Gases sulfur dioxide

For environmental reasons, the entire process is handled by enclosed equipment. Lead recoveries of 96% can be obtained from the raw materials, and sulfur dioxide gas released in the process is used to produce sulfuric acid. Four plants are in operation as of 1994. Three are in Russia and one is in Italy. 

Combustion of Sulfur. For most chemical process appHcations requiring sulfur dioxide gas or sulfurous acid, sulfur dioxide is prepared by the burning of sulfur or pyrite [1309-36-0], FeS2. A variety of sulfur and pyrite burners have been developed for sulfuric acid and for the pulp (qv) and paper (qv) iadustries, which produce and immediately consume about 90% of the captive sulfur dioxide produced ia the United States. Information on the European sulfur-to-sulfuric acid technology (with emphasis on Lurgi) is available (255). 

To produce commercial (99.5%) tellurium, tellurium dioxide is dissolved in hydrochloric acid. The tellurium solution is saturated with sulfur dioxide gas to yield commercial tellurium powder, which is washed, dried, and melted. 

Analytical and Test Methods. An aqueous solution of sodium thiosulfate forms a white precipitate with hydrochloric acid and evolves sulfur dioxide gas which is detected by its characteristic odor. The white precipitate turns yellow, iadicatiug the presence of sulfur. The addition of ferric chloride to sodium thiosulfate solutions produces a dark violet color which quickly disappears. 

The ancient process of stoving is stiU occasionally used to bleach wool and silk with sulfur dioxide. In this process, wet fabrics are hung in chambers of burning sulfur or sulfur dioxide gas for at least 8 h. The fabrics are then washed with sodium sulfite to remove excess sulfur dioxide. Fabric so treated may have unpleasant odors, and the original color eventually returns, but the process is simple and inexpensive. 

Sulfur Dioxide Reductant. The Mathieson process uses sulfur dioxide, sodium chlorate, and sulfuric acid to produce chlorine dioxide gas with a much lower chlorine content. The sulfur dioxide gas reductant is oxidized to make sulfuric acid, reducing the overall acid requirement of the process. Air is used to dilute the chlorine dioxide produced by this process. The exit gases flow through a scmbber to which chlorate is added in order to remove any unreacted sulfur dioxide. Spent Hquor, containing some unreacted chlorate, sulfuric acid, and sodium sulfate, continuously overflows from this process. 

Small amounts of chlorine, amounting from 1 to 5% of the chlorine dioxide, ate present in the chlorine dioxide gas product from the Mathieson process. The purity of the chlorine dioxide gas can be increased at the expense of higher chlorate content in the spent Hquor if NaCl is not used in the reactor and a small amount of sulfur dioxide gas is present in the generator chlorine dioxide product gas stream. 

The Inco flash smelting process produces a very high strength sulfur dioxide gas by using pure oxygen for smelting. Liquid sulfur dioxide is obtained upon compression. 

Fire Hazards - Flash Point Not flammable Flammable Limits in Air (%) Not flammable Fire Extinguishing Agents Not pertinent Fire Extinguishing Agertts Not To Be Used Not pertinent Special Hazards of Combustion Products Irritating sulfur dioxide gas may form in fire Behavior in Fire Not pertinent Ignition Temperature Not pertinent Electrical Hazard Not pertinent Burning Rate Not pertinent. 

This case applies to drying processes (B = dry air), condensation, and absorption, such as the diffusion of sulfur dioxide gas through a calcium oxide. 

A crude oil burned in electrical generating plants contains about 13% sulfur by mass. When the oil bums, die sulfur forms sulfur dioxide gas ... 

Dichlorine oxide is used as bactericide to purify water ft is produced by the chlorination of sulfur dioxide gas. 

Hydrogen sulfide gas (H2S) is responsible for die fiwl odor of rotten eggs. When it reacts with oxygen, sulfur dioxide gas and steam are produced. 

Nevertheless, as pressures increase, the steam and condensate pH levels begin to drop significantly. This pH depression is accelerated with higher BW sulfite levels. At 700 psig, with a BW sodium sulfite reserve of, say, 40 ppm, the condensate can dip to as low as pH 4.2. This ultimately produces a very corrosive situation caused by the production of sulfur dioxide gas (S02) and hydrogen sulfide gas (H2S). 

Sodium bisulfite is used in almost all commercial wines to prevent oxidation and preserve flavor. It releases sulfur dioxide gas when added to water or products containing water. The sulfur dioxide kills yeasts, fungi, and bacteria in grape juice before fermentation. When the sulfur dioxide levels have subsided, after about twenty-four hours, fresh yeast is added for fermentation. 

Estimate the molar heat capacity (at constant volume) of sulfur dioxide gas. In addition to translational and rotational motion, there is vibrational motion. Each vibrational degree of freedom contributes R to the molar heat capacity. The temperature needed for the vibrational modes to be accessible can be approximated by 6 = />vvih/, where k is Boltzmann s constant. The vibrational modes have frequencies 3.5 X... 

In the copper production stage, copper sulfide is oxidized to molten copper metal, known as blister copper and so named because when liquid copper cools, the evolution of the residual sulfur and oxygen from the metal as sulfur dioxide gas causes blisters to form on the surface of the metal. The conversion reaction may be shown as ... 

The pregnant solution is then treated with sulfur dioxide gas by which the reduction of the chlorate ions contained in the solution takes place according to the reaction ... 

Smelting releases sulfur dioxide gas from a metal sulfide ore. Before the twentieth century, most of the sulfur dioxide expelled in the smelting process poured out of the factory s smokestacks directly into the atmosphere. Sulfur dioxide in the atmosphere, however, is a powerful greenhouse gas. Today, most of the hot sulfur dioxide gas released in the smelting process is captured, cooled, cleaned, and converted into sulfur trioxide ... 

Thomas and Hill (16) showed that sulfur dioxide fumigation of alfalfa increased the sulfate content of the leaves. In later work Thomas et al. (H) reported that the pH of alfalfa leaf tissue fluids was lowered 0.3 pH unit after fumigation with sulfur dioxide. Similar responses occur when lemons are incubated in sulfur dioxide gas, or when they are treated with elemental sulfur or with hydrogen sulfide (18). Likewise lemons treated with dilute sulfuric acid gave similar responses. 

The radioactivity of the hydrogen sulfide produced by 28 lemons treated with radioactive elemental sulfur dust, 28 lemons treated with radioactive sulfur dioxide gas, and 28 lemons treated with a radioactive sulfuric acid solution is expressed as per cent specific activity (Table II), which for the purpose of this report is defined as ... 

One way to control gaseous pollutants like SO2 and SO3 is to remove the gases from fuel exhaust systems by absorption into a liquid solution or by adsorption onto a solid material. Absorption involves dissolving the gas in a liquid while adsorption is a surface phenomenon. In each case, a subsequent chemical reaction can occur to further trap the pollutant. Lime and limestone are two solid materials that effectively attract sulfur dioxide gas to their surfaces. The ensuing chemical reaction converts the gaseous pollutant to a solid nontoxic substance that can be collected and disposed or used in another industry. 

While the use of low-sulfur fuels is one mechanism to reduce sulfur dioxide emission, alternatively most approaches focus on scrubbing or ridding the emissions in smoke stacks of sulfur dioxide gas. A number of different types of scrubbers, i.e., sulfur dioxide removal systems, are available for industry. One system sprays the flue gas into a liquid solution of sodium hydroxide. The hydroxide combines with SO2 and O2 to form the corresponding sulfate which can be removed from the aqueous solution ... 

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