Brief introduction of the technology of the assistant plating agent for hot dip galvanizing
1、 Technical background
Hot dip galvanizing, electro galvanizing, mechanical galvanizing and thermal spraying (plating) galvanizing are commonly used in industry, among which hot dip galvanizing accounts for 95% of the total galvanizing, the amount of zinc used for hot dip galvanizing accounts for 40% of the zinc output in the world, and about 30% of the zinc output in China. Hot dip galvanizing has become the most widely used anticorrosion technology for steel materials due to its mature technology and low cost. The general characteristics of the national batch hot-dip galvanizing industry are: large quantity, wide distribution and low industrial concentration; affected by the transportation radius and logistics cost of bulk materials, there are generally hot-dip galvanizing (DIP) enterprises in production and operation in provinces with industrial basis. The market scale of batch hot-dip galvanizing industry is huge, and the products processed by hot-dip galvanizing can be applied in the fields of hardware workpiece, electric power tie-in, communication tie-in, railway, highway protection, street lamp pole, marine workpiece, building steel structure workpiece, substation auxiliary facilities, etc. At present, the areas with high concentration of hot galvanizing factories in China are basically located in the Yangtze River Delta economic belt, the Bohai Gulf economic belt, the Pearl River Delta economic belt, and then some parts of the Yangtze River Basin in Sichuan, Hubei, Chongqing and Northeast China. With the development of the whole area along the way, new hot galvanizing plants have been started in Inner Mongolia, Qinghai, Gansu and Xinjiang. It is preliminarily estimated that the annual processing capacity of the batch hot-dip galvanizing plant is more than 100 million tons, and the market output value reaches 100 billion yuan. The overall process technology level of batch hot-dip galvanizing industry is relatively backward, the automation level is relatively low compared with the galvanizing market, the process control level is uneven, the overall level of the industry is not high, and the pollution is serious. With the tightening of the government's environmental protection policy, the environmental protection pressure increases. In the process of batch hot-dip galvanizing, the annual consumption of traditional zinc ammonium plating aid is about 500000 tons. Although the process has the characteristics of low cost, high stability and good plating effect, with the implementation of clean production in hot-dip galvanizing industry in recent years, the traditional zinc ammonium plating aid produces a lot of smoke in the production process, which has a negative impact on the environment, and the composition of ammonium chloride in the plating aid gives the surrounding ring Water quality and air pollution caused by environment are always problems that cannot be ignored. Through the research of non ammonium assistant plating agent and non ammonium assistant plating process, the traditional zinc ammonium assistant plating agent is replaced by non ammonium assistant plating agent, and the clean production of hot dip galvanizing industry is fundamentally realized.
2、 Technology Overview
1. Product features
(1) Small smoke, no missing plating.
Using this technical product, the product is non ammonium formula, which can reduce more than 70% of the smoke in the galvanizing process, significantly improve the operating environment, reduce the emission of ammonium containing waste gas, and there will be no missing plating in the production process.
(2) No explosion, high quality product appearance.
After the treatment of the technical product, the hot pot will not burst when the galvanized parts are lowered into the pot, and the surface quality of the galvanized products is high, and the surface smoothness and glossiness are improved compared with the ordinary products.
(3) Save zinc ingot.
By using this technology, 3-5kg zinc ingot resources can be saved per ton of plating parts, and the cost of galvanizing process can be greatly reduced.
(4) Self purification characteristics.
The technical product has the self purification feature, can significantly extend the service life of the plating aid solution, and the cleaning cycle of the plating aid solution can be extended at least by one time.
2. Operation method
(1) Storage and transportation of plating AIDS: the plating aids are clear liquid, mainly water solvent products, and the solute is ordinary chemical products, with pH value of 3-4, excluding flammable and explosive components. They can be transported by ordinary freight vehicles, and stored in ordinary workshops away from light and moisture.
(2) Usage of plating AIDS: if the original zinc ammonium plating bath is changed to a new product, one-third of the total amount needs to be replaced at one time, which can reflect the product effect; for each 10-15 tons of plating product (calculated by small pieces), add 35 kg of this product, and the rest make up water; if the new bath uses this product, add 35 kg of this product every day after configuration as required, and the rest make up water for sustainable use.
(3) If there are special requirements for the products in the downstream process of the operation site, please inform the technical personnel in time. The technical support can be dynamically deployed according to the specific needs.
(4) If there is special fluctuation in the process or workpiece, please contact the technical personnel in time to adjust the formula.
(1) If there is a little turbidity in the treatment solution, it can be stirred or shaken to continue to use, without affecting the use effect;
(2) It is a normal phenomenon that the color of workpieces is not the same after the treatment of treatment fluid due to the different material of workpieces;
(3) Human health matters: if the skin is stained with the treatment solution during the use, wash it with clear water, and then dry it. When eating by mistake, rinse mouth with water, drink milk or egg white, do not wash stomach, do not induce vomiting;
(4) It is strictly prohibited to mix with other inorganic, organic, oxidant and reducing agent for loading, transportation and storage;
3、 Supporting unit
The technology relies on the Institute of process engineering, Chinese Academy of Sciences, to establish a special technology research team and form a key core technology. Process Engineering Research Institute of Chinese Academy of Sciences focuses on energy chemical industry, biochemical engineering, material chemical industry, resource / environmental engineering and other fields. The existing State Key Laboratory of biochemical engineering and national Biochemical Engineering Technology Research Center (Beijing), State Key Laboratory of multiphase complex system, State Engineering Laboratory of hydrometallurgy clean production technology, Key Laboratory of green process and engineering of Chinese Academy of Sciences, Beijing Key Laboratory of ionic liquid clean process, process engineering research and Development Center, biomass research and Development Center Research Center, circular economy technology research center, process pollution control environmental engineering research center, solar energy research center, process engineering Zhongguancun open laboratory and other scientific research institutions. At present, the Institute has 4 academicians of the Chinese Academy of Sciences and 1 academician of the Chinese Academy of engineering; 1 candidate of the national overseas high-level talent training program (Thousand Talents Program), 5 young people; 12 winners of the National Science Fund for Distinguished Young Scholars, and 6 winners of the National Science Fund for outstanding young scientists. The relevant research team of the Institute of process engineering of the Chinese Academy of Sciences has made use of its own technical advantages to carry out centralized technical research on the processing technology of galvanized sheet, forming a series of core technologies.
4、 Benefit accounting
The economic benefit is only calculated by a single pot small-scale galvanizing enterprise (> 600 ℃ high temperature galvanizing pot), with a processing capacity of 300 tons / month and zinc consumption of 70 kg / ton. The zinc ingot saving amount is calculated as 3kg / T, which can save 900kg of zinc ingot resources every month, and the zinc ingot saving amount is calculated as 24000 yuan / T, which can save 21600 yuan of cost; according to the 35 kg / 10 ton adding amount, about 1 ton of plating aid needs to be added every month, with the price of 10000 yuan / T, and the adding cost is 10000 yuan / month; Assuming that the cost of adding traditional plating aid is 5000 yuan / month (including the cost of adding explosion-proof agent which is generally larger than this amount), and the cost of adding is 5000 yuan / month, the comprehensive economic benefit is 2.16 - (1-0.5) = 16600 yuan. In addition, the product also has the characteristics of small smoke, no leakage of plating, no explosion of the pot, high product appearance quality and self purification of the plating solution, and the comprehensive advantages are particularly obvious. The larger the scale of galvanizing production line, the more considerable the overall benefit. The application of new technology can greatly alleviate the urgent technical needs of related enterprises due to the upgrading of environmental protection requirements, and provide strong protection for reducing environmental pollution in production areas, improving the working environment of operators, improving the economic benefits of enterprises, and increasing local government taxes. At present, the technology has been popularized and applied in more than 40 galvanizing enterprises in Taigu County, Shanxi Province, which has produced remarkable economic and environmental benefits. Once the technology is applied in large-scale industrialization in the industry, it will play a strong role in solving common technical problems in the industry and driving the technical progress of the industry.
(5) The vessels, pipelines, feeding pumps and other process pipelines containing the product which are in frequent contact with the product shall be inspected and maintained regularly.