Sulfur oxide chlorides chloride

Most newer plants and facilities contain control rooms, electric motor control centers, instrument control rooms, and computer centers. These are usually maintained under a slight positive pressure with makeup air being introduced from the outside. In many instances it is possible for this air to be contaminated with atmospheric pollutants such as sulfur oxides, hydrogen chloride, chlorides, hydrogen sulfide, dust, and others. These gases and dust can cause serious damage to sensitive circuitry found in computers, microprocessors, microswitches, and other delicate electronic equipment. If corrosive gases are removed from these makeup streams, costly maintenance and downtime will be prevented. 

The stimulator is about the size of a matchbox and also includes a lithium sulfur oxide chloride (LiSOCIj) primary battery with an operating life ranging from three to eight years depending on the stimulating pulse parameters. 

Sulfur dioxide [7446-09-5] is formed as a result of sulfur oxidation, and hydrogen chloride is formed when chlorides from plastics compete with oxygen as an oxidant for hydrogen. Typically the sulfur is considered to react completely to form SO2, and the chlorine is treated as the preferred oxidant for hydrogen. In practice, however, significant fractions of sulfur do not oxidi2e completely, and at high temperatures some of the chlorine atoms may not form HCl. 

Meta.1 Conta.mina.nts and Ash. Alkali metals form basic oxides that are very reactive toward acidic species such as the acid gases, siHcates, and alurninates. These form stable salts with acid gases if the off-gas contains such gases. Sodium, the most common of these metals, prefers to form chlorides ahead of sulfates. Sodium carbonate only forms in the absence of haHdes and sulfur oxides, SO. There usually is too Htde NO present to form nitrates (see Sodium compounds). 

In the initial thiocyanate-complex Hquid—Hquid extraction process (42,43), the thiocyanate complexes of hafnium and zirconium were extracted with ether from a dilute sulfuric acid solution of zirconium and hafnium to obtain hafnium. This process was modified in 1949—1950 by an Oak Ridge team and is stiH used in the United States. A solution of thiocyanic acid in methyl isobutyl ketone (MIBK) is used to extract hafnium preferentially from a concentrated zirconium—hafnium oxide chloride solution which also contains thiocyanic acid. The separated metals are recovered by precipitation as basic zirconium sulfate and hydrous hafnium oxide, respectively, and calcined to the oxide (44,45). This process is used by Teledyne Wah Chang Albany Corporation and Western Zirconium Division of Westinghouse, and was used by Carbomndum Metals Company, Reactive Metals Inc., AMAX Specialty Metals, Toyo Zirconium in Japan, and Pechiney Ugine Kuhlmann in France. 

Compounds considered carcinogenic that may be present in air emissions include benzene, butadiene, 1,2-dichloroethane, and vinyl chloride. A typical naphtha cracker at a petrochemical complex may release annually about 2,500 metric tons of alkenes, such as propylenes and ethylene, in producing 500,000 metric tons of ethylene. Boilers, process heaters, flares, and other process equipment (which in some cases may include catalyst regenerators) are responsible for the emission of PM (particulate matter), carbon monoxide, nitrogen oxides (200 tpy), based on 500,000 tpy of ethylene capacity, and sulfur oxides (600 tpy). 

The principal air pollutants from dye manufacturing are VOCs, nitrogen oxides (NOJ, hydrogen chloride (HCl), and sulfur oxides (SOJ. Stack gas scrubbing and/or... 

Fire Hazards - Flash Point (deg. F) 252 OC Flammable Limits in Air (%) Not pertinent Fire Extinguishing Agents Water Fire Extinguishing Agents Not To Be Used Not pertinent Special Hazards of Combustion Products Toxic fumes include oxides of phosphorous, sulfur and hydrogen chloride Behavior in Fire Containers may rupture Ignition Temperature (deg. F) 338 Electrical Hazard No data Burning Rate No data. 

As reagents concentrated sulfuric acid, hydrochloric acid, liquid sulfur dioxide, thionyl chloride, phosphorus pentachloride, zinc oxide" and even silica gel can be used. Reagents like phosphorus pentachloride (as well as thionyl chloride and others) first convert the hydroxy group of the oxime 1 into a good leaving group ... 

The practical route for oxidizing leuco diphenylmethanes 15 demands inital conversion to an imine salt 16. The imine salt is obtained by heating a mixture of diphenylmethane, sulfur, ammonium chloride, and sodium chloride at 175°C in a current of ammonia or by heating a mixture of diphenylmethane, urea, sulfamic acid, sulfur, and ammonia at 175°C (Scheme 3). Dyes 16 can be represented as the quinonoid resonance structure 17. Dyes of this class, known as auramines, are all yellow, with the only commercial representative being auramine O 16a. Due to its poor lightfastness and instability to hot acids and bases, its use has been restricted to dyeing and printing cotton, paper, silk, leather, and jute. 

Emissions from sinter plants are generated from raw material handling, windbox exhaust, sinter discharge (associated sinter crushers and hot screens), and from the cooler and cold screen. The primary source of particulate emissions, mainly irons oxides, magnesium oxide, sulfur oxides, carbonaceous compounds, aliphatic hydrocarbons, and chlorides, are due to the windbox exhaust. Contaminants such as fluorides, ammonia, and arsenic may also be present. At the discharge end,... 

Particulate iron and sulfur oxides, carbonaceous compounds, aliphatic hydrocarbons, chlorides... 

Atomic hydrogen is a powerful reducing agent, even at room temperature. For example, it reacts with the oxides and chlorides of many metals, including silver, copper, lead, bismuth, and mercury, to produce the free metals. It reduces some salts, such as nitrates, nitrites, and cyanides of sodium and potassium, to the metallic state. It reacts with a number of elements, both metals and nonmetals, to yield hydrides such as NH3, NaH, KH, and PH3. Sulfur forms a number of hydrides the simplest is H2S. Combining with oxygen, atomic... 

A simplified series of reactions between a hafnium salt and sulfuric acid is given in Fig. 4.3. The reactions showcase important facets of thin-film synthesis (but do not address the precise identities of intermediates or complexities of aqueous hafnium chemistry.) In the first step, a hafnium oxide chloride crystal hydrate is dissolved in water to disperse small hafnium-hydroxo molecular clusters. Sulfato ligands are subsequently added in the form of sulfuric acid. Since sulfato binds more strongly than chloro, hafnium-hydroxo-sulfato aqueous species are created. Under mild heating, these species readily poly-... 

Upper respiratory toxicants include hydrogen halides (hydrogen chloride, hydrogen bromide), oxides (nitrogen oxides, sulfur oxides, sodium oxide), and hydroxides (ammonium hydroxide, sodium dusts, and potassium hydroxides). Lower respiratory toxicants include monomers (such as acrylonitrile), halides (fluorine, chlorine, bromine), and other miscellaneous... 

Hasenclever An improvement to the Deacon process for oxidizing hydrogen chloride to chlorine, in which the hydrogen chloride is first dried with concentrated sulfuric acid. 

Longmaid-Henderson A process for recovering copper from the residue from the roasting of pyrites to produce sulfur dioxide for the manufacture of sulfuric acid. The residue was roasted with sodium chloride at 500 to 600°C the evolved sulfur oxides and hydrochloric acid were scrubbed in water and the resulting solution was used to leach the copper from the solid residue. Copper was recovered from the leachate by adding scrap iron. The process became obsolete with the general adoption of elemental sulfur as the feedstock for sulfuric acid manufacture. 

The use of aqueous foams to control fume or vapour release from reactive chemicals is discussed. An acid-resistant foam NF2 controlled fume emission from 35% and 65% oleum, and from titanium tetrachloride, but was not effective for sulfur trioxide and chlorosulfuric acid. An alcohol-resistant foam NF1 suppressed ammonia vapour emission by 80%, and Universal fire foam reduced evaporation of ethylene oxide, vinyl chloride and methanethiol, and reduced vapour emission of 1,3-butadiene by 60%. Safety aspects of foam blanketing are discussed [1]. Equipment and application techniques are covered in some detail [2],... 

Rate constant data for reactions of post-combustion gases including nitrogen oxides, hydrogen chloride, ozone, and sulfur oxides are presented in Tables C8-C11. 

Chemical radicals—such as hydroxyl, peroxyhydroxyl, and various alkyl and aryl species—have either been observed in laboratory studies or have been postulated as photochemical reaction intermediates. Atmospheric photochemical reactions also result in the formation of finely divided suspended particles (secondary aerosols), which create atmospheric haze. Their chemical content is enriched with sulfates (from sulfur dioxide), nitrates (from nitrogen dioxide, nitric oxide, and peroxyacylnitrates), ammonium (from ammonia), chloride (from sea salt), water, and oxygenated, sulfiirated, and nitrated organic compounds (from chemical combination of ozone and oxygen with hydrocarbon, sulfur oxide, and nitrogen oxide fragments). ... 

Emits toxic fumes of chlorides and sulfur oxides when heated to decomposition (Lewis, 1990). 

A thiophene ring can also be produced from two methylene groups. Here 2,5-dicarbethoxy-3,4-dicyanomethylthiophene 19 reacted with sulfur mono-chloride to give tetrasubstituted thieno[3,4-c]thiophene 20 in moderate yield (2002JCX72453). A mechanism for the thiophene 20 formation was proposed and 1,2-dithiine derivative 21 was likely to be an intermediate (Scheme 10) because sulfur monochloride gave higher yields of 20 than SCl2. At the next step (21 20), sulfur monochloride apparently acted as an oxidant. 

Phenoxathiin and thianthrene can be chlorinated without oxidation into the corresponding sulfoxides using sulfuryl chloride and AICI3 to form the 2,3,7,8-tetrachloro derivatives 41 and 42, respectively. Use of BMS reagent- a mixture of sulfur monochloride, sulfuryl chloride, and aluminium chloride - results in exhaustive chlorination of phenoxathiin and thianthrene with formation of perchlorinated products 43 and 44. It is noteworthy that using sulfuryl chloride in dichloromethane, the sulfoxides were isolated as the major products <1997CHE333>. 

Other species that can initiate this sulfur oxidation chemistry are N03 (discussed in Chapter 7.D.1) and ClJ. The latter radical anion is formed in sea salt particles when atomic chlorine is generated and reacts with chloride ion. In addition, Vogt et al. (1996) have proposed that oxidation of SO2- by HOC1 and HOBr in sea salt particles may be quite important. Table 8.13 summarizes the aqueous-phase chlorine chemistry that occurs in sea salt particles and Table 8.14 the oxidation of S(IV) by reactive chlorine and bromine species in solution. 

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