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R&D Focus

LCD Waste Recycling System Developed for a Circular Economy

Billions of LCDs are manufactured annually; therefore how to properly dispose of the toxic waste of these products becomes an important issue. ITRI’s LCD Waste Recycling System is a zero-waste, eco-friendly, and cost-effective total solution for waste LCD panels treatment. It integrates sequential separation, ppb-level purification, and nanopore technologies to recycle liquid crystals, indium, and glass.

ITRI’s processing method extracts liquid crystals for reuse. This not only allows the recycled indium and glass not to contain liquid crystals, but also reduces the production of new liquid crystals, therefore lessening environmental pollution. Through ITRI’s technology, extracting liquid crystals from waste LCD panels achieves a nearly 100% liquid crystal recovery rate. After purification, liquid crystals can be reused in new LCDs or liquid crystal smart windows. Moreover, the indium, with a recycling rate up to 90%, can be turned to indium targets by the indium recycling industry. With liquid crystals removed, glass can become soundproof or heat-insulating construction material, or heavy-metal adsorbent for waste water treatment.

ITRI’s LCD Waste Recycling System can effectively replace traditional LCD waste disposal techniques, such as burying, incineration, and physical treatment. It features a 6-step process of separation, extraction, purification, scrubbing, concentration, and modification, which enables the reuse of liquid crystals, indium, and glass from waste LCD panels.

• Separation: A panel-smashing system shatters the LCD panel, exposing the liquid crystal.
• Extraction: The separated LCD panel enters the continuous liquid crystal extraction system, using an agent to extract liquid crystals which are exposed on the surface of the glass substrate, enabling the system to shorten the processing time by integrating the extraction and purification functions.
• Purification: The impurity is removed by the salt adsorption method, using ITRI’s patented technology.
• Scrubbing: Once liquid crystals have been removed, the panel fragments enter the indium extraction system and an agent is used repeatedly as a scrub, enabling removal of the indium from the panel fragment.
• Concentration: The indium-containing precipitate is dissolved with an agent and enters the indium concentration system, where it is concentrated through precipitation principles. Therefore, the indium on the panel (only about several hundreds of ppm) is concentrated into a powder with an indium content of 30% or greater.
• Transformation: After removing most of the cell materials, the glass is collected. Some additives are mixed into the glass and the mixture is melted with a special thermal treatment procedure to form the microporous structure. The transformed glass can be used for green construction material and heavy-metal adsorbent, known as ITRI’s Green Glass Adsorbent.

ITRI built a pilot plant for the technical verification of the LCD Waste Recycling System, working with LCD manufacturers and e-waste recycling companies. The pilot plant can treat 3 tons of waste LCD panel per day of operation, producing 3 kg of liquid crystals (worth US$15,000), 750 grams of indium (US$158), and about 2,550 kg of glass, which can be reused as green construction material or heavy-metal adsorbent (around US$17,000).

In sum, ITRI’s LCD Waste Recycling System is an ideal solution to treating waste LCD panels as it can transform the panels’ material (liquid crystals, indium, and glass) into valuable products, while increasing profits and reducing the production of waste material. Benefits of this system include low cost, ease of downstream processing, high production yields, and scalability.