Cleaning operations

A low incidence of explosions has been reported when precipitation is effected without a nucleating agent and during the screening process. Precautions must be taken during detonator loading to prevent dusting and to maintain a scmpulously clean operation. 

Hydrogen chloride and the aqueous solution, muriatic acid, find appHcation in many industries. In general, anhydrous HCl is consumed for its chlorine value, whereas aqueous hydrochloric acid is often utilized as a nonoxidizing acid. The latter is used in metal cleaning operations, chemical manufacturing, petroleum well activation, and in the production of food and synthetic mbber. 

L. M. Brown,. Springer, and M. Bower, Chemical Substitution for 1,1,1 -Trichloroethane and Methanol in an Industrial Cleaning Operation, U.S. EPA, Cincinnati, Ohio National Technical Information Service, Springfield, Va., 1992. 

The sulfur dioxide produced by the process is usually converted to sulfuric acid, or sometimes Hquified, and the design of modem roasting faciUties takes into account the need for an efficient and environmentally clean operation of the acid plant (see SuLFURiC ACID AND SULFURTRIOXIDe). 

Principal uses of KOH include chemicals, particularly the production of potassium carbonate and potassium permanganate, pesticides (qv), fertilizers (qv), and other agricultural products soaps and detergents scmbbing and cleaning operations, eg, industrial gases dyes and colorants and mbber chemicals (qv) (10,34). 

Sulfamic acid has a unique combination of properties that makes it particularly well suited for scale removal and chemical cleaning operations, the main commercial appHcations. Sulfamic acid is also used in sulfation reactions, pH adjustment, preparation of synthetic sweeteners (qv), and a variety of chemical processing appHcations. Salts of sulfamic acid are used in electroplating (qv) and electroforrning operations as well as for manufacturing flame retardants (qv) and weed and hnish killers (see Herbicides). 

AH volatile organic solvents are toxic to some degree. Excessive vapor inhalation of the volatile chloriaated solveats, and the central nervous system depression that results, is the greatest hazard for iadustrial use of these solvents. Proper protective equipment and operating procedures permit safe use of solvents such as methylene chloride, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene ia both cold and hot metal-cleaning operations. The toxicity of a solvent cannot be predicted from its chlorine content or chemical stmcture. For example, 1,1,1-trichloroethane is one of the least toxic metal-cleaning solvents and has a recommended threshold limit value (TLV) of 350 ppm. However, the 1,1,2-trichloroethane isomer is one of the more toxic chloriaated hydrocarboas, with a TLV of only 10 ppm. 

Carbon tetrachloride is the oldest and was the most extensively used chlorinated solvent in degreasing and dry-cleaning operations for many years. Consequently, its narcotic and toxic properties have been the subject of much investigation. Carefiil investigations have repeatedly shown carbon tetrachloride to be one of the most harm fill of the common solvents (37). 

Aluminum. Eor aluminum alloys such as 1100 and 3003 only a cleaning operation is necessary before apphcation of enamel. Eor ahoy 6061, deoxidation and alkaline-chromate pretreatment processes may also be used to improve both the cleanliness of the surface and the development of enamel adherence. The spent chromium-containing solutions can present disposal problems and should be handled in accordance with existing regulations (19). 

Filtrate is collected in the underdrain system, which may be as simple as a network of perforated pipes covered by graded gravel or a complex structure with slotted nozzles or conduits that will retain the finest sand media while maintaining high flow rates. This latter design allows the use of both air and liquid for the backwashing and cleaning operations. 

This question refers to situations where the toller himself is carrying out cleaning operations at his own premises. Cleaning is a very important element of toller s effort to maintain quality. The assessor should read and check all written procedures carefully. 

Perhaps the most useful application of ISS stems from its ability to monitor very precisely the concentration and thickness of contaminants on metals during development of optimum processing and cleaning operations. One particularly important application involves quantitatively monitoring total carbon on cleaned steels before paint coating. This has been usefid in helping to develop optimum bond... 

J. L. Goodier, E. Boudreau, G. Coletta, and R. Lueas. Industrial Health and Safety Criteria for Abrasive Blast Cleaning Operations. HEW Publication no. (NIOSH) 75-122. NIOSH (. krthur D. Little), 1974. 

The explosion hazard on ships is not confined to cargoes of explosives, however. Explosions can also occur from flammable gases and liquids, particularly during transfer and cleaning operations. 

Lubrication of Wire Rope after Socket Attachment. After the resin has cured, relubricate the wire rope at the base of the socket to replace the lubricant that was removed during the cleaning operation. 

No matter which method of cleaning is adopted, it is desirable to apply the primer or coating immediately after the cleaning operation. 

Cleaning. Various organic and inorganic compounds enter the wastewater stream from cleaning operations. 

Utilizing electrolytic recovery, customized resins, selective membranes, and adsorbents to separate metal impurities from plating baths, acid/caustic dips, and solvent cleaning operations. 

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