Electrodialytically treated MSWI fly ash use in clay bricks

Abstract

Fly ash from municipal solid waste incineration (MSWI) is classified as hazardous waste, due to high heavy metal and salt content. Thus, beneficial use is restricted, and the fly ash hazardousness should be reduced before testing reuse options. Electrodialytic treatment can remove heavy metals and soluble salts and be used to decontaminate MSWI fly ash. In Greenland, MSWI fly ash is stored at uncontrolled disposal sites, and a more sustainable solution for handling fly ash is needed. At the same time, most construction materials are imported from Europe to Greenland, and increased use of local materials would greatly benefit the circular economy in the area. In this study, it was investigated if local Greenlandic resources could have potential in brickmaking. Two different clays; a Danish clay (used commercially in brick production) and one Greenlandic (not used commercially) and raw and electrodialytically treated MSWI fly ash from Sisimiut, Greenland were used. Small clay discs with a 0, 10, 20 and 30 % substitution of clay by MSWI fly ash were fired at 1000 º C for 24h. Substituting clay with fly ash generally resulted in lower technical properties of the clay discs. From this initial screening, the clay discs with electrodialytically treated fly ash and Greenlandic clay showed the lowest porosity and water absorption, which could be beneficial for use as construction material in cold climates.

Influence of Sintering on Thermal, Mechanical and Technological Properties of Glass Foams Produced from Agro-Industrial Residues

“…Today, there is a growing worldwide concern regarding the uncontrolled disposal of wastes in the environment, which makes recycling fundamental in the production of new materials [ 1 ] because it presents advantages such as decreased energy consumption and mitigation of greenhouse gas (CO 2 , SO x and NO x ) emissions [ 2 , 3 , 4 ]. Recycling can reduce the use of natural and synthetic raw materials, adding value to waste by transforming it into a co-product, and thus strengthening the circular economy of regions through its commercialization and processing [ 5 , 6 , 7 , 8 ].…”

MSWI Fly Ash Multiple Washing: Kinetics of Dissolution in Water, as Function of Time, Temperature and Dilution

“…The re-valorization of MSWI-FA, or at least its safe disposal, is primarily related to being able to enhance its stability in water and curb as much as possible its heavy metal leaching, using treatments of low environmental impact that are economically sustainable. Among the most common treatments to remove/curb chloride and heavy metals (primarily Zn, Pb, Cu, and Cd) are: washing with water, deionized, or added with basic leaching solvents [23][24][25]; thermal treatments in rotary kilns [26]; bioleaching (or microbial leaching, a biohydrometallurgical technology that can be applied for metal recovery) [27]; electrolytic treatments [28,29]; carbonation, reacting with CO 2 to produce stable carbonate [30]; and geo-polymerization, a geosynthetic reaction of aluminosilicate minerals in the presence of an alkali solution at low temperatures, to stabilize and immobilize fly ash [31,32].…”

A Novel Process for the Containment of SO2 Emissions from Class C Fly Ash in the Fired Materials by Haüyne Formation

“…The fundamental component in the raw materials mixture for the preparation of ceramic tiles is alkali-activated coal Class F fly ash (e.g., quartz, hematite, mullite, glass phase) [ 11 , 12 ]. CCFA has been successfully used for the preparation of glass-ceramic materials [ 13 , 14 , 15 , 16 ] and fired bricks [ 17 , 18 , 19 ]. The milling of fly ashes improves the sintering activity of fly ash-clay mixtures [ 6 , 20 ].…”

“…Despite abundant laboratory research [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], there are no examples of a broad application of CCFA within the production of fired building materials because the decomposition of anhydrite and the resulting re-release of sulfur dioxide (SO 2 ) into the atmosphere has not been solved. The previous research only provides information about the temperature ranges of the SO 2 content in the flue gas during the firing of pure CCFA bodies or the mixtures containing CCFA [ 24 , 25 ].…”