Pickle Tanks

Acid fumes, being heavy, will vaporize over the tanks. They must be vented quickly to the atmosphere through an exhaust on the pickling tank otherwise the completed phosphate surfaces may be adversely affected. Apparently, the surfaces may not show rusting immediately, but may develop it while the equipment is in operation. 

Fume scrubber water recycle. The steel finishing industry uses fume scrubbers to capture acid gases from pickling tanks. Scrubber water, which may contain a dilute caustic solution, is neutralized and recirculated continuously to adsorb the acid. Makeup water is added to replace water lost through evaporation and water that is blown down to end-of-pipe metals treatment. 

Treatment of Wastewater from Acid Pickling Tanks in a Galvanized Pipe... 

Acid Pickling Tanks Using Hydrochloric Acid. 1202... 

In the case of batch pickling, the product is dipped into a pickling tank and then rinsed in a series of tanks. The quantity of wastewater discharged from a batch process is less than that from continuous operation. The wastewater is usually treated by neutralization and sedimentation. 

TREATMENT OF WASTEWATER FROM ACID PICKLING TANKS IN A GALVANIZED PIPE MANUFACTURING FACTORY USING SULFURIC ACID... 

MANAGEMENT AND TREATMENT OF WASTEWATER AND AIR EMISSIONS FROM ACID PICKLING TANKS USING HYDROCHLORIC ACID... 

The above equation constitutes the theoretical or stoichiometric amount of liquid hydrochloric acid needed to pickle 1 ton of steel. Stoichiometric means as per chemical formula, using absolutely pure materials with no losses.16 In practice, it is not possible to use up all the acid in the pickle tank if pickling is to be complete in any acceptable time. Depending on the pickling equipment, between 70% and 80% of the free acid will be used up in dissolving the scale, and 20-30% will remain as free acid in the spent pickle liquor.16... 

Sulfur Mortars Hot melt-and-pour sulfur mortars are ancient, doubtless one of the oldest of all chemical resistant materials still used today. They are very resistant to non-oxidizing acids and weak alkalies below 200°F over a pH range of 0-12. Three types of sulfur mortars are typically employed (1) One containing an all-silica filler with minimum plasticizer, used to bond acid brick (2) A mortar with an all-carbon filler and minimum plasticizer, used primarily to lay carbon brick for nitric-hydrofluoric acid pickling tanks (to clean stainless steels) and the underlying floors and (3) A much more flexible all-silica filled product with double the amount of plasticizer of the other two mortars, used to join vitrified clay (terra cotta) pipe conveying waste acids and other effluent chemicals, and to assemble "pole line hardware" for the power industry. 

Sheppard, W.L., Jr., Materials of Construction of Pickling Tanks, Blast Furnace and... 

Figure 5-6 Detail of a wood bumper inside a brick lining in a pickling tank. Note that with this design, all hardware is kept out of the tank to prevent any chemical attack. Courtesy of the Pennwalt Corp.

Hot asphalt applications had been used for many years in concrete tanks, inner lined with brick for similar service, and also, of course, unlined wood tanks made from timber, and small pickling tanks made by hollowing out cavities in granite blocks. But the use of hot asphalt as a liner for steel tanks had been unsatisfactory due to the erratic cold flow of the asphalt which demonstrated selective adhesion to steel and so would tear and open cracks in the membrane system in the areas of cold flow below the points where it adhered. To overcome this difficulty, a number of inventive persons experimented with the manufacture of asphalt sheet lining materials, similar in form to the sheets of natural rubber, in which the asphalt was compounded with various admixtures, including rubber. These asphaltic compound sheets were then warmed sufficiently to make... 

When the asphalt membrane is to be used in an exposure involving acid fluorides (such as a nitric-hydrofluoric pickling solution in a pickling tank for stainless steel), the designer should specify that the polyester fabric given above be used for reinforcing rather than the above glass cloth. 

Pickle tanks can be continuous or batch processes that use sulfuric or other acids at elevated temperatures to condition and clean basic metals products. Conventionally pickle tanks are lined with two or more courses of acid-resistant brick set in a suitable acid-resistant mortar over a rubber membrane. More than one course of brickwork is usually needed to reduce the temperature to the desired level at the hot face of the membrane and to provide stability. 

The insulating power and chemical resistance of the glass block allows for a thinner lining and better membrane protection for pickle tanks where stability is not a concern. The tank is first lined with the rubber membrane, the block is bonded over that with its urethane asphalt adhesive/membrane and finally a course of acid-resistant brick laid in acid-resistant mortar is placed over the block for mechanical protection. 

As an internal insulation in a process vessel, reducing the surface temperatures on the membrane to an acceptable level. Examples (1) Steel pickling tank in a steel mill, lined with rubber sheet. Top service temperature of the rubber 160°F, but bath temperature 210°F. The brick lining provides sufficient insulation to get the surface temperature of the rubber sheet down to 140°F. (2) The same system to protect the membrane in process vessels or (3) to prevent live steam from cutting out the asphalt membrane on a floor. 

Use Plating barrels, rayon-manufacturing equipment, pickling tanks, electrical and thermal insulation, oil-handling equipment, steel rolling-mill bearings, chemical-handling valve bodies, paper-mill suction box covers and equipment. 

A. Self-supporting Tube Pickling Tank (Figure 1)... 

B. Insert for Existing Carbon Steel Tube Pickling Tank... 

Figure I. Self-supporting-tube pickling tank.

Figure 2. Insert for carbon-steel-tube pickling tank.

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