Aluminum processing plants

A very limited amount of individual plant specific data for the aluminum forming industry is available. Data available on the influent and effluent streams are discussed briefly in the following subsections for specific plants. This aluminum processing plant uses lime precipitation (pH adjustment) followed by coagulant addition and sedimentation as its treatment system. Data... 

Na AlFg, 5—7% AIF., 5—7% CaF2, 2—6% AI2O2, and 0—7% LiF with an operating temperature of 950°C. Ideally fluorine is not consumed in the process, but substantial quantities of fluorine are absorbed by the cell lining and fluorine is lost to the atmosphere. Modem aluminum industry plants efficiently recycle the fluorine values. 

Both the Toth and Alcoa processes provide aluminum chloride for subsequent reduction to aluminum. Pilot-plant tests of these processes have shown difficulties exist in producing aluminum chloride of the purity needed. In the Toth process for the production of aluminum chloride, kaolin [1332-58-7] clay is used as the source of alumina (5). The clay is mixed with sulfur and carbon, and the mixture is ground together, pelletized, and calcined at 700°C. The calcined mixture is chlorinated at 800°C and gaseous aluminum chloride is evolved. The clay used contains considerable amounts of silica, titania, and iron oxides, which chlorinate and must be separated. Silicon tetrachloride and titanium tetrachloride are separated by distillation. Resublimation of aluminum chloride is requited to reduce contamination from iron chloride. 

Some electrochemicals are produced in very large quantity. Chlorine and sodium hydroxide production in 1991 were 10,727,000 t and 11,091,000 t, respectively (1). Aluminum was produced at the rate of 4,100,000 t/yr and had an annual market value of about 5.4 biUion. Other electrochemically produced products are required in smaller volume. The production of the metals cadmium, lithium, and nickel were at the rates of 1600 t, 2800 t, and 8400 t, respectively for 1991 (see Table 1). Electrochemical processing plants produce a variety of products in a wide range of capacities. 

Primary Lead Smelters Primary Aluminum Reduction Plants Phosphate Fertilizer Industry Wet-Process Phosphoric Acid Plants... 

The main criteria in the selection of aluminum and its alloys for chemical plants are corrosion resistance, ease of fabrication and price. High-quality aluminum grades are used for chemical and process plant applications. 

This is used widely for chemical and process plant applications where its resistance to corrosion and high thermal conductivity are desirable characteristics. The strength of aluminum can be increased by cold working, as shown in Table 3.29. 

Of the approximately 15 aluminum forging plants, three use wet scrubbers to control particulates and smoke generated from the partial combustion of oil-based lubricants in the forging process. 

Heat treatment of aluminum products frequently involves the use of a water quench in order to achieve the desired metallic properties. Of the 266 aluminum forming plants, 84 use heat treatment processes that involve water quenching. The sampling data for classical and toxic pollutants from... 

FIGURE 22.3 General wastewater treatment process flow diagram at an aluminum fluoride plant. 

The molds in a RIM-process plant are located in a separate assembly, which has devices for opening and clamping a mold and, in some cases, for changing it. The pressure in the RIM-process is considerably lower than in traditional injection molding of thermoplastics thus, the requirements for the mold material are less rigid. Molds may be made from aluminum or reinforced plastics, since high-strength steel is not necessary. 

Scientists at PNNL have developed an automated radiochemical sample preparation-separation-detection system for the determination of total "Tc in nuclear-waste process streams.46 85 86 144145 This analyzer was designed to support a technetium removal process planned as part of the development of a nuclear-waste processing plant. The process stream composition is both complex and variable, with a high pH, high salt matrix. Depending on the source of the feed, the total base content, the concentration of organics, and complexant concentrations will vary, as will the aluminum, nitrate, nitrite, dichromate, and radionuclide composition. 

Castner, Hamilton Young — (Sep. 11, 1858, Brooklyn, New York, USA - Oct. 11,1899, Saranac Lake, New York, USA) Castner studied at the Brooklyn Polytechnic Institute and at the School of Mines of Columbia University. He started as an analytical chemist, however, later he devoted himself to the design and the improvement of industrial chemical processes. He worked on the production of charcoal, and it led him to investigate the Devilles aluminum process. He discovered an efficient way to produce sodium in 1886 which made also the production of aluminum much cheaper. He could make aluminum on a substantial industrial scale at the Oldbury plant of The Aluminium Company Limited founded in England. However, - Hall and - Heroult invented their electrochemical process which could manufacture aluminum at an even lower price, and the chemical process became obsolete. Castner also started to use electricity, which became available and cheap after the invention of the dynamo by - Siemens in 1866, and elaborated the - chlor-alkali electrolysis process by using a mercury cathode. Since Karl Kellner (1851-1905) also patented an almost identical procedure, the process became known as Castner-Kellner process. Cast-... 

Standards of Performance for Secondary Emissions From Basic Oxygen Process Steelmaking Facilities for Which Construction Is Commenced After January 20, 1983 Standards of Performance for Sewage Treatment Plants Standards of Performance for Primary Copper Smelters Standards of Performance for Primary Zinc Smelters Standards of Performance for Primary Lead Smelters Standards of Performance for Primary Aluminum Reduction Plants... 

Alumtnum phosphide, hke aluminum nitride, reacts with moisture but in this case the gaseous product is phosphine, PH3, a very toxic gas. For this reason, AlP is used as a fumigant to control insects in stored products such as raw agricultural products, animal feeds, processed foods (for example, flour and sugar), tobacco, wood, paper, leather, hair, and feathers. It is also used for control of rodents such as rats, mice, squirrels, and gophers in and around mills, food processing plants, warehouses and silos, and in rail cars, ships, and shipping containers. 

The material losses of alternate RDF processing plants depend mainly on the sophistication and plant. This should depend upon economics if it is economically justified to recover more combustibles, it should be done. There is a limit to the investment and operating costs which can be justified to recover the last Calorie. The same applies to recovering aluminum and glass. At this date fuel energy is the valuable product ferrous metals have low economic value, aluminum recovery... 

Romundstad, R, Haldorsen, T, and Ronneberg, A. (1999). Exposure to RAH and fluoride in aluminum reduction plants in Norway Historical estimation of exposure using process parameters and industrial hygiene measurements. Am J Ind Med 35, 164-174. 

A modification of the Redox process, the U-hexone process, was used at the Idaho Chemical Processing Plant of the U.S. AEC, to recover highly enriched uranium from U-A1 alloy fuel elements irradiated in the Materials Testing Reactor. The aluminum nitrate needed as salting agent was provided when the fuel was dissolved in nitric acid. The plutonium content of the fuel was too low to warrant recovery. Plutonium was made trivalent and inextractable before solvent extraction and thus routed to the aqueous high-level waste. 

The Idaho Chemical Processing Plant is a versatile, multipurpose facility used for recovering highly enriched uranium from a variety of fuels in naval propulsion, research, and test reactors. Materials processed [Al] include aluminum-alloyed, zirconium-alloyed, stainless steel-based, and graphite-based fuels. The West Valley plant, although designed primarily for low-enriched uranium fuel from power reactors, also processed plutonium-enriched and thorium-based fuels. It is the only U.S. plant to have reprocessed fuel from commercial nuclear power plants. 

Electrolytic dissolution in nitric acid has been used at the Savannah River [B22] and Idaho Qiemical Processing plants [AlO, All] to dissolve a wide variety of fuels and cladding materials, including uranium alloys, stainless steel, aluminum, zircaloy, and nichrome. The electrolytic dissolver developed by du Pont [B22], pictured in Fig. 10.4, uses niobium anodes and cathodes, with the former coated with 0.25 mm of platinum to prevent anodic corrosion. Metallic fuel to be dissolved is held in an alundum insulating frame supported by a niobium basket placed between anode and cathode and electrically insulated from them. Fuel surfaces facing the cathode undergo anodic dissolution in a reaction such as... 

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