Preparation of phosphoric acid-based porous geopolymers

Liu, Leping; Xue-min, Cui; Qiu, Shuheng; Jun-li, Yu; Zhang, Lin

doi:10.1016/j.clay.2010.10.004

Cited by 146 publications

(45 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Later on, the aluminosilicate precursors consolidated by phosphates or orthophosphoric acids were explored for preparing refractory castables (Kingery, 1950(Kingery, , 1952 which can be defined as phosphate activation of the aluminosilicates to yield an SAP geopolymer with excellent durability and high temperature resistance (Wagh, 2016). The use of phosphate or phosphoric acid as an activator allows the chemical interaction with the aluminosilicates to produce geopolymeric binder with condensed poly(silico-alumino-phosphate) phases (Cao et al, 2005;Liu et al, 2010).…”

Section: Sap Geopolymermentioning

confidence: 99%

“…Thus, such high-connectivity molecular structures of the formed products can perform excellently in terms of strength and durability (Walkley et al, 2017). Later on, the phosphate-activated aluminosilicate was developed and incorporated into the geopolymer category due to the similar condensation process (Liu et al, 2010;Davidovits, 2011;Guo et al, 2016;Wang et al, , 2018b.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review

2019

View full text Add to dashboard Cite

Chemically activated materials (often termed as geopolymer) have received attracting attentions in civil, material and environmental research fields as a toolkit alternative to traditional Portland cement in specific applications. This paper presents a comparative review on silico-aluminophosphate (SAP) geopolymers in terms of definition, chemistries involved during geopolymerization, mechanical performance, durability, environmental impacts, and their potentials in applications relative to conventional alkali-aluminosilicate (AAS) geopolymers. Recommendations for future applications are also highlighted. It is found that S-A-P gels with six-coordinated aluminum environment dominate in SAP geopolymers, while the aluminum in N-A-S-H gels formed in the AAS geopolymers is characterized by four-coordinated features. Besides, the slow performance development of SAP geopolymer matrix under ambient temperature curing can be compensated through incorporating additional countermeasures (e.g., metal sources) which allow the tailored design of such geopolymers for certain in-situ applications. Generally, the calcium-bearing C-(A)-S-H gels co-existing with N-A-S-H gels are dominant in AAS geopolymers, while the S-A-P gels enhanced by phosphate-containing crystalline/amorphous phases are the main products in SAP geopolymers. The SAP geopolymers show their environmental friendliness relative to the AAS geopolymers due to the utilization of phosphate activators that require lower production energy relative to silicate-containing activators. However, the higher cost of phosphate activators may confine the applications of SAP geopolymers in some exquisite or special fields.

show abstract

Section: Sap Geopolymermentioning

confidence: 99%

mentioning

confidence: 99%

Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review

2019

View full text Add to dashboard Cite

show abstract

“…Even though the term geopolymer is sometimes used imprecisely to describe all inorganic chemically bonded solids, including the ones produced from mixture of phosphoric acid and a source of aluminosilicate (Douiri et al 2014;Le-ping et al 2010;L. Liu et al 2012), this review will limit the use of the term geopolymerization exclusively to alkali activated processes.…”

Section: Phosphate Bonded Ceramics and Processingmentioning

confidence: 99%

“…Heat pretreatments, namely calcination, are usually done for purpose of increasing the reactivity in the raw material. Kaolin can be calcined to produce metakaolin, which in addition to alkali activation, can be used as a precursor for phosphate bonded ceramics as well (Le-ping et al 2010;Douiri et al 2014). On the other hand, excessively high solubility and dissolution rate of some laboratory grade oxides such as MgO, CaO and ZnO is undesired, since overly rapid reactions only produce precipitates instead of an extensive 3Dnetwork.…”

Section: Pretreatments To Adjust Reactivity For Phosphate Bond Formationmentioning

confidence: 99%

Recycling mine tailings in chemically bonded ceramics – A review

Kinnunen

Ismailov

Solismaa

et al. 2018

Journal of Cleaner Production

161

View full text Add to dashboard Cite

Mine tailings account for most of the environmental incidents related to the extractive industry, with risks increasing due to steadily rising tonnage of low-grade ore and extreme weather events. Recycling of tailings in raw-material-intensive applications presents an interesting alternative to costly tailings management with associated restoration efforts. Chemically bonded ceramics may offer a route to upgrading mine tailings into raw materials for ceramics. In this review such chemically bonded ceramic methods that may be used to recycle mine tailings as raw materials, are reviewed while focusing in particular on two methods: 1) geopolymerization/alkali activation and 2) chemically bonded phosphate ceramics. The aim of the review is not to give exhaustive review on the wide topic, but to scope the required boundary conditions that need to be met for such utilization. According to the findings, alkali activation has been studied for 28 separate silicate minerals in the scientific literature, and presents a viable method, which is already in commercial use in calcium-rich cement-like binder applications. Phosphate bonding literature is more focused on phosphate containing minerals and waste encapsulation. Very little work has been done on low-calcium tailings utilization with either technology, and more knowledge is needed on the effect of different pretreatment methods to increase reactivity of mine tailings in chemically bonded ceramics.

show abstract

“…The phases of MK-based geopolymers obtained with phosphoric acid were reported to be thermally stable, with linear shrinkage of 5.3% after exposure at 1450 °C [14]. Also, phosphoric acid activation of synthetic Al 2 O 3 -2SiO 2 powders showed extremely high thermal stability of phases with no sign of melting up to 1550 °C [15].…”

Section: Introductionmentioning

confidence: 99%

Phase and dimensional stability of volcanic ash-based phosphate inorganic polymers at elevated temperatures

Djobo

Elimbi

2020

SN Appl. Sci.

View full text Add to dashboard Cite

Phosphate geopolymers are part of chemically bonded phosphate cements obtained from an aluminosilicate and phosphate solution. Their structure consisting of phosphate bonds makes them suitable for use as refractory material. This study deals with the influence of phosphoric acid concentration (6, 8 and 10 mol/L) on the stability of volcanic ash-based phosphate geopolymers exposed to 100, 600 and 1000 °C. The results reveal that the onset of crystallization is about 600 °C with the formation of aluminum phosphate (V) and tridymite, then crystallization of iron (III) phosphate (V) and hematite at 1000 °C. The degree of crystallization of these phases increases with phosphoric acid concentration. The geopolymers obtained with 8 mol/L of phosphoric acid showed the best thermal stability at 1000 °C in terms of compressive strength change. The maximum thermal linear shrinkage recorded was 3%. The major phases of all geopolymers remain stable up to 1000 °C, after which the melting of phases happens.

show abstract

Preparation of phosphoric acid-based porous geopolymers

Cited by 146 publications

References 10 publications

Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review

Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review

Recycling mine tailings in chemically bonded ceramics – A review

Phase and dimensional stability of volcanic ash-based phosphate inorganic polymers at elevated temperatures

Contact Info

Product

Resources

About