dystrophic changes, in a mucous membrane of uric ways — signs of an inflammation come to light.
First aid and emergency treatment consist in immediate introduction of Unithiolum, glucose with ascorbic to - that, inhalation of the moistened oxygen; hospitalization is necessary. Depending on a condition of the victim in a hospital the hemodialysis can be made. Symptomatic treatment, vitamin therapy, drugs of calcium, alkaline inhalations, good nutrition.
Examination of working capacity at poisoning of T. and by its connections it is carried out taking into account degree of manifestation and weight of symptoms of poisoning, the character of a current of the recovery period and working conditions working.
Measures of the prevention of poisonings during the work with T. and its connections: strict observance of technical specifications, sealing of the equipment, processes of unloading of the breed containing T., mechanization of manual operations, the general and local positive-pressure ventilation (see), observance of rules of personal hygiene, protection of skin against contact with T. by means of protective pastes (see Pastes protective) and gloves, protection of a respiratory organs by means of respirators (see) and industrial gas masks (see). Carrying out preliminary and periodic medical examinations is obligatory (see. Medical examination). Contraindications for the work connected with contact with T. and its connections, diseases of a respiratory organs, kidneys and a liver serve.
Maximum allowable concentration of tellurium in air of a working zone of 0,01 mg/m‘ 3, telluride of molybdenum of 0,1 mg/m3, telluride of tungsten of 0,01 mg/m3.
Bibliography: Harmful substances in the industry, under the editorship of N. V. Lazarev and I. D. Gadaskina, t. 3, page 83, D., 1977; Glinka H. JI. General chemistry, JI., 1980; Israelson Z. I., Mogilev O. Ya. and Suvorov S. V. Questions of occupational health and professional pathology during the work with rare metals, page 258, M., 1973; H e to r and with about in B. V. Fundamentals of the general chemistry, t. 1 — 2, M., 1973.
V. P. Mishin; N. Yu. Tarasenko (gigabyte.).