Characteristics and reactivities of Ca(OH)2/silica fume sorbents for low-temperature flue gas desulfurization

Lin, Ren-Bin; Shih, Shin‐Min; Liu, Chiung-Fang

doi:10.1016/s0009-2509(03)00222-7

Cited by 54 publications

(46 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8). The appearance of these morphologies (also confirmed by EDAX analysis) and their prevalence was a clear evidence of the large extent of the pozzolanic reaction, confirming previous data of XRD and TG studies [42,43]. In the control group (NS-free sample) irregular agglomerations of scalenohedral calcite crystals could be observed together with a few hexagonal plate-like crystals of portlandite not yet carbonated.…”

Section: Assessment Of the Fresh-and Hardened-state Propertiessupporting

confidence: 87%

Long-term mechanical resistance and durability of air lime mortars with large additions of nanosilica

Durán

Navarro-Blasco

Fernández

et al. 2014

Construction and Building Materials

View full text Add to dashboard Cite

The performance of air lime mortars modified by the incorporation of large amounts of nanostructured colloidal silica -nanosilica, NS -(6, 10 and 20 wt.% with respect to lime) was the main objective of this work. Fresh mixture properties (water demand, setting time and plastic shrinkage), mechanical strengths up to one year and specimens' durability after accelerated ageing conditions (climatic chamber, freeze-thaw cycles and sulfate attack by MgSO 4 corrosion test) were evaluated. NS was seen to have a strong pozzolanic activity in air lime media. Although the addition of NS gave rise to an increase in volume contraction, the superficial cracking caused by the drying shrinkage was reduced. A noticeable increase in the compressive strength values was observed in the NS-bearing mortars owing to the NS filler effect and the C-S-H formation, as proved by SEM examination and MIP analysis. A honeycomb-shaped network of C-S-H phases appeared as the prevailing microstructure in mortars with large NS additions.In the face of accelerated ageing processes, the presence of NS made the mortars more durable, delaying the progress of decay.3

show abstract

Section: Assessment Of the Fresh-and Hardened-state Propertiessupporting

confidence: 87%

Long-term mechanical resistance and durability of air lime mortars with large additions of nanosilica

Durán

Navarro-Blasco

Fernández

et al. 2014

Construction and Building Materials

View full text Add to dashboard Cite

show abstract

“…On the other hand, SEM micrographs show different C-S-H structures, 489 made up of honeycomb, fibres and flakes or thin foil shapes (Fig. 9) [25,57]. 490…”

mentioning

confidence: 99%

Influence of nanosilica and a polycarboxylate ether superplasticizer on the performance of lime mortars

Fernández

Durán

Navarro-Blasco

et al. 2013

Cement and Concrete Research

123

View full text Add to dashboard Cite

39The effect of individual and combined addition of both nanosilica (NS) and 40 polycarboxylate-ether plasticizer (PCE) admixtures on aerial lime mortars was studied. 41The sole incorporation of NS increased the water demand, as proved by the mini-spread 42 flow test. An interaction between NS and hydrated lime particles was observed in fresh 43 mixtures by means of particle size distribution studies, zeta potential measurements and 44 optical microscopy, giving rise to agglomerates. On the other hand, the addition of PCE 45 to a lime mortar increased the flowability and accelerated the setting process. PCE was 46shown to act in lime media as a deflocculating agent, reducing the particle size of the 47 agglomerates through a steric hindrance mechanism. Mechanical strengths were 48 improved in the presence of either NS or PCE, the optimum being attained in the 49 combined presence of both admixtures that involved relevant microstructural 50 modifications, as proved by pore size distributions and SEM observations. 51 the technical characteristics of the final product and/or addressing environmental issues 58 [3][4][5]. The addition of nanosilica (NS) has attracted increasing interest because of the 59 filling effect, which improves the particle size distribution, thus reducing porosity, and 60 the pozzolanic reaction between NS and calcium hydroxide (CH) yielding calcium 61 silicate hydrates (C-S-H). These actions result in enhanced mechanical strength [6][7][8]. 62The filling of the interparticle space leads to a denser packing and reduces the water 63 demand, as there is no need to fill the space with water. In this case, the use of a 64 superplasticizer is required in order to guarantee workability [9]. Furthermore, the 65 strong tendency of NS to agglomerate also may make it necessary to use a dispersing 66 additive in order to overcome this problem and to ensure enough reactive surface for the 67 filling effect and C-S-H formation [7,10,11]. Dispersing additives are the so-called 68 plasticizers or superplasticizers, which have a water reducing action on cement 69 materials. When superplasticizers are added, workability at a constant water/cement 70 ratio is improved. Alternatively, the same workability as that of plain cement paste can 71 be reached with an outstanding reduction in water content. In the latter case, cement 72 materials with higher mechanical strengths can be obtained. The adsorption of the 73 plasticizer molecules on the solid particles, either by modifying the surface charge (zeta 74 potential) of the particles, thus increasing the electrostatic repulsion, or by steric 75 hindrance, causes a dispersing action, which has been claimed to be responsible for the 76 increase in fluidity of the cement paste [12]. The interaction between the 77 superplasticizer and the particles of the binder could be affected by the presence of 78 4 mineral additions (such as NS, silica fume or fly ash), which means that the 79 compatibility between them needs to be studied [13]. 80 81The interest in usi...

show abstract

“…In addition, SO2 and SO3 are harmful gases that contribute to formation of submicron acid particles that can penetrate human lungs and be absorbed into the bloodstream [144]. Many researchers have reported that blending FA with Ca(OH)2 or CaO can produce an adsorbent via a hydration process with a better SO2 reduction than that of hydrated lime [145][146][147]. Lee et al [148] found similar results, as shown in Figure 13.…”

Section: Sulfur Dioxidementioning

confidence: 83%

Fabrication of Multifunctional Hybrid Composites Using Fly Ash to Control Environmental Pollutants: A Review

Ge¹,

Yoon²,

Choi³

2018

Preprint

View full text Add to dashboard Cite

Air pollutants such as volatile organic compounds (VOCs), nitrogen oxides (NOx), sulfur dioxide (SO2), as well as water pollutants including heavy metal, are harmful to human and environment. Effective control and reduction of their pollution is therefore an important topic for today's scientists. Fly ash (FA) is a type of industrial waste that can cause multiple environmental problems if discharged into the air. On the other hand, because of its high porosity, large specific surface area, and other unique characteristics, the FA can also be used as a low-cost and high efficient adsorbent with some simple modifications. This paper reviews the effects of FA on treatment of the above air and water pollution based on our research experience over many years, including to the current status of global FA utilization, physicochemical properties, principle of adsorption, and the application direction of FA in the future. It focuses on the use of nanocomposite technology to fabricate functional FA fibrous membranes to adsorb VOCs from air, and treat heavy metal wastewater. This present review first describes the fabrication technology of FA nanocomposites and their mechanism of adsorption VOCs from air. Utilization of nanofiber technology to fabricate multi-functional FA emerging composite materials to mitigate air and water pollution has great potential in the future, especially use of pollutant material to control other pollutants.

show abstract

Characteristics and reactivities of Ca(OH)2/silica fume sorbents for low-temperature flue gas desulfurization

Cited by 54 publications

References 22 publications

Long-term mechanical resistance and durability of air lime mortars with large additions of nanosilica

Long-term mechanical resistance and durability of air lime mortars with large additions of nanosilica

Influence of nanosilica and a polycarboxylate ether superplasticizer on the performance of lime mortars

Fabrication of Multifunctional Hybrid Composites Using Fly Ash to Control Environmental Pollutants: A Review

Contact Info

Product

Resources

About