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The Nature, Sources, and Environmental Chemistry of Hazardous Wastes
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Some wastes that might exhibit a degree of hazard are exempt from RCRA regulation by legislation. These exempt wastes include the following: Fuel ash and scrubber sludge from power generation by utilities.Oil and gas drilling muds.By-product brine from petroleum production.Cement kiln dust.Waste and sludge from phosphate mining and beneficiation.Mining wastes from uranium and other minerals.Household wastes.
Summary of Other Remediation Systems
Published in Jimmy H.C. Wong, Chin Hong Lim, Greg L. Nolen, Design of Remediation Systems, 2020
Jimmy H.C. Wong, Chin Hong Lim, Greg L. Nolen
Solidification refers to the addition of chemicals to the soil structure to produce an inmobile mass. It is also known by various other terms, such as soil stabilization, encapsulation, or chemical fixation. The basis for the remediation is not destruction of the contaminant, but immobilization. Chemicals incorporated into the contaminated soil include Portland cement and other lime-containing products, such as flyash, groundblast furnace slag, or cement kiln dust.
The Use of Scrap Tires in Rotary Cement Kilns
Published in Robert E. Landreth, Paul A. Rebers, Municipal Solid Wastes, 2020
Michael H. Blumenthal, Edward C. Weatherhead
Another point of interest is that tires tend to have a lower percentage of sulfur than most coals. Sulfur in tires ranges from 1.24 to 1.30% by weight. Sulfur in coal ranges from 1.1 to 2.3% or higher, depending on the coal quality. The average coal used in cement manufacturing will run approximately 1.5% sulfur. Calcium carbonate, the largest single ingredient in cement, is one of the most effective natural sulfur gas scrubbers. The presence of calcium carbonate helps control sulfur emissions from a cement kiln. Emissions data from a variety of kilns has clearly demonstrated a consistent reduction in sulfur and other emissions with the use of TDF (Figure 7.2a–2d). Since all the components of the tires are either destroyed, combined into the clinker or captured in the APCD, there is no ash disposal. Finally, the components of the scrap tire, once chemically combined into the clinker, are not capable of leaching out. This is comparable to silica not leaching from glass. In short, the cement kilns use 100% of the scrap tire in an environmentally sound manner.
Long-term effects of Cement Kiln Dust (CKD) on erosion control of a soil slope
Published in International Journal of Geotechnical Engineering, 2022
Hamid Ranjkesh Adarmanabadi, Arezou Rasti, Mehrdad Razavi
Erosion control uses one or more techniques based on the area’s geometry and geotechnical properties to prevent soil movement or make it less (Fay, Akin, and Shi 2012). Slope stabilization may be done by adding a surface cover, support structure, or changing the slope’s geometry and material to prevent failure or reduce erosion. Chemical compounds complying with environmental laws can stabilize soil (Faramarzi, Rasti, and Abtahi 2016; Ghazvinian and Razavi 2010). Cement kiln dust (CKD) is one of the chemical additives for soil stabilization. It is the waste of cement production releasing from the cement factory to the environment (Adaska and Taubert 2008). CKD is a fine, powdery, and highly alkaline material that contains sodium chlorides, potassium chlorides, sulphates, and volatile metal compounds. CKD collected from kiln exhaust in the term of cement production (Siddique 2006). CKD can be used in manufacturing, agriculture, civil engineering, and environmental sectors. The most crucial application of CKD includes blended cement and concrete, mine reclamation, agricultural amendment, water treatment, sewage treatment, asphalt mixtures, building ceramics, waste stabilization, and soil stabilizing (Siddique 2014).
Flexural properties of chemically stabilised subgrade in designing semi-rigid pavements
Published in Road Materials and Pavement Design, 2019
Moeen Nazari, Rouzbeh Ghabchi, Musharraf Zaman
Due to stabilisation with chemical additives, such as cement kiln dust (CKD), lime, cement, and fly-ash (CFA), the soil gains tensile strength (Little, 2000). Therefore, the flexural characteristics of the chemically-stabilised subgrade (CSS) layer become more dominant compared to untreated subgrades (Zhang, Li, & Wei, 2010). Thus, it is important to consider the flexural behaviour of a CSS layer in pavement design. The significance of determining the flexural modulus of the CSS layer in evaluating the overall performance of the pavement structure has been highlighted by several researchers (Arnold, Morkel, & van der Weshuizen, 2012; Austroads, 2004; Jameson, Sharp, & Yeo, 1992; Pretorius & Monismith, 1972; Siripun, Jitsangiam, Nikraz, & Leek, 2012; Yeo, 2008; Zaman, Khouri, & Solanki, 2009). Also, previous studies show that if the flexural modulus is measured at the strain levels and load/strain application rates close to those occurring in the field, the flexural modulus values could be higher than the resilient modulus of the CSS material (Mandal, 2013; Nazari, Ghabchi, Zaman, & Commuri, 2016; Solanki, 2010).
A review on soil stabilisation of unsealed road pavements from an Australian perspective
Published in Road Materials and Pavement Design, 2023
J. Pooni, D. Robert, F. Giustozzi, C. Gunasekara, S. Setunge
Cement kiln dust (CKD) is a by-product from cement manufacture removed from the cement kiln exhaust gases by the pollution control system. CKD contains high calcium oxide (CaO) and high alkali contents making it effective in soil stabilisation (Baghdadi et al., 1995; Baghdadi & Rahman, 1990; Miller & Azad, 2000; Peethamparan et al., 2008). However, the chemical and physical properties of CKD largely vary among plants, being influenced by the type of cement kiln, the properties of the raw materials used in the production of the cement, and the type of dust collection system (Miller & Zaman, 2000; Peethamparan et al., 2008; Peethamparan & Olek, 2008; Si & Herrera, 2007).