Glass bottle recycling method

The glass material is characterized by being 100% recyclable and can be used both for its original purpose and for transformation and utilization. However, if it is not recycled, it will not only increase the load of the burying work, but also cannot be decomposed by the organism; if it enters the incinerator, it may also cause damage to the furnace body. Therefore, the recycling of glass bottles is particularly important.

Due to its strong barrier properties and high transparency, glass bottles are widely used as packaging containers for beer, beverages, condiments and cosmetics. The market for these glass bottles is a special market where old and new bottles coexist, and there are many old bottles. The recycling of glass bottles has created the following social benefits: saving energy, reducing landfill of glass waste, reducing the exploitation of glass raw materials ore, and reducing exhaust emissions from glass smelting processes. At present, the recycling methods of glass bottles include: prototype reuse, remelting, raw materials recycling, and transformation and utilization.

Prototype reuse

The prototype reuse of waste glass packaging means that the glass bottles are still used as packaging containers after recycling. The glass bottles can be divided into two types: the same packaging and the more packaging. At present, prototype packaging for glass bottle packaging is mainly for low-value and high-volume commodity packaging, such as beer bottles, soda bottles, soy sauce bottles, vinegar bottles, and some cans. As a high-value liquor bottle, medicine (medical) bottle, cosmetic bottle, there is almost no recycling. It can be said that the relationship between the packaging recovery rate and the value of the goods is inversely proportional to the higher the value of the glass bottle recycling rate of the lower the product.

Similar packaging use

Similar packaging uses the same brand and different brands of packaging. For example, recycling of beer glass bottles for beer packaging is similar to the use of packaging. If the same brand of beer is packaged before and after the recycling bottle, it is called the use of the same brand of packaging. On the contrary, it is the use of different brands of packaging.

Most of the current recycling on the market is the use of different brands of packaging. For example, the use of recycled glass bottles in the beer industry is a typical example. Last year, China produced 23.6863 million tons of beer, which required nearly 35 billion bottles. If these bottles are completely made of quartz raw materials, the amount of raw materials needed and the amount of exhaust gas produced can be imagined. In fact, 82% of the glass bottles containing beer are recycled bottles and the new bottles only account for 18%. The difference between each new bottle and the recycling bottle averages 0.2-0.3 yuan, and the difference in the cost of holding one tonne of beer is about 308-463 yuan. It can be seen that the recycling of glass bottles has saved the brewers a lot of costs.

In addition, nearly 60% of the products in the sauce vinegar market use recycled bottles.

However, the sanitation and safety of the bottle should be ensured during the reuse process. Glass bottles must undergo strict cleaning and disinfection. In terms of safety, the requirements for wine bottles are high. It requires the bottles to have strong impact resistance and internal pressure resistance. Studies have shown that the normal use period of the “B” bottle commonly used in the market is two years. After five consecutive recycling operations, its strength is only 50% of the new bottle, and bottle explosion accidents may occur.

More use of packaging

The use of packaging materials is also more common. If there are many manufacturers that produce vinegar, beer glass bottles, soy sauce glass bottles, etc. that are recycled will be used for vinegar packaging. Some manufacturers use bottles of vinegar similar in shape as beer bottles, but this is not worth promoting. Because the vinegar-proof vinegar bottle has extremely low pressure resistance, it is prone to an explosion accident when it is loaded with beer and collided or oscillated.

Cleaning process

Before reusing the recycling bottles, the bottles must be cleaned and disinfected.

The usual practice is: First of all, the recovered glass bottles are sorted according to their size, shape and color so that they can be used according to their purpose. Then, the labels on the bottles, especially the plastic labels, are removed. Bottles that are incomplete at the mouth of the bottle are removed to prevent them from falling into the bottle contents due to mechanical pressure cracking; then, the dirt in the bottle is cleaned with detergent; finally, the bottle is sterilized, especially for packaged foods. The requirements for medical supplies or cosmetics are more stringent.

The prototype reusing method eliminates the waste of quartz raw materials consumed when manufacturing new bottles and avoids the generation of large amounts of exhaust gas, which is worthy of promotion. However, there is a big disadvantage in that it consumes a large amount of water and energy, and the cost must be included in the cost estimate when using this method.

Remelting

Re-melting and recycling refers to the use of recycled packaging glass bottles for the remanufacturing of similar or similar packaging bottles, which is essentially a method of recycling semi-finished raw materials for glass bottle manufacturing.
The specific operation is to carry out preliminary cleaning, cleaning, color classification, and other pretreatments for the recycled glass bottles; then, the melting in the reflow furnace is the same as the original manufacturing process, and is not described here in detail; finally, the regenerated material is blown through the reflow furnace. System, adsorption and other different ways of manufacturing all kinds of glass bottles.

Recycling furnace regeneration is a method for recycling glass bottles that are difficult to reuse or that cannot be reused (eg, damaged glass bottles). This method consumes more energy than the prototype reuse method.

Reuse of raw materials

The reuse of raw materials refers to the use of various glass bottle packaging wastes that cannot be reused as raw materials for the production of various glass products. The glass products here are not only glass packaging products, but also other product wastes such as other building materials and daily-use glass products. This method consumes more energy than the first two recycling methods.

The addition of crushed glass in an appropriate amount contributes to the manufacture of the glass, because the cullet can be melted at a lower humidity than other materials. Therefore, recycling glass bottles requires less heat and the furnace body wear can also be reduced. The tests showed that glass containers produced from recycled glass have the same transparent walls and container strength as the glass containers produced with new raw materials, and that the use of recycled secondary materials can save 38% energy compared to using raw materials to manufacture glass products. Reduce air pollution by 50%, water pollution by 20%, and waste by 90%. In addition, since the loss during the regeneration of the glass is small, the above recycling process can be repeated. Visible, its economic benefits and ecological benefits are very significant.

The use of discarded glass bottles or broken glass materials for the recycling of raw materials for glass products should pay attention to two issues.

One is to remove impurities. Metals, ceramics and other impurities in the glass bottle recycling material must be completely removed because of the high purity of raw materials required for the manufacture of glass containers. If there is a metal cover in the cullet, it may form oxides that interfere with the operation of the furnace, and if it is mixed with ceramics and other foreign materials, it will cause defects in the finished product.

The second is color selection. Different glass products have different requirements for the color of raw materials. For example, tinted glass cannot be used to make colorless flint glasses, whereas amber glass is only allowed to add 10% green or flint glass. Therefore, post-consumer broken glass must be selected manually or by machine. If cullet is used directly without color selection, it can only be used to produce light green glass containers.

Transformation and utilization

Due to the rise of various packaging containers and the diversification of container materials, the current demand for glass bottles has declined. Therefore, it is necessary to open up the application of glass waste in other fields than bottle making, that is, transformation and utilization, and directly process the recycled glass packaging to make other useful materials.

This use method is divided into two categories, one is a heating type, and the other is a non-heated type.

Non-heated

Non-heated use is also called mechanical use. The specific method is to directly crush or first recover the worn-out glass according to the use conditions, such as washing, sorting, drying and other pre-processing, and then mechanically crush them into small particles, or grind them into small glass balls for use. There are several ways to use it:

* The use of glass shards as a combination of pavement, construction bricks, glass wool insulation and honeycomb structure materials;

* Mix and mix the crushed glass directly with the building material components to make an overall building prefabricated piece;

* Used to make reflective sheet materials and clothing accessories;

* Used to decorate the building's surface to provide beautiful optical effects;

* Grind directly into a variety of shapes, then glue into arts and crafts or small decorations such as buttons;

* The mixture of glass and plastic waste can be molded into synthetic stone products;

* Can be used to produce sewage pipelines.

Heating type

In the heating type, the waste glass is crushed, melted in a high-temperature melting furnace, and then glass fiber is prepared by rapid drawing. This glass fiber can be widely used in making asbestos tiles, glass jars and various building materials and daily necessities.

In this regard, the exploitation technology developed by Japan is more advanced. For example, CRYSTAL CLAY Co., Ltd. grinds the acquired glass bottles into pieces of broken glass with a diameter of less than 1.2 mm and mixes them with clay to make new types of bricks and tiles for paving and building walls. Even unsorted and colored waste glass can be blended in as much as 70% of the waste, greatly reducing the amount of clay used and reducing the damage to the ecological environment. The sintering temperature is 1000°C, which is 200°C lower than the sintering temperature of ordinary tiles, which means that energy is saved and 26% of the CO2 emission is reduced.

The production of glass bottles is one of the most energy-intensive packaging products, and its recycling is very valuable.

Of the above four recycling methods, the prototype multiplexing method is the most ideal and is an energy-saving and economical recycling method. The use of transformation is a method of recycling that needs urgent development. We believe that in the future there will be more new and value-added technologies for transformation and utilization.