Flue fumes

SMOKE, FLUE FUMES, LIQUID PARTICLES m GASES... 

Production. Indium is recovered from fumes, dusts, slags, residues, and alloys from zinc or lead—zinc smelting. The source material itself, a reduction bullion, flue dust, or electrolytic slime intermediate, is leached with sulfuric or hydrochloric acid, the solutions are concentrated, if necessary, and cmde indium is recovered as 99+% metal. This impure indium is then refined to 99.99%, 99.999%, 99.9999%, or higher grades by a variety of classical chemical and electrochemical processes. 

Miscellaneous. Where a copper refinery is adjacent to a lead (qv) plant it is feasible to recover the selenium in slimes by smelting them in conjunction with lead-bearing materials. Utilizing the lower temperatures needed to melt lead, the selenium is volatilized from a lead bath or cupel blown with air. The selenium is recovered from flue dust and fume by scmbbing. This is the process used by Union Miniere at its Hoboken plant in Belgium. 

As a result of the larger flues and the restric ted surface area per unit of gas passed, regenerators employed with this type of furnace exhibit much lower efficiency than would be reahzed with smaller flues. In view of the large amount of iron oxide contained in open-hearth exhaust gas and the alkah fume present in glass-tank stack gases, however, smaller checkerbrick dimensions are considered imprac tical. 

Smoke pellets are produced in a range of sizes and are commonly used tor the resting of household flues and chimneys. The pellet is ignited and will burn for about 10 seconds producing a dense white smoke. Because this is a combustion process there are obvious restrictions on its use (nonflammable atmo spheres, nonflammable surfaces, etc.). In addition the smoke is buoyant because of the heat generated. The smoke can also be an irritant and/or toxic. The production of smoke cannot be controlled, but pellets are inexpensive, easy to use, and readily available, and the smoke is produced in sufficient quantities to make them useful in the evaluation, for example, of fume cupboards and Ixroths. 

Dunst, m. vapor steam, fume, damp smoke haze fine shot flue dust, -abzug, m. hood (for fumes), ab2ug rohr, n. vent pipe, dnostartig, a. vaporous. 

CONFINED SPACE A spacc which is substantially, although not always entirely, enclosed and where there is a reasonably foreseeable risk of serious injury from hazardous substances or conditions within the space or nearby. The risks may include flammable substances oxygen deficiency or enrichment toxic gases, fume or vapour ingress or presence of liquids free-flowing solids presence of excessive heat. For the purpose of the Confined Spaces Regulations 1997 a confined space means any place, including any chamber, tank, vat, silo, pit, trench, pipe, sewer, flue, well or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk. 

Many mechanical separations involve the movement of solid particles or liquid drops through a fluid. The fluid may be gas or liquid, and it may be flowing or static. As some assortment of examples mention may be made of the removal of dust and fumes from air or flue gas, the removal of solids from liquid wastes to permit discharge into public domain, and of the recovery of acid mists from an acid plant gaseous wastes. 

Nitro-substituted PAH have received increased attention as an important class of environmental pollutants. They have been detected in an ample variety of sources, including automobile exhaust fumes, wood and cigarette smoke, kerosene heater flue, emissions of coal-driven power stations and grilled meat. These subjects have been reviewed472,473. 

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