Leaching characteristics of Cr in municipal solid waste incineration fly ash solidified/stabilized using blast furnace slag-based cementitious materials

2021 ◽  
Author(s):  
K. Wang ◽  
K. Li ◽  
X. Huang ◽  
W. Ni ◽  
S. Zhang
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Municipal Solid Waste ◽  
Blast Furnace Slag ◽  
Waste Incineration ◽  
Cementitious Materials ◽  
Municipal Solid Waste Incineration ◽  
Leaching Characteristics ◽  
Furnace Slag ◽  
Waste Incineration Fly Ash

scholarly journals Use of Slag from the Combustion of Solid Municipal Waste as A Partial Replacement of Cement in Mortar and Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1593
Author(s):  
Monika Czop ◽  
Beata Łaźniewska-Piekarczyk
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Municipal Solid Waste ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additives ◽  
Furnace Slag

In Europe, the use of wastes in the cement and construction industry follows the assumptions of sustainability and the idea of circular economy. At present, it is observed that cement plants introduce wastes to the cement in the form of so-called mineral additives. The most often used mineral additives are: fly ash with silica fume, granulated blast furnace slag and silica fume. The use of mineral additives in the cement is related to the fact that the use of the most expensive component of cement—Portland cement clinker—is limited. The purpose of the article is a preliminary evaluation of the suitability of slag from the municipal solid waste incineration plant for its use as a replacement of cement. In this article, slag from the municipal solid waste incineration (MSWI) replaces cement in the quantity of 30%, and presents the content of oxides and elements of slag from the MSWI. The obtained results are compared to the requirements that the crushed and granulated blast furnace slag need to meet to be suitable for use as an additive of type II to the concrete. The conducted analyses confirmed that the tested slag meets the requirements for the granulated blast furnace slag as an additive to the concrete in the following parameters: CaO ≤ 18.0%, SO3 ≤ 2.5% and Cl ≤ 0.1%. At the same time, mechanical features were tested of the designed mortars which consisted of a mixture of Portland cement (CEM I) with 30% of slag admixture. The designed mortar after 28 days of maturing reached a compressive strength of 32.0 MPa, and bending strength of 4.0 MPa. When compared to the milled granulated blast furnace slag (GBFS), the obtained values are slightly lower. Furthermore, the hardened mortars were subject to a leachability test to check the impact on the environment. Test results showed that the aqueous extracts from mixtures with 30% of slag admixtures slightly exceed the limits and do not pose a sufficiant threat to the environment as to eliminate the MSWI slag from economical use.

scholarly journals Use of Ladle Furnace Slag and Other Industrial By-Products to Encapsulate Chloride in Municipal Solid Waste Incineration Fly Ash

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 925 ◽  
Author(s):  
Ying Wang ◽  
Wen Ni ◽  
Prannoy Suraneni
Keyword(s):  
Fly Ash ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Material System ◽  
Ladle Furnace ◽  
Municipal Solid Waste Incineration ◽  
Friedel’S Salt ◽  
Furnace Slag ◽  
Waste Incineration Fly Ash

Municipal solid waste incineration fly ash (MSWIFA) is a hazardous by-product of waste incineration. The objective of this research is to encapsulate the chloride in MSWIFA and to develop a utilizable construction material using MSWIFA, ground granulated blast-furnace slag (GGBFS), ladle furnace slag (LFS), and gypsum. A secondary objective of the work is to explain the hydration and encapsulation mechanisms in this material system using isothermal calorimetry (IC), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and ion chromatography (IC). The predominant hydration products are ettringite, Friedel’s salt, and C-S-H gel, with Friedel’s salt and C-S-H dominating in systems high in LFS and ettringite and C-S-H gel dominating in systems low in LFS. The chloride encapsulation showed a strong correlation with the Friedel’s salt amount; however, some encapsulation was also likely due to physical binding in the C-S-H gel. In a system with 30% MSWIFA (by mass), the optimal amount of LFS for strength and chloride encapsulation is 20%–40% (by mass).

scholarly journals Optimal Mixture Designs for Heavy Metal Encapsulation in Municipal Solid Waste Incineration Fly Ash

2020 ◽  
Vol 10 (19) ◽  
pp. 6948
Author(s):  
Ying Wang ◽  
Wen Ni ◽  
Siqi Zhang ◽  
Jia Li ◽  
Prannoy Suraneni
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Strength Development ◽  
Municipal Solid Waste Incineration ◽  
Mixture Designs ◽  
Furnace Slag ◽  
Waste Incineration Fly Ash

Mixing municipal solid waste incineration fly ash (MSWIFA) with industrial by-products such as ground granulated blast furnace slag (GGBFS) and ladle furnace slag (LFS) can lead to a hardened system which can encapsulate the heavy metals present in the MSWIFA. The objective of this study is to find optimal mixture designs to effectively encapsulate these heavy metals. The nature of the hydrates and the strength of the mixtures are studied to develop a sustainable and practical construction material incorporating MSWIFA. Heavy metals including Cr, Cu, Zn and Cd are safely encapsulated in several developed mixtures with leachate concentration below EPA drinking water limit. The encapsulation behavior is complex and depends on metal type, age of testing, and hydration products. In general, mixtures containing LFS have more aluminate hydrates, and show greater encapsulation capacity for most heavy metals. However, they also generally show significant Sb leaching. Mixtures which show satisfactory encapsulation for all ions and adequate strength development are identified. Three ideal mixtures, including one containing zero cement, are identified which satisfy both leaching and strength requirements.

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