工艺参数对玻璃微粉粉煤灰基地质聚合物强度的影响

利用粉煤灰和废玻璃微粉为主要原料,通过氢氧化钠和水玻璃的混合激发,制备地质聚合物.讨论了水玻璃掺量和模数、液固比和养护温等因素对地质聚合物抗压强度的影响.研究表明:矿物聚合物抗压强度均随着水玻璃掺量及模数、液固比、养护温度的增大而先增大后减小.得出了优化的工艺条件为:水玻璃掺量10％、水玻璃模数1.4、固液比0.45,养护温度40～60℃,抗压强度可达36 MPa以上.     

循环流化床燃烧底渣制备地聚合物的试验研究

研究了以循环流化床燃烧底渣为主要原料，制备地聚合物时的液固比、水玻璃模数、水玻璃中钾含量对所制备的地聚合物力学性能的影响，结果表明，液固比对地聚合物强度的影响起主要作用，而水玻璃模数和水玻璃中钾含量的影响则相对较小。控制液固比为1：2、采用KOH含量为6％和模数为1．2的水玻璃制备的地聚合物样品28d抗压强度可达84．4MPa。地聚合物经800℃高温处理2h后其样品形貌仍保持完整，且抗压强度还有不同程度地增长。     

工业废渣制备地聚合物的试验研究

研究了不同粉磨时间的机械粉磨对炼钢过程产生的次生废渣性能的影响,并以最优时间下粉磨的废渣为原料,用水玻璃激发制备地聚合物,研究液固比、水玻璃模数和养护温度对所制备的地聚合物力学性能的影响,将最优组合下的地聚合物经养护28d后进行耐高温性能测试。试验结果表明控制液固比为0.4,用1.5M水玻璃激发的废渣地聚合物经60°C养护的抗压强度最大,为47.25MPa。样品可在一定程度上耐受高温,强度随温度升高而有所升高。     

废玻璃取代部分硅质原料的可行性分析

以固废再利用为出发点,为研究废玻璃取代部分硅质原料用于生产水泥的可行性问题,将0～2.03wt％废玻璃掺加到生料中,烧制熟料,制备水泥,分析水泥的标准稠度用水量、凝结时间、强度等性能,同时通过荧光分析法、滴定法等测定碱、f-CaO等成分含量.结果显示,随着生料中废玻璃掺量的增加,熟料中的碱、f-CaO含量增加,水泥的标准稠度用水量增加,凝结时间缩短,早期强度提高,后期强度降低;合理控制废玻璃的掺量,所制备的水泥指标可以满足国标相关规定,同时带来可观的经济效益和显著的社会效益.     

粉煤灰基地质聚合物制备及其对Cu~(2+)的吸附性能

为探讨地质聚合物的制备条件对其孔隙结构和吸附性能的影响,以粉煤灰为原料、水玻璃为碱激发剂,分别改变水玻璃模数、液固比、养护温度、养护时间制备地质聚合物,改变溶液的pH值、地质聚合物加入量、吸附时间、Cu~(2+)初始浓度进行Cu~(2+)吸附试验,采用N_2吸附法测量粉煤灰基地质聚合物的孔隙结构,并采用分光光度法分析粉煤灰基地质聚合物对Cu~(2+)的吸附效果。结果表明:不同条件下制备的地质聚合物,孔径主要分布在1~3 nm和70~110 nm;当液固比为0.9、养护温度80℃、养护时间3 d、水玻璃模数为1.4时,制备的地质聚合物比表面积最大,Cu~(2+)吸附量达46.3 mg/g;液固比为1.1时,地质聚合物中1.5~6.0 nm孔含量最高,Cu~(2+)吸附量为43.1 mg/g,养护温度对吸附效果的影响不大;随着养护时间的增加,地质聚合物对Cu~(2+)吸附量增加;地质聚合物对Cu~(2+)的单位吸附量与地质聚合物的比表面积有关,比表面积越大,吸附量越大。在Cu~(2+)溶液pH4的情况下,地质聚合物对铜离子的单位吸附量随p H值的降低而减少,其吸附等温线符合Freundlich吸附方程。     

硫酸/丙醇法制备淀粉硫酸钠的工艺研究

提出了以浓硫酸和正丙醇的混合溶液为磺化剂、玉米淀粉为原料、低温下磺酸化反应制备淀粉硫酸钠的工艺路线.考察了反应温度、反应时间、液固比、反应液配比等对淀粉硫酸钠取代度和得率的影响,得到优化制备条件为:硫酸/正丙醇的摩尔比为1.8,反应液/淀粉的液固比为30,反应温度-2℃,反应时间16h,淀粉硫酸钠取代度可达0.58.通过调节反应条件,可控制取代度在0.1～0.6之间.所开发的淀粉硫酸钠制备新工艺,比较环保和经济,过程避免使用有毒试剂,产品可用于医药用途.     

太阳能硅片切割废砂浆的分离及回收研究

以太阳能硅片切割废砂浆为原料,采用固液分离、酸溶和碱溶提纯等方法,除去废砂浆中的铁及不锈钢粉等杂质,回收聚乙二醇、硅和碳化硅微粉。结果表明,以水为溶剂,按液固体积质量比(mL/g)为10∶1、常温下搅拌10min溶出废砂浆中的聚乙二醇,精馏回收;用盐酸处理废砂浆中铁及不锈钢粉的最佳工艺条件:c(盐酸)=3.0 mol/L、温度为40℃、反应时间为1 h、液固比为10∶1;采用酸溶和碱溶方法除硅,可使碳化硅微粉中硅的质量分数降到0.5%以下。     

不同固液比和原料粒度对脱硫石膏制备硫酸钙晶须的影响

以脱硫石膏为原料。采用水热法工艺制备硫酸钙晶须。并借助XRD、高分辨显微镜等分析方法,深入探讨了不同固液比和原料粒度对硫酸钙晶须生长行为的影响。结果表明：随着固液比的不断减小,硫酸钙晶须的长径比呈先升高后降低的趋势;当固液比为1：10时,长径比达到最大,其值为68．65;随着原料粒度的减小．硫酸钙晶须的直径不断减小,硫酸钙晶须的长径比不断增加,当原料粒度为1．60μm时,长径比达到68.65。     

固废制备多孔微晶玻璃研究进展

固废多孔微晶玻璃是以固体废物、发泡剂及其他辅助试剂为原料，制备出的一种绿色材料。由于其主要原料为冶金固废、尾矿和城市固废等，且产品具有较高的机械强度、硬度，显著的耐腐蚀性，绝热、吸声、防火、防潮，使其在实现固废增值的同时，能应用于各种工业领域。文章阐述了烧结法制备固废多孔微晶玻璃的机理，重点论述了固废原料的选择和复合固废组成设计、发泡剂种类、掺量和材料性能、热处理制度对固废多孔微晶玻璃结构和性能的影响规律等方面国内外研究进展，介绍了固废多孔微晶玻璃的应用，对固废多孔微晶玻璃的研究和应用发展趋势进行了展望。     

复合固废微晶玻璃研究现状

工业固废高炉渣、污泥、飞灰、废玻璃、尾矿等,均含有大量不同成分配比的Al2 O3、SiO2、MgO、CaO等组分,这些组分是制备微晶玻璃的原料.单种固废成分往往无法直接制备性能良好的微晶玻璃,然而利用几种不同固废成分的互补作用,可以在不添加或者添加少量的辅料条件下,协同制备出复合固废微晶玻璃.本文主要综述了国内外一种高效处理固废的方式,即利用两种以上固体废物协同制备微晶玻璃,并对复合固废微晶玻璃的不足和前景进行了讨论.     

Partial replacement of metakaolin with red ceramic waste in geopolymer

Metakaolin was incrementally replaced (33.3%, 50% and 66.6%) by red ceramic waste in geopolymer formulation to study the effect on geopolymerisation and its resultant properties. The geopolymer binders composed of two calcined aluminosilicates (viz. Metakaolin and Red ceramic waste), NaOH and sodium silicate. In the experimental compositions, metakaolin was replaced gradually up to 66.6% in the clay fraction, the Si/Al increased from 3.36 to 5.16 and Na/Al increased from 0.93 to 1.38. The FTIR spectroscopic studies of geopolymer pastes along with XRD analysis indicated that the red ceramic waste partly reacts with alkali and takes part in geopolymer formation. Replacement of 33.3% metakaolin by the red ceramic waste in geopolymer binder did not reduce the compressive strength with respect to the pure metakaolin geopolymer here. Additional replacement resulted in a drastic decrease in the compressive strength of the geopolymer binder. However, the compressive strength of geopolymer mortars revealed interesting synergy between the amount of binder and particle packing in the mortar. Despite having a lower amount of binder phase, mortars with 33% and 50% red ceramic waste exhibited maximum compressive strength values. This has been attributed to improved particle packing through incorporation of red ceramic waste particles.     

Mechanical and microstructural characterization of geopolymers synthesized from FCC waste catalyst and silica fume

A FCC waste catalyst-based geopolymer was synthesized from FCC waste catalyst and silica fume, which were used as the main silicon-aluminum raw material and correction material, respectively. Meanwhile, NaOH and water glass composite were used as alkaline activator in the preparation process. Herein, the effects of silicon correction materials, alkaline activator modulus, and silica fume content on the compressive strength performance of prepared geopolymers were discussed. The microstructure was comprehensively analyzed by X-ray diffraction, fourier infrared spectroscopy, nuclear magnetic resonance spectroscopy and scanning electron microscope. The results showed that the prepared geopolymer has good early property when the silica fume content is 50% and the water glass modulus is 1.2. The 3d compressive strength of the obtained sample reaches 23.77 MPa. Microstructure and geopolymerization process analysis indicate that the FCC waste catalyst and silica fume have a good synergistic effect, which confirms the feasibility of preparing the geopolymer by using these industrial waste materials.     

纤维对地聚合物抗压强度的影响研究

为提高粉煤灰基地聚合物抗压强度,以纤维作为增韧材料,重点考察了纤维种类和掺量对地聚合物强度的影响.木质素纤维、聚酯纤维和玻璃纤维的最佳掺比分别为0.3%、0.1%和0.3%.过量木质素纤维导致地聚合物局部强度降低,过量玻璃纤维使得地聚合物孔隙增加,导致强度降低.掺加玻璃纤维的粉煤灰基地聚合物抗压强度高(33.25 MPa),其微观结构分析表明Si-O-Si和Si-O-Al聚合度较高.     

水热热压法制备地质聚合物

地质聚合物材料是一种新型的环保型无机复合材料,具有性能优越、价格低廉的特点.本研究采用水热热压技术,以粉煤灰、玻璃粉为主要原料,在200℃、8.5MPa的水热热压条件下制备粉煤灰基地聚合物材料.研究了不同碱激发剂的含量、浓度及玻璃粉添加量对材料抗压强度、收缩率的影响.结果表明,粉煤灰与玻璃粉的质量比为2∶1,添加25％的浓度为5 mol/L NaOH溶液时,固化体试样中有纤维状的地聚物生成,材料的抗压强度最高达到103.34MPa.     

The microstructural and mechanical properties of geopolymer composites containing glass microfibres

This paper presents the effects of microfibre contents on mechanical properties of fly ash-based geopolymer matrices containing glass microfibres at 0, 1, 2 and 3 mass%. The influence of glass microfibres on the fracture toughness, compressive strength, Young's modulus and hardness of geopolymer composites are reported, as are the microstructural properties investigated using scanning electron microscopy. Results show that the addition of 2 mass% glass microfibres was optimal, exhibiting the highest levels of fracture toughness, compressive strength, Young's modulus and hardness. The results of the microstructural analysis indicate that the glass microfibres act as a filler for voids within the matrix, making a dense geopolymer and improving the microstructure of the binder. This leads to favourable adhesion of the composites, and produces a geopolymer composite with good mechanical properties, comparable to pure geopolymer. The failure mechanisms in glass microfibre-reinforced geopolymer composites are discussed in terms of microstructure.     

Assessment of recycling use of GFRP powder as replacement of fly ash in geopolymer paste and concrete at ambient and high temperatures

Environmental issues caused by glass fiber reinforced polymer (GFRP) waste have attracted much attention. The development of cost-effective recycling and reuse methods for GFRP composite wastes is therefore essential. In this study, the formulation of the GFRP waste powder replacement was set at 20–40 wt%. The geopolymer was formed by mixing GFRP powder, fly ash (FA), steel slag (SS) and ordinary Portland cement (OPC) with a sodium-based alkali activator. The effects of GFRP powder content, activator concentration, liquid to solid (L/S) ratio, and activator solution modulus on the physico-mechanical properties of geopolymer mixtures were identified. Based on the 28-day compressive strength, the optimal combination of the geopolymer mixture was determined to be 30 wt% GFRP powder content, an activator concentration of 85%, L/S of 0.65, and an activator solution modulus of 1.3. The ratios of compressive strength to flexural strength of the GFRP powder/FA-based geopolymers were considerably lower than those of the FA/steel slag-based geopolymers, which indicates that the incorporation of GFRP powder improved the geopolymer brittleness. The incorporation of 30% GFRP powder in geopolymer concrete to replace FA can enhance the compressive and flexural strengths of geopolymer concrete by 28%. After exposure to 600 °C, the flexural strength loss for geopolymer concretes containing 30 wt% GFRP powder was less than that of specimens without GFRP powder. After exposure to 900 °C, the compressive strength and flexural strength losses of geopolymer concretes containing 30 wt% GFRP powder were similar to those of specimens without GFRP powder. The developed GFRP powder/FA-based geopolymers exhibited comparable or superior physico-mechanical properties to those of the FA-based geopolymers, and thus offer a high application potential as building construction material.     

室温碱激发低钙粉煤灰地质聚合物配比试验研究

为得到室温下粉煤灰与碱激发剂质量比、水玻璃与氢氧化钠溶液质量比和氢氧化钠溶液摩尔浓度对粉煤灰地质聚合物力学性能的影响,以低钙粉煤灰为原料,制备了地质聚合物胶凝材料。采用正交试验方法,分析粉煤灰地质聚合物抗压强度,探讨碱激发剂配比对粉煤灰地质聚合物力学性能的影响,结合SEM、XRD和FTIR对试样进行表征,并对该材料的应力-应变曲线进行了研究。结果表明:粉煤灰地质聚合物的抗压强度随着激发剂掺量的减少而增大,水玻璃在激发剂中的比值与粉煤灰地质聚合物的抗压强度呈现正相关,其中粉煤灰与碱激发剂质量比为1.8,水玻璃与氢氧化钠溶液质量比为2.5且氢氧化钠溶液的浓度为10 mol/L时,120 d龄期的抗压强度可达51.98 MPa。对应力-应变曲线分析得出,在一定程度上,激发剂的掺入量对粉煤灰地质聚合物的破坏应变和弹性模量有较大影响。SEM、XRD和FTIR分析表明随着养护时间增长,胶凝材料体系内结构更致密,生成了更多的硅铝酸盐凝胶。     

Suitability of Sarawak and Gladstone fly ash to produce geopolymers: A physical,chemical, mechanical,mineralogical and microstructural analysis

Two types of fly ash sourced from Sarawak, Malaysia and Gladstone, Australia reflect differences in chemical compositions, mineral phase and particle size distributions. In this paper, the Sarawak fly ash was used to produce geopolymer in comparison to the well-developed Gladstone fly ash-based geopolymer. Characteristics of fly ash and mixtures proportions affecting compressive strength of the geopolymers were investigated. It is found that the variations of both fly ash types on particle size distributions, chemical compositions, morphology properties and amorphous phase correspond to the compressive strength. The results obtained show that after 7 days, geopolymer using Sarawak fly ash has lower compressive strength of about 55 MPa than geopolymer using Gladstone fly ash with strength of about 62 MPa. In comparison with Gladstone fly ash-based geopolymer, it showed that Sarawak fly ash-based geopolymer can be a potential construction material. Moreover, the production of Sarawak fly ash-based geopolymer aids to widen the application of Sarawak fly ash from being treated as industrial waste consequently discharging into the ash pond.     

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

Zeolites are the preferred inorganic ion exchange materials for purifying radioactive waste liquid. Radionuclide-loaded zeolites, which are considered to be radioactive waste, are strictly required to be encapsulated within a solid matrix. In this paper, we investigate the feasibility of immobilizing exhausted zeolite A, loaded with ⁹⁰Sr radionuclide, in metakaolin based-geopolymer. The geopolymer solidification blocks had better mechanical performance and leaching resistance in deionized water, sulfuric acid, magnesium sulfuric and acetic acid buffer solutions than the cemented blocks. While the compressive strength of the geopolymer solidification product was 37.62 MPa after curing for 28 days, the equivalent value for the cement block was only 11.32 MPa. The geopolymer solidification blocks also exhibited even lower compressive strength loss after high-temperature and freeze-thaw cycles tests. XRD and EDS analysis indicated that most of the strontium radionuclide in the geopolymer solidification blocks was incorporated in the zeolite structure as the charge balancing cation. The microscopic analysis revealed that geopolymer matrix appeared more compact and dense, and encapsulated the Sr-loaded zeolite A more tightly than did the cement. Therefore, it could be concluded that metakaolin based-geopolymer are more compatible with exhausted zeolite A and present a remarkable advantage for radioactive waste immobilization.     

煅烧高铝煤矸石-矿渣-水玻璃系地聚合物材料的研究

根据地聚合物合成原理，采用煅烧高铝煤矸石-磨细矿渣-水玻璃系合成地聚合物类材料。深入研究了高铝煤矸石-矿渣-水玻璃系统材料的制备、性能的测试评价、水化硬化机理和最优制备工艺参数选择。材料中矿渣对早期强度起主要作用，煅烧高铝煤矸石对后期强度贡献较大。在矿渣和高铝煤矸石质量比处于合理状态时，材料各龄期强度均较优。高铝煤矸石类地聚合物材料的抗压强度随水玻璃模数的减小而增大，随水玻璃掺量的增大而增大，随液胶比的减小而增大。水玻璃模数为1．049，矿渣与煅烧高铝煤矸石的配比为4：6，激发剂掺量为22％，液胶比为0．35时，复合材料28d抗压强度达到了41．7MPa。