Galvanizing is one of the effective methods to prevent steel wire corrosion. There are generally two methods of galvanizing, one is galvanizing, the other is hot galvanizing. The disadvantage of hot galvanizing is that the strength loss is large. In the production process of small size steel wire rope, electro galvanizing is mostly used as the raw material for wire rope coating processing. The advantages of electro galvanizing are that the thickness of steel wire coating is uniform and dense, and the mechanical properties of steel wire before and after plating change little, which can also be adjusted according to the requirements; the disadvantage is that if the steel wire is not cleaned before plating, the adhesion between the coating and the steel wire substrate is poor, and dezincification is easy to occur. Therefore, the quality control of galvanized steel wire is very important. The production process of electro galvanizing is as follows: setting out → pickling → washing → galvanizing → cold washing → hot water washing → drying → winding up. Zinc sulfate was used for electroplating. The mass concentration of zinc sulfate was 400-600 g / L, and the pH value of electroplating solution was 2-4. In the process of electro galvanizing, the key factors affecting the quality of galvanizing are the cleanliness of steel wire pickling before electroplating, the concentration of electroplating solution, the control of pH value and the size of single wire current. The quality of pickling directly affects the bonding strength between the coating and the substrate, and the mass concentration of the plating solution directly determines the ion replenishment speed in the solution after ion migration, thus eliminating the phenomenon of concentration polarization. 1. Adjust electroplating process parameters. (1) Strictly control the pH value of the plating solution. The research shows that the pH value of the plating solution directly affects the quality of the steel wire coating. If the pH value is not controlled properly, the coating will be loose. When the pH value is greater than 3, the steel wire coating has burr caused by fine dendrite, and the surface is not smooth. (2) The current density should be strictly controlled. From the micro morphology, the higher the current density is, the larger the grain deposition of zinc layer is, and the less dense the corresponding zinc layer is. On the contrary, the denser the ion deposition, the better the quality of zinc layer. Under the condition that the surface zinc layer is compact and bright, the process parameters should be optimized as follows: current density is 16 ~ 20A / DM2, mass concentration of zinc sulfate solution is 500 g / L, pH value is 2.5 ~ 3.0. Second, adjust the water tank drawing process parameters. (1) The total compression ratio is 96.48% and the scraping of zinc layer is reduced. (2) The material of the whole drawing die is composed of tungsten steel die and polycrystalline die. The angle of working cone of drawing die is 12 ° to 16 ° and the length of sizing belt is 0.15 of steel wire diameter, so as to ensure the deformation of zinc layer and steel wire matrix are basically synchronized. (3) The cooling circulation system uses spray method to cool the drawing die, and take away a large amount of heat generated by the wire drawing machine in high-speed drawing, so as to ensure the quality of steel wire. (4) Control drawing process parameters: take-up speed 10-12 MGS; take-up tension 8-10n; fixed length 30km; lubricant mass fraction 3.5-4.5%; lubricant pH 7-8; lubricant temperature 30-40 ℃. After process optimization, the mass production of galvanized steel wire with diameter of 0.80 mm is controlled in 80-90 g / m2, and the quality difference of zinc layer is very small; the zinc layer detection is carried out on the subsequent steel wire for rope drawing in water tank, and the results show that the average zinc layer mass is 14.5 g / m2, the loss of zinc layer is less than 5%, and the tensile strength of steel wire is 2300-2500 MPa. It not only effectively controls the quality of zinc layer of raw steel wire for galvanizing rope, but also reduces unnecessary waste and production cost.

This kind of wastewater is generally strong acid water quality, the water quality is complex, the composition is not easy to control, which contains chromium, cadmium, nickel, copper, zinc, gold, silver and other heavy metal ions and cyanide, some of which are carcinogenic, teratogenic and mutagenic toxic substances. When these heavy metals enter the water body, they have a magnifying effect on the food chain and can accumulate in some organs of the human body, causing chronic poisoning and endangering human health. In the treatment of electroplating wastewater, because the wastewater contains many expensive heavy metals, if the heavy metals in the wastewater are recycled as a resource, it will not only solve the pollution of heavy metals, but also have certain economic benefits. At present, the commonly used methods of heavy metal wastewater treatment include chemical precipitation, reduction, adsorption, membrane separation, coagulation, ion exchange, electrochemical method and so on. It is found that the selection of polyacrylamide for the treatment of this kind of wastewater is directly related to the pH value of the wastewater. The best use method of polyacrylamide for electroplating wastewater and matters needing attention 1. The best model of polyacrylamide and the best dosage of the product were determined by small scale test. 2. The product is prepared into 0.1% (refers to solid content) of aqueous solution, and neutral water without salt is suitable. 3. When dissolving water, the product should be evenly sprinkled into the stirred water and heated properly (< 60 ℃) to form a solution. 4. Solid products are packed in polypropylene woven bags lined with plastic bags, 25kg each. 5. Solid products should not be scattered on the ground to prevent the ground from becoming slippery after absorbing moisture. 6. When preparing PAM aqueous solution, it should be carried out in enamel, galvanized, aluminum or plastic barrels, not in iron containers. 7. When dissolving, attention should be paid to adding the product evenly and slowly into the dissolver with stirring and heating measures. It should be avoided to solidify. The solution should be prepared at a suitable temperature. Excessive mechanical shear should be avoided for a long time. It is suggested that the agitator should be 60-200 rpm, otherwise it will lead to polymer degradation and affect the use effect. When the majority of electroplating wastewater is in strong acid condition, we generally choose cationic coagulant, coagulate in alkaline condition, and select anionic polyacrylamide with ultra high molecular weight as coagulant aid. What should be noted here is that due to the characteristics of electroplating wastewater itself, its pH value is relatively high. Before selecting reagents, it is better to select water samples for beaker test, and determine the type selection and dosage. Generally, 20-100 kg of product is needed for every thousand tons of electroplating wastewater to be treated. The dosage of Polyacrylamide in the treatment of electroplating wastewater is about 2-10 G. The amount of polyacrylamide used in electroplating wastewater should be determined by considering the turbidity of wastewater, molecular weight of polyacrylamide and impurities in water.

As the name implies, plastic electroplating begins with the analysis of the nature of plastic materials. For example, in the subject part of plastic electroplating processing, plastic itself can not conduct electricity, so the conductive treatment part of the electroplating process needs to be carried out first, that is, the activation and chemical plating of electroplating materials are required, After finishing this electroplating process, the later electroplating process is similar to the electroplating process of hardware metal material products. However, with the different product quality requirements of electroplating processing, there are different electroplating process details that need to be paid attention to. The problems in the process of using after electroplating are different Compared with the electroplating process of various metals and other metals, there is still a potential difference between the basic body of the material product and the coating. If the potential of the electroplating layer of the hardware product is positive, it will be the cathodic plating layer, which can only play a common protective role. If there are pores on the surface of the plating layer or the surface is damaged during the electroplating process, the potential difference between the basic body and the coating layer is still existed, If it is in the presence of electrolyte, the basic body of the product material is first corroded by chemical substances, such as the steel we often use to process copper plating; if the potential on the surface of the coating is negative, we call it anode electrodeposition, which not only has the ordinary protection function of organic machinery, but also has the basic electrochemical protection function, The electroplating layer is usually corroded first. If steel is used for galvanizing, Yongchang electroplating plant will first remove the zinc coating of the waste galvanized products, and the surface of the material workpiece is still intact, which is rarely corroded by weather factors or other reasons. This is the principle or reason Electroplating of metal products can be described by the following process flow: mounting → degreasing and washing → derusting and washing → activation and washing → electroplating → washing → drying → inspection → packaging. Among them, electroplating, common are: zinc plating, copper plating, nickel plating, gold plating, silver plating, tin plating, rhodium plating, palladium plating and alloy electroplating. It can be single-layer plating or multi-layer plating. Electroplating types: single metal plating (such as the above), alloy plating, composite plating, chemical plating. Vacuum coating and ion sputtering are also called electroplating by many people. Such as aluminum oxidation, blackening / bluing chemical polishing, electrochemical polishing, passivation, etc., are also classified as electroplating.