影响中压注浆石膏模具寿命因素的探讨

从石膏粉、制模工艺、注浆工艺操作、泥浆四方面入手分析了影响中压注浆石膏模具寿命的因素，根据实践，提出了提高模具寿命的重要途径。     

脱硫石膏掺杂氧化锌转晶制备高性能建筑石膏

脱硫石膏经过热处理批量制备建筑石膏,不仅可以缓解环境污染问题,还具有一定的经济效益。以电厂脱硫石膏为原料,添加氧化锌为转晶助剂,通过热处理调控脱硫石膏煅烧产物的晶体结构,从而制备高性能的建筑石膏,并研究了氧化锌添加量和煅烧温度对建筑石膏性能的影响。结果显示,氧化锌助剂的添加拓宽了脱硫石膏煅烧成半水石膏的温度范围,还改善了煅烧产物的结晶度。脱硫石膏中添加0.6%氧化锌（以质量分数计）,在180 ℃煅烧制备的建筑石膏性能最佳。水化2 h产物的形貌为相互交叉堆积的针状或纤维状晶体,2 h抗折和抗压强度分别达到3.8 MPa和9.2 MPa,符合3.0等级建筑石膏标准的要求,可以实现脱硫石膏的规模化资源利用制备高性能的建筑石膏。     

湿法烟气脱硫石膏制备建筑石膏影响因素探讨

通过对湿法烟气脱硫石膏性质的分析,利用建筑石膏三相分析原理,从脱硫石膏原料纯度、残余二水石膏含量、粉磨工艺、煅烧设备等方面,对利用烟气脱硫石膏煅烧制备建筑石膏的影响因素进行了研究探讨。     

石膏模具的改性研究

本文介绍了以苯丙乳液为改性剂对α－石膏进行改性研究的情况,通过研究选出了改性剂的品种及最佳加入量,所进行的洗面器中压注浆试验证明,改性后的石膏模可用于卫生瓷中压注浆成形工艺中。     

脱硫石膏制备高强石膏工艺现状

介绍了我国脱硫石膏综合利用的现状。在此基础上,总结了以脱硫石膏为原料制备α型半水石膏(高强石膏)的主要制备方法以及当前国内外学者研究的进展和成果。最后比较了蒸压法和水热法制备高强石膏的优缺点。     

利用脱硫石膏制备干粉粉刷石膏的研究

研究了脱硫石膏在干粉粉刷石膏生产中的应用。根据煅烧石膏的矿物组成,标准稠度用水量,选取最佳煅烧制度。以最佳煅烧制度煅烧所得的石膏为基材配制面层和底层粉刷石膏。     

高含氯脱硫石膏制备石膏砂浆研究进展

湿法脱硫是燃煤烟气脱硫的主流技术,该过程会产生大量脱硫石膏,制备砂浆等绿色建材产品是其资源化利用的重要途径。但由于脱硫系统工艺水循环使用,加之脱硫废水零排放要求,使脱硫石膏中氯离子含量较高,严重影响石膏砂浆性能。因此,对高含氯脱硫石膏中氯离子进行控制,以抑制其对石膏砂浆制品性能的不利影响,已成为当前研究热点。介绍了氯离子对石膏砂浆的作用机理,包括对石膏水化过程、吸水性能的影响等。对目前氯离子的控制技术做出系统梳理,包括物理层面吸附氯离子及堵塞氯离子迁移孔道,以及化学层面转化成氯铝酸盐。此外,对高含氯石膏砂浆的制备条件进行了总结,其中,脱硫石膏在150~180℃下煅烧1.5~2.5 h,得到的脱硫建筑石膏具有较高的致密度以及较低的孔隙率,可阻碍氯离子迁移;缓凝剂能延长凝结时间,但不利于氯离子迁移的控制;保水剂能够提高石膏砂浆保水性,但会加快氯离子迁移;减水剂可降低水灰比,抑制氯离子迁移;防水剂改善了孔隙结构,抑制了砂浆表面氯化钙的生成。并对未来采用高氯脱硫石膏制备石膏砂浆的发展趋势进行了展望。     

注浆成型《插芯注浆》法

注浆成型中,对于厚壁制品.尤其是实心的厚制品.通常采用的双面吸浆、单面吸浆,难于保证制品的成型成活率,即使制成的坯体也易出现开裂、分层等弊端.为解决厚制品注浆成型缺陷.仅介绍《插芯注浆法》.一、注浆成型基本原理注浆成型法,即把有良好流动性、厚化性能的料浆,注入到模型中,由模型吸收料浆中的水份,使模型中的料浆逐步失去水份而硬     

脱硫石膏的热处理及其对矿渣水泥若干性能的影响

研究了在不同温度下处理的脱硫石膏对矿渣水泥若干性能的影响，确定其在水泥基材料中循环利用的可行性。研究结果表明，经低温烘干焙烧处理的脱硫石膏，掺入到矿渣水泥中并控制适当的SO3掺量，水泥凝结时间正常，强度略有提高，并且明显降低了硬化水泥浆体的失水率和干缩率，可以有效防止收缩裂缝的产生：并进一步探讨了脱硫石膏对矿渣水泥性能的影响机理。     

Porous alumina ceramics for slip casting molds

Although a slip cast process using a gypsum mold enables large and complicated dense green body to be made, the green body is contaminated with calcium and sulfur impurities from the gypsum mold. In the case of a resin mold, external pressure must be applied due to its poor water wettability. Porous alumina ceramics are used as a mold material for the first time to overcome these problems. The porous alumina ceramics show higher water wettability than gypsum or resin. The porous alumina molds have submicron pores, and provide larger penetration pressure and higher casting rate than gypsum molds.     

Mineralogical and chemical properties of FGD gypsum from Florina,Greece

BACKGROUND: The aim of this work is to define the chemical and mineralogical composition of the fuel gas desulphurization (FGD) gypsum produced from the Meliti thermal power plant in the region of Florina in North West Greece, in order to investigate potential uses in the cement industry. Mineralogical and microprobe analyses were carried out on FGD gypsum samples collected from the Meliti 330 MW lignite‐fired power plant. RESULTS: Results show that the main component of the FGD gypsum is pure mineral gypsum (CaSO₄·2H₂O). The particle size of the gypsum ranges from 5 to 50 µm and the crystals are mainly of rhomboid shape. Microprobe analysis shows that the concentration of CaO and SO₃, which are the main components, range from 31.9%–32.5% and from 45.90–46.40%, respectively. CONCLUSION: This FGD gypsum can easily substitute the natural gypsum used in the production of cement. Copyright © 2007 Society of Chemical Industry     

脱硫石膏联产水泥与硫酸技术

结合鲁北集团60kt／a水泥-40kt／a硫酸中试装置数据,介绍用电厂烟气脱硫石膏联产水泥与硫酸的原料性质、工艺流程、控制指标及成本构成。指出用脱硫石膏联产水泥与硫酸具有技术和经济可行性,既可减少环境污染,又可实现废物的资源化利用。     

Verification of lime and water glass stabilized FGD gypsum as road sub-base

Flue gas desulfurization (FGD) gypsum is a by-product created when sulfur is removed from flue gases in power plants. The utilization of FGD gypsum as a road sub-base for construction purposes is unsatisfactory when compared with other by-products such as fly ash and steel slag. As a result, FGD gypsum has generally been treated as a waste product and landfill. A new type of semi-rigid road sub-base is proposed, which is a mixture of FGD gypsum, water glass and slaked lime. Laboratory studies of moulded samples of this new material were investigated using different curing methods and measuring unconfined compressive strength, soundness and water stability. The experimental results showed that the road sub-base material reflects excellent mechanical properties and soundness durability. This contributes not only to improved road performance, but also represents a new and improved beneficial use of FGD gypsum.     

流延法制备Ni-YSZ/YSZ复合基膜及性能测试

采用传统有机流延法制备NiO-YSZ/YSZ复合基膜,其中包括流延浆料配制及流延工艺过程.采用共烧结方式制备均匀平整的SOFC多孔阳极支撑的致密电解质膜,阳极支撑层厚度1000 μm、阳极功能层20 μm、致密电解质层40 μm左右.并对阳极孔隙率和电解质气体渗透率、显微结构及膨胀系数等进行测试.结果表明通过复合流延的方式可以制备出具有良好组织结构和性能的SOFC阳极支撑系统.     

锥管状电解质支撑的固体氧化物燃料电池的制备及其性能

用石膏模注浆成型法制备了摩尔分数为8%氧化钇稳定氧化锆的致密锥管状电解质.在1 500℃下煅烧4h,样品的相对密度达到97.7%.锥管的大开口端直径为16.5 mm,小开口端直径为15 mm,管壁长为12 mm,壁厚为0.177 mm.用甘氨酸-硝酸盐燃烧法制备了超细电极材料.将制备的锥管状电解质和电极材料组装成电解质支撑的固体氧化物燃料单电池,以氢气为燃料、空气为氧化剂,研究了该电池的性能.结果表明:电池开路电压(open circuit voltage,OCV)随温度的变化与理论结果一致,在800 ℃时,OCV达1.013 V,最大输出功率约为190 mW.阻抗谱测量结果表明:电解质的欧姆电阻是影响电池性能的主要原因.     

Five-layer reverse tape casting of IT-SOFC

Tape casting is a well-established method for manufacturing thin ceramic layers with controllable thickness and porosity. This study investigates the potential of 10Sc1CeSZ material for the electrolyte and anode layers for intermediate-temperature solid oxide fuel cells (IT-SOFC) in an anode-supported cell (ASC) geometry. In order to use La_0.6Sr_0.4Co_0.2Fe_0.8 Oxide (LSCF) cathode material, a Gd_0.2Ce_0.8 Oxide (GDC) barrier layer is needed; however, thermal expansion coefficient mismatch results in delamination of the GDC from the electrolyte during high temperature sintering when fabricated by conventional tape casting procedures. For the first time, ASCs have been manufactured by a five-layer tape casting technique; barrier layer, novel composite layer, electrolyte, anode functional layer, and anode substrate. Ni-ScCeSZ composite cells were tested between 650 and 800°C in H₂:N₂ fuel (85% H₂) on the anode and air on the cathode to yield a maximum power density of .46 W/cm². These results demonstrate the feasibility of this new five-layer tape casting technique to produce IT-SOFC.     

Influences of solid content of slurry on the microstructure of CaO crucible prepared by slip casting

CaO crucible was prepared from Ca(OH)₂ slurry via a slip-casting method in order to avoid hydration problem caused by free CaO during preparation process. The effect of solid content of Ca(OH)₂ slurry on microstructure of CaO crucible was investigated. It was found that the rheological property of the slurry was significantly improved when the solid content of the slurry within a certain range. The change of solid content of slurry affects the microstructure of the final products. When the solid content of the slurry was 71 wt%, the manufactured CaO crucible was of smallest mean pore size (2.58 μm) after 1600°C heating treatment. The heated CaO sample was of lower apparent porosity (4.1%) and higher bulk density (2.93 g/cm³). And the size distributions of most CaO grains are between 10 and 40 μm.     

脱硫建筑石膏三相分析方法研究及应用

从脱硫建筑石膏各相所具有的水化和脱水特性角度,利用卤素水分测定仪,提出一种用于脱硫建筑石膏相组成分析的简单而有效的方法.就残余二水石膏及无水石膏含量对脱硫建筑石膏性能的影响进行试验研究,对相组成在煅烧设备及煅烧工艺改进方面的应用进行探讨,从而肯定了相分析的重要性及有效性.     

微波加热分解脱硫石膏生产烧结矿研究

研究了在微波炉中配加无烟煤磁铁矿的烟气脱硫石膏混合料的升温特性及还原分解性能,应用X射线衍射、扫描电镜和微机快速测硫仪对分解渣进行检测分析。微波加热下,配加10%磁铁矿和8%无烟煤(质量分数)的脱硫石膏混合粉的升温效果最佳,混合物料在80min内升温到1000℃,保温60min后,脱硫率为93.86%。作为催化剂和微波吸收剂,磁铁矿的加入提高了微波加热物料的温度,促进脱硫石膏分解生成Ca_xFe_yO_z,放出SO₂气体。随着Ca_xFe_yO_z含量的增加,物料的脱硫率提高。混合物料分解渣的SEM图像显示,微波加热下,配加磁铁矿和无烟煤的脱硫石膏混合物料分解的过程中发生粒子团聚烧结。配加5%分解渣的烧结矿化学成分与太钢烧结矿的化学成分无显著区别,此分解渣可以作为高炉烧结矿的熔剂配料来使用。