Self-Propagating Reactions for Environmental Protection:  Treatment of Wastes Containing Asbestos

Porcu, Martina; Orru, Romano V. A.; Cincotti, Alberto; Cao, Giacomo

doi:10.1021/ie040058c

Cited by 18 publications

(11 citation statements)

References 28 publications

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“…In general, combustion wave velocity and maximum combustion temperature decreased with the increase in CRT glass amount. This was similar to a previous report studied on the treatment of wastes containing asbestos by SHS [24], where the combustion wave velocity and the combustion temperature also decreased as the amount of chrysotile in the starting mixture increased. This could be attributed to the fact that increasing CRT glass content in the starting mixture could decrease the relative amounts of Fe 2 O 3 and Mg, leading to the decrease in thermal energy released from the starting mixture.…”

Section: Self-propagating Processsupporting

confidence: 91%

“…In particular, 0.05 cm/s seemed to be the minimum combustion wave velocity for this system since mixture with a combustion wave velocity lower than 0.05 cm/s could not maintain self-combustion. The same limitation of 0.05 cm/s was also found in other SHS system used in treating/recycling asbestos [24].…”

Section: Self-propagating Processsupporting

confidence: 72%

“…It is also characterized by process simplicity, short reaction time, easy-to-build equipments, lowenergy requirements and the possibility of obtaining complex or meta-stable phases [22]. Furthermore, hazardous wastes, such as radioactive wastes [23], asbestos [24], and zinc hydrometallurgical waste [25], can be fixed into a highly insoluble polysilicate or pervoskite structure if the thermite reactions were appropriately designed. In this paper, SHS was used to dispose hazardous waste CRT glass.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Detoxification of cathode ray tube glass by self-propagating process

Chen

Zhang

Zhu

2009

Journal of Hazardous Materials

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a b s t r a c tA novel process for the treatment of hazardous waste Cathode Ray Tube (CRT) glass, based on selfpropagating reaction, was proposed. In the process, various types of CRT glass powders were blended with suitable amount of ferric oxide and magnesium, and the mixtures could generate self-propagating reaction once locally ignited by a thermal source. Generally, the self-propagating reaction could be well maintained when the CRT glass content in the mixture was no more than 60 wt.%, and the combustion wave velocity and maximum combustion temperature decreased along with the increase in glass amount. XPS experiments showed that heavy elements in the final products became more stable and were solidified during the process. Leaching tests demonstrated that heavy metals in the final products fulfilled the environmental regulations of USEPA. It is supposed that the detoxified products have the potential of being used as construction materials.

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Section: Self-propagating Processsupporting

confidence: 91%

Section: Self-propagating Processsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

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Detoxification of cathode ray tube glass by self-propagating process

Chen

Zhang

Zhu

2009

Journal of Hazardous Materials

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“…insulation, fire-retardants, floor tiles, and roofing products) (Porcu et al, 2005;Colangelo et al, 2011). In light of the potential detrimental effects on human health caused by chrysotile asbestos, the World Health Organization (WHO) has classified all types of asbestos as carcinogenic to humans and restricts use of asbestos in structural materials (Nishikawa et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

High-Temperature Transformation of Asbestos Tailings by Carbothermal Reduction

Huang

Pan

et al. 2013

Clays and clay miner.

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The production and industrial use of asbestos cement and other asbestos-containing materials have been restricted in most countries because of the potential detrimental effects on human health and the environment. Chrysotile is the most common form of asbestos and investigations into how to recycle this serpentine phyllosilicate mineral have attracted extensive attention. Chrysotile asbestos tailings can be transformed thermally, at high temperature, by in situ carbothermal reduction (CR). The CR method aims to maximize use of the chrysotile available and uses high temperatures and carbon to change the mineral form and structure of the chrysotile asbestos tailings. When chrysotile asbestos is employed as the raw material and coke (carbon) powder is used as the reducing agent for CR transformation, stable, hightemperature composites consisting of forsterite, stishovite, and silicon carbide are formed. Forsterite (Mg 2 SiO 4 ) was the most abundant crystalline phase formed in samples heat treated below 1500ºC. At 1600ºC, forsterite was exhausted through decomposition and b-SiC formed by reduction of stishovite. A larger proportion of b-SiC was generated as the carbon content was increased. This research revealed that both temperature and carbon addition play key roles in the transformation of chrysotile asbestos tailings.

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“…Self-propagating reaction of ACW using the thermite reaction with ferric oxide and magnesium has been reported for the alternative approach to decompose ACW [19]. The mechanochemical method, by which ACW is converted into amorphous materials, is a very simple process [20].…”

Section: Introductionmentioning

confidence: 99%

A novel decomposition technique of friable asbestos by CHClF2-decomposed acidic gas

Yanagisawa

Kozawa

Onda

et al. 2009

Journal of Hazardous Materials

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Asbestos was widely used in numerous materials and building products due to their desirable properties. It is, however, well known that asbestos inhalation causes health damage and its inexpensive decomposition technique is necessary to be developed for pollution prevention. We report here an innovative decomposition technique of friable asbestos by acidic gas (HF and HCl) generated from the decomposition of CHClF 2 by the reaction with superheated steam at 800 °C.Chrysotile-asbestos fibers were completely decomposed to sellaite and magnesium silicofluoride hexahydrate by the reaction with CHClF 2 -decomposed acidic gas at 150 °C for 30 min. At high temperatures beyond 400 °C, sellaite and hematite were detected in the decomposed product. In addition, crocidolite-asbestos containing wastes and amosite-asbestos containing wastes were also decomposed by CHClF 2 -decomposed acidic gas at 500 °C and 600 °C for 30 min, respectively. The observation of the reaction products by phase-contrast microscopy (PCM) confirmed that the resulting products did not contain any asbestos.

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Self-Propagating Reactions for Environmental Protection: Treatment of Wastes Containing Asbestos

Cited by 18 publications

References 28 publications

Detoxification of cathode ray tube glass by self-propagating process

Detoxification of cathode ray tube glass by self-propagating process

High-Temperature Transformation of Asbestos Tailings by Carbothermal Reduction

A novel decomposition technique of friable asbestos by CHClF2-decomposed acidic gas

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