COKE-CHEMICAL PRODUCTION — industrial receiving coke with simultaneous catching and processing of the chemicals which are formed during the coking.
Coke — the solid fuel having high caloric power is used during the receiving cast iron (blast-furnace process) and its fusion before pouring in forms (foundry production). Coke turns out in the course of decomposition during the heating of black coal without access of air to t ° 900 — 1100 °.
As raw materials in To. items are used furnace charges (mix) consisting of coking coals of various brands. Coking is carried out in coke furnaces for which heating use blast-furnace, generator or coke oven gas. Ready coke from furnaces by means of a koksovytalkivatel goes to the tushilny car where it is extinguished by phenolic water or inert gases. After suppression coke moves the conveyor on sorting. Hot coke oven gas (600 — 700 °) is cooled therefore coal tar is condensed. Pitch is exposed to distillation, nadsmolny (ammoniac) water together with unstripped gas is used for receiving ammonium sulfate. After release from ammonia gas is cooled and goes for catching of crude benzene again — benzene hydrocarbons.
Coal tar heats up to 380 — 400 ° in tubular furnaces; mix of its vapors disperses on fractions from which allocate phenols (see), naphthalene (see) and other organic compounds. The rest (pitch) is exposed to further heat treatment.
At uglepodgotovitelny factories processes of crushing, unloading of bunkers, supply of coal on conveyors is followed by dust formation. At service of coke-oven plants working can be affected by all ingredients of coke oven gas which are emitted in air during the loading of furnace charge, via hatches, at thinnesses of communications and various disturbances tekhnol. process. Special value has receipt in air carbon monoxide (see), benzene (see), ammonia (see), sulfur dioxide gas, hydrogen sulfide (see). Air temperature at insufficient heat insulation of the equipment can reach 42 — 50 ° and more; tension of radiant heat at furnaces — 5 — 8 kal/cm 2 / mines above. At suppression of coke phenolic waters along with the called harmful substances phenols, and also vapors of mercury in the presence in furnace charge of the coals containing come to air mercury (see).
In koksosortirovochny workshops during the loading of coke in the bunker and other operations in air dust and harmful gases — carbon monoxide, etc. is emitted. The mass of the coke cooled only to 125 — 200 ° allocates a large amount of heat. The process of condensation of pitch which is conducted under vacuum is not followed by release of harmful substances in air.
In tar-distilling workshops the elevated temperature of air is noted; air contains naphthalene and, as a rule, in small concentration phenol, benzene, pyridine (see), hydrogen sulfide, vapors of mercury. Receipt in air of a working zone and in free air 3,4-is possible benzpyrene (see).
In air of working zone maximum allowable concentration for carbon monoxide of 20 mg/m 3 , benzene — 5 mg/m 3 , ammonia — 20 mg/m 3 , carbon sulfur — 10 mg/m 3 , pyridine — 5 mg/m 3 , vapors of mercury — 0,01 mg/m 3 , naphthalene — 20 mg/m 3 , phenol — 5 mg/m 3 , hydrogen sulfide — 10 mg/m 3 , hydrogen cyanide and cyanides (in terms of hydrogen cyanide) — 0,3 mg/m 3 .
On To. items are possible acute and hron, poisonings of working. At suppression of coke the phenolic waters containing more than 0,3 g of phenol in 1 l described cases of acute poisoning with phenols and carbon monoxide; during the processing of coal tar — the combined intoxications aromatic hydrocarbons, sulfur compounds, phenols and unsaturated hydrocarbons.
Under the influence of coal tar there can be damages of skin, especially sharply they are expressed at action of pitch: the sharp irritation of skin which is expressed the reddening, hypostasis and strong burning amplifying at action of a sunlight. Conjunctivitis, burning sensation in eyes, a photophobia, and also the phenomena of irritation is at the same time noted from upper respiratory tracts and bronchial tubes. In hard cases the headache, dizziness, nausea, vomiting, a loss of consciousness can join.
At hron, influence of harmful substances in To. items are noted expressed funkts, frustration of c. the N of page, went. - kish. path, disease of an organ of sight and skin. At the persons which are affected by products of heat treatment of black coal (phenols, naphthalene, anthracene, baked, etc.), damages of a liver are possible. In smolopererabatyvayushchy workshops at workers damages of skin — folliculites, melanodermas, warty growths are noted.
In the USSR on To. items are carried out mechanization of processes, the automatic control and management of the most part of operations. Radical improvement of working conditions gives introduction of continuous coking of coal, dry quenching of coke inert gases, a bessaturatorny way of receiving ammonium sulfate, etc.
Continuous coking completely excluded tekhnol. operations at which workers were affected by carbon monoxide and other toxic compounds, intensive radiant heat and high temperature of air. Transition from coke, wet on dry quenching, sharply reduced impurity phenol and other substances of the soil and air in the territory of the plant, platforms, tunnels of coke furnaces, galleries of conveyors, rooms of a koksosortirovka, and also free air in the next settlements. Before suppression of coke phenolic waters carry out their dephenolizing, dilution by pure water.
The good recreational effect gives implementation of the program automatic feed of furnaces with distance steering on modern pekokoksovy installations, a semi-automatic way of loading of furnaces, automation of sorting of coke, mechanization of cleaning of doors and frames, etc. These actions substantially facilitated heavy physical. work of workers, 3,4 benzpyrenes reduced concentration in air of peak aerosols, acridine.
Introduction of the rotating drum devices for cooling of naphthalene excluded need for centrifuges that reduced concentration of naphthalene in air to marginal. The correct design of the industrial platform, placement tekhnol are important for fight against heat, dust and harmful gases. the equipment with carrying out on open air of the equipment allocating large amounts of heat. Along with heat insulation, sealing of the equipment and communications effective air exchange in production rooms by means of aeration lamps and mechanical stitched is provided ventilation (see). For catching of harmful substances from an exhaust air various treatment facilities, in particular condensers are used.
Except remote methods of management of processes, mechanization of the operations reducing time of stay of workers at sources of radiant heat special mobile screens, an air dushirovaniye, special protective clothes are used (see. Clothes protective ). For protection against dust, harmful vapors and gases are used respirators (see) and gas masks with the Box of brand A (see. Gas masks ), during the cleaning of the equipment — the hose or oxygen isolating gas masks, during the work with pitch — antidust overalls with a hood from dustproof fabric, the mittens reaching the middle of a forearm, tight points with dark glasses. For protection of skin Dolgov's paste consisting of equal amounts of zinc oxide, talc, alcohol, glycerin and a liquid paraffin with addition of salol (7% of lump) and also Beam paste of Svoboda factory, etc. are used.
On To. items will be organized life-saving stations, and also the special laboratories controlling observance a gigabyte. standards, including and maximum allowable concentration of harmful substances in air of a working zone, and also in free air and reservoirs around placement of production.
Workers To. items are exposed obligatory preliminary at revenues to work and to periodic medical examinations of 1 times in 12 months taken with distillation of coal tar and rectification of aromatic hydrocarbons — 1 times in 6 months. Medical examination is performed by the dermatologist and according to indications the therapist, the neuropathologist, the oculist and the urologist. Surely at the same time determination of amount of hemoglobin, leukocytes and ROE. As contraindications to employment serve diseases of skin with hypersensitivity by a sunlight, precancerous diseases of skin, fat seborrhea, diseases of the follicular device of skin, hron, diseases of eyes.
In contact with benzene of the woman are not allowed to works. Teenage young men are allowed to work and inservice training to separate professions in To. the item by individual and brigade preparation not earlier than 18 years. Working in To. items use the shortened working hours, additional issues, receive special food.
Bibliography: Zhukov A. M. Research of the air environment and ventilation of the tar-distilling workshop, Gigabyte. work and the prof. having got sick., No. 12, page 43, 1971; Kapitulsky V. B. and Liplavk I. L. Hygienic characteristic of pekokoksovy production, Gigabyte. and dignity., No. 6, page 111, 1967, bibliogr.; To l and p and N and c of e r I. L. and d river. A research benz (and) pyrene in products of anthracene fraction of coal tar, the Gigabyte. work and the prof. having got sick., No. 3, page 47, 1977; P e of t r about in and N. I, and Yeremeyev A. D. Mercury danger in coke-chemical production, there she, No. 11, page 45, 1972.
Yu. L. Egorov.