Cathode Ray Tube Funnel Glass Research Articles

A comparative study on the feasible use of recycled beverage and CRT funnel glass as fine aggregate in cement mortar

The rapid development of the electronic industry has led to a growing hazardous waste management and disposal problem related to the management of cathode ray tube (CRT) waste. This study aimed to compare the feasibility of using CRT recycled glass: non-treated funnel glass (n-TFG, crushed without treatment) and treated funnel glass (TFG, crushed and treated with acid nitric to remove lead on the glass surface) as fine aggregates in cement mortar. Fresh and hardened properties of the cement mortars, including their x-ray radiation shielding and potential lead leaching were investigated. The mortar prepared with crushed beverage glass (CBG, lead-free) was also evaluated for comparison purposes. The experimental results show that the use of glass cullets, irrespective of glass type, improved the fluidity and drying shrinkage but reduced the strength. About 60% enhancement in x-ray radiation shielding property was achieved with the use of 100% CRT glass in the cement mortar owing to the increase of mortar density due to the presence of lead in the CRT glass. Furthermore, lead leaching (based on TCLP test) from the mortar samples prepared with the TFG complied with the regulatory limits. The results have demonstrated that the CRT glass (an original hazardous material) can be treated, processed, and re-utilized for making cement mortars. The mechanical performance of the cement mortar is comparable to that made with beverage glass.

Leaching behavior of CRT funnel glass

The leaching behavior of cathode ray tube (CRT) funnel glass containing 23 mass percent of Pb in 0.001N HCl, distilled water, and 0.001N NaOH at 90°C was investigated using a static method. The weight loss and leached amount of each component was measured and surface changes observed by SEM. The leaching mechanism is discussed. In acid solution, the leached amount of Pb showed t1/2 dependence, that is, diffusion-controlled dependence, which is common in lead silicate glasses. In water and basic solutions, the leached amount showed saturation after higher initial dissolution than in acid and the deposition of many particles on the surface was observed. The amount leached was less for Pb than other components. The deposited particles formed a protective layer, which suppressed the dissolution of the glass. This dense layer must be formed as a result of a high initial dissolution rate.

Recycling of scrap cathode ray tubes.

It is estimated that approximately 50% of the weight of a computer monitor is composed of cathode ray tube (CRT) glass. Thus, the successful recycling of scrap CRT glass can greatly relieve the disposal problem created by scrap monitors. CRT glass may be considered a hazardous waste due to its high lead concentration. A CRT can be divided into panel (front) glass and funnel (back) glass. Several coatings have been applied to the surface of the CRT panel and funnel glass. These coatings may present an adverse effectto the environment by obstructing the recycling and reuse of the CRT glass. To recycle CRT glass, a series of tests has been conducted to remove the coatings from scrap CRT glass. In this study, the CRT panel and funnel glass obtained from scrap computer monitors was cleaned by wet-scrubbing and ultrasonic cleaning methods. This cleaned CRT glass is intended to be recycled and reused by CRT manufacturers. This study shows that the wet-scrubbing method has a better coating removal performance and no associated pollution problem (i.e., no additional chemical additives). Thus, the wet-scrubbing method is recommended for use as a CRT coating removal method. The results of these tests are presented in this paper.