Mechanism of mechanical–chemical synergistic activation for preparation of mullite ceramics from high-alumina coal fly ash
Source abstract
Abstract
High-alumina coal fly ash (HAFA) is a special solid waste due to the existence of more than 45% alumina and 35% silica, which can be applied to prepare Al-Si series ceramics if the impurities can be removed and the Al/Si mass ratio can exceed 2.55 (Mullite: 3Al2O3.2SiO2). In this work, a new mechanical–chemical synergistic activation–desilication process is proposed, and the contents of different impurities can be lowered up to less than 1%, and the Al/Si mass ratio can be elevated from 1.26 to 2.71. Especially, the mechanism of this process is investigated in detail. The analysis of the mechanism shows that the decrease of Q4(3Al) and the increase of Q4(0Al), Q4(1Al), and Q4(2Al) improve amorphous silicate reactivity through synergistic activation, and the exposed amorphous Si-O-/Si-O-Si can be removed by OH- during the desilication process (desilicated ratio>55%), which help the fine mullite to exhibit excellent properties (bulk density > 2.85 g/cm3, apparent porosity < 0.5%) during the sintering process. Finally, this process not only decreases the pollution but also alleviates the shortage of Al/Si resources and promotes the clean development of coal-fired power generation.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Coal and Its By-products · Recycling and utilization of industrial and municipal waste in materials production · Advanced ceramic materials synthesis
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (34)
Show source-provided references
1. Alkali desilicated coal fly ash as substitute of bauxite in lime-soda sintering process for aluminum production10.1016/S1003-6326(10)60034-9 ↗
2. Synthesis and properties of zeolite/hydrated iron oxide composite from coal fly ash as efficient adsorbent to simultaneously retain cationic and anionic pollutants from water10.1016/j.fuel.2013.07.126 ↗
3. Feasible recycling of industrial waste coal fly ash for preparation of anorthite-cordierite based porous ceramic membrane supports with addition of dolomite10.1016/j.jeurceramsoc.2015.11.012 ↗
4. A review of the multi-component utilisation of coal fly ash10.1016/j.fuel.2012.03.024 ↗
5. Characteristics and the behavior in electrostatic precipitators of high-alumina coal fly ash from the Jungar power plant, Inner Mongolia, China
6. Abundances and distribution of minerals and elements in high-alumina coal fly ash from the Jungar Power Plant, Inner Mongolia, China10.1016/j.coal.2009.03.005 ↗
7. Asturian fly ash as a heavy metals removal material10.1016/S0016-2361(98)00027-1 ↗
8. The effect of mechanically and chemically activated fly ashes on mortar properties10.1016/j.fuel.2006.03.031 ↗
9. Conversion of coal fly ash to zeolite utilizing microwave and ultrasound energies: a review10.1016/j.fuel.2014.09.077 ↗
10. Comparative study on extracting alumina from circulating fluidized-bed and pulverized-coal fly ashes through salt activation10.1021/ef401659e ↗
11. Extraction of aluminum hydroxide from coal fly ash by pre-desilication and calcination methods
12. Alumina extraction from alumina rich fly ash generated from inner-Mongolia Chinese coal
13. Porous mullite ceramics derived from coal fly ash using a freeze-gel casting/polymer sponge technique10.1007/s10934-012-9591-0 ↗
14. Thermal expansion of slag and fly ash from coal gasification in IGCC power plant10.1016/j.fuel.2006.05.015 ↗
15. Utilization of coal fly ash in the glass–ceramic production10.1016/j.jhazmat.2007.07.044 ↗
16. Comparison of the properties of glass, glass–ceramic and ceramic materials produced from coal fly ash10.1016/j.jhazmat.2007.08.071 ↗
17. Effects of metal ions with different valences on colloidal aggregation in low-concentration silica colloidal systems characterized by continuous online zeta potential analysis10.1016/j.colsurfa.2015.04.024 ↗
18. Effects of sodaelimeesilica waste amorphous on mullite formation kinetics and micro-structures development in vitreous ceramics10.1016/j.jenvman.2013.02.048 ↗
19. Present situation and prospect of bauxite desiliconization technology
20. Microbe mineral processing for bauxite
21. Selective crushing and grinding to process bauxite with middle -low grad
22. Experimental study on feasibility of gravity separation of a low-grade bauxite ore
23. Action of sodium bexametaphosphateand sodium oleate on bauxite mineral
24. Study on the necessity and flexibility of selective grinding for bauxite
25. Desilication from diasporic bauxite by roasting-alkali leaching process (I)
26. Preparation of mullite from desilication-fly ash10.1016/j.fuel.2010.07.042 ↗
27. Effects and Mechanism Research of the Desilication Pretreatment for High-Aluminum Fly Ash10.1021/ef4012005 ↗
28. Acid activation for pre-desilicated high-alumina fly ash10.1016/j.fuproc.2016.05.036 ↗
29. Reaction mechanism of desilification process of high aluminum fly ash by alkali solution
30. Kinetics of desilication process of fly ash with high aluminum from pulverized coal fired boiler in alkali solution
31. Kinetics of desilification pretreatment from high-aluminium coal fly ash in alkaline medium under pressure10.1007/s40242-017-6230-y ↗
32. Preparation of Al–Si composite from high-alumina coal fly ash by mechanical–chemical synergistic activation10.1016/j.ceramint.2017.02.075 ↗
33. Alkaline activation of fly ashes. A 29Si NMR study of the reaction products10.1111/j.1551-2916.2004.01141.x ↗
34. The role played by the reactive alumina content in the alkaline activation of fly ashes10.1016/j.micromeso.2005.11.015 ↗