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.     

钙铝渣预熔合成及其在炼钢中的应用

为提高炼钢脱硫效果,以天然矿石(方解石、铝矾土)为原料,以焦炭为燃料,采用熔融法合成钙铝渣。研究了钙铝渣的组成性质,通过钙铝渣分别在轴承钢、低合金钢、不锈钢脱硫精炼工艺中与传统工艺的比较,证实脱硫率平均可提高20%,脱硫速度也显著提高,精炼时间大大缩短。用钙铝渣取代萤石,可防止氟污染,并降低对钢包衬的强烈腐蚀作用。     

钙铝渣预熔合成及其在炼钢中的应用

为提高炼钢脱硫效果,以天然矿石(方解石、铝矾土)为原料,以焦炭为燃料,采用熔融法合成钙铝渣.研究了钙铝渣的组成性质,通过钙铝渣分别在轴承钢、低合金钢、不锈钢脱硫精炼工艺中与传统工艺的比较,证实脱硫率平均可提高20%,脱硫速度也显著提高,精炼时间大大缩短.用钙铝渣取代萤石,可防止氟污染,并降低对钢包衬的强烈腐蚀作用.     

The Early Strength of Slag Cements with Addition of Hydrate Microcrystals

The effect of hydrate microcrystals such as calcium silicate hydrates ( CSH ) and ettringite on the early strength of slag cements was studied, The authors existed the possibility of improving the early strength of the slag cement by applying crystal seed technology. It is shown that slag crystal seeds make the early strength of the cement increased due to the action of hydrate crystal seeds, which speed up the hydration of dinker minerals in the nucleation of ettringite. Therefore, the early strength of the slag cement is obviously improved.     

Cementing properties of steel slag activated by sodium silicates and sodium hydroxide

Steel slag which is mainly composed of γ-Ca2SiO4 and other silicates or alumino-silicates is activated by sodium sificates and sodium hydroxide. The powders of such steel slag are usually inert to hydrate and subsequently have very low ability of cementing. But when sodium silicates and sodium hydroxide are used as activators the steel slag shows very good properties of cementing. When activated with NaOH solution the hardened slurry of the steel slag has a compressive strength of 11.13 MPa after being cured for 28 days. When activated with Na2SiO3 solution the samples after being cured for 28 days have an average compres- sive strength of 40.23 MPa. While the steel slag slurry which is only mixed with water has a compressive of 0.88 MPa after being cured for 28 days.     

一种钢渣基新型膨胀剂的制备及其性能

将特殊工艺生产的钢渣粉、硫铝酸盐水泥熟料、石膏按1∶(0.5~1)∶(1~1.5)的质量比进行粉磨、混合、均化,利用其水化反应所得的多元膨胀源制得一种具有持续稳定膨胀功能的钢渣基新型膨胀剂.研究结果表明,该膨胀剂完全符合《混凝土膨胀剂》(JC 476-2001)标准,其7和28 d水中限制膨胀率分别为4×10-4~6×10-4和6×10-4~9×10-4,空气中21 d限制膨胀率为3×10-4~5×10-4;钢渣基膨胀剂对混凝土硬化后期(28~90 d)体积变化的补偿收缩优势优于UEA膨胀剂.     

Synthesis of steel slag ceramics:chemical composition and crystalline phases of raw materials

Two types of porcelain tiles with steel slag as the main raw material (steel slag ceramics) were synthesized based on the CaO–Al2O3–SiO2 and CaO–MgO–SiO2 systems, and their bending strengths up to 53.4...     

磨细钢渣高性能混凝土的实验研究

笔者在总结发展高性能混凝土的重要性及其实现形式的基础上，以磨细后的本溪钢厂钢渣为例，探讨了磨细钢渣等矿物掺和料在混凝土中的作用与作用机理，通过实验证明在混凝土中掺加一定比例的磨细钢渣可以改善混凝土的流动性和后期强度，并得出其在混凝土中的最佳掺量范围，最后以本溪钢厂磨细钢渣为掺和料试配出具有较高强度的高性能混凝土．     

钢渣去除可溶性淀粉及其动力学过程研究

为了开发利用钢渣的吸附性能,研究了钢渣细度、用量、溶液温度、pH值对钢渣吸附去除淀粉的影响以及钢渣吸附淀粉的动力学曲线和等温吸附方程,试验结果表明,钢渣对可溶性淀粉的吸附速度快,吸附容量大,吸附过程符合Langmuir等温吸附方程,动力学过程可用Langergen准一级反应动力学方程描述。     

新型粉煤灰基硅酸钙造纸填料的物化特性

对新型粉煤灰基硅酸钙的物化特性进行了分析.结果表明,粉煤灰基硅酸钙纯度高,主要成分为含水硅酸钙,表面呈现褶皱多孔的蜂窝状结构,平均粒径较大,可达21.5μm,白度为90.5%ISO,具有较高的比表面积、孔隙率、沉降体积和吸油值,而且磨耗值较低,可用作造纸填料.     

超细钢渣粉体分形特征的测试与评价

对钢渣进行不同程度的超细加工,应用分形理论探讨钢渣粉体粒度分布的特征,并分析评价其形态,细度对水泥基材料早期和后期活性的影响。     

改性钢渣除藻效果研究

对改性钢渣在机械搅拌条件下的除藻效果进行了研究,并分析了改性钢渣预处理与混凝联用工艺对藻类的去除效果和协同作用.实验表明,钢渣经改性后,既能有效地去除水中的藻类,又能降低藻的光合活性,抑制藻的生长;高温活化改性钢渣预处理与混凝联用工艺对藻类有很好的去除效果,其对叶绿素a的平均去除率达91.4％,远高于单纯的钢渣预处理和混凝工艺.这暗示了两者之间在除藻方面存在协同作用.     

添加氧化钙的硅酸锆陶瓷的性能

以硅酸锆和硝酸钙为原料,采用湿磨的方法实现原料的均匀混合,制备了系列的添加氧化钙的硅酸锆陶瓷,利用阿基米德法和X-射线衍射技术对硅酸锆陶瓷的密度、物相变化进行了表征,测试了其显微结构和抗折强度,重点讨论氧化钙添加量和烧成温度对硅酸锆陶瓷的影响.结果表明,1 450℃和1 500℃烧结试样的体积密度随氧化钙添加量改变有较小变化,1 550℃烧结试样密度则随着氧化钙添加量增大而减小,密度最大值可达4.19克/立方厘米;样品的物相由硅酸锆和单斜氧化锆及少量稳定氧化锆组成,主晶相为硅酸锆;硅酸锆陶瓷有较多的气孔,是其致密度小的主要原因,硅酸锆陶瓷的主要断裂方式是沿晶断裂;硅酸锆陶瓷的抗折强度随着烧成温度的升高明显降低,随氧化钙添加量增大而先减小再增大,抗折强度最高可达186.0兆帕.     

Effect of barium oxide on the formation and coexistence of tricalcium silicate and calcium sulphoaluminate

Formation and coexistence of tricalcium silicate (C₃S) and calcium sulphoaluminate (C₄A₃ ) minerals in Portland cement clinker containing calcium sulphoaluminate were investigated. The f-CaO content, mineral composite and formation of mineral in the clinker were analyzed respectively by chemical analysis, differential scanning calorimetry(DSC) and X-ray diffraction. The results show that, adding a suitable amount of BaO can improve the burnability of raw meal and promote the f-CaO absorption. Tricalcium silicate and calcium sulphoaluminate minerals can form and coexist in clinkers at 1 234–1 317 °C by the addition of BaO to the raw meal. A suitable amount of BaO expanded the coexistence temperature of two minerals by 58 °. Funded by the National Basic Research Program of China (No. 2009CB623100), National Eleven Five-Year Scientific and Technical Support Plans (No. 2006BAF02A24), the Natural Science Fund for Colleges and Universities in Jiangsu Province(No. 08KJB430006), the Open Fund for the Key Laboratory of Inorganical and Composite Materials in Jiangsu Province(No. wjjqfhxc1200801) and the Innovation Fund of Doctoral Dissertation of Nanjing University of Technology (No. BSCX200705)     

Effect of Fine Steel Slag Powder on the Early Hydration Process of Portland Cement

1 IntroductionSteel slag is the waste residue of fluxing mineralsused in the process of steel producing. Its dischargeamount is about 10 % of the production of steel . Steelslag hasn’t been utilized widely and effectively in a longperiod of time[1]. Hundreds of million tons of steel slagare deposited,andthe amount is still increasing withtensof milliontons every year .The deposited steel slag occu-pies great amounts of farmlands and induces serious en-vironment problems . The main chemical c…     

钢渣对蔗糖葡萄糖果糖的吸附性能研究

为了减少钢渣澄清甘蔗汁过程中对蔗糖的吸附,减少蔗糖损失,研究了钢渣对蔗糖、葡萄糖、果糖的吸附动力学曲线以及钢渣对蔗糖的吸附等温线方程,结果表明钢渣对甘蔗汁浓度范围内的蔗糖的吸附量较小,不会在钢渣澄清甘蔗汁过程中造成蔗糖的大量损失,具有较好的应用前景.     

钢渣对水中有机物和营养物质去除的试验研究

论文对炼钢厂钢渣进行了一系列的特性分析,并通过圆柱试验了解其对水中溶解性有机碳(DOC)和营养物质的去除性能.为了保证试验圆柱良好的透水性,在试验圆柱中添加了石英砂,并设置了石英砂对比圆柱.通过64 d试验,钢渣对水中DOC、PO4-P、TP、NH3-N、NOx-N、DON和TN的去除率分别为51%、99%、87%、-15%、32%、29%和23%,吸收容量分别为6 317 mg/kg、135 mg/kg、126 mg/kg、-14 mg/kg、27 mg/kg、154 mg/kg和167 mg/kg.试验表明,钢渣对水中的有机物和营养物质有很好的去除效果.     

Recycling of industrial waste and performance of steel slag green concrete

Workability and mechanical properties of steel slag green concrete with different types of steel slag and different dosages of admixtures were investigated. The effectiveness of steel slag powder on suppressing alkali aggregate reaction (AAR) expansion was assessed using the method of ASTM C441 and accelerated test method. Experimental results show that mechanical properties can be improved further due to the synergistic effect and mutual activation when compound mineral admixtures with steel slag powder and blast-furnace slag powder are mixed into concrete. In addition, about 50% decrease in expansion rate of mortar bars with mineral admixtures can be achieved in AAR tests. Mineral admixtures with steel slag powder as partial replacement for Portland cement in concrete is an effective means for controlling expansion due to AAR.     

钢渣集料路用现状及前景分析

钢渣作集料用于道路工程,不仅可解决优质天然砂石短缺问题,而且可提高道路的工程性能。介绍了钢渣作集料的粉煤灰钢渣基层材料和钢渣集料水泥混凝土的性能,指出了钢渣集料应用中存在的问题,并展望了钢渣集料的应用前景。     

钢渣桩在湿陷性黄土地基中的应用探讨

通过钢渣桩在湿陷性黄土中的静荷载试验、土压力测试等试验结果的基础上,对钢渣桩复合地基、桩间土和钢渣单桩的p-s曲线以及其各自的承载力和相应的沉降量进行了分析,探讨了附加应力沿深度变化规律;研究了桩间土承载力、桩土应力比和桩土荷载比的变化规律,对钢渣单桩和碎石桩以及钢渣桩复合地基和石灰粉煤灰桩复合地基等的承载力特性进行了对比分析;对单桩施工影响范围和施工时地基隆起量进行了观测。