Preparation of Ultra-light Xonotlite Thermal Insulation Material Using Carbide Slag

Using carbide slag as the calcareous materials, xonotlite thermal insulation material was successfully prepared via dynamic hydrothermal synthesis. The experimental results show that the xonotlite thermal insulation material is made up of large numbers of chestnut bur shape particles. Optimum conditions of calcination temperature of carbide slag, synthesis reaction temperature and time, stirring rate, CaO/SiO2 mol ratio, water/solid weight ratio, amount of fiberglass, molding pressures, dryness temperatures...     

A composite thermal insulator based on xonotlite and perlite

A low cost thermal insulating material can be produced by compounding an active xonotlite slurry, fired-perlite, HOMOPAN fibers and glass fibers. The maximum service temperature of the product is 800C; linear shrinkage after 800℃×16 h firing is0.9%; the cold crushing strength is 1.56 MPa; the flexural strength at ambient temperature is 0.81 MPa; the thermal conductivity atambient temperature (25℃) is 0.056 and 0.128 W/(m·K) at 800℃. The production cost of such a composite is only 1/3 of that of thenormal xonotlite thermal insulators. It can substitute the normal xonotlite thermal insulators on most occasions with a similar cost to that of normal perlite products.     

Hydrothermal synthesis of xonotlite-type calcium silicate insulation material using industrial zirconium waste residue

Xonotlite-type insulation material was prepared by hydrothermal synthesis technology using industrial zirconium waste residue in this paper,and the phase analysis together with the observation of micro–morphology were also carried out by XRD,SEM and TEM.The density and thermal conductivity were measured finally.The results indicate,chlorine ion impurity contained in zirconium waste residue can be removed effectively via water washed process,and the reactive activity of silicon dioxide is almost not affected,which make it be a good substitution of silicon material for the preparation of calcium silicate insulation material by hydrothermal synthesis technique.The density and thermal conductivity of xonotlite-type calcium silicate insulation material obtained by hydrothermal synthesis technique can reach 159 kg/m3,0.049 W/(m·° C),respectively,meeting with National Standard well,when synthesis conditions are selected as follows:Ca/Si molar ratio equal to 1,synthesis temperature at 210°C and kept for 8 hrs.It provides a new approach to realize lightweight and low thermal conductivity of calcium silicate insulation material.     

Influence of Thermal Load on Mechanical Property of Cemented Carbide Material and Heavy Cemented Carbide Inserts Life

A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,and the results show that the bending strength and fracture toughness of cemented carbide material decrease obviously under cyclic thermal load,while in the cooling process,the material mechanical property changes worse suddenly.The high-temperature mechanical property of SCS is the most stable,and that of YT15 is the worst.Further,a relation model among cutting temperature,cutting parameters and insert life is established.Finally,the measures to improve heavy cemented carbide inserts life are summarized from the aspects of cutting parameters selection,insert optimization design and TiCN,Al2O3,TiN complex insert coating.The research results are expected to provide support and reference for heavy cutting technology and insert technology.     

Molten salts/ceramic-foam matrix composites by melt infiltration method as energy storage material

A new type of high temperature energy storage material was obtained through the melt infiltration method, using compounding SiC ceramic foam as matrix and Na₂SO₄ as phase change material. The resulting composite material was measured by XRD, SEM, TG-DSC methods. The experimental results indicate that the composite is composed of silicon carbide, sodium sulfate and square quartz, and no chemical reactions occurs between Na₂SO₄ and SiC matrix. Na₂SO₄ has a good bonding with the SiC ceramic foam matrix. As the composite material is characterized by high thermal energy storage density and high thermal conductivity, it is suit for energy storage under high temperature. Funded by the “863” Hi-Tech Research and Development Program of China (2008AA05Z418)     

不同固体废弃物对保温材料形成和性能的影响

通过XRD、SEM和强度测试技术等分析手段探讨了炉渣、废玻璃、糖滤泥不同固体废弃物对保温材料形成和性能的影响。结果表明,以炉渣质量分数25%、糖滤泥质量分数28%、废玻璃质量分数14%、水曲柳质量分数33%,在成型压力为20MPa、烧成温度1 060℃、保温时间0.5h下,可制备出抗折强度大于14MPa、密度为1.204g/cm3、孔隙率达到35%、导热系数小于0.40 W/(m.K)的陶瓷保温材料。物相组成分析其制品成分主要晶相为莫来石、方石英,同时存在玻璃相、气相以及少量钙长石相。SEM观察其微观结构制品中有大量气孔存在,气孔所占体积比可达35%,气孔呈封闭状态。     

电石渣脱硫的实验研究

利用热重分析仪对电石渣脱硫性能进行了实验研究,证明了电石渣脱硫的可行性.实验发现电石渣在850℃时脱硫效果最好,这与石灰石温度接近;并且其在低温情况下也可以实现脱硫,这是石灰石不能实现的.     

New activated carbon with high thermal conductivity and its microwave regeneration performance

Using a walnut shellas a carbon source and ZnCl_2 as an activating agent,we resolved the temperature gradient problems of activated carbon in the microwave desorption process.An appropriate amount of silicon carbide was added to prepare the composite activated carbon with high thermalconductivity while developing VOC adsorption-microwave regeneration technology.The experimentalresults show that the coefficient of thermalconductivity of SiC-AC is three times as much as those of AC and SY-6.When microwave power was 480 W in its microwave desorption,the temperature of the bed thermaldesorption was 10 ℃ to 30 ℃ below that of normalactivated carbon prepared in our laboratory.The toluene desorption activation energy was 16.05 k J·mol~(-1),which was 15% less than the desorption activation energy of commercialactivated carbon.This study testified that the process could maintain its high adsorption and regeneration desorption performances.     

循环流化床电石渣脱硫性能研究

对采用电石渣进行循环流化床烟气脱硫做了实验研究.利用热重分析仪,探讨了脱硫温度和不同煅烧温度对电石渣脱硫速率的影响,确定了电石渣脱硫的最佳反应温度.在自制的循环流化床烟气脱硫装置上,进行了用电石渣作为脱硫剂的试验.研究结果表明,Ca/S摩尔比为2,床温为850℃时,脱硫效率可达到90%左右.     

循环流化床电石渣脱硫性能研究

对采用电石渣进行循环流化床烟气脱硫做了实验研究.利用热重分析仪,探讨了脱硫温度和不同煅烧温度对电石渣脱硫速率的影响,确定了电石渣脱硫的最佳反应温度.在自制的循环流化床烟气脱硫装置上,进行了用电石渣作为脱硫剂的试验.研究结果表明,Ca/S摩尔比为2,床温为850℃时,脱硫效率可达到90%左右.     

赤泥-高炉矿渣-钢渣三元体系注浆材料试验研究

为解决地下工程灾害治理中大量消耗水泥造成的环境污染、造价高等问题,本文基于协同理论制备了赤泥-高炉矿渣-钢渣基三元体系全固废类注浆材料,系统研究了钢渣对赤泥-高炉矿渣二元体系工作性能、力学强度的作用规律,并结合X射线衍射、傅里叶变换红外光谱、扫描电镜、压汞仪等微观测试手段分析其作用机理。试验结果表明：钢渣对赤泥-高炉矿渣二元体系力学强度具有提升作用,当其掺量为10%时,28 d抗压强度可达12.78 MPa,增幅为59.84%。钢渣经机械粉磨和高温活化后,其协同作用可进一步提高,随着钢渣粒度的减小,浆液结石体力学强度逐渐增强;随着活化温度提升,结石体力学强度呈先增加后减小的趋势。钢渣在10%最优掺量下,活化温度为700 _^oC,粒径为200目时,赤泥-高炉矿渣-钢渣基注浆材料结石体的力学强度最优,28 d强度达到15.1MPa。此外,钢渣的掺入还可以促进赤泥-高炉矿渣基浆液的凝结,凝结时间缩短,浆液的流动性降低。微观分析表明：钢渣可参与赤泥-高炉矿渣体系的水化反应,而且钢渣微粒在浆液结石体中具有充填效应,使结石体更加密实,进而提高结石体力学强度;此外,在高温条件下,钢渣中生成钙芒硝,硅酸二钙,硅酸三钙,铝酸钙胶凝矿物,可促进钙矾石和水合铝酸钙的生成,对强度具有提升作用。     

Promoting sludge granulation by putting xonotlite into the UASB reactors during starting-up stage

Four reactors of up-flow anaerobic sludge blanket (UASB) were concurrently operated to examine the effects of the xonotlite secondary particles on promoting the sludge granulation during the starting-up stage at room temperature. The results show that the putting of the xonotlite secondary particles into the UASB reactors can increase the basicity of the reacting liquid significantly. The particles can act as the media for biomass accumulation. Thus, the granulation process of the sludge within the reactor can be largely promoted by the special performances of the particles both in physical and chemical aspects.     

外墙外保温体系裂缝分析研究

外墙外保温是墙体节能的重点推广技术,而裂缝的出现会大大降低其性能.通过对外保温裂缝形成原因的分析,指出温度场的重新建立以及材料性能的差异是导致裂缝出现的主要原因;并结合外保温构造做法,提出了避免裂缝产生的三大原则;最后,就外墙外保温的发展进行了讨论.     

掺粉煤灰的保温隔热屋面材料的试验

为研究开发具有良好的保温隔热屋面材料,有效改善室内居住环境和节约能耗,通过试验,采用电厂粉煤灰为主要基料,废旧聚苯乙烯泡沫塑料为主要隔热单元,在满足保温隔热屋面材料质量要求的条件下,经水泥、外加剂复合制成具有良好的保温隔热屋面材料。这种材料具有表观密度低和导热系数小的特点,其它性能均满足屋面使用质量要求,符合国家对建筑节能和生态建材的需求,是一种有较大发展前景的绿色建筑材料。     

MPM复合保温材料导热系数的测定及实验装置的改进

MPM复合材料是一种导热系数较小的保温材料 ,单纯采用石棉作为绝热壁不能克服实验过程中大量的热损失。利用改进护热平板构造出有效的绝热壁的实验装置 ,对 MPM复合保温材料的导热系数进行了实验测试。结果表明 :在所研究的温度范围内该种材料的导热系数与温度呈线性关系 ,即λ=( 2 .0 1 8+ 0 .1 2 2 T)× 1 0 - 2 W· ( m·℃ ) - 1;导热系数的值域说明了此种材料具有较好的隔热保温性能 ;证实了该实验装置误差小于 5 %～ 1 0 %。     

基于废弃物利用的自保温墙体配套砂浆制备及性能研究

采用淤泥陶砂、废弃加气混凝土结合传热系数小的玻化微珠为砂浆骨料,基于"复合化"思想,制备自保温墙体配套砂浆。采用正交实验探讨混掺砂浆的合理配比,控制4项参数:胶凝材料用量、陶砂(或废料)与玻化微珠体积比、硅灰取代量和胶粉掺量,以干容重、抗压强度、导热系数为考核指标,制备综合利废效果最佳的新型混掺复合保温砂浆。结果表明,陶砂玻化微珠复合砂浆导热系数0.16～0.29W/(m.K),随着陶玻比增大而增大,因此陶砂体积含量增加有利于提高保温性能,加气废料玻化微珠复合砂浆的导热系数0.10～1.14W/(m.K),与陶砂复合保温砂浆相比,有较大的降低。     

Combustion Synthesis and Densification of NiAl／TiB2 Composites

A suitable combustion synthesis and densification process was designed to fabricate dense NiAl/TiB2 composites from Ni-Al-Ti-B system. Combustion synthesis processing and microstructure characteristies of products were studied in detail. The results show that the amount of TiB2 ceramics has a great influence on the combustion synthesis processing and microstructure; with the increase of the amount of TiB2 ceramics, the combus-tion temperature and combustion velocity increase rapidly. The volume of synthesized products and the grain size of ceramics particle size are also affected by the amount of TiB2 ceramics. TiB2 ceramics fiber can be produced in this synthesis system. The dense NiAl/TiB2 composites with residual porosity of no more than 1% are fabricated by the combustion synthesis and hot pressing, the mechanical properties of the dense NiAl/TiB2 composites increase with increase of the amount of TiB2 ceramics.     

直埋保温管道与地沟敷设管道经济效益分析

结合供热工程施工,分析比较了几种保温材料的物理性能,总结了各种供热管道敷设方法的投资费用,测定了保温效果。结果表明,直埋具有防火、阻燃、耐高温、耐老化、保温隔热效果好、机械强度高等特点的“硬泡”保温管投资最低,保温效果最佳。     

变形工艺对GCr15钢在线球化的影响

根据离异共析原理,对GCr15钢采用先促进碳化物析出,再变形破碎的工艺,即分别采用两道次变形工艺和三道次变形工艺在Gleeble-2000型热模拟机进行变形实验,对比不同变形工艺下GCr15钢的显微组织和硬度,分析变形道次、碳化物析出区间冷却起始温度和冷却速度对组织球化的影响。结果表明:三道次变形工艺在实现GCr15钢组织球化和材料软化方面较两道次变形工艺有明显优势;对于GCr15钢,在三道次变形工艺中,把未再结晶区变形温度控制在900℃,并在900～800℃采用1℃/s的冷却速度,能够形成大量的球化组织,材料明显软化,可实现钢大部分组织在线球化。     

Research on non-steam-cured and non-fired fly-ash thermal insulating materials

A thermal insulating material is synthesized via a non-steam-cured and non-fired route by using fly-ash, sorel cement and hydrogen peroxide solution as raw material. Properties such as apparent density, compressive strength, bending strength, ther-mal conductivity, water resistance, and thermal tolerance of this matrial are studied, some influencing factors on its performance discussed. This material has an apparent density of 360 kg/m3, a compressive strength of 1.86 MPa, a thermal conduction coeffi-cient of 0.072 W/(m·K), a softening coefficient of 0.55, and a thermal tolerant temperature of 300 ℃. Test results show that this material is light in weight, of high strength, and good thermal insulation. In addition, neither steam-curing nor sintering is needed in producing it. Further more, large amount of fly ash is used in this material, making it a low cost and environment-friendly building material.