Immobilization of strontium-loaded zeolite A by metakaolin based-geopolymer

Fabrication and Fireproofing Performance of the Coal Fly Ash-Metakaolin-Based Geopolymer Foams

“…As can be seen from Figure 4, when the addition amount of CFA increases from 0% to 12%, the thermal conductivity of GFs declines from 0.0944 W/(m·K) and 0.0871 W/(m·K), which is close to the results in the present study [36,37]. In fact, the increase of porosity reduces the volume of the skeleton structure, and the thermal conductivity of it is much higher than which suggested that the mechanical strength usually decreases with the increase of porosity [26][27][28], the porosity increase of the GFs has not had a negative impact on the strength development in this investigation. This is mainly owing to the following two reasons: (1) the high pozzolanic activity of CFA would be helpful to improve the mechanical strengths of MK GFs [29][30][31][32]; (2) the CFA addition could improve the rheological property of geopolymer slurry and help to form the porous geopolymer blocks with more uniform porous structure [24], which may be beneficial to the mechanical strengths development [33,34].…”

“…With the increase of the CFA addition amount, the compressive strength and flexural strength increase from 0.38 Mpa to 0.5623 Mpa and 0.108 Mpa to 0.283 Mpa, respectively. Unlike other research, which suggested that the mechanical strength usually decreases with the increase of porosity [26][27][28], the porosity increase of the GFs has not had a negative impact on the strength development in this investigation. This is mainly owing to the following two reasons: (1) the high pozzolanic activity of CFA would be helpful to improve the mechanical strengths of MK GFs [29][30][31][32];…”

Alkali aluminosilicate geopolymers as binders to encapsulate strontium-selective titanate ion-exchangers

“…90 Sr 2+ , 137 Cs + ). [31][32][33] Studies using geopolymer binders to encapsulate zeolite-type ion-exchangers have shown that geopolymer waste forms were more mechanically durable and chemically stable than Portland cement-based waste forms, 17,34,35 even though chemical interaction between the zeolite ion-exchangers and the gel binders was observed. 17,34 However, there has not been any published study of the chemical and physical stability of geopolymer waste forms encapsulating titanate-type spent ion-exchangers.…”

Solidification of electroplating sludge with alkali-activated fly ash to prepare a non-burnt brick and its risk assessment

“…[15][16][17] In addition, geopolymers usually have lower CO 2 emission, lower-cost raw materials, simpler preparation process, more energy-saving ability, much better chemical corrosion resistance and more effective immobilization of toxic HMs when compared with Ordinary Portland Cement (OPC). 11,[18][19][20][21][22][23] The addition of OPC is benecial for the compressive strength development of y ash geopolymers under ambient conditions, which is supported by some studies. [24][25][26][27][28] According to the literature, several scientists have used geopolymers for the solidication of ES.…”