Obtaining Foamed Glass-Ceramics from Diamond Concentration Tailings

At a Glance

Metadata	Details
Publication Date	2023-05-18
Journal	Ceramics
Authors	O. V. Suvorova, N. K. Manakova, A.I. Novikov, D. V. Makarov
Institutions	Kola Science Centre
Citations	4
Analysis	Full AI Review Included

Technical Documentation & Analysis: Diamond Concentration Tailings for Foamed Glass-Ceramics

Executive Summary

This research demonstrates a successful method for recycling diamond concentration tailings and waste glass into low-density, heat-insulating foamed glass-ceramics. While the study focuses on utilizing diamond waste for low-performance building materials, 6CCVD leverages advanced MPCVD technology to produce high-purity synthetic diamond materials essential for high-performance engineering applications.

Core Achievement: Production of heat-insulating foam materials (thermal conductivity 0.060-0.066 W/m·K) from 50 wt.% diamond concentration tailings and 50 wt.% waste glass.
Optimal Recipe: The best material properties were achieved using a fine fraction of tailings (<0.05 µm), 0.5 wt.% SiC (foaming agent), and 1 wt.% Fe₂O₃ (oxidizer).
Optimal Processing: Sintering was optimized at 1030 °C for 30 minutes, yielding an apparent density of 0.28 ± 0.02 g/cm³ and a compressive strength of 1.20 ± 0.02 MPa.
Microstructure: The optimal temperature (1030 °C) resulted in a uniform, finely porous structure with polydisperse pores (1.29-3.87 mm), maximizing strength at minimum density.
6CCVD Contrast: This research utilizes diamond by-products for low-end thermal insulation. 6CCVD specializes in high-purity, synthetic SCD and PCD diamond, offering thermal conductivity exceeding 2000 W/m·K, critical for extreme thermal management and high-power optical systems.
Value Proposition: 6CCVD provides engineers and scientists with the highest quality MPCVD diamond wafers, custom dimensions, and precise surface finishes required to advance high-tech research and device fabrication, far exceeding the capabilities of recycled ceramic foams.

Technical Specifications

Parameter	Value	Unit	Context
Optimal Sintering Temperature	1030	°C	Yielded optimal microstructure and strength
Optimal Exposure Time	30	min	Used at maximum sintering temperature
Apparent Density (Optimal)	0.28 ± 0.02	g/cm³	Best performance sample (1030 °C)
Compressive Strength (Optimal)	1.20 ± 0.02	MPa	Best performance sample (1030 °C)
Thermal Conductivity (Range)	0.060-0.066	W/m·K	Classified material as heat-insulating foam
Porosity (Optimal)	88.3 ± 0.09	%	High porosity achieved at 1030 °C
Water Absorption (Optimal)	9.5 ± 0.19	% (by volume)	Measured at optimal sintering temperature
Optimal Pore Size Range	1.29-3.87	mm	Polydisperse, dense interpore partitions
Tailings Particle Size (Optimal)	<0.05	µm	Fine fraction required for strong foaming
Foaming Ratio (Maximum)	1.65	Ratio	Achieved with 3 wt.% Fe₂O₃ at 1050 °C (Sample 22)

Key Methodologies

The foamed glass-ceramics were produced using a powder process involving specific material ratios and controlled thermal cycling.

Raw Material Preparation: Diamond concentration tailings were processed to isolate the sand fraction, then reground to a fine particle size of <0.05 µm. Waste glass was also ground to <0.05 µm.
Charge Formulation (Optimal Composition):
- Diamond Concentration Tailings: 50 wt.%
- Waste Glass: 50 wt.%
- Silicon Carbide (SiC, foaming agent): 0.5 wt.%
- Iron Oxide (Fe₂O₃, oxidizer): 1 wt.%
Mixing and Molding: The feed charge was thoroughly homogenized, mixed with 5-8 wt.% water as a binder, and pressed into cubic (3 mm edge) or cylindrical (20 ± 2 mm) samples.
Sintering and Foaming: Samples were loaded into a preheated “Nabertherm” electric furnace. The optimal sintering temperature was 1030 °C, maintained for an exposure time of 10-50 minutes (30 minutes for the optimal sample).
Annealing: After foaming, samples were subjected to an arbitrary decrease in temperature (cooling in the furnace) over 15-20 hours to ensure stress relief.
Characterization: Material composition and structure were analyzed using X-ray Diffraction (XRD), Thermal Gravimetric-Differential Scanning Calorimetry (TG-DSC), and high-temperature optical microscopy (ZEISS MHO-2).

6CCVD Solutions & Capabilities

This research highlights the potential for recycling diamond mining by-products. However, for engineers and scientists focused on high-performance applications—such as quantum computing, high-power optics, and advanced thermal management—the purity and crystalline perfection of MPCVD diamond are paramount. 6CCVD provides the materials necessary to move beyond waste utilization and into cutting-edge device fabrication.

Applicable Materials for Advanced Research

The low thermal conductivity (0.06 W/m·K) of the foamed ceramic is insufficient for modern electronic or optical heat dissipation. 6CCVD offers materials designed for extreme performance:

Optical Grade Single Crystal Diamond (SCD): Required for high-power laser windows, beam splitters, and quantum applications (e.g., NV centers). Our SCD offers superior purity and surface finish (Ra < 1 nm), ensuring minimal absorption and scattering losses.
High Thermal Grade Polycrystalline Diamond (PCD): Essential for heat spreading in high-density electronics, RF devices, and power modules. Our PCD provides thermal conductivity exceeding 1800 W/m·K, a factor of >30,000 times better than the ceramic foam produced in this study.
Boron-Doped Diamond (BDD): Ideal for electrochemical sensors, high-performance electrodes, and p-type semiconductor applications, offering extreme chemical inertness and wide electrochemical windows.

Customization Potential for Replication and Extension

While the paper utilized small, rough cylindrical samples (20 ± 2 mm), 6CCVD specializes in providing materials tailored for precise integration into advanced systems:

Requirement in Paper (Ceramic Foam)	6CCVD Capability (MPCVD Diamond)	Value Proposition
Small, rough samples (20 ± 2 mm)	Custom Dimensions up to 125mm: We supply large-area PCD wafers and custom-cut SCD plates.	Enables scaling for industrial thermal management and large optical systems.
Thickness up to 20 mm (sample height)	Precise Thickness Control: SCD (0.1 µm - 500 µm), PCD (0.1 µm - 500 µm), Substrates (up to 10 mm).	Critical for optimizing thermal resistance and optical path length.
No surface finishing specified	Ultra-Low Roughness Polishing: SCD polished to Ra < 1 nm; Inch-size PCD polished to Ra < 5 nm.	Essential for high-power optics and minimizing interface thermal resistance in electronics.
Simple oxide/carbide composition	Custom Metalization: In-house deposition of Au, Pt, Pd, Ti, W, Cu, and other adhesion layers.	Facilitates direct integration into electronic packages, sensors, and micro-electromechanical systems (MEMS).

Engineering Support

6CCVD’s in-house PhD team provides expert consultation on material selection, orientation, and surface preparation for projects requiring extreme performance. We assist researchers transitioning from low-value waste streams to high-value diamond applications, such as:

Optimizing SCD orientation for maximum thermal spreading in High-Power Laser Systems.
Designing custom BDD electrodes for Advanced Electrochemical Sensing.
Selecting the ideal PCD grade and thickness for 5G/6G RF Heat Sinks.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We offer global shipping (DDU default, DDP available) to ensure timely delivery of your critical materials.

View Original Abstract

The possibility of obtaining building foamed glass-ceramic using the diamond concentration tailings of the Lomonosov deposit in Arkhangelsk Region, Russia, is demonstrated here. The effect of the tailings’ particle size distribution, feed temperature, the addition of a foaming agent, and the content of oxidizer on the feed charge foaming is established. The process conditions for obtaining foamed glass-ceramic materials are described. The specifications of the materials with the optimal composition (tailings 50 wt.%, glass waste 50 wt.%, SiC 0.5 wt.%, Fe2O3 1 wt.%) foamed at 1020-1050 °C were as follows: apparent density 0.23-0.51 g/cm3, compression strength 0.58-2.40 MPa, water absorption (by volume) 8.7-19.0%. Based on the combination of the measured properties when used in dry conditions, the obtained materials can be considered heat-insulating foam materials. The thermal conductivity was 0.060-0.066 W/m·K.

Tech Support

Original Source

DOI: https://doi.org/10.3390/ceramics6020068

References

2012 - Making foam glass based on natural and technogenic aluminosilicates [Crossref]
2021 - Use of bulk industrial wastes in the production of glass foam materials [Crossref]
2014 - Justification and design of electrochemical recovery of saponite from recycled water [Crossref]
2017 - Electrochemical modification of saponite for manufacture of ceramic building materials [Crossref]
2006 - Glass-ceramics: Their production from wastes—A Review [Crossref]
2013 - Self glazed glass ceramic foams from metallurgical slag and recycled glass [Crossref]
2018 - Preparation of sintered foamed ceramics derived entirely from coal fly ash [Crossref]
2018 - Preparation of glass-ceramic foams using extracted titanium tailing and glass waste as raw materials [Crossref]