TECHNOLOGY FOR PRODUCING COMPOSITE GLASS-CRYSTAL FACING MATERIALS BASED ON MIXED CULLET
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2020-02-20 |
| Journal | Bulletin of Belgorod State Technological University named after V G Shukhov |
| Authors | N. I. Bondarenko, О. В. Пучка, Vasiliy Bessmertnyy, S A Chuev, I. A. Izotova |
| Institutions | National Technical University “Kharkiv Polytechnic Institute”, Belgorod University of Cooperation, Economics and Law |
| Analysis | Full AI Review Included |
Executive Summary
Section titled “Executive Summary”This research details the development of an effective, energy-saving technology for producing high-strength composite glass-crystal facing materials using industrial and municipal waste streams.
- Core Value Proposition: The technology utilizes mixed-color glass cullet (sheet and container glass) and waste porcelain, transforming low-value waste into competitive, high-performance construction cladding.
- Energy Efficiency: The use of liquid sodium glass (5.0 wt.%) as a flux successfully lowered the optimal sintering temperature from 750 °C to 725 °C.
- Material Strength: The optimized composite material achieved a high compressive strength of 79 MPa.
- Reinforcement Mechanism: Fine porcelain powder (10 wt.%) acts as a reinforcing component, forming a strong spatial crystalline framework (containing mullite, quartz, and cristobalite) that enhances mechanical and thermal properties.
- Optimal Formulation: The best results were achieved with 10 wt.% fine porcelain powder and 5.0 wt.% dried sodium liquid glass, combined with a specific three-fraction blend of mixed glass cullet (35%, 35%, 30%).
- Waste Utilization: The process addresses the challenge of recycling mixed-color glass cullet, which is often rejected by primary glass manufacturers.
Technical Specifications
Section titled “Technical Specifications”Data extracted from the optimal composition (Table 4, Composition 5*) and raw material analysis.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Optimal Sintering Temperature | 725 | °C | Thermal processing of the composite |
| Compressive Strength (Max) | 79 | MPa | Optimal material performance |
| Porosity (Optimal) | 16.9 | % | Resulting material property |
| Porcelain Powder Content | 10 | wt.% | Optimal reinforcing additive |
| Liquid Sodium Glass Content | 5.0 | wt.% | Optimal sintering temperature reducer |
| Liquid Sodium Glass Density | 1.45 | g/cm3 | Raw material specification |
| Optimal Cullet Fraction 1 | 35 | wt.% | Size 0.63-0.80 mm |
| Optimal Cullet Fraction 2 | 35 | wt.% | Size 0.80-1.25 mm |
| Optimal Cullet Fraction 3 | 30 | wt.% | Size 1.25-3.15 mm |
| Hard Porcelain Al2O3 Content | 25.9 | wt.% | Key component for mullite formation |
| Hard Porcelain SiO2 Content | 68.1 | wt.% | Primary component |
| Compressive Strength (Porcelain) | 350-370 | MPa | Property of the reinforcing raw material |
| Linear Thermal Expansion (Porcelain) | (3.8-6.7)·10-6 | K-1 | Property of the reinforcing raw material |
Key Methodologies
Section titled “Key Methodologies”The technology involves precise preparation and thermal treatment of three main components: mixed glass cullet, hard porcelain cullet, and liquid sodium glass.
- Glass Cullet Preparation: Mixed sheet and container glass was crushed using a jaw crusher, followed by screening to achieve the optimal fractional composition (35% fine, 35% medium, 30% coarse). Oversized particles (>3.15 mm) were re-crushed.
- Porcelain Preparation: Hard porcelain cullet was initially crushed, then finely ground in a 10 L ball mill for two hours to produce a fine powder (10 wt.% of the final mix).
- Sodium Glass Preparation: Liquid sodium glass (water glass) was dried in a drying oven at 105 °C for one hour to remove moisture, preventing clumping during mixing. The dried material was then finely ground in a 6 L ball mill for 30 minutes (5.0 wt.% of the final mix).
- Batching and Mixing: Components were weighed according to the optimal formulation (e.g., Composition 5*). The fractionated glass cullet was first averaged with the fine porcelain powder. This mixture was then averaged with the finely ground, dried sodium glass in a paddle mixer for 15 minutes.
- Forming and Compaction: The prepared mixture was placed into 50 x 50 mm metal molds and compacted (densified).
- Thermal Processing (Sintering): The filled molds were placed in a muffle furnace and subjected to thermal treatment (sintering) at the optimized temperature of 725 °C.
- Finishing and Quality Control: Facing tiles were extracted from the molds, edges were trimmed using a diamond saw, and the finished products were tested for compressive strength and porosity.
Commercial Applications
Section titled “Commercial Applications”This technology is directly relevant to industries focused on sustainable construction, waste valorization, and high-performance architectural finishes.
- Sustainable Construction: Production of high-strength, durable, and aesthetically versatile facing tiles (cladding) for both interior and exterior architectural applications.
- Waste Valorization: Provides a robust, high-volume pathway for utilizing challenging waste streams, specifically mixed-color glass cullet and ceramic/porcelain manufacturing waste.
- Energy-Efficient Manufacturing: The low sintering temperature (725 °C) makes the process highly attractive for manufacturers seeking to reduce energy consumption and operational costs compared to traditional ceramic or glass-ceramic production.
- Infrastructure and Public Works: Suitable for producing durable, chemically resistant, and thermally stable materials for public spaces, facades, and high-wear areas.
- Resource Independence: Enables the production of competitive building materials using local, non-deficit secondary raw materials, reducing reliance on expensive virgin inputs.
View Original Abstract
An effective energy-saving technology for producing composite glass-crystal facing materials based on fractionated cullet of sheet and container glasses, cullet of porcelain and sodium liquid glass has been developed. The use of fine porcelain powder in the composition of composite glass-crystal facing materials in an amount of up to 10 wt is justified. % and liquid sodium glass up to 5 wt. %. It is shown that the optimal fractional composition of granulated mixed cullet is 35 wt. % fraction 0.63-0.80 mm; 35 wt. % - fractions of 0.80-1.25 mm and 30 wt. % fraction of 1.25-3.15 mm. Polytherms of viscosity of colorless, green and brown container glasses, as well as sheet glass, are calculated. The possibility of using mixed cullet for obtaining composite glass-crystal facing materials is on the basis of obtained dependencies. The chemical composition of sheet and container glasses and porcelain is studied using x-ray fluorescence analysis. Optimal charge compositions have been developed to obtain glass-crystal materials with compressive strength up to 79 MPa. The technology of obtaining composite glass-ceramic facing material includes the following technological operations: milling of glass breakage; grinding cullet of porcelain; drying of sodium liquid glass; the screening of crushed cullet on fractions; the grind of crushed cullet of China; grinding the dried sodium silicate glass; weighing the components in accordance with the developed formulations, the averaging of the graded cullet with fine porcelain; averaging the mixture of finely ground dried sodium silicate glass; stacking the mixture in a metal mold; compaction of the mixture in metal molds; heat treatment in a muffle furnace (sintering); extraction of facing tiles from molds; trimming the edges of the tiles with a diamond saw; quality control of finished products.