Steel pickling operations

Parker Amchem. Rodine Acid Inhibitors for Industrial Cleaning and Steel Pickling Operations. Technical and marketing document. Parker Amchem, Inc. (Henkel), USA. 

Wet air pollution control (WAPC) devices are used to treat exhaust gases from stainless steel pickling operations, thereby generating wastewater, which are treated using the selective catalytic reduction (SCR) technology in which anhydrous ammonia is injected into the gas stream prior to a catalyst to reduce NO, to nitrogen and water. The most common types of catalysts are a metal oxide, a noble metal, or zeolite. 

In order to estimate emissions from pickling facilities, U.S. EPA developed 17 model plants to represent five types of pickling operations and one acid regeneration process.12 The model plants include one or more size variation for each process model. The model plants were developed from information obtained from a survey of steel pickling operations and control technologies. U.S. EPA estimated emission rates for model facilities. Using these emission rates and the production and hours of operation for the model pickling plants, emission factors were calculated. These appear in Table 28.12. 

Annual Emission Estimates from Steel Pickling Operations... 

Acid pickling. Steel products are immersed in heated acid solutions to remove surface scale during pickling operations. This generates wastewater from three sources ... 

California Steel Industries, Inc., located in Fontana, CA, reclaimed wastes to increase profits and address water use issues. The facility, a steel mill, is situated in an area that does not have a ready supply of process water. Also, the offsite recycling facility used to dispose of spent process pickle liquor was soon to become unavailable. As a result of these concerns, the company constructed an onsite recycling facility designed to recover ferrous chloride for resale and to reuse water and hydrogen chloride for use in steel processing operations. Environmental benefits include the recovery and resale of 20 to 25 t/d of ferrous chloride, 13,440 L/d of hydrogen chloride, and 49,200 L/d of water. In addition, corporate liability was minimized because spent liquor was no longer sent to a disposal facility. 

Flydrochloric acid regeneration. This process is used to treat the spent pickle liquor containing free hydrochloric acid, ferrous chloride, and water that is obtained from steel finishing operations. The liquor is concentrated by heating to remove some of the water, followed by thermal decomposition in a roaster at temperatures (925 to 1050°C) sufficient for complete evaporation of water and decomposition of ferrous chloride into iron oxide (ferric oxide, Fe203) and hydrogen chloride (HC1) gas.19 The iron oxide is separated for offsite recovery or... 

In a steel product manufacturing plant involving acid pickling operation, disposal of hazardous metal sludge is the most expensive engineering task, and treatment of pickling liquor and rinse water is the second most expensive engineering task. 

Uses. Production of chlorinated organic chemicals production of dyes and dye intermediates steel pickling oil well acidizing operations to dissolve subsurface dolomite or limestone formed during thermal decomposition ofPVC... 

Listed Waste K062 Spent pickle liquor generated by steel finishing operations of plants that produce iron or steel August 8, 1988... 

Constrained only by the ability to condition the solution to the guideline levels of conductance and contamination, the AQUATECH System is a versatile unit operation in a wide variety of industry areas. In addition to our commercial stainless steel pickling acid recovery plant and the specialty metals waste recycling described above, AQUATECH Systems has developed and patented numerous other process schemes including ... 

About 70% of all iron oxide pigments are produced synthetically. Copperas or ferrous sulfate heptahydrate (FeS04-7H20) is the primary source of iron. It is a byproduct of the sulfate process for the manufacture of titanium dioxide as well as a by-product of pickling operations in the steel industry. Other sources of iron include ferric sulfate, ferrous chloride, ferric chloride, and the iron oxide slurry from the production of aniline by nitrobenzene reduction. 

Table 21.13 reviews the (known) different plants installed worldwide with above membranes and the corresponding estimated membrane area. The first bipolar system was delivered in 1986 to Washington Steel in Pennsylvania for the recovery of hydrofluoric and nitric acids from stainless steel pickling liquor and the most recent one has been installed in China for the production of an organic acid. In the last few years, some of the plants in operation in the United States have been closed due mainly to overall plant shutdowns, product line changes, or other economical reasons. 

K062. . Spent pickle liquor from steel finishing operations Secondary Lead ... 

Note All solid stainless-steel grades include the base extra of 6 cents per pound for annealing and pickling. This is done to make the solid base price comparable to iltat of staiiilcss-clad steel since the annealing and pickling operations are included in. stainless-dad base prices. 

In practice, inhibitors are often defined according to their field of application. In aqueous environments, inhibitors for acid environments are typically used to minimize metal corrosion during pickling of steel, an operation that removes oxide scales by dissolution in an acid. In the petroleum industry, large quantities of inhibitors for acid environments are used to avoid corrosion of drilling equipment. Inhibitors for neutral environments are used above all for the protection of cooling-water circuits. Inhibitors not only reduce the rate of uniform corrosion, but they also serve to protect metals from localized corrosion and stress corrosion cracking [18]. 

Zirconium heat exchanger A new direction for pickling operations. Iron Steel Engineering, 52 55. 

HCl gas reacts with metal oxides to form chlorides, oxychlorides, and water. Therefore, all the steel equipment should be pickled to remove the oxide scales before it is put in service. Because oxidi2ing agents in the HCl gas such as oxygen or chlorine significantly affect the corrosion rate, it is essential that the operating temperature of the steel equipment be kept below the temperature (316°C) at which ferric chloride is vapori2ed from the metal surface. 

Treatment of Industrial Wastes. The alkaline nature and inexpensive price of lime make it ideal for treatment of acid waste Hquors (6), including waste pickle Hquids from steel plants, wastes from metal plating operations, eg, chrome and copper plating, acid wastes from chemical and explosives plants, and acid mine wastewaters. 

Sheet steel is normally prepared for application of enamel by a sequence of operations including thorough degreasing, acid pickling and neutralisation. A nickel dip stage is often included to deposit a thin, porous layer of nickel applied at about 1 g/m especially when conventional groundcoat is not used (see Section 13.7). 

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