Removal of Cu2＋ from Aqueous Solutions Using Na-A Zeolite from Oil Shale Ash

Na-A zeolite was synthesized using oil shale ash （OSA）, which is a solid by-product of oil shale proc- essing. The samples were characterized by various techniques, such as scanning electron microscopy, X-ray diffrac- tion and Brunaner Emmet Teller method. The batch isothermal equilibrium adsorption experiments were performed to evaluate the ability of Na-A zeolite for removal of Cu （II） from aqueous solutions. The effects of operating pa- rameters, such as concentration of copper solutions, adsorbent dosages, pH value of solutions and temperature, on the adsorption efficiency were investigated. The equilibrium adsorption data were fitted with Langmuir and Freundlich models. The maximum adsorption capacity of Na-A zeolite obtained from the Langmuir adsorption iso- therm is 156.7 mg.g-t of Cu （lI）. The increase of pH level in the adsorption process suggests that the uptake of heavy metals on the zeolite follows an ion exchange mechanism. The batch kinetic data fit the pseudo-second order equation well. The thermodynamic parameters, such as changes in Gibbs free energy （AG）, enthalpy （AH） and en- tropy （AS）, are used to predict the nature of the adsorption process. The negative AG values at different tempera- tures confirm that the adsorption processes are spontaneous.

Preparation of Single Phase Na-X Zeolite from Oil Shale Ash by Melting Hydrothermal Method

A single phrase Na - X zeolite was synthesized from pretreated oil shale ash by alkaline fusion and hydrotherreal treatment. Eff3cts of the NaOH concentration, crystallization time ant temperature on the formation of Na-X zeolite were studied in detail. The single phase Na- X zeolite powders can. be prepared by alkaline fusion o.f pretreated oil shale ash at 600 ℃ .for 1 h, and crystalli-zation at 80 - 100 ℃ .for 8 - 10 h with NaOH concentration of 3 -3. 5 tool · L-1. Na - A zeolite appears when decreasing NaOH concentration, crystallization time or temperature, ant an unnamed zeolite emerges when prolonging crystallization time or raising crystalli-zation, temperature. SEM micrographs suggest that the aggregates of Na-X zeolite particles have perfect dispersity and uniform granular with about 1.5 μm in size, and most of the Na-X zeolite crystals display a regular octahedral structure with the size of about 500 nm. The specific surface area of the powders with single Na-X zeolite phase reaches the maximum value of 488. 163 2 m2· g -1, larger than that of multiple zeolite powders.

Leachability of Oil Shale Ash from Isfir Al-Mahata Oil Shale, Southern Jordan

This paper presents the first study on the oil shale (OS) ashing and OS ash leachability of Jordanian OS located further in the south. The studied OS is from Isfir Al-Mahata subsurface OS located 10 km south of Ma’an. Chemical and physical characterization of the OS ash was performed and compared with original OS. Ashing OS was conducted at different temperatures. Important parameters affecting OS ash leachability were also investigated. The leachability of certain heavy metals was investigated based on clear leaching protocol. The Fisher Assay analysis result indicates that this OS type has quite higher moisture content, lower oil content, and higher spent shale compared with other Jordanian oil shales. Ashing of OS at higher temperatures (950°C) resulted in the disappearance of silica, due to its complete reaction with lime and Al, and formation of Anhydrite and cement materials like, Portland cement. The leachability analysis indicates that for most elements the leachability is high at low pH. The released heavy metals concentrations are below EPA limits. Chromium and lead are leached out more than other elements with the exception at low pH. In general, the higher the ashing temperature is, the lower the release of elements is. The chemical composition of the ash and the leachability results suggests that it has high fixing capacity toward the heavy metals present in the ash.

Adsorption of Heavy Metal Ions from Aqueous Solutions by Zeolite Based on Oil Shale Ash： Kinetic and Equilibrium Studies

Na-A zeolite was successfully synthesized via the alkaline fusion method with oil shale ash as the raw material. The adsorption capacity of it was tested by removing Cu2＋, Ni2＋, Pb2＋ and Cd2＋ from aqueous solutions. The results reveal the maximum adsorption capacity of adsorbent for Pb2＋, Cu2＋, Cd2＋ and Ni2＋ were 224.72, 156.74, 118.34 and 53.02 mg/g, respectively. The effects of contact time and pH value of solutions on the adsorption effi- ciency of the zeolite were evaluated. Besides, The equilibrium adsorption data and the batch kinetic data were correlated with Langmuir and Freundlich models and the pseudo-first-order and pseudo-second-order models separately. The results show that the Langmuir isotherm and the pseudo-second-order equation were more suitable for the adsorption of Na-A zeolite for the metal ions. In addition, Thermodynamic parameters of the adsorption（the Gibbs free energy, entropy, and enthalpy） were also evaluated and discussed. The results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions and the synthesized zeolite was an effective adsorbent for the removal of metal ions from aqueous solution.

Synthesis of Na-X zeolite from Longkou oil shale ash by alkaline fusion hydrothermal method

Na-X zeolites were synthesized by Longkou oil shale ash with the alkaline fusion hydrothermal method.The effects of fusion temperature,ash to NaOH ratio,solid-liquid ratio,crystallization time and crystallization temperature on the crystallinity of zeolites were investigated.The synthetic products were characterized by Xray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),29Si nuclear magnetic resonance spectroscopy(29Si NMR)and N2 adsorption-desorption.The results showed that the conditions to synthesize Na-X zeolite were:Longkou oil shale ash to sodium hydroxide ratio 1:1.2 g・g^(-1),fusion temperature 600℃,solid-liquid ratio 1:4 g・mL^(-1),crystallization time 24 h and crystallization temperature 80℃.The zeolite with high crystallinity(91.32%)was synthesized:the product exhibiting octahedral particles observed by SEM,and the calculated Si/Al ratio in Na-X zeolite being 1.23 from^(29)Si MAS NMR spectra,which was consistent with the observation from XRD.

Removal of Chromium（VI） from Groundwater Using Oil Shale Ash Supported Nanoscaled Zero-valent Iron

Oil shale ash（OSA） supported nanoscaled zero-valent iron（OSA-nZVI） was used as a rapid and efficient reductant for Cr（VI） reduction. The optimal mass ratio of nZVI to OSA and the optimal dosage were explored. The effects of initial pH, reaction temperature, initial Cr（VI） concentration, and common cations and anions in ground- water on Cr（VI） reduction were determined in batch experiments. The results show that the optimum initial pH is 5.0. The reaction temperature has a positive effect on Cr（VI） reduction while the real groundwater has a negative effect. Additionally, 84.22% Cr（VI） was still reduced by 3 g/L OSA-nZVI（1：2）（mass ratio of OSA to Fe^0 was 1：2） within 120 min for 50 mg/L Cr（VI） under conditions of 10℃ and unadjusted pH.

油页岩添加对准东高钠煤灰熔融行为影响的研究

准东煤中碱金属钠的含量高,在气化过程中生成的飞灰导致换热器积灰、腐蚀等问题的发生,对气化炉的安全稳定运行带来极大的挑战。煤灰的熔融行为是阐明飞灰沉积行为的重要参数,选取含Si、Al较高的油页岩为添加剂,研究了油页岩添加对准东高钠煤灰熔融行为的影响及机理,探讨使用油页岩解决准东高钠煤气化利用中的飞灰沉积问题。结果表明,随着油页岩添加量的增加,准东高钠煤红沙泉和将二矿煤灰的初始烧结温度与液相烧结温度区间长度增加,煤灰的沉积倾向减轻;矿物质分析显示,油页岩的添加降低了初始煤灰中硫酸钙的含量,提高石英的含量,同时熔融过程中生成大量夕线石,是准东高钠煤灰熔点升高的主要原因。对于红沙泉与将二矿煤,分别添加15%和20%的油页岩可有效提高煤灰的熔融特征温度,避免在气化过程中飞灰发生沉积。最后,基于神经网络模型,建立了准东高钠煤添加油页岩后的煤灰变形温度(DT)及流动温度(FT)的预测模型。

碱焙烧条件对油页岩灰制备白炭黑的影响研究

采用碱焙烧法处理油页岩灰,并盐酸酸洗以达到除去灰中其他杂质从而制得高纯度白炭黑产品的目的。设计四因素三水平正交实验,研究了焙烧时间、焙烧温度、碱与油页岩灰质量比以及氢氧化钠与碳酸钠质量比四个因素对制得的白炭黑纯度的影响。通过对试验结果进行极差分析以及方差分析可得,影响白炭黑纯度的主次因素为:m(NaOH)/m(Na_(2)CO_(3))>焙烧温度>m(NaOH)/m(Na_(2)CO_(3))×焙烧温度>m(NaOH)/m(油页岩灰)>焙烧时间。最佳工艺条件为:以Na OH为活化剂,Na OH与油页岩灰质量比为1.5∶1,焙烧温度800℃,焙烧时间60 min。在此条件下制备的白炭黑二氧化硅质量分数高达98.54%。通过对添加碱混合焙烧后的油页岩灰进行表征,分析可得800℃下,碱可与油页岩灰充分反应,生成易与盐酸反应的硅酸钠等物质。这使得在酸洗过程中包裹于硅铝相中的杂质可以与盐酸充分接触,溶解于液相中,易与固态的硅酸分离,达到提纯的目的。

燃用约旦油页岩循环流化床锅炉结渣沾污分析

约旦Attarat电站277 MW机组是世界上容量最大的纯燃油页岩循环流化床机组,为探究其运行过程中床层结渣、受热面积灰原因,通过试验明确床层结渣原因,并通过Factsage计算进一步验证;根据现场实际情况,分析了受热面积灰原因。结果表明:油页岩入炉粒度偏大或布风板流化不良,导致局部温度过高引起床层结渣,局部最高温度可达1150℃,此时液相质量占整个体系质量22%。此外,油页岩灰分高,锅炉飞灰在流经尾部对流受热面时,在热泳和惯性碰撞的共同作用导致受热面积灰严重。通过改善油页岩入炉粒径、更换合理结构的布风板、及时调整一次风量等措施可有效缓减结渣问题。通过更换效率更高的吹灰器、使用除灰剂等手段可有效解决锅炉受热面沾污问题。

石长沟油页岩燃烧灰分物理特性

油页岩灰分是油页岩综合利用的主要物质之一。对石长沟油页岩进行马弗炉燃烧实验,制备不同燃烧终温(200~800℃)的油页岩灰分;并借助多种实验仪器研究不同温度燃烧下的灰分构成成分、结构特征及微观孔隙演化过程。结果表明:油页岩有机质以脂肪族为主;燃烧过程中,各有机元素(N、S、C、H、O)含量呈现下降趋势,自由水析出,结构水脱离,碳酸盐和脂肪族逐渐分解,在800℃高温时,C完全转化为CO_(2)逸出;灰分的构成成分主要为二氧化硅和碳酸盐,孔隙以微孔和中孔为主,随着燃烧温度升高,中孔数量增加,比表面积和分形维度先增后减,峰值均在400℃处。研究结果为分析石长沟油页岩不同燃烧温度下灰分的物理状态提供了理论基础,对了解石长沟油页岩的燃烧特性具有一定的借鉴意义。

污泥与油页岩半焦制备陶粒滤料的研究

采用造粒、干燥、预热、烧结工艺,以油页岩半焦、粉煤灰、污泥三种固体废弃物为原料制备污水处理厂用人工陶粒滤料。以盐酸可溶率、筒压强度、空隙率和比表面积为陶粒滤料主要性能指标,探究陶粒烧制过程中原料配比、烧结温度及原材料特性等因素对陶粒性能的影响。实验结果表明:油页岩半焦与粉煤灰的最佳比例为3∶5,煅烧温度超过1125℃时陶粒的比表面积和空隙率有明显的降低。随着陶粒原料中污泥含量的提高,盐酸可溶率和筒压强度逐渐降低,而空隙率和比表面积逐渐升高,但仍符合CJ/T 299-2008标准的要求。油页岩半焦中残余的有机组分有利于陶粒制备过程中孔隙的形成。

新疆宝明油页岩污水氨氮吹脱工艺应用研究

为更好地实现油页岩环保、清洁综合开发利用,提出采用新疆宝明矿业油页岩干馏过程中氨氮产生的原因及采用氨氮吹脱工艺消除氨氮对生产及周边环境的影响。通过具体分析氨氮产生的主要原因、处理前后氨氮含量及指标,氨氮吹脱工艺的选择,包括除油、氨氮吹脱与制氨水、吹脱设备的影响因素、pH调节、温度、水力负荷、气液比和填料控制具体应用实践,为油页岩开发过程中涉及到的氨氮问题提供参考。研究结果有助于降低污水中的氨氮含量,对减少循环水冷却油页岩灰渣过程中氨氮的溢出,具有显著的技术经济效益。

某油页岩电站CFB锅炉流渣原因分析及应对措施

某2×235 MW油页岩电站项目锅炉采用燃烧油页岩的循环流化床锅炉(CFB锅炉),油页岩中灰分占比达到60%以上,要求锅炉排渣系统能够稳定高效地运行。从冷渣器的结构和锅炉运行的角度,针对滚筒冷渣器流渣原因进行研究分析,总结流渣规律并确定流渣原因,最终对滚筒冷渣器的结构设计和运行逻辑等方面提出优化方案,并在入炉燃料粒径控制、锅炉运行方式等方面提出抑制冷渣器流渣的应对措施。通过采用一系列应对措施,滚筒冷渣器的流渣现象得到抑制;锅炉负荷调整过程中,滚筒冷渣器运行较为稳定。

燃烧过程对页岩灰孔隙结构的影响

页岩灰为油页岩及其半焦的燃烧产物,可作为建筑原材料、化工填料和吸附剂等,具有一定的工程应用价值。采用氮气等温吸附/脱附法对油页岩燃烧生成的页岩灰的孔隙结构进行了测量,并对不同升温速率和不同终温所得到的页岩灰的孔隙结构进行了比较,结果表明:如果油页岩在快速升温条件下燃烧所放出的热量能够被周围环境吸收而使得油页岩颗粒温度始终低于其灰熔点温度,所得到的页岩灰的孔容积和孔比表面积较大,适宜工业应用。

利用油页岩灰渣制备通用硅酸盐水泥

采用正交试验确定水泥熟料最佳组成配比:石灰饱和系数为0.92、硅率为2.5、铝率为1.5;水泥熟料最佳煅烧温度为1 350℃。按上述条件,利用工业原料配制水泥熟料,根据其XRD结果可知,矿物组成与吉林亚泰水泥厂的熟料相似。将油页岩灰渣作为混合材,直接掺加到水泥厂熟料中。实验结果表明:随着油页岩灰渣掺量的增加,3d强度下降明显;但后期补强作用较高,28d强度较为稳定;在水泥强度满足PC32.5标准的前提下灰渣的最大掺加量以35%～40%为宜。

油页岩灰渣制备人造大理石及其性能

利用油页岩灰渣、不饱和聚酯树脂为主要原料,辅助加入固化剂和促进剂,室温固化合成一种新型人造大理石装饰材料。运用实验系统研究原料配比、固化剂和促进剂用量、固化时间、树脂类型与填料粒度等因素对材料性能的影响,并确定了大理石制备的最佳配方。基层最佳配方（质量分数）：不饱和树脂1号为20%～27%、引发剂0.5%～2.25%、促进剂0.5%～1.5%、油页岩灰渣50%～70%、碳酸钙粉5%～20%;表层最佳配方（质量分数）：不饱和树脂1号为25%～30%、引发剂0.5%～2.0%、促进剂0.5%～2.0%、氢氧化铝40%～50%、碳酸钙粉20%～30%。采用该方法制备的人造大理石外形平整美观,压缩强度为79 MPa,弯曲强度为7.4 MPa,放射性比活度IRa和Ir分别为0.67、0.45,质量符合国家标准。

油页岩灰渣提取白炭黑的方法

以油页岩灰渣制备的水玻璃为原料,结合传统沉淀法和热风干燥工艺成功地制备了白炭黑。实验过程中研究了各种因素对白炭黑性质的影响,并确定了白炭黑的最佳制备工艺：水玻璃中w（SiO2）为8.1%、c（H2SO4）为1.5 mol/L,陈化时间为8 h,反应温度为70~80℃,pH值为8.0。透射电镜分析结果表明：采用热风干燥技术制备的白炭黑平均粒径约为50 nm,而且团聚体较少,性能优于烘箱干燥制备的白炭黑。

油页岩飞灰对重金属离子的吸附动力学及热力学

采用批式振荡吸附法研究了燃油页岩电厂循环流化床锅炉飞灰对重金属离子Pb2+、Cu2+、Zn2+、Cd2+的吸附动力学及吸附热力学特性,并提出了吸附机理。结果表明,油页岩飞灰对Pb2+、Cu2+、Zn2+、Cd2+的吸附平衡数据符合Langmuir和Freundlich吸附等温方程,但Freundlich方程能够更好地描述吸附等温线。在油页岩飞灰对重金属离子吸附的初始阶段,拉格朗日准一级动力学方程、准二级动力学方程、Elovich方程、粒子内扩散模型均能很好地反映吸附模式,而整个吸附过程则遵循二级反应动力学方程,其吸附过程是液膜扩散和粒子内扩散共同作用的结果。油页岩飞灰对Pb2+、Cu2+、Zn2+、Cd2+的吸附是吸热反应。

油页岩灰作水泥混合材的研究

通过试验研究确定大庆油页岩灰符合火山灰质混合材要求,能与熟料掺混生产水泥。配制了不同油页岩灰掺混量的水泥样品,按照国标进行强度试验,并采用X-射线衍射仪分析了28d胶砂试块的物相组成。结果表明:随着油页岩灰掺量的增加,水泥样品胶砂强度整体呈下降趋势,且前期下降幅度大,后期小;高掺混量时熟料中的C3A矿物含量不足,试样检测出钙矾石;油页岩灰掺量为5～10%,水泥样品强度仍能达到与熟料的相同的强度等级;掺量为15～20%,其强度亦接近熟料的强度等级;掺量在20%以上时,强度下降显著。

二氧化钛改性油页岩渣对水溶液中亚甲基蓝和六价铬的吸附

以油页岩渣及其二氧化钛改性材料为吸附剂,探究它们去除水溶液中亚甲基蓝和六价铬的能力.通过实验,控制溶液的pH值、温度、初始浓度和接触时间,观察吸附效果变化特征,研究其动力学和热力学性能.实验表明,改性油页岩渣吸附亚甲基蓝和六价铬的吸附率是未改性的2—3倍,且改性油页岩渣对亚甲基蓝的吸附率可达97%,对六价铬的吸附率不到25%.吸附亚甲基蓝时,pH值越大,吸附效果越好;而吸附六价铬时,最适pH值为4.改性油页岩渣吸附亚甲基蓝实验符合准二阶动力学方程,计算得反应活化能为13.29 kJ.mol-1,表明此过程主要是物理吸附.在热力学方面,由范特霍夫方程计算得ΔG<0、ΔH>0,表明此过程自发吸热,可见此过程还伴有化学吸附.Langmuir和Freundlich等温模型拟合结果表明,Langmuir模型数据拟合甚佳,R2=0.9999,说明改性油页岩渣吸附亚甲基蓝是单分子层吸附.二氧化钛改性油页岩渣经7次回收利用后,对亚甲基蓝的吸附效果仅减少约1.5%.