Hot Dip Galvanizing Agent
Introduction to hot dip galvanizing agent technology
First, technical background
The common galvanizing processes in the industry include hot-dip galvanizing, electro-galvanizing, mechanical galvanizing, and thermal spraying (galvanizing). Among them, hot-dip galvanizing accounts for about 95% of the total galvanization, and hot-dip galvanizing is used for zinc. It accounts for 40% of zinc production worldwide, and about 30% of zinc production in China. Due to its mature technology and low cost, hot-dip galvanizing has become the most widely used anticorrosion technology for steel materials. The overall characteristics of the national batch hot-dip galvanizing industry are: large number, wide distribution and low concentration; affected by the transportation radius of bulk materials and logistics costs, generally provinces with industrial bases have hot-dip galvanized (dipped) zinc companies. Production run. The market size of the batch hot-dip galvanizing industry is huge, and the products after hot-dip galvanizing can be applied to hardware workpieces, power iron bridges, communication iron bridges, railways, highway protection, street light poles, marine workpieces, construction steel structure workpieces, substation auxiliary facilities, etc. field. At present, the areas with a high concentration of domestic hot-dip galvanizing plants are basically in the Yangtze River Delta Economic Belt, Tianjin-Jiangxi-Lu Bohai Bay Economic Belt, and the Pearl River Delta Economic Belt, and later in Sichuan, Hubei, Chongqing, and Northeast China in the Yangtze River Basin. With the development of the Belt and Road Initiative, new batches of hot-dip galvanizing plants have also begun in Inner Mongolia, Qinghai, Gansu, and Xinjiang. It is initially estimated that the annual processing capacity of batch hot-dip galvanizing plants exceeds 100 million tons, and the market output value reaches 100 billion yuan. The overall process technology level of the batch hot-dip galvanizing industry is relatively backward, the degree of automation is relatively low compared to the electrogalvanized market, the level of process control is uneven, the overall level of the industry is not high, and pollution is serious. As the government's environmental protection policy is tightened, the environmental protection pressure is increasing. In the process of batch hot dip galvanizing, the annual consumption of traditional zinc-ammonium plating solution is about 500,000 tons. Although the process has the characteristics of low cost, high stability and good plating effect, in recent years, with the hot dip galvanization industry, The implementation of clean production, the traditional zinc ammonium plating agent due to its production of a large amount of smoke, which has a negative impact on the environment, the water quality and air pollution caused by the ammonium chloride component of the plating agent to the surrounding environment can not be ignored The problem. This technology researches the ammonium-free flux and the ammonium-free flux plating process, and replaces the traditional zinc-ammonium flux with the ammonium-free flux to fundamentally achieve clean production in the hot-dip coating industry.
II. Technical Overview
1, Product Features
(1) The smoke is small and does not leak.
Using this technology product, the product is an ammonium-free formula, which can reduce more than 70% of the smoke in the galvanizing process, which can significantly improve the operating environment, reduce the emission of ammonium-containing exhaust gas, and there will be no missing plating in the production process.
(2) Does not burst the pot, the appearance quality of the product is high.
后 After the products processed by this technology are used, galvanized parts will not burst when they are lowered, and the surface quality of the plated products is high, and the surface smoothness and gloss are improved compared with ordinary products.
(3) Save zinc ingots.
The use of this technology product can save an average of 3-5 kg of zinc ingot resources per ton of plated parts, which can greatly reduce the cost of the galvanizing process and has obvious economic value.
(4) Self-purification characteristics.
技术 This technology product has self-purification characteristics, which can significantly prolong the service life of the plating solution, and the cleaning cycle of the plating solution can be at least doubled.
2, operation method
(1) Storage and transportation of plating aids: The plating aids are clear liquids, mainly water-solvent products, solutes are common chemical products, pH value is 3-4, flammable and explosive components are not included, and they can be transported by ordinary freight vehicles. General workshops should be stored away from light and protected from moisture.
(2) Application method of plating aid: If the original zinc-ammonium plating bath is changed to new products, one-third of the total amount needs to be replaced at one time, which can reflect the product effect; 10-15 tons of products (in small pieces) Calculate), add 35 kg of this product, and replenish the rest; if you use this product in a new tank, add 35 kg of this product every day after the configuration is completed, and the rest will be replenished for sustainable use.
(3) Operate the downstream process on site. If there are special requirements for the product, please inform the technical staff in time. Technical support can be dynamically deployed according to specific needs.
(4) If there are special fluctuations in the process or workpiece, please contact the technical staff in time to adjust the formula.
(1) If there is a little turbidity in the treatment solution, it can be used after stirring or shaking without affecting the use effect;
(2) When the material of the workpiece is different, the inconsistency in the color of the workpiece after the treatment liquid is normal;
(3) Human health matters: If the skin is contaminated with the treatment solution during use, rinse with water and dry it. When ingested, gargle with water, drink milk or egg white, do not lavage the stomach, do not induce vomiting;
4 (4) It is strictly forbidden to mix, transport and store with other inorganic substances, organic substances, oxidants and reducing agents;
5 (5) The process pipelines that are in contact with the product, such as containers, pipelines, and pumps, that contain this product must be determined.
Inspection and maintenance are carried out in the next period.
III. Relying Units
Technology relies on the Institute of Process Engineering of the Chinese Academy of Sciences, and has formed a specialized technical research team to form key core technologies. The Institute of Process Engineering of the Chinese Academy of Sciences focuses on energy chemical engineering, biochemical engineering, materials chemical engineering, and resource / environment engineering. The State Key Laboratory of Biochemical Engineering and the National Biochemical Engineering Technology Research Center (Beijing), the State Key Laboratory of Multiphase Complex Systems, the National Engineering Laboratory of Cleaner Production Technology for Hydrometallurgy, and the Key Laboratory of Green Process and Engineering of the Chinese Academy of Sciences Laboratory, Beijing Key Laboratory of Ionic Liquid Cleaning Process, and process engineering R & D center, biomass 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. The Institute currently has 4 academicians of the Chinese Academy of Sciences and 1 academician of the Chinese Academy of Engineering; 1 selected from the National Overseas High-level Talent Training Program (Thousand Talents Program), 5 young people; 12 National Outstanding Youth Science Fund winners, the National 6 winners of the Natural Science Foundation Outstanding Youth Science Fund. The relevant research team of the Institute of Process Engineering of the Chinese Academy of Sciences has used its own technical advantages to carry out concentrated technical research on galvanized sheet processing technology and formed a series of core technologies.
24. Benefit Accounting
Economic benefits, calculated by taking a single-pot small galvanizing enterprise (> 600 ℃ high-temperature galvanizing pot) as an example, with a processing capacity of 300 tons / month and a zinc consumption of 70 kg / ton. Zinc ingot savings are calculated based on 3 kg / ton, monthly zinc ingot savings can be saved
Source 900 kg, zinc ingot based on 24,000 yuan / ton, can save costs 21,600 yuan; based on 35 kg / 10 tons added amount, need to add about 1 ton per month, the price of 10,000 yuan / ton, per month The added cost is 10,000 yuan / month; assuming that the traditional plating agent addition cost is 0.5 million yuan / month (including the general addition cost of the explosion-proof agent is greater than this amount), the added cost is increased by 0.5 million yuan / month; then the comprehensive economic benefit is 2.16 -(1-0.5) = 11.6 thousand yuan. In addition, the product has the characteristics of low smoke, no leakage plating, no pot explosion, high product appearance quality, and self-purification of the plating solution, and the comprehensive advantages are particularly obvious. The larger the scale of the galvanizing production line, the greater the overall benefits. The application of new technologies can greatly alleviate the industry's urgent demand for technology due to environmental protection requirements upgrades, and can provide strong guarantees for reducing environmental pollution in production areas, improving the working environment of operating workers, increasing economic benefits for enterprises, and increasing local government taxes. . At present, this technology has been promoted and applied in more than 40 galvanized enterprises in Taigu County, Shanxi Province, and has produced significant economic and environmental benefits. Once the technology is applied in large-scale industrialization in the industry, it will solve common technical problems in the industry and drive the industry Technical progress has a strong impetus.