Abstract: A process and apparatus are provided for producing an electrolytically coated, hot-rolled steel strip without any intervening strips. The apparatus includes a chemical pickling section being combined in one line with an electrolytic coating section containing electrolytic cells so that the pickled steel strip is fed directly to the electrolytic coating section without any intermediate steps. The spent electrolyte solution from the electrocoating section to the pickling section to pickle the steel. The spent pickling acid can also be used to generate the electrolyte solution that is fed to the electrocoating section.

Abstract: In order to reduce pollutants in the waste gas of regeneration plants for spent hydrochloric acid from pickling plants a process is provided, comprising the thermal decomposition of iron chloride in the spent pickling acid to iron oxide and gaseous hydrochloric acid, wherein to the spent pickling acid at least one compound is admixed which contains nitrogen having a low oxidation number, for example ammonium compounds, ammonia, urea or amides.

Abstract: A system and method is provided for electrolytic pickling a metal strip, where the electric current is conducted through the strip indirectly without electrically conductive contact between the strip and the electrodes. The strip is run vertically or substantially vertically through the process, and the electrolyte liquid is fed in between the strip and the electrodes.

Abstract: In a process for post-treatment of pickled steel products by rinsing with water in continuous rinsing plants, inert gas or rare gas is blown into at least one of the rinsing sections (1,2,3 or 4) of the rinsing plant. This prevents the formation of hydrolysis stains on the surface of the steel products in case of the strip standing still. The device for carrying out the process consists of several rinsing sectors 1, 2, 3, 4, with at least one feed opening 8 for liquid medium, with at least one of the rinsing sections 1,2,3 or 4 being provided with at least one feed opening 19, 20 for blowing in gases.

Abstract: A process for continuous surface treatment, in particular for pickling and cleaning of metal strip in a treatment chamber through which the strip runs in a roughly horizontal path and to which a treatment liquid, in particular pickling liquid, is fed. An increased local shearing force is applied between the surface to be treated and the treatment liquid, by passing the strip through a constriction. In addition the invention is directed to a device for implementation of the process, characterized by, in particular, several processing stations such as venturi modules being provided in the treatment chamber which cause an increase in the shearing force between the strip and the treatment liquid.

Abstract: During the pickling, etching, chemical shaping etc. of steels, stainless steels, special alloys and special metals and the dissolution of those metals, metalliferous solutions of the acids employed arise in the course of such processes which must either be disposed of by neutralization or be used for the recovery of the acids and metals by expensive processes. According to the invention the production or recovery of nitric acid or a mixture of nitric acid and hydrofluoric acid takes place by spray-roasting the solutions at temperatures of 200.degree. to 500.degree. in a reactor (1) and subsequent absorptions or condensation of the gases generated in column means (7, 8) at temperatures of 0.degree. to 70.degree. C.