Corrosion problems and materials selection for emissions control equipment can be difficult because of varied corrosive compounds present and the severe environments encountered. This article discusses the selection of materials for construction of flue gas desulfurization systems. It addresses the problems associated with materials for incinerator off-gas treatment equipment. The off-gases can be classified according to their corrosiveness as: industrial chemical, hospital, municipal solid, and sewage sludge. The article provides information on the selection of materials for the three most common types of dust collection equipment used in bulk solids processing, namely, fabric filters, electrostatic precipitators, and wet scrubbers. It also discusses a wide variety of corrosion problems encountered in chemical and pharmaceutical industries.

This article describes the specific features and mechanisms of oxidation in thermal spray coatings. It discusses the two forms of hot corrosion in sulfur-containing combustion, namely high-temperature hot corrosion and low-temperature hot corrosion. The article reviews the behavior of corrosion-resistant coatings in boilers. The effects of high-temperature corrosion in waste incinerators are detailed. The article also examines the effects of erosion-corrosion in fluidized bed combustion boilers.

This article describes the corrosion modes in a waste-to-energy boiler. It discusses the corrosion protection and alloy performance with an emphasis on two main areas of the boiler: furnace water walls and super heaters.

The primary fossil fuels are generally defined as coal, oil, natural gas, tar sands, and shale oil. This article discusses the characteristics and the types of fuels used in fossil and fuel industries. It describes the energy conversion in fuels and outlines the efficiency of a heat engine with the help of the Carnot equation.

The corrosion process that occurs in industrial systems is often difficult to discern until extensive deterioration has occurred. For boilers to function properly, the incoming water must be processed to meet the water quality required for the boiler. This article discusses pretreatment methods of the incoming water and preboiler corrosion protection methods. It analyzes internal treatment and condensate treatment of boilers. The article discusses three types of cooling systems: once-through systems, open recirculating systems, and closed recirculating systems. The corrosion processes which occur in water-recirculating systems and the effect of dissolved gases, temperature, pH, suspended solids, dissolved salts, and scale deposition on corrosivity of water, are also reviewed. The article also considers anodic and cathodic inhibitors and the control of corrosion in municipal water systems.

This article provides information on the municipal wastewater system components such as piping, pump stations, headworks, clarifiers, aeration structures, digesters, biosolids dewatering equipment, and sludge stabilization. It explains the major corrosion damage mechanisms to which those component parts of the system are exposed. It presents useful guidelines for selecting and using protective coatings in municipal sewerage collection systems and water reclamation facilities in wastewater treatment plants. The article includes annotated flow diagrams of a wastewater collection system, wastewater treatment plants, and spreadsheets listing the most widely used generic coating systems by structure and substrate material. It concludes with a section on quality watchouts when selecting or using protective coatings in municipal wastewater systems.

This article presents information regarding the use of protective coatings in municipal potable water systems, including raw water collection and transmission, water treatment plants, and treated water distribution. It provides useful guidance for the selection and use of protective coatings in these municipal water systems. The most commonplace corrosion-damage mechanisms are highlighted. The article describes the most common materials of construction found in municipal water systems, namely, cast iron, ductile iron, carbon steel, precast concrete cylinder pipe and reinforced concrete pipe, prestressed concrete tanks, and stainless steel. It provides information on the most common generic coating systems used for new steel tanks and water storage tanks. It concludes with a discussion of quality watch-outs when selecting or using protective coatings in municipal water systems.

This article focuses on the recycling of metals including iron and steel, stainless steel, superalloys, nickel, aluminum, copper, precious metals, lead, magnesium, tin, titanium, and zinc. It provides information on the identification and sorting of scrap metals and discusses the equipment and procedures used for small-scale and large-scale scrapping operations.

Many nonferrous metals, including aluminum, nickel, copper, and others, are among the few materials that do not degrade or lose their chemical or physical properties in the recycling process. As a result, these metals can be recycled an infinite number of times. This article focuses on the recycling of nonferrous alloys, namely, aluminum, copper, magnesium, tin, lead, zinc, and titanium, providing details on the sources, consumption and classification of scrap, and the technological trends and developments in recycling.

Environmental and worker health regulations have increased the costs associated with cadmium coating application and cadmium-beating waste disposal, thus creating economic incentives for industrial users to seek cadmium plating replacements. This article presents a cadmium replacement identification matrix that includes information on the specifications, corrosion control performance, environment-assisted cracking, coating lubricity, environmental and worker health regulations, and cost and performance factors for various replacement processes.

Explosion welding (EXW) is a solid-state metal-joining process that uses explosive force to create an electron-sharing metallurgical bond between two metal components. This article discusses the process attributes of EXW, including metallurgical attributes, metal combinations, size limitations, configuration limitations, and bond zone morphology. It provides an overview of the common industrial applications and shop welding applications of EXW products. The article reviews different safety standards and regulations, such as noise and vibration abatement and process geometry. It concludes with a section on the EXW process sequence for welding a two-component flat plate product.

Aluminum possesses many characteristics that make it highly compatible with recycling. Production of aluminum from scrap has a number of advantages. This article discusses the technology for the recovery, sorting, and remelting of aluminum. It describes the collection and acquisition of aluminum scrap in transportation, packaging, electrical and electronic, and building and construction sectors. The article reviews the technologies used to accomplish comminution for aluminum: shearing, knife shredding, and swing-hammer shredding. It provides a description of the devices used in scrap sorting, such as hand sorting, air classification, magnetic separation, eddy-current separation, heavy-media separation, and sensor-based sorting. The article also describes thermal processing, refining and casting, and dross processing of aluminum. It provides information on reverberatory and electric furnaces used for melting aluminum.

This article discusses postconsumer plastics recyclate quantities, the classification of plastics recycling into primary, secondary, tertiary, and quaternary categories, and how the life cycle of plastics is affected by recycling. The recycling processes of polyethylene terephthalate (PET), which accounts for the largest percentage of plastic recycling, high-density polyethylene (HDPE) plastics, the other large-volume plastic recyclate, as well as vinyl resins and polycarbonate resins are described. The life cycle of plastics has four phases: poly formation, part fabrication, product service, and disposal. Landfilling is still the primary method of final disposal, and incineration is another option, but recycling has become a viable alternative. The article presents a comparison between secondary and tertiary recycling.

This article describes selected U.S. environmental statutes and regulations that are pertinent to material surface finishers. It provides information on the applicability, requirements, and permitting conditions of the Clean Air Act, the Resources Conservation and Recovery Act, the Superfund Amendments and Reauthorization Act, and the Clean Water Act.

Erosion occurs as the result of a number of different mechanisms, depending on the composition, size, and shape of the eroding particles; their velocity and angle of impact; and the composition of the surface being eroded. This article describes the erosion of ductile and brittle materials with the aid of models and equations. It presents three examples of erosive wear failures, namely, abrasive erosion, erosion-corrosion, and cavitation erosion.

The presence of certain impurities in coal and oil is responsible for the majority of fireside corrosion experienced in utility boilers. In coal, the primary impurities are sulfur, alkali metals, and chlorine. The most detrimental impurities in fuel oil are vanadium, sodium, sulfur, and chlorine. This article describes the two categories of fireside corrosion based on location in the furnace: waterwall corrosion in the lower furnace and fuel ash corrosion of superheaters and reheaters in the upper furnace. It discusses prevention methods, including changes to operating parameters and application of protective cladding or coatings.

High-frequency resistance welding (HFRW) is a process that uses high-frequency currents to concentrate the welding heat at the desired location. This article focuses on the fundamentals, advantages, limitations, and applications of HFRW. It discusses the personnel and equipment requirements as well as safety considerations necessary for the process. The article concludes with a discussion on the techniques for inspection and quality control of HFRW.

Erosion is the progressive loss of original material from a solid surface due to mechanical interaction between that surface and a fluid, a multicomponent fluid, an impinging liquid, or impinging solid particles. The detrimental effects of erosion have caused problems in a number of industries. This article describes the processes involved in erosion of ductile materials, brittle materials, and elastomers. Some examples of erosive wear failures are given on abrasive erosion, liquid impingement erosion, cavitation, and erosion-corrosion. In addition, the article provides information on the selection of materials for applications in which erosive wear failures can occur.

This article addresses two issues on thermodynamics, namely, the calculation of solubility lines and the calculation of the activity of various components. It discusses alloying elements in terms of their influence on the activity of carbon. The article describes the desulfurization and deoxidation of cast iron and steel. It illustrates the thermodynamics of the iron-carbon system and the iron-silicon system. The article examines solubility and saturation degrees of carbon in multicomponent iron-carbon systems. One of the main applications of the thermodynamics of the iron-carbon system is the calculation of structure-composition correlations. The article concludes with information on the structural diagrams for cast iron: the Maurer diagram and the Laplanche diagram.