Development of steel drum environmental protection technology

The quality of environmental protection steel drums produced by steel drums and environmental protection The most serious quality problem of steel drums is leakage. This has caused the attention of many barreling experts, but it has not yet been completely resolved. The content of steel drums is varied, including food, petroleum products, chemical raw materials, and medicines. Some of them are highly toxic, others are susceptible to corrosion or pollution from the outside world, and some are flammable and explosive.... The accidents caused by the leakage of steel drums or the events that cause environmental pollution have occurred from time to time.

The leakage of steel drums is mainly caused by the barrel welds of steel drums and the quality of the winding seals at the top of the drums. In order to solve this problem, the steel drum structure in China has been improved from the original five-layer rectangular crimping to seven-layer circular crimping. The welding machine has been semi-automatically improved from manual to automatic, thereby improving the sealing quality of the steel drum and reducing leakage. And all products by the pressure test, basically eliminate the leakage of steel drum factory.

The closed steel drum structure specified in national standard GB325-91 "Steel drum for packaging containers" of steel drum structure and environmental protection has the problem of internal residue, which not only causes waste but also pollutes the environment. After the steel drums with leftovers are discarded, some residues may cause environmental pollution. If steel drums are refurbished and reused, cleaning the steel drums will bring more pollution. In recent years, there have been several types of steel bucket structures without residue left on the world, such as arched bucket tops or trench drainage structures, such as arched bucket tops or trench drainage structures. Closed drums using this structure should be promoted.

Drum coating material and environmental protection For many years, China's steel drum coating has not developed much. It has only been improved from the coating process. Although environmental pollution is reduced, it still causes certain pollution during the coating process of steel drums. . In recent years, there have been many kinds of new environmental protection coatings at home and abroad. The domestic steel barrel industry should increase the use and popularity of these new coatings.

In addition, the precoat coating is a major change in the coating. It changes the final coating of the steel drum to the coating of raw materials, thereby reducing the contamination of the coating process.

Water-based paint is a new type of white-water paint developed after the anion and anode electrophoretic coating. It is characterized by water as a dispersion system and does not contain any organic solvents. It conforms to international regulations and is conducive to environmental protection.

Adhesive coatings are a class of polymeric films coated with colored paints and adhesives. Due to its good durability and weatherability, it can be easily applied to the outer surface of the barrel. Because it replaces solvent-based liquid coatings, it is an environmentally friendly coating.

For the first time, powder coating has achieved solvent-free dry coating production, which fundamentally eliminates the scattering of harmful solvents, and overspray powder can be recycled. Not only the coating quality is good and the efficiency is high, but also environmental pollution is reduced or eliminated, labor conditions are improved, and energy is saved. This is a new trend in the development of steel drum painting.

Improvement of steel drum production process Due to the limitations of equipment and technology, most of the production process of the barrel factories in China still has a large number of unfavorable environmental protection technologies. Some are still not known, and some are still considered as Advanced technology is promoted, and some have set up corresponding environmental protection facilities, but they are idle for a long time. This situation will gradually improve with the improvement of national environmental awareness and technological progress.

The improvement of barrel edge welding edge processing is to pre-treat the joints of the barrel plate joints before seam welding. Its purpose is to eliminate oxides, oils, etc. on the edge of the barrel to facilitate seam welding. At present, the main process in China is edging, that is, 4-8 sets of grinding machines are used to grind the welding edges.

Those who see the edging production with their own eyes will be shocked because the working environment here is too harsh, deafening noises, dust, toxic gases, etc.. The working environment inspection department will often request that the rectification be carried out as soon as possible.

In recent years, a variety of new welding edge processing technologies have emerged in the country, such as edge milling, cleaning, flexible grinding, and automatic high-frequency welding. The edge milling process and cleaning process eliminate noise and dust, but the cleaning process uses hydrochloric acid, etc. to corrode the oxides and oils on the welding edge. This can produce poisonous and harmful gases, and there is also the problem of cleaning waste liquid, which is still unfavorable to environmental protection. . Only automatic high-frequency welding process eliminates the processing process, which not only reduces labor intensity, reduces production costs, but also reduces environmental pollution.

Improvement of coating production technology Steel drum coating is one of the greatest environmental hazards in the steel drum production process. The large amount of waste gas, waste water, and waste residue (three wastes) produced by steel drum coating mainly come from chemical treatment such as degreasing, rust removal, phosphating, and passivation on the surface before coating, and scattering of organic solvents and paint mist during coating process. Solvent evaporation during drying.

If the three wastes in the coating process are not effectively managed, the harm to the environment and operators is serious. In the past, the treatment of the three wastes in China was a remedial type, which caused the environmental protection work to fall into a vicious cycle of pollution after the first pollution. Therefore, the use of pollution-free or low-pollution production technology is the real way out. At present, the environmental protection coating technology at home and abroad has developed rapidly. Nowadays, a variety of advanced coating methods such as high-pressure airless spray coating, electrophoretic spray coating, electrostatic spray coating, and powder coating, etc., have been widely used for mechanization and automated assembly lines. In these modern advanced coating methods, techniques such as automatic program and microcomputer control and closed circuit motor control and robot operation were introduced. The new high-protection, high-decoration, low-toxicity, low-pollution paints and thinners are matched with dipping, showering, roller coating, and photocuring, radiation-curing coating methods for semi-mechanized, mechanized, and automated assembly lines. With the extensive adoption of new technologies and new processes, the pollution caused by the steel drum production process is gradually decreasing.

Environmental problems in the use of steel drums often result in environmental pollution due to the improper use of steel drums. The common causes of pollution are caused by improper selection of steel drums and unreasonable storage and transportation methods.

Drum Material Compatibility There may be compatibility issues when using drums to hold certain materials. Commonly seen problems with interior paint, sealant problems, and seals.

Inner paint, sealant and seals should be compatible with the contents and must not react. If they are incompatible, the contents will be contaminated and the drum seal performance will be lost, resulting in unpredictable consequences. The case of serious leakage of seawater caused by the abundance of chemical substances that have occurred in the past was caused by compatibility problems. Therefore, when producing and ordering drum packaging products, both parties should clarify this issue so as to avoid irreparable consequences.

The leakage of environmental steel drums in use during storage and transportation is mostly related to uncivilized loading and unloading. Due to improper loading and unloading, the steel drums collided and fell and deformed and leaked, causing pollution. At present, some domestic companies use automated assembly line operations for the filling and decoration of steel drums, thereby reducing the leakage pollution caused by man-made uncivilized handling.

The correct storage and transportation of steel drums are not allowed to place the steel drums in open space. In particular, the steel drums are not allowed to stand upright in the open air, that is, the mouth of the drums is upward. The steel drums were placed in the open space. In addition to the damage to the steel drums due to the wind, sun and rain, the more important is the effect of thermal expansion and contraction on the sealing performance of the drums. In addition, when standing in the open air, it is easy to collect water at the top of the bucket and infiltrate into the bucket through the poorly sealed barrel mouth, causing contamination of the contents. When the contamination of the contents cannot be used, it becomes new waste.

Recycling used steel drums There are generally two methods for recycling waste steel drums. First, the old steel drums are cleaned, stripped, reshaped, and re-applied and reused; the second is to use old drum stock to make other products. .

Old Barrel Renovation and Environmental Protection Currently, the enterprises engaged in the renovation of old barrels are gradually increasing, and technologies and equipment are continuously being developed. However, the main problem is that there are still a large number of wastes arising from the cleaning, stripping and re-coating processes. The three waste treatment technologies are quite mature at present, as long as they pay attention to governance, environmental pollution can be better controlled.

The environmental effect of the mechanical paint stripping is obviously better than that of the chemical method; the environmental effect of the cleaning process using the residual waste liquid after reuse is obviously better than the direct discharge. Therefore, whether the three waste treatment methods are advanced or not is directly related to the effect of environmental protection.

Some enterprises that use old barrels to manufacture other products will use old barrels to chisel out and use stamping and other methods to make other products. Some make the sheets into smaller-capacity buckets. In the recycling process, if the waste sheet still needs to be cleaned and stripped, attention should be paid to the treatment of the three wastes to reduce the pollution to the environment.