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Development of high volume rice husk ash alumino silicate composites

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 654-659页

作者： Ubolluk Rattanasak Prinya Chindaprasirt Prasert Suwanvitaya Department of Chemistry and Center for Innovation in Chemistry Faculty of Sciences Burapha University Department of Civil Engineering Faculty of Engineering Khon Kaen University Department of Civil Engineering Faculty of Engineering Kasetsart University

The development of high volume rice husk ash （RHA） alumino silicate composites （ASC） was studied. RHA was used as the source of silica and aluminium in the ASC. The mass ratios of RHA：Al（OH）3 of 70：30 to 99：1 were tested. The results indicate that the obtained ASC mortars are not stable and disintegrate in water. Boric acid was introduced to the mixture to overcome this problem. Stable ASC mortars with high RHA：Al（OH）3 mass ratios of 90：10 to 97.5：2.5 were obtained with the use of boric acid and 115oC curing. The compressive strength of the mortar of 20 MPa was gained. The immersion test indicates that high volume RHA ASC mortars show good resistance in 3vol% H2SO4 solution, but is slightly less durable in 5wt% MgSO4 solution.

关键词： composite materials rice husk ash aluminium hydroxide boric acid alumino silicates sulphate attack

Effect of silica forms in rice husk ash on the properties of concrete

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 252-258页

作者： Le Anh-tuan Bui Chun-tsun Chen Chao-lung Hwang Department of Construction Engineering Taiwan University of Science and Technology

The strength and durability properties of concrete with or without three types of rice husk ash （RHA）, namely, amorphous, partial crystalline, and crystalline RHA, were investigates. The three types of RHA were added into concrete at a 20% replacement level. Consequently, the pozzolanic reactivity of amorphous RHA was higher than that of partial crystalline and crystalline RHA. Concrete added with amorphous RHA showed excellent characteristics in its mechanical and durability properties. The results showed that the higher the amount of crystalline silica in RHA, the lower the concrete resistivity value became. When compared with each other, concretes with 20% of the ce- ment replaced with these types of RHA achieved similar ultrasonic pulse velocity values, but all were lower than that of the control concrete. The incorporation of these kinds of RHA significantly reduced chloride penetration. The results not only encourage the use of amorphous materials, they also support the application of crystalline or partial crystalline RHA as mineral and pozzolanic admixtures for cement.

关键词： rice husk ash silica concrete compressive strength durability waste management

Preparation of fly ash and rice husk ash geopolymer

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International Journal of Minerals,Metallurgy and Materials 2009年第6期16卷 720-726页

作者： S. Detphan P. Chindaprasirt Department of Civil Engineering Khon Kaen University

The geopolymer of fly ash （FA） and rice husk ash （RHA） was prepared. The burning temperature of rice husk, the RHA fineness and the ratio of FA to RHA were studied. The density and strength of the geopolymer mortars with RHA/FA mass ratios of 0/100, 20/80, 40/60, and 60/40 were tested. The geopolymers were activated with sodium hydroxide （NaOH）, sodium silicate, and heat. It is revealed that the optimum burning temperature of RHA for making FA-RHA geopolymer is 690oC. The as-received FA and the ground RHA with 1%-5% retained on No.325 sieve are suitable source materials for making geopolymer, and the obtained compressive strengths are between 12.5-56.0 MPa and are dependent on the ratio of FA/RHA, the RHA fineness, and the ratio of sodium silicate to NaOH. Relatively high strength FA-RHA geopolymer mortars are obtained using a sodium silicate/NaOH mass ratio of 4.0, delay time before subjecting the samples to heat for 1 h, and heat curing at 60oC for 48 h.

关键词： geopolymer fly ash rice husk ash sodium hydroxide sodium silicate

Production of porous silica by the combustion of rice husk ash for tundish lining

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Journal of University of Science and Technology Beijing 2008年第3期15卷 307-313页

作者： Y.M.Z.Ahmed E.M.Ewais Z.I.Zaki Central Metallurgical Research and Development Institute(CMRDI)

In order to study the production of porous silica compacts by the combustion of rice husk ash （RHA） for tundish lining, the experimental design technique was used to evaluate the effect of firing temperature, soaking time and compaction pressure on controlling both the porosity degree and compressive strength of rice husk ash compacts. The results revealed that while the porosity degree of the compacts decreased with the increase in the entire studied parameters, the compressive strength exhibited another trend especially at a lower soaking time. At a lower soaking time, the increase in firing temperature led to a slight decrease in compressive strength and then increasing thereafter. The porous silica compacts having 30% porosity and 〉 2.5 MPa compressive strength suitable for tundish lining could be obtained from the combustion of rice husk ash compacts.

关键词： porous silica rice husk ash tundish lining compressive strength porosity

Fresh and hardened properties of high-performance fiber-reinforced concrete containing fly ash and rice husk ash:Influence of fiber type and content

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Frontiers of Structural and Civil Engineering 2022年第12期16卷 1621-1632页

作者： Nguyen-Trong HO Viet Quoc DANG Minh-Hieu NGUYEN Chao-Lung HWANG Trong-Phuoc HUYNH Faculty of Civil Engineering VSB-Technical University of OstravaOstrava-Poruba 70800Czech Republic Faculty of Bridge and Road Construction Mientrung University of Civil Engineering(MUCE)Tuy Hoa City 56100Vietnam Vinh Long Department of Construction Vinh Long City 85000Vietnam Taiwan Building Technology Center Taiwan University of Science and TechnologyTaipei 10607China Faculty of Civil Engineering College of EngineeringCan Tho UniversityCan Tho City 94000Vietnam

Although fibers are used only infrequently as an additive in concrete in the construction industry,fiberenhanced concrete is known to provide a wide range of advantages over conventional *** main objective of this study was to investigate the influences of fiber type and content on the mechanical properties and durability of highperformance fiber-reinforced concrete(HPFRC)designed using a novel densified mixture design algorithm with fly ash and rice husk *** types of fiber,including polypropylene(PP)fiber,steel fiber(SF),and hybrid fiber(HF),were *** on the results,the inclusion of fibers decreased HPFRC flowability,regardless of fiber *** the compressive strength of HPFRC with 1.6%PP fiber content was 11.2%below that of the reference HPFRC specimen at 91 d of curing age,the 91-d compressive strengths of both SF and HF-enhanced HPFRC specimens were significantly better than that of the reference HPFRC ***,the HPFRC specimens incorporating SF and HF both exhibited better splitting tensile and flexural strengths as well as less drying shrinkage than the HPFRC specimens incorporating PP ***,the fiber-enhanced specimens,especially those with added SF,registered less surface electrical resistivity and greater vulnerability to chloride ion penetration than the reference HPFRC specimen.

关键词： high-performance fiber-reinforced concrete fly ash rice husk ash durability mechanical strength

Studies on Physical Chemistry of Rubber-rice husk ash Composites

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Journal of Renewable Materials 2019年第2期7卷 171-192页

作者： V.Subrahmanian M.Albert Noble Einstien Department of Rubber and Plastics Technology Anna UniversityMIT CampusChrompetINDIA 60044 Master of Technology Rubber and Plastics DepartmentAnna UniversityMIT Campus

Nowadays an alternate source of filler from renewable and plant derivatives are being thought of in rubber industries due to their reliability,environmental and economic *** husk ash(RHA)a byproduct of the rice milling industry is obtained on partial and as well as full combustion of the rice *** ash is a good source of silica,silicates and needle shaped carbon and hence can be used as filler for *** the present study,a detailed investigation was carried out to understand the RHA as reinforcing material using mechanical properties and fractography using *** rubbers studied were natural rubber(NR),poly chloroprene(CR)and ethylene propylene diene monomer(EPDM).Interestingly,the RHA added NR stock on open mill mixing generated considerable amount of static *** properties of NR were found to be as good as regular *** compounds behaved well during *** the properties were found to be ***-RHA compounds were found to result in higher viscosity and the properties were not as *** SEM studies showed surprisingly cohesive failure as evidenced with the presence of flow lines and the fibrous filler(RHA)remains embedded in the matrix regardless of the chemistry of the repeating unit,NR,EPDM and the chlorine containing monomer inCR.

关键词： rice husk ash rubber composites natural rubber polychloroprene rubber EPDM Mooney Scorch SEM fractography

Effect of grinding on chemical and physical properties of rice husk ash

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International Journal of Minerals,Metallurgy and Materials 2009年第2期16卷 242-247页

作者： Sumrerng Rukzon Prinya Chindaprasirt Rattana Mahachai Department of Civil Engineering Rajamangala University of Technology Phra NakhonBangkok 10300Thailand Department of Civil Engineering Faculty of EngineeringKhon Kaen University40002Thailand Department of Chemistry Faculty of ScienceKhon Kaen University40002Thailand

The effect of grinding on the chemical and physical properties of rice husk ash was studied. Four rice husk ashes with different finenesses, i.e. coarse original rice husk ash （RHA0）, RHA1, RHA2, and RHA3 were used for the study. Ordinary Portland cement （OPC） was partially replaced with rice husk ash at 20% by weight of binder. The water to binder ratio （W/B） of the mortar was maintained at 110%±5% with flow table test. Specific gravity, fineness, chemical properties, compressive strength, and porosity test of mortars were determined. The differences in chemical composition of the rice husk ashes with different finenesses from the same batch are small. The use of RHA3 produces the mortars with good strength and low porosity. The strength of the mortar improves with partial replacement of RHA3 in comparison with normal coarse rice husk ash. The use of RHA3 results in a strong and dense mortar, which is due to the better dispersion and filling effect, as well as an increase in the pozzolanic reaction.

关键词： fineness grinding mortar physical properties rice husk ash

Removal of elemental mercury by iodine-modified rice husk ash sorbents

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Journal of Environmental Sciences 2010年第10期22卷 1629-1636页

作者： Pengfei Zhao,Xin Guoff,Chuguang Zheng State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China [a] State Key Laboratory of Coal Combustion Huazhong University of Science Technology Wuhan 430074 China

Iodine-modified calcium-based rice husk ash sorbents （I2/CaO/RHA） were synthesized and characterized by X-ray diffraction, X-ray fluorescence, and N2 isotherm adsorption/desorption. Adsorption experiments of vapor-phase elemental mercury （Hg^0） were performed in a laboratory-scale fixed-bed reactor. I2/CaO/RHA performances on Hg^0 adsorption were compared with those of modified Cabased fly ash sorbents （I2/CaO/FA） and modified fly ash sorbents （I2/FA）. Effects of oxidant loading, supports, pore size distribution, iodine impregnation modes, and temperature were investigated as well to understand the mechanism in capturing Hg^0. The modified sorbents exhibited reasonable efficiency for Hg^0 removal under simulated flue gas. The surface area, pore size distribution, and iodine impregnation modes of the sorbents did not produce a strong effect on Hg^0 capture efficiency, while fair correlation was observed between Hg^0 uptake capacity and iodine concentration. Therefore, the content of 12 impregnated on the sorbents was identified as the most important factor influencing the capacity of these sorbents for Hg^0 uptake. Increasing temperature in the range of 80-140℃ caused a rise in Hg^0 removal. A reaction mechanism that may explain the experimental results was presumed based on the characterizations and adsorption study.

关键词： mercury sorbents fly ash rice husk ash iodine impregnation

Effect of chemical and thermal activations on the properties of rice husk ash-based solidified wastes

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Journal of Environmental Sciences 2010年第12期22卷 1993-1998页

作者： Nipon Tanpaiboonkul Suwimol Asavapisit Wichai Sungwornpatansakul Division of Environmental Technology School of Energy Environment and MaterialsKing Mongkut's University of Technology Thonburi National Center of Excellence for Environmental and Hazardous Waste Management Department of Environmental EngineeringKing Mongkut's University of Technology Thonburi Department of Civil Engineering Faculty of EngineeringKing Mongkut's University of Technology Thonburi

Strength development, leachability and microstructure of heavy metals from the solidified waste using synthesis rice husk ash （sRHA） and lime blended at the weight ratio of 1：1 were used as binders. The heavy metal-containing sludge was used at the level of 0 wt.%, 30 wt.%, and 50 wt.% dry weight, respectively. The sample specimens with and without 1.5 wt.% of sodium silicate （SiO2/Na2O = 1.0） were cured under the ambient condition and elevated temperature curing at 50℃ for 24 hr. Experimental results showed that the introduction of sodium silicate solution and elevated temperature curing to sRHA-based solidified waste containing 30 wt.% of heavy metal sludge gave one day strength of 20 kg/cme compared to 0.9 kg/cm^2 for the control sample. XRD patterns indicated that most metal-sulfides present in the sludge were appeared in the solidified waste and SEM coupled with EDX techniques reveal these metal-sulfide particles were trapped within the lime-sRHA matrices. In addition, cumulative leaching behavior by tank test （EA NEN 7375：2004） showed that solidified waste containing up to 30 wt.% of heavy metal sludge was suitable to dispose in a secured landfill.

关键词： rice husk ash heavy metals sodium silicate strength leaching microstructure