Mineral extraction from asbestos-containing waste (ACW) and changes in its morphology during treatment with ammonium salts

ABSTRACT

Asbestos is a known carcinogen and a banned hazardous material. However, the generation of asbestos-containing waste (ACW) is increasing because of the demolition of old constructions, buildings, and structures. Therefore, asbestos-containing wastes need to be effectively treated to render them harmless. This study aimed to stabilize asbestos wastes by using for the first time three different ammonium salts at low reaction temperatures. The treatment was performed with ammonium sulfate (AS), ammonium nitrate (AN), and ammonium chloride (AC) at concentrations of 0.1, 0.5, 1.0, and 2.0 M and reaction times of 10, 30, 60, 120, and 360 min intervals at 60 °C. Asbestos waste samples were treated in both plate and powder form during the experiment. The results demonstrated that the selected ammonium salts could extract the mineral ions from asbestos materials at a relatively low temperature. Concentrations of the minerals extracted from powdered samples were higher than those extracted from plate samples. AS treatment demonstrated better extractability compared to that of AN and AC, based on the concentrations of magnesium and silicon ions in the extract. The results implied that among the three ammonium salts, AS had better potential to stabilize the asbestos waste. This study demonstrated the potential of ammonium salts for treating and stabilizing asbestos waste at low temperatures by extracting the mineral ions from the asbestos fibers.

Implications: This study aims to establish an effective treatment to stabilize the hazardous asbestos waste to harmless forms. We have attempted treatment of asbestos with three ammonium salts (ammonium sulfate, ammonium nitrate, ammonium chloride) at relatively lower temperature. The selected ammonium salts could extract the mineral ions from asbestos materials at a relatively low temperature. These results suppose that asbestos containing materials could change the harmless state by using simple method. Among the ammonium salts, especially, AS has better potential to stabilize the asbestos waste.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, [Gwangmok Kim] and first author [Sangwon Park] upon reasonable request.

Additional information

Funding

This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Science, ICT and Future Planning.This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korean government (MOTIE) (20212010200080, In-situ carbonation technology development using CO₂ emissions from the cement industry).

Notes on contributors

Sangwon Park

Sangwon Park is a Ph.D in chemical engineering. He has been studying CO2 utilization and waste reuse method. His specialities include: CO2 absorption, CO2 utilization and developing its process, recovery of the valuable metals and minerals from waste, waste management etc. He is currently working for Korea institute of geoscience and mineral resources(KIGAM) as a principle researcher.

Yeon-Sik Bong

Yeon-Sik Bong is a Ph.D scientist who has worked in the Korea Basic Scientist Institute(KBSI) for more than 20 years. Her specialties include isotope geochemistry, and traces country of geographical origin using stable isotope ratio mass spectrometer.

Gwangmok Kim

Gwangmok Kim is a Ph.D in civil engineering. His research interests are multi- and cross-disciplinary, and are primarily concerned with micromechanics of advanced engineering materials, and development of sustainable and functional construction materials with an emphasis on the integration with nano-technology. He is currently working for Korea institute of geoscience and mineral resources as a senior researcher.