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Hydrogen sulfide is actually very dangerous: Think of a few years ago a major KAIXIAN hydrogen sulfide gas leakage accident, resulting in 243 deaths due to hydrogen sulfide poisoning, hydrogen sulfide poisoning in 2142 people were hospitalized, Ma Fucai the oil executives to step down.
; M _ / {, ^ 'r4 | * c physical and chemical properties of hydrogen sulfide: a colorless gas. A rotten egg odor. Formula H2-S. Molecular weight of 34.08. The relative density of 1.19. Melting point -82.9 . Boiling point -61.8 . Soluble in water, also soluble in alcohol, petroleum solvents and crude oil. Flammable limit of 45.5%, lower limit of 4.3%. Burning 292 . Hydrogen sulfide in the lower limit of the ignition point of explosion is 373 , the upper limit of spontaneous combustion in the explosion point is 304 , while the equivalent concentration in the explosive reaction when the ignition point is 216 . Upper explosive limit% (V / V): 46.0 explosive limit% (V / V): 4.0, is a flammable gas.
: C-B8 H3 h '^ 4 @ $ y-`9 B) W sulfide toxicological profile. Y1 M $ O: Y% ~
Physical and Chemical Properties English: Hydrogen Sulfide GB Number: 21006CAS No. : formula: H2S molecular weight: 34.076 Physical and Chemical Properties Appearance: colorless gas at room temperature for the odor: irritating (rotten egg) smell Melting point: -85.5 Boiling point: -60.4 Vapor Pressure: 2026.5kPa/25.5 Flash point: <-50 Solubility: soluble in water, ethanol. Soluble in water (dissolved rat


io of 1:2.6) as the hydrogen sulfate (reaction of hydrogen sulfide is not with the water) density: the relative air density 1.19 (air density is set to 1). Stability: unstable, reversible reaction under heating H2SH2 S risk markers: 4 (flammable gases) Uses: used in chemical analysis of metal ions such as the identification of the environmental impact of health hazards
Hydrogen sulfide pathways: inhalation health hazards: This product is a powerful nerve poison, have a strong stimulating effect on the mucous membrane. Toxicology information and environmental behavior of acute toxicity: LC50618 mg / m (rat inhalation) sub-acute and chronic toxicity: rabbit inhalation 0.01mg / L, 2 hours / day, 3 months, the function of the central nervous system changes trachea, bronchial mucous membrane irritation, cerebral cortex appeared pathological changes. Long-term exposure to low concentrations of sulfide in mice fluoride, a small airway damage. Pollution s: hydrogen sulfide is rarely used in industrial production in general as some of the chemical reactions and protein product of the natural decomposition process and the composition of some natural products and impurities, and often exist in a variety of production processes and the natural world. Such as mining and nonferrous metal smelting. Low-temperature coking coal, sulfur oil exploration, refining, rubber, leather, dyes, and sugar industries have produced hydrogen sulfide. Excavation and remediation marshes, ditches, printing and dyeing, sewers, tunnels and garbage, feces and other operations, as well as natural gas, volcanic jet, spa there is also often accompanied by hydrogen sulfide. Hazardous characteristics: flammable mixture with air can form explosive mixtures case of fire, high-heat combustion caused the explosion. With concentrated nitric acid, fuming sulfuric acid or other strong oxidant reacts violently exploded. Gas is heavier than air and can spto the lower Department of considerable local and met the fire will cause backdraft. Combustion (decomposition) products: sulfur dioxide. Chemical equation: 2H2S 3O2 = lit = 2H2O 2SO2 (O2 excess) 2H2S O2 = lit = 2H2O 2S (O2 less than) Emergency Monitoring Methods portable gas detection instruments: Coulometric detector of hydrogen sulfide, hydrogen sulfide gas electrode detector; common Rapid chemical analysis: detection tube method of lead acetate, lead acetate paper method indicates "sudden environmental pollution monitoring and emergency treatment and disposal technologies" editor million copies too fast testing of the gas tube (Beijing insurance products, the German company Draeger products) Laboratory Monitoring monitoring methods categories of air by gas chromatography GB/T14678-93 iodimetry GB/T11601.1-1998 GB/T11601.2-1998 natural gas natural gas methylene blue methylene blue spectrophotometry "air of harmful substances in the Determination "(second edition), Hang Shi-ping series of air environmental standards in China (TJ36-79) Workplace air the maximum allowable concentration of harmful substances: 10 mg / m
Determination of hydrogen sulfide control in China (TJ36-79) Residential District in the atmosphere of harmful substances maximum allowable concentration: 0.01 mg / m (a value) of China (GB14554-93) factory boundary standards for odor pollutants (mg / m): a level of 0.03; II 0.06 ~ 0.10; levels of 0.32 to 0.60 in China (GB14554-93) emission standards for odor pollutants: 0.33 ~ 21kg / h emergency treatment and disposal methods a leakage contingency rapid withdrawal from air leakage supremacy wind staff, and immediately isolated, small leakage isolati50m, a large leakage isolation 300m, strictly restricted. Cut off the fire . Recommended emergency personnel wearing positive pressure self-contained breathing apparatus and wear protective clothing. Enter the site from upwind. Cut off the of leakage as possible. Reasonable ventilation, accelerated proliferation. Spray diluted solution. Build a causeway or trenching asylum produce a lot of wastewater. If possible, the residual gas or use exhaust gas leakage sent washing tower or towers connected with the ventilation hood. Or its aqueous solution by ferric chloride, to prevent the return devices installed pipe to suck the solution. Leaking containers should be properly handled, repair, testing later use. Second, the protective measures respiratory protection: concentration in air overweight, wearing transitional (half-mask). Emergency rescue or evacuation, it is recommended to wear breathing apparatus or air respirator. Eye protection: Wear protective chemical safety glasses. Physical protection: wear anti-static clothing. Hand protection: Wear chemical gloves. Other: work site no smoking, eating and drinking. Work completed, take a shower. Wash clothes in a timely manner. Workers should learn self-help and mutual aid. Into the tank, restricted space or other high-concentration operations, someone custody. Third, first-aid measures Skin : Remove contaminated clothing, mobile water rinse. Medical treatment. Eye : immediately filed eyelid, with plenty of water or saline thoroughly washed at least 15 minutes. Medical treatment. Inhalation: rapidly from the scene to fresh air. Keep the airway open. If breathing is difficult, give oxygen. If breathing has stopped, that is, artificial respiration. Medical treatment. Fire fighting methods: Firefighters must wear fire protective body suits. Cut off the gas . If you can not immediately cut off the gas , it is not extinguished the burning gas. Water cooling containers, if possible, the container from the scene empty Department. Extinguishing agent: water spray, foam, carbon dioxide, dry powder. Preparation method: The reaction of iron sulfide can be obtained with dilute sulfuric acid hydrogen sulfide gas.
Method for making hydrogen sulfide FeS H2SO4 = FeSO4 H2S (g) because the solid iron sulfide is insoluble, the reaction without heating, the system can be obtained when the hydrogen similar to the device used. Such as the use of sodium sulfide and dilute sulfuric acid reaction, soluble in water due to reaction of sodium sulfide was too intense and can not control. So do not. Principle of a non-oxidizing strong acid and weak acid salt (FeS) reaction. Can generate hydrogen sulfide gas (H2S dissolved in the water that is too acidic hydrogen sulfate). FeS H2SO4 (diluted) = FeSO4 H2S FeS 2HCl = FeCl2 H2S H2S gas can dissolve in water, water law can not be collected. Because of the density of hydrogen sulfide than air, can bottle up the exhaust air gathering were collected. Supplies Kipp generator or simple gas generator, set cylinders, glass, FeS, dilute hydrochloric acid (or dilute H2SO4) solution, lead nitrate test strips can be used operating system to take H2S system Kipp gas generator or simple device. Kipp generator FeS into the spherical body, funnel into the dilute HCl. H2S required when the Pistons open the airway, FeS s with dilute HCl produced H2S, to stop using gas, simply turn off the piston can stop the reaction. Moistened with lead nitrate (or lead acetate) solution, test strips, oral test on the set of cylinders, if the test strip is proven set of cylinders in black have been filled with H2S gas. Pb H2S = PbS 2H Notes (1) should be used in ferrous sulfide newly acquired, stored too long, FeS, Fe and S will be oxidized, thus affecting the experimental results. (2) into the gas generator in the iron sulfide particles to the size of the block Zacheng beans. (3) can not be with concentrated hydrochloric acid, concentrated hydrochloric acid due to hydrogen sulfide volatilized leaving impure hydrogen chloride. (4) can not be concentrated HNO3 or H2SO4, because they are oxidizing acid, and FeS oxidation reduction reaction, and can not produce hydrogen sulfide. See reaction. (5) H2S toxic experiment should pay attention to ventilation, excess H2S in time pass into the NaOH solution (or a metal salt solution) for absorption. FeS 2H2SO4 (concentration) = FeSO4 SO2 S 2H2OFeS 4HNO3 (diluted) = Fe (NO3) 3 S NO 2H2O; 1. Flammability reaction equation uses the basic types of reaction phenomena combined light 2CO O2 ===== 2CO2 CO burning in air, given a blue flame, and produce heat, combustion gases generated colorless gas can clarify the cloudy limewater become the main component for fuel 2. reductive reaction equation uses the basic types of reaction phenomena CuO CO == == Cu CO2 / black, becoming red CuO Cu, and produces a clear limewater to become cloudy, colorless gas reduction of CuO (copper smelting) high temperature Fe2O3 3CO ==== 2Fe 3CO2 / / Restore Fe2O3 (refining iron) heat Fe3O4 4CO ==== 3Fe 4CO2 / / Restore Fe3O4 (iron) contrast: H2 CuO ==== Cu H2O replacement solid black to red, the wall has chemical properties of water droplets refined Cu: unstable: H2S = H2 S (heating, reversible) acidic: H2S hydrogen sulfate solution is called, is a binary weak acid. 2NaOH H2S = Na2S 2H2O reduction: H2S in the price of S is -2, with a strong reduction, it is easy to be SO2, Cl2, O2 and other oxidation. Flammability: ignition generation of sulfur dioxide in the air and water: 2H2S 3O2 ==== 2SO2 2H2O (blue flame) (condition is lit.) Insufficient or lower temperature if the air is generated when sulfur and water. Clinical manifestations of poisoning rapid onset of acute hydrogen sulfide poisoning in general, appear to brain and (or) damage to the respiratory system-based clinical manifestations, but also with heart and other organ dysfunction. Clinical presentation of the concentration of hydrogen sulfide due to factors such as exposure to different significant differences. 1. The most common central nervous system damage (1) after exposure to high concentrations of hydrogen sulfide headache, dizziness, fatigue, ataxia, mild disturbance of consciousness can occur. Often appear first on the eyes and respiratory tract irritation. (2) after exposure to high concentrations of hydrogen sulfide showed significant Achillea encephalopathy, headache, dizziness, irritability, staggering gait, irritability, confusion, delirium, epileptic seizures can be presented a generalized tonic clonic seizures, etc.; coma may be sudden; breathing difficulties may also occur after cardiac arrest or respiratory arrest. Fundus examination showed papilledema individual cases have. Some patients may be accompanied by pulmonary edema. Encephalopathy symptoms often appear more respiratory symptoms is earlier. Occurrence of irritation effect may take some time. (3) exposure to high concentrations of hydrogen sulfide can occur after the electric shock-like death, that is, within seconds or minutes after with respiratory arrest, cardiac arrest can occur after a few minutes; also available immediately or within a few minutes a coma and breathing together Stop and death. Death can occur without awareness of the situation, when the hydrogen sulfide odor detected immediately anosmia, a few cases can be in a coma before the moment of sickening sweet smell. General without aura symptoms before death can be deep and rapid breathing, followed by stops breathing together. Acute poisoning occur at the scene when the multi-coma, the degree of exposure to hydrogen sulfide due to the concentration and time differences, even may be associated with or without respiratory failure. In some cases transferred to hospital from the accident scene or en route to recovery. Arrival at the hospital remains vital signs of patients, without hypoxic encephalopathy, and more rapid recovery. Coma after a long time in the recovery may have headaches, dizziness, visual or hearing loss, disorientation, ataxia or epileptic convulsions, most cases can be fully restored. Has been reported 2 cases of delayed encephalopathy, were in deep coma two days after recovery, respectively, in 1.5 days and 3 days after the coma again, and were 2 weeks and 1 month after recovery. Very serious central nervous symptoms, and mucous membrane irritation is not obvious, perhaps because of the time is short, has not yet occurred irritation; or because of symptoms of serious attention they pass it. Acute poisoning or only early morphological changes in brain function without those anatomical structures on the EEG and brain imaging technique, such as brain computer tomography scan (CT) and magnetic resonance imaging (MRI) of the less sensitive, and single photon emission computer brain scan (SPECT) / positron emission scanning (PET) abnormalities and clinical manifestations and electrophysiological examination of the relevant good. 1 case of deep coma after the poisoning, the state was to cortex, CT showed bilateral globus pallidus lesions site to reduce the density. Another 1 case of poisoning, coma patients no abnormal head CT and MRI; in an accident 3 years after the PET examination showed bilateral temporal lobe, parietal lobe, the left thalamus, striatum metabolism; six months after the SPECT showed bilateral putamen flow reduction, no abnormal cerebral cortex. Patients with olfactory loss, extrapyramidal symptoms, memory deficits and other symptoms. Foreign reports of 15 cases of acute hydrogen sulfide poisoning has a history of repeated aftermath of fatigue, drowsiness, headache, agitation, anxiety, memory loss and other symptoms. 2. Respiratory system damage can occur chemical bronchitis, pneumonia, pulmonary edema, acute respiratory distress syndrome. A small number of poisoning cases can be the main clinical manifestations of pulmonary edema, and mild neurological symptoms. May be associated with conjunctivitis. Keratitis. 3. The course of the poisoning, myocardial injury, may occur in some cases heart palpitations, shortness of breath, chest tightness or angina-like symptoms; small number of cases in the coma recovery, symptoms improved after 1 week of myocardial infarction-like performance. ECG showed acute myocardial death-like graphics, but may soon disappear. The mild, short course, a good prognosis, treatment methods and coronary heart disease due to atherosclerosis in different myocardial infarction, it is considered toxic diffuse myocardial damage. Myocardial enzymes can have varying degrees of abnormal examination. Acute hydrogen sulfide poisoning diagnosed according to 1, there is a clear history of exposure to hydrogen sulfide in patients with the clothes and breath smell of rotten eggs can be used as exposure indicators. Scene of the accident can produce hydrogen sulfide or measured. Patients before the onset of smell rotten egg smell for reference. 2, the clinical features: the above-mentioned brain and (or) damage to the respiratory system-based clinical performance. 3, laboratory examination: There is no specific laboratory indicators. (1) the blood content of hydrogen sulfide or sulfide can be used as absorption index increased, but is inconsistent with the severity of poisoning, and the half-cut and short, it takes a short time after the cessation of with blood. (2) can increase urinary thiosulfate levels, but may be subject to determination of time and the sulfur content of the diet and other factors interfere. (3) of sulfur in the blood hemoglobin (Sulfhemoglobin, SHb) can not be used as a diagnostic indicator, not a result of hydrogen sulfide and sulfur combine to form hemoglobin, normal hemoglobin, which has nothing to do with the poisoning mechanism; Many studies show that the lethal hydrogen sulfide was no blood in humans and animals hemoglobin concentration of sulfur significantly. (4) The body of the sulfur content of the blood and tissues may be subject to corruption and other factors interfere with the body, affecting the reference value. 4, the differential diagnosis: electric shock-like death scene with other chemicals such as carbon monoxide or cyanide poisoning, acute cerebral vascular disease, myocardial infarction phase identification, also need with access to high concentrations of chemicals such as methane or nitrogen Erzhi hypoxic environment of air asphyxiation phase identification. Other symptoms should be due to other causes of coma after a similar disease or injury caused by falling phase identification. Rescue workers in the event of hydrogen sulfide poisoning treatment 1. Rescuing extremely important, because the air contains high concentrations of hydrogen sulfide is often caused by people in the field of electric shock-like death, such as the timely rescue to reduce mortality, reduce the number of transfers alleviate the condition. So that patients from the scene immediately to fresh air. Immediately given oxygen conditions. On-site rescue personnel should have knowledge of self-help and mutual aid, emergency treatment to enter the scene to prevent self-poisoning. 2. To maintain vital signs. Respiratory or heart shall immediately stop the purposes of poly cardiopulmonary resuscitation. In the scene of the accident, such as respiratory arrest were artificial resuscitation in time, you can avoid the consequential cardiac arrest. In applying mouth to mouth artificial respiration should be implemented when the exhaled breath of patients to prevent inhalation of the escape of hydrogen sulfide or clothing to avoid secondary poisoning. 3. To symptomatic support therapy. Hyperbaric oxygen therapy to accelerate the recovery and prevention of coma species has an important role in brain water, where the coma patient, regardless of whether the recovery of hyperbaric oxygen therapy should be given as soon as possible, but must meet the comprehensive treatment. Clearly are required for the early symptoms of poisoning, adequate, short-range to give the adrenal glucocorticoid, has contributed to the prevention of cerebral edema, pulmonary edema and myocardial damage. Control of convulsions and prevention of cerebral edema and pulmonary edema, see and. Heavier patients need ECG and myocardial enzymes were measured in order to detect changes in condition, timely manner. Have symptoms of eye irritation, rinse immediately with water, symptomatic treatment. 4. Methemoglobin formation on the application of the indications and methods of agents there is no unified opinion. In theory, the formation of methemoglobin agent for the treatment of cells caused by suffocation of hydrogen sulfide, and reflex inhibition of the nervous system, respiration is invalid. Appropriate application of amyl nitrite, sodium nitrite or 4 - dimethyl amino phenol (4-DMAP), so that the blood hemoglobin oxidized to methemoglobin, which can be used with free sulfur sulfhydryl to form high-speed rail hemoglobin (Sulfmethemoglobin, SMHb) and detoxification; can be captured with cytochrome oxidase sulfhydryl binding, the enzyme complex energy, to improve the anoxia. But the judge is currently no simple and practical indicators of suffocation cells, and sulfide oxidation in the body rapidly inactivated, the use of these drugs actually worsened tissue hypoxia. Methylene blue (methylene blue) should not be used, because high doses can only methemoglobin formation, there are serious side effects overdose. At present the use of such drugs can only be determined by the clinical experience of physicians. Causes of hydrogen sulphide gas in the coal mine hazards and preventi, H2S hydrogen sulfide causes the formation mechanism based on the nature of the hydrogen sulfide can be divided into 5 genetic types: biodegradable, microbial sulfate reduction and thermal chemical decomposition, sulphate thermal chemical reduction and magmatic origin. Biodegradation is the role of corruption under the guidance of the process of formation of hydrogen sulfide. Putrefaction of organic matter in the formation of sulfur after, when the assimilation of the environment changes, the occurrence of corruption and decomposition of organic sulfur to hydrogen sulfide release. In this way early in coalification, the size and content of hydrogen sulfide generated will not be very difficult to gather. Use of sulfate-reducing microorganisms Yin to restore organic matter or hydrocarbons sulfate, in the direct formation of hydrogen sulfide under the action of alienation. Role in this process, sulfate-reducing Yan metabolism of only a small portion of the sulfur incorporated into the cells, most of the sulfur is absorbed by the biological aerobic energy metabolism to complete the process. Some species of organic decomposition products may be required for some species absorb nutrients, which causes absorption of organic matter by sulfate-reducing Yin conversion efficiency, which produce large amounts of hydrogen sulfide. The Yin to sulfate-reducing sulfate-reducing way to produce hydrogen sulfide, also known as microbial sulfate reduction (BSR). The process is the primary role of hydrogen sulfide causes the type of Biochemistry, due to reduction of this alienation is strictly anaerobic environments, and it is for the preservation and accumulation of hydrogen sulfide generated, but the general abundance of the formation of hydrogen sulfide no more than 2%, and the ground conditions must be suitable for sulfate-reducing media growth and reproduction of Yin, it is difficult to occur in the deep. Biodegradation, microbial sulfate reduction of H2S gas formed mostly native biogenic gas, in the early stages of coalification, from a relatively low temperature and shallow depth of peat in the peat swamp or low-rank coal (lignite), through bacterial decomposition generated a series of complex processes. Early due to coalification coal or peat contains a lot of water, take a considerable amount of coal and rock porosity, when the native bio-gas generated in the adsorption amount of coal in the small, most of the biological causes of hydrogen sulfide and carbon dioxide may be dissolved in the formation water in the later compaction and coalification emission from coal seams under. And the microstructure of the early coal has not fully developed structure for the accumulation of gases. Thus, the general that the early generation of the original biogenic H2S gas can not be retained in the coal seam in large numbers. Microbial sulfate reduction may also be formed in the secondary biogenic gas phase H2S gas, as a result of tectonic movement after coal, coal is uplift, erosion to the near-surface, surface water infiltrating bacteria into the coal, at relatively low temperatures so that the moisture produced during coalification, n-alkanes and other organic compounds by bacterial degradation and secondary metabolism of biogas generated. The geochemical composition similar to primary biogenic gas, the main difference is that the thermal evolution of coal over gas generation protists stage, Ro, max% wider range, generally 0.30% -1.50%, and coal generally was raised to shallow coal seams ground temperature fell below 75 , especially the local temperature down to the most suitable temperature of the large population of sulfate-reducing bacteria, the coal is reduced in sulfate rocks to generate more H2S, in the role of bacteria from the flow through permeable coal or other organic-rich water into surrounding rock. Heat causes chemical decomposition of organic sulfur in coal is in the heat under the effect of breaking the formation of heterocyclic sulfur, hydrogen sulfide, hydrogen sulfide, also known as cracked. In this way the formation of hydrogen sulfide concentration is generally less than 1%. Sulfate reduction is the main cause of sulfate and organic matter or hydrocarbons play a role, will generate H2S and sulfate minerals reducing CO2. Sulfate reduction is caused by generation of high natural gas and hydrogen sulfide hydrogen sulfide gas in the main form of type, it occurs the temperature is generally greater than 150 . Ro, max% in the 0.50% -3. 70% of the stage, coal would be formed under the heat of pyrolysis gas and pyrolysis gas gas. Sulfur coal and surrounding rock of organic matter and sulfate of thermal chemical decomposition (pyrolysis) and the thermal effect of chemical reduction, can produce H2S gas. Organic matter due to coal and rock in the sulfate sulfur content and sulfur content in coal is very low, the formation of H2S content in general will not exceed 2%. If the surrounding rocks in the higher levels of sulfate, can produce more H2S gas. Magmatic origin. Sulfur as the Earth's interior is much higher than the abundance of the crust, magmatic activity deep crustal rocks to melt and produce hydrogen sulfide containing volatile ingredients, it often contains hydrogen sulfide magma. The content of hydrogen sulfide depends on the composition of magma and gas migration conditions, the hydrogen sulfide content of the magma very unstable, and only in certain conditions, migration and reservoir can be gathered in the coal seam down. 2, coal mine gas in the coal for the cause of abnormal H2S CO2, CH4, N2 adsorption experiments showed that the adsorbed material with the gas adsorption capacity increased with increasing boiling point. H2S gas in the lowest boiling point -60. 33


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