FRP waste treatment method

Discarded glass steel products, the traditional treatment method is to bury and burn. Buried landfills have the disadvantage of occupying large amounts of land and contaminating groundwater. Burning has the disadvantage of polluting the environment with harmful gases. In particular, recent studies have confirmed that styrene, the main raw material for unsaturated polyesters, is an environmental hormone. Its chemical structure is stable, it can not be biodegradable, has a high environmental retention, has become a persistent organic pollutant, and can be strongly adsorbed on particles in air, water, or soil. Terrestrial food chains continue to be enriched, causing damage to the ecological environment. Human consumption of contaminated animals and plants will have serious consequences. Mainly manifested in: 1) environmental hormones cause a decline in male reproductive capacity; 2) the degree of feminization of men is intensified; 3) environmental hormones cause cancer in the female reproductive system.
Foreign processing methods 1 as a raw material for cement. In this method, FRP waste is first crushed into powder with a particle size of 10 mm, blown into a cement kiln, and burned as fuel. The residue is used as a raw material for cement.
The feature of this method is that it can completely dispose of the glass fiber reinforced plastic waste. Part of the FRP waste is converted into energy, which can reduce part of the fuel consumption and thus reduce carbon dioxide emissions. Due to the high temperature in the kiln, there are few harmful gases and there is no problem of polluting the air with harmful gases.
2Used as a reducing agent for blast furnace ironmaking. The FRP waste is pulverized into a powder having a particle size of 1 to 10 mm, blown into a blast furnace, reacts with the carbon of the waste to produce carbon monoxide, and reduces the iron oxide powder to iron. Its features are basically the same as the first method.
3 Physical recovery. FRP waste is crushed into powders with different particle sizes and used as fillers.
This method has the lowest production cost and simple processing method. However, when the micropowder is manufactured, the crushing cost is relatively high. As the micropowder is added to the BMC, SMC or other glass steel products, the strength of the new product is often reduced as the added amount increases. .
4 Chemical recovery method. This method dissolves the crushed fine powder in ethylene glycol, decomposes the resin under the action of an alkali catalyst at a high temperature of 230°C to 245°C, separates the glass fiber, and then adds maleic acid or antimony. Butanedioic acid is re-reacted, unsaturated polyester is regenerated, the molecular weight of the obtained unsaturated polyester is increased, and the product performance is greatly improved.
There are three advantages of this method: (1) Discarded glass steel can be decomposed by ethylene glycol at 230°C to 245°C. (2) General synthetic resin equipment can be used for decomposition of discarded glass fiber, which does not require additional equipment investment. (3) The decomposition product does not need to be refined and can be directly used as a synthetic raw material, and then the unsaturated polyacid resin can be synthesized.
The method that should be adopted in China After more than 40 years of development, the glass steel industry in China has developed very rapidly after the 1980s, but 80% of the output is produced by township and village enterprises. Most of them are artificial hand lay-up products, and their mechanization and automation are low. Many glass steel manufacturers use inferior quality raw materials and produce raw materials. The service life of these products is much lower than that of similar foreign products. The scrap produced during processing is also higher than that of foreign countries, and there is basically no treatment for discarded fiberglass products. The vast majority of landfills or burning in the natural environment cause a great deal of pollution to the environment. The recovery and utilization of waste glass fibres has become an urgent problem to be solved in the glass steel industry.
The author believes that relevant government departments should formulate relevant policies and regulations as soon as possible, establish a set of waste collection, processing, and disposal systems to coordinate the disposal of waste by manufacturers, raw material manufacturers, and users. On the other hand, when using glass fiber reinforced plastics, we must conscientiously demonstrate reasonable material selection, promote the use of easily recycled materials as much as possible, and minimize the use of fiberglass. The promotion of new processes, the use of advanced production equipment, to minimize the production of scrap in the production of glass steel.
Regarding the disposal of discarded glass fiber reinforced plastics, based on the advanced experience of foreign countries, combined with China's basic national conditions, the author believes that there are currently two methods that are more economical and practical.
1. As a raw material for cement plant combustion method is best. Combustion can save energy and reduce the production of carbon dioxide. After combustion, the residue does not contain chlorine and phosphorus. As a cement raw material, it has almost no effect on the quality of cement, and the utilization rate can reach 100%. There are many cement factories in China. The production facilities of the factory are sufficient to support the disposal of discarded glass steel.
2. Physical recovery, the powder filling method is also a better method. Can handle a large number of glass steel waste, such as BMC, SMC filling up to 30% to 50%, although the strength has a certain decline, but it can meet the general use requirements, but also can make the product ratio decreased, made light product.
Although the chemical regeneration method is the most perfect method, it can be used to decompose waste glass fiber into raw materials, but the cost is too high. China's economy is not yet well-developed and its funds are limited. Currently, this method cannot be used on a large scale, but with economic Development and scientific and technological advances, chemical treatment methods will be the best way.