Sinter plants

The Utah deposit is located in southwestern Utah near Cedar City. The iron ore deposits are of contact metamorphic origin. The cmde ore contains 35 to 65% iron, primarily in the form of magnetite and goethite. Mining is done by the open pit method. The cmde ore is cmshed, screened at —75 mm (—200 mesh size) and shipped as lump ore containing 54% iron. The ore is rescreened at the steel mill to produce lump ore (10—64 mm) for the blast furnace and sinter feed (0—10 mm) for the sinter plant. 

Opera.tlon, Because of the long residence time of the materials (8—10 h), the blast furnace process can exhibit considerable inertia, and control is usually appHed where the goal is maintaining smooth, stable input conditions. One of the most important aspects of blast furnace control is supply of consistent quaUty raw materials, which is why there is a strong emphasis on quaUty control at coke plants, peUeti2ing plants, and sinter plants (see Quality ASSURANCE/QUALITY control). 

Other Le d Smeltings Processes. Stricter regulations concerning lead emissions and ambient lead in ak levels (see Airpollution), and the necessity to reduce capital and operating costs have encouraged the development of alternative lead smelting processes to replace the sinter plant—blast furnace combination. 

W. Gericke, "The Establishment of a 500,000 tpa Sinter Plant at Samancor s Mamatwan Manganese Ore Mine," Proceedings of the 5th International Ferroalloys Congress (fnfacon). New Orleans, La., Apr. 1989. 

Permeability Bulk sohd permeability is important in the iron and steel industiy where gas-solid reactions occur in the sinter plant and blast furnace. It also strongly influences compac tion processes where entrapped gas can impede compaction, and solids-handling equipment where restricted gas flow can impede product flowabihty. The permeabihty of a granular bed is inferred from measured pressure drop under controlled gas-flow conditions. 

S 111 fi 1 r-reco ve ry p lants Carbon-black plants (furnace process) Primary lead smelters Fuel-conversion plants Sintering plants Secondary metal-production plants Chemical-process plants ... 

An electrostatic precipitator is used to remove more tar from coke oven gas. The tar is then sent to storage. Ammonia liquor is also separated from the tar decanter and sent to wastewater treatment after ammonia recovery. Coke oven gas is further cooled in a final cooler. Naphthalene is removed in a separator on the final cooler. Light oil is then removed from the coke oven gas and is fractionated to recover benzene, toluene, and xylene. Some facilities may include an onsite tar distillation unit. The Claus process is normally used to recover sulfur from coke oven gas. During the coke quenching, handling, and screening operation, coke breeze is produced. The breeze is either reused on site (e.g., in the sinter plant) or sold offsite as a by-product. 

Use dry SO, removal systems such as carbon absorption for sinter plants or lime spraying in flue gases. 

Recycle iron-rich materials such as iron ore fines, pollution control dust, and scale in a sinter plant. 

Emissions from sinter plants are generated from raw material handling, windbox exhaust, sinter discharge (associated sinter crushers and hot screens), and from the cooler and cold screen. The primary source of particulate emissions, mainly irons oxides, magnesium oxide, sulfur oxides, carbonaceous compounds, aliphatic hydrocarbons, and chlorides, are due to the windbox exhaust. Contaminants such as fluorides, ammonia, and arsenic may also be present. At the discharge end,... 

At some plants the blast furnace dust is recycled as feedstock to the sinter plant. At plants without sintering operations, blast furnace dust is sometimes mixed with other byproduct residues, briquetted, and recycled back to the blast furnace. In other plants, the dust is landfilled or stockpiled.1 Several techniques are available for removing the zinc and lead. The majority of blast furnace sludge is land disposed as solid waste or stockpiled. Because of the similarity between wastewater sludges generated by sinter plants and blast furnaces, these streams are commingled and cotreated.1 The blast furnace slag is cooled and processed to be reused for various applications such as onsite in-land reclamation and landfill construction. 

Wang, L., Lee, W., Tsai, P, Lee, W., and Chang-Chien, G., Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from stack flue gases of sinter plants, Chemosphere, 50(9), 1123-1129, 2003. 

Stationary sources Waste incineration Steel industry Recycling plants Energy production Municipal solid waste, clinical waste, hazardous waste, sewage sludge Steel mills, sintering plants, hot-strip mills Non-ferrous metals (melting, foundry Al, Cu, Ptx, Zn, Sn) Fossil fuel power plants, wood combustion, landfill gas... 

In a population of sinter plant workers, the risk of death from cancer of the lung or nose has not been shown to decrease even 30-40 years after the workers left the sinter plant (Muir et al. 1994). Although the workers left the sintering operation, many were still exposed to nickel compounds, in operations that have not been associated with cancer. The investigators note that persisting nickel deposits could act as carcinogenic agents. 

Chovil A, Sutherland RB, Halliday M. 1981. Respiratory cancer in a cohort of nickel sinter plant workers. Br J Ind Med 38 327-333. 

Muir DCF, Jadon N, Julian JA, et al. 1994. Cancer of the respiratory tract in nickel sinter plant workers effect of removal from sinter plant exposure. Occup Environ Med 51(1) 19-22. 

Off-gases (top gas) leave the top of the furnace through uptake pipes, reverse direction in the downcomer, and enter the dust catcher, in which condensed water and dust are separated from the gases. The wet dust is emptied into a rail car for transport to a sinter plant for recycle or to a landfill. 

Fig. 3 Percent homolog composition of tri- to octaCNs in source-related samples from the Great Lakes region for Halowaxes, Aroclors, and industrial fly ashes from a municipal solid waste incinerator (MSWI), a medical waste incinerator (Med Waste), a cement kiln, and an iron sintering plant [126,137,139]...

The sintering machine is a relatively small part of the equipment needed for a complex sintering plant. Auxiliary devices include conveying and storage equipment, mixing and proportioning equipment, fans, dust collectors, etc. 

Details of a number of ferrous sintering machines are found in Table 6.2. A typical modern machine may be 13 ft (4 m) wide by 200 ft (61 m) long with a capacity of 8000 t/day (7200 Mg/day). Included in Table 6.2 are particulars on a large Japanese sinter plant. Such large machines have grate surfaces 16.4 ft (5 m) wide by 394 ft (120 m) long and a production capacity of over 20,000 tons (18,000 Mg) of sinter per day. 

Bennett and Lopez [2] have summarized the factors affecting the operation of sinter plants. The capacity of a sintering strand is related directly to the rate at which the burning zone moves downward through the bed. This rate, which is of the order of 1 in. (2.5 cm) per minute, is controlled by the... 

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