Pickling bath

In the pickling process, use countercurrent flow of rinse water use indirect methods for heating and pickling baths. 

Reduce nitrogen oxide emissions by use of natural gas as fuel, use low-NO, burners, and use hydrogen peroxide and urea in stainless steel pickling baths. 

Beiz-artikel, m. (Calico) mordant style, -bad, n. mordant bath, pickling bath, etc. (see Beize), behandlung, /. mordanting, pickling, etc. (see beizen). -briichigkeit, /. (Metal.) acid brittleness, -brtihe,/. (Leather) bate, drench, -biitte,/. (Leather) drench pit, bate tub. -charakter, m. (Dyeing) mordant character. 

Pickel, m. pimple pickax, pick pickle, brine (see also Pokel). -bad, n. pickle bath, pickle, -bildimg, /. (Metal.) pitting, -bruhe, /. pickle. 

The regeneration and copper recovery system for the primary pickle bath... 

Block B shows the electrolytic copper recovery cell, which recovers metallic copper and regenerates sulfuric acid from the metal salts in the hot sulfuric acid pickle solution. It was originally felt that trace metals (zinc, tin, lead) would interfere with the recovery of pure copper. By controlling current density at 50 to 100 A/m 1 2 3, however, pure copper can be recovered while maintaining the copper concentration in the pickle bath at 15 g/L. 

Spent pickle liquor in the acid pickling wastewaters is listed as hazardous waste K062, regulated under RCRA, as it contains considerable residual acidity and high concentrations of dissolved iron salts.2 Exhausted pickling baths are mainly composed of nitrate (150 to 180 g/L), fluoride (60 to 80 g/L), iron (III) (30 to 45 g/L), chromium (III) (5 to 10 g/L), and nickel (II) (3 to 5 g/L). 

Maranon, E., Fernandez, Y., Suarez, F.J., Alonso, F.J., and Sastre, H. Treatment of acid pickling baths by means of anoinic resins. Industrial Engineering Chem. Res. 39(9), 3370-3376. (2000). 

Nitric Acids from Stainless Steel Pickling Baths... 

Stripping HNO3 and HF from the organie solution with water in a second pulsed column operation and recyeling the aeids back to the pickling bath... 

Similar extraction procedures [17] using a mixture of trialkylphos-phine oxides (CYANEX 923) for extraction of the mineral acids from electroplating and stainless steel pickling baths are reported as the ARSEP procedure. 

Fig. 14.10 Recovery of acids from stainless steel pickling baths.

CZE-ELD, with a Au microelectrode at —0.6 V vs. SSCE and a Pt wire as auxiliary electrode, using sodium borate buffer and dodecyltrimethylanunonium bromide for dynamic coating of the capillary internal surface, can be applied for separation and determination of ultra-trace amounts of many oxidizing substances. Thus, the concentration of peroxodisulfate (S208 ) and peroxomonosulfate (S05 ) ions in pickling baths can be monitored by this method. The faster emergence of the heavier peroxodisulfate ion is attributed to different adsorption of the two analyte ions by the capillary coating . ... 

H. Matschiner and W. Thiele, Proc. BMBF Conf. Recycling of Pickling Baths, UTECH, Berhn, 1998,... 

Pickling baths Stirrer vessels Filter vessels Slurry tanks Ion exchangers Pipe spools. 

Lining for Acid pickling baths and electroplating baths ... 

Bipolar membrane synthesis also holds promise for regenerating spent pickling liquors in stainless steel manufacture. As shown in Fig. 43(b), waste acid laden with metal ions can be continuously neutralized, filtered to remove the precipitated metal oxide, and the clarified salt solution split into its acid and base components in a bipolar membrane unit [Type (IV) shown in Table IX], As much as 95% of the hydrofluoric and nitric acid used are returned to the pickling bath, thereby solving a waste... 

FIGURE 43 Bipolar membrane processes for (a) S02 removal from stack gases and (b) stainless steel pickling bath waste acid regeneration. 

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