After comprehensive evaluation, for those scrap metals that do not contain activated products (such as Co.Mn.Ni, ag, etc.) or less, it is advisable to use chemical decontamination, decontamination, disassembly, and reduction of scrap metal size. The technical route of decommissioning scrap metal treatment consisting of one or two steps of waste, conditioning, temporary storage and disposal is more reasonable. The choice of decontamination technology is critical when dealing with radioactively contaminated scrap metal. Factors affecting the selection of radioactive waste metal decontamination technologies may include: pollution nuclide, pollution level; type and geometry of radioactively contaminated scrap metal; national current standards (cleaning and decontamination levels, radioactive waste classification, personal dose limits, etc.); Waste management costs; the country's economic affordability in decommissioning waste management and the technical and economic comparison of different decontamination technologies. After a brief technical and economic assessment of the existing decontamination technology, according to the actual situation in China, it is possible to obtain a reasonable technical route for decommissioning scrap metal treatment by reasonably combining the decontamination technologies. Radioactive Scrap Metal Treatment Technology At present, the radioactive contaminated scrap metal decontamination technologies that have been developed in China include: preliminary chemical methods, deep decontamination techniques; preliminary mechanical methods, deep decontamination techniques; and deep decontamination techniques for smelting methods. In evaluating the advantages and disadvantages of these decontamination technologies, the main focus is on the following aspects: safety and environmental safety of existing decontamination technologies: decontamination efficiency; maturity of existing technologies and related operating costs; scrap metal resources Recyclable or restricted use possibilities; full waste management costs; adaptability and effectiveness of prior art to various types of scrap metal; from a variety of facilities to be decommissioned : Stainless steel, carbon steel, nickel and nickel based alloys, copper and copper based alloys, aluminum and aluminum based alloys. Due to the complexity of the various facilities and the differences in tasks, the geometry of scrap metal varies widely.
1. Chemical method preliminary deep decontamination technology Generally speaking, the preliminary decontamination technology is used for the disassembly of metal equipment before it is used, the role of which is to reduce the radioactive materials in the equipment as much as possible, so as to reduce the occupational exposure dose of the decommissioning workers, and Demolition creates conditions. Decontamination is often used for decontamination of metal equipment after disintegration. Its role is to achieve as low a level of cleansing and decontamination as possible. There are many kinds of preliminary decontamination techniques and deep decontamination technologies in foreign chemical methods. The most important ones are inorganic (organic) acid, antimony, redox, complexation and dissolution. The most commonly used reagents are nitric acid, hydrochloric acid, tranexamic acid (salt), oxalic acid (salt), tartaric acid (salt), formic acid, sodium hydroxide, potassium permanganate, low-valent vanadium salt, hydrogen peroxide, and high-priced persimmon. Salt, sodium carbonate, carbonic acid, sodium diacetate sodium salt, and the like. In general, chemical decontamination or deep decontamination techniques have matured and have been used industrially. China has accumulated rich experience in the initial decontamination technology, but in the chemical depth decontamination technology, it is still in the laboratory stage and has not been verified by industrial applications. The application of chemical preliminary and deep decontamination techniques is not very complicated and relatively effective. Surface decontamination of different classes of metals can be achieved by selecting different detergent formulations. After the metal device is disintegrated, deep decontamination can be performed, and in general, the predetermined decontamination target can be achieved. However, the preliminary and deep decontamination techniques of chemical methods cannot solve the removal of body pollution, and the decontamination effect is not ideal for objects with complex geometric shapes. In addition, this decontamination technique does not remove radioactive material from metal gaps, which are a common phenomenon. Chemical method The preliminary deep surface decontamination technology requires the use of various chemical reagents. During the process, smoke may be generated. Due to the strong corrosiveness and toxicity of some of the chemical agents, the workers are relatively unsafe, and the wastewater is relatively unsafe. The emissions are also potentially harmful to the environment. Chemical decontamination has a high probability of causing pollution, especially when it is necessary to limit the amount of secondary waste generated, or when using cyclic decontamination, it is more likely to be contaminated. When performing chemical surface decontamination, considerable operating cost support is required due to the use of various chemical reagents and corresponding specialized equipment and power. However, such operating costs are generally acceptable. However, since chemical surface decontamination produces a large amount of secondary waste liquid, their processing, conditioning, temporary storage and disposal costs may be much higher than the decontamination itself. After the initial decontamination of chemical methods, in general, metal objects do not reach the level of cleaning and control or the level of restricted use control. When the metal equipment is dismantled, deep chemical decontamination may result in low residual pollution of most metals. At the level of cleaning and control or the level of restricted use control. However, due to the presence of gaps or deep pollution, a considerable portion of scrap metal has to be treated as radioactive waste. Due to these shortcomings in the chemical deep decontamination method, the application of the chemical decontamination technology is often limited.
2. Mechanical method preliminary, deep decontamination technology Mechanical decontamination technology is often used for decontamination of the outer surface of metal equipment or the inner surface of equipment after disintegration. Some mechanical decontaminations are preliminary decontamination techniques, while others are deep decontamination techniques. Mechanical decontamination technology has been widely used in decommissioning projects abroad and has gained a wealth of experience. In addition to high pressure water, arc planing and simple mechanical polishing decontamination technology, mechanical decontamination technology has not been widely used in engineering implementation. Some mechanical decontamination techniques (such as ultra-high pressure water jet, abrasive jet) can effectively reduce the scrap metal, and in some specific cases, reduce the level of residual radioactive contamination on the metal surface to a level of clean-up or Restricted use level. However, the decontamination technology is ineffective for body-contaminated scrap metal, and it is difficult to achieve effective decontamination of metal objects having complex geometries. In addition, these decontamination techniques are limited to the initial decontamination of the decontamination of the scrap metal parts after disassembly or the relatively large space and the external irradiation dose is not too high. For the initial decontamination of online equipment and pipelines, the appropriate decontamination technology may only be high temperature and high pressure water circulation decontamination or high temperature and high pressure Yanqi decontamination technology. Due to the large amount of soot and mist generated during the use of this type of decontamination technology, the air quality in the working environment deteriorates, and corresponding measures must be taken to protect the health and environmental safety of workers. In addition, industrial safety is also a potentially serious problem due to the application of high pressure water or air. The application of these decontamination techniques has the potential for cross-contamination, but is relatively light compared to chemical decontamination techniques. The application of mechanical decontamination technology needs to be equipped with special and corresponding auxiliary systems. Some technologies also require special facilities. Therefore, equipment investment may be higher than chemical decontamination. Due to the diversity of mechanical decontamination technologies, secondary waste generated by some decontamination technologies is easy to handle, and some decontamination technologies will produce a large amount of secondary waste liquid. The storage, treatment, conditioning, temporary storage, disposal, etc. of these waste liquids Subsequent waste management costs are also considerable.
As one of the world's largest producers of Pvc floor mats, China can offer competitive prices. Under the scale of our productivity, the labor cost is relatively low, which makes the price of China's Non Slip Floor Mats in the international market has the advantage of being low, which fully meets the demand for economic products in the European and American markets, and our supply chain production capacity can meet large orders and complete a stable and continuous supply, which ensures that the market needs are met.
PVC Floor Mats,Pvc Mats Online,Custom Plastic Floor,Industrial Non Slip Rubber Matting,Kitchen Mats
Jiangyin Yining E-Commerce Co., Ltd , https://www.jspvcmatyining.com