A pickling production line comprises a material-holding apparatus, a pickling zone, and a water wash zone; the pickling zone and the water wash zone are independently arranged; the material-holding apparatus is filled with magnesium alloy waste, and self-rotates successively in the pickling zone and the water wash zone for pickling and water washing respectively. In the pickling production line for magnesium alloy waste material, the magnesium alloy waste material is pickled and washed more thoroughly; coatings and impurities on the surface of the magnesium alloy waste material are removed, the efficiency of the cleaning and the consistency of the cleaning are high, and each piece of equipment in the entire production line is connected in a compact manner; the invention has a high degree of automation, low environmental pollution, conserves resources, is highly efficient in production, and is suitable for the bulk pickling and cleaning of magnesium alloy waste material.

The present disclosure relates to a workpiece cleaning device and a cleaning method. The workpiece cleaning device comprises: a frame (1); and a plurality of cleaning tanks disposed on the frame (1) side by side, comprising a molten salt cleaning tank (2) for cleaning a workpiece with molten salt, a first rinsing tank (5) for rinsing the workpiece cleaned with the molten salt, a de-rusting cleaning tank (6) for cleaning the workpiece rinsed in the first rinsing tank (5) with a de-rusting agent, a second rinsing tank (7) for rinsing the workpiece cleaned with the de-rusting agent, and an anti-rust cleaning tank (8) for cleaning the workpiece rinsed in the second rinsing tank (7) with anti-rust liquid, which are sequentially disposed from upstream to downstream in terms of procedure.

The present disclosure relates to a workpiece cleaning device and a cleaning method. The workpiece cleaning device comprises: a frame (1); and a plurality of cleaning tanks disposed on the frame (1) side by side, comprising a molten salt cleaning tank (2) for cleaning a workpiece with molten salt, a first rinsing tank (5) for rinsing the workpiece cleaned with the molten salt, a de-rusting cleaning tank (6) for cleaning the workpiece rinsed in the first rinsing tank (5) with a de-rusting agent, a second rinsing tank (7) for rinsing the workpiece cleaned with the de-rusting agent, and an anti-rust cleaning tank (8) for cleaning the workpiece rinsed in the second rinsing tank (7) with anti-rust liquid, which are sequentially disposed from upstream to downstream in terms of procedure.

A process for chemical cleaning and corrosion inhibition of pipework, typically in closed loop systems, that avoids or significantly minimises the requirement for wastewater discharge where the system is first acidified using a mixture of cleaning agents capable of dissolving metal oxides. The method then precipitates any dissolved contaminants and separates the precipitate from the carrying fluid. Further elements of a combined corrosion inhibitor package are then added to any cleaning agent ions that remain in solution to develop a fully functional corrosion inhibition package to protect the metals of the system.

A process for chemical cleaning and corrosion inhibition of pipework, typically in closed loop systems, that avoids or significantly minimises the requirement for wastewater discharge where the system is first acidified using a mixture of cleaning agents capable of dissolving metal oxides. The method then precipitates any dissolved contaminants and separates the precipitate from the carrying fluid. Further elements of a combined corrosion inhibitor package are then added to any cleaning agent ions that remain in solution to develop a fully functional corrosion inhibition package to protect the metals of the system.

A pickling process of a metallic strip is provided including the steps of: passing said metallic strip through at least a pickling bath being at a temperature between 1 and 100° C., applying an alternating current, having a current density of 1x10.sup.2 to 1x10.sup.5 A.m.sup.−2 of unit surface of said metallic strip to said metallic strip passing through said at least one pickling bath.

The present invention relates to a method of purifying waste hydrochloric acid, and more particularly, to a method of purifying waste hydrochloric acid which includes preparing an extraction solution by dissolving an extractant in an organic solvent (S1), extracting metallic components with the organic solvent by adding the extraction solution to the waste hydrochloric acid (S2), separating a waste hydrochloric acid layer and the organic solvent containing the metallic components (S3), and obtaining purified hydrochloric acid by recovering the separated (fractionated) waste hydrochloric acid layer (S4), wherein the extractant is used in an amount of 40 moles or more based on 1 mole of iron (Fe) included in the waste hydrochloric acid, and the waste hydrochloric acid and the extraction solution are mixed in a volume ratio of 1:0.1 to 1:1.

There is provided a method for manufacturing a bottomed cylindrical body, the method being capable of achieving both a conventional hard can manufacturing process such as drawing and ironing and reduction in the cost and the environmental load in a degreasing step. The method for manufacturing a bottomed cylindrical body includes a lubricant application step of applying liquid (lubricant) having a viscosity of lower than 200 mPa.Math.s to a surface of a metal plate, a drawing step of drawing the metal plate to which. the lubricant has been applied, with use of a forming member having a processing surface having a hardness of Hv 1000 to 12000, an ironing step of ironing, with use of another forming member having a processing surface having a hardness of Hv 1500 to 12000, a workpiece with a coolant interposed between the workpiece and the another forming member, to form a bottomed cylindrical body, and a degreasing step of degreasing oil on a surface of the bottomed cylindrical body with use of a cleaning agent. The concentration of oil contained in the coolant is lower than 4.0 percent by volume. The cleaning agent contains any one of sulfuric acid, hydrofluoric acid, potassium carbonate, sodium hydroxide, and potassium hydroxide. The temperature of the cleaning agent in the degreasing step is lower than 75° C.

A novel process for treating pickling acid residue and recovering sulfates and nickel therefrom has been developed. By lowering the pH of a magnesium compound slurry to 4-5.5 with sulfuric acid containing pickling acid residue in the presence of ammonium sulfate, both magnesium sulfate and nickel sulfate are solubilized. Magnesium sulfate and nickel sulfate solution is separated from the solids by filtration and an iron hydroxide and chromium hydroxide residue is obtained as a precipitate. Magnesium sulfate and nickel sulfate are then separated from the solution.

The present invention relates to a method for the serial surface treatment of metal components that have zinc surfaces, wherein the method comprises an alkaline pretreatment, and a method for the selective removal of zinc ions from an alkaline bath solution for the serial surface treatment of metal surfaces that have zinc surfaces. According to the invention, in order to perform each method, part of the alkaline aqueous bath solution is brought in contact with an ion exchange resin that bears functional groups selected from —OPO.sub.3X.sub.2/n and/or —PO.sub.3X.sub.2/n, wherein X is either a hydrogen atom or an alkali metal and/or alkaline-earth metal atom to be exchanged having the particular valency n.