金矿尾砂配料烧制硅酸盐水泥熟料的研究

研究了矽嘎岩型金矿尾配料烧制硅酸盐水泥熟料对熟料煅烧及水泥性能的影响。结果表明，该类尾砂适宜用来配制水泥生料，可以代替全部铁粉，部分石石和部分粘土，所配生料易烧性好，熟料强度高。     

铜尾矿替代粘土煅烧硅酸盐水泥熟料的研究

以铜尾矿、石灰石、铁矿石为原料,进行水泥生料配方优化试验,开展煅烧硅酸盐水泥熟料研究,f-CaO测定、XRD矿物分析为手段确定水泥熟料煅烧的配比参数.实验结果表明,以铜尾矿替代粘土,辅以钙质、铁质及铝质校正原料,采用0.88的石灰饱和系数,2.4的硅率,1.530的铝率可制备出水化活性较高的硅酸盐水泥熟料,为铜尾矿的处理利用寻找到一条很好的出路.     

废弃混凝土再生水泥熟料的配制与性能

以完全不用天然石灰石、粘土、页岩和砂岩,废弃混凝土在生料中的质量百分含量高达95％～99％和普通煅烧工艺制备出了水泥熟料(以下简称再生熟料).将再生熟料与用天然石灰石和砂岩制备的水泥熟料进行了对比试验与分析,结果表明:2种熟料具有完全相同的XRD特征峰位,再生熟料的熟料矿物形成正常;2种熟料化学成分相近,再生熟料的率值设计中更倾向于高钙低硅;再生熟料的f-CaO含量满足安定性要求;再生熟料制备的水泥的3d强度达到42.5级硅酸盐水泥的要求,28 d强度达到52.5级硅酸盐水泥的要求.     

污泥制备水泥及其重金属释出的初步研究

城市污泥的最佳出路是无害化处理，资源化利用，产业化发展，将城市污泥作为生态水泥的生产配料是目前污泥资源化利用的新途径。该文将城市污泥作为配料分别按照6％和20％的比例与粘土混合制成水泥并养护7天后，测定水泥熟料的一些物理化学性质以及水泥固结体的重金属浸出含量。研究结果表明：与粘土相比，污泥有烧失量大、杂质含量高、A1203含量偏低的特点；以低比例污泥制备成的水泥熟料的化学成分、矿物组成和物理性能更接近于普通水泥熟料；水泥固结体中铅、镉、总铬、铜和锌可浸出含量未超出GB5085．3—1996浸出毒性标准，表明污泥中的重金属离子得到有效的束缚。     

基于煅烧煤矸石的复合水泥碳化研究

以煅烧煤矸石为主要混合材料,辅以石灰石和石膏,配制了熟料含量分别为50%和60%的2种复合水泥,研究了加速碳化对复合水泥胶砂结构和性能影响。实验结果表明：煅烧煤矸石中偏高岭土含量较低,其与熟料水化产物、石灰石的协同水化效应发挥不足,后期力学性能增幅较小;2种复合水泥抗碳化能力较弱,熟料含量50%的复合水泥制备的胶砂加速碳化14 d即接近完全碳化;加速碳化条件下,复合水泥胶砂力学性能增长明显。加速碳化后,复合水泥胶砂孔径粗化、大孔相对体积增加且孔径分布范围增宽,总孔容和总孔隙率降低。碳化产物碳酸钙结晶长大且堆积或镶嵌于C-S-H凝胶中,同时碳化反应生成的硅胶填充了砂与水泥浆体的界面空隙,界面密实度增加。     

高温煅烧石膏硅酸盐水泥早期水化产物的研究

利用DTA、XRD、IR、化学结合水和Ca（OH）2生成量测定等方法,研究了煅烧石膏、二水石膏对硅酸盐水泥早期水化过程的影响。结果表明：在水化龄期相同时,掺煅烧石膏水泥浆体中水化产物同掺二水石膏相比,Ca（OH）2生成量大;在一天前无AFt生成;结合水量在一天前前者高于后者,而一天后则相反。指出了煅烧石膏提高水泥强度的机理在于：由于煅烧石膏的溶解速度较低,在水泥水化初期（1d前）,存在于水泥中的铝酸盐相不能形成AFt,从而减缓了AFt对水泥水化的延缓作用,加速了整个熟料矿物相的水化,提高了水泥的强度。     

粉煤灰为原料的高铁水泥熟料的实验研究

本文用粉煤灰完全替代粘土原料,运用正交试验方法,探索研制符合国家标准的高强水泥熟料的最佳配料方案及煅烧制度;利用X射线衍射分析、扫描电镜及岩相检验等测试手段对所得熟料和水泥水化试样进行测试,得出了“高铁”、低温烧成的优选方案,探讨了各种因素对熟料质量的影响。     

石膏的形态对C2S浆体强度的影响

研究了二水石膏、600℃、800℃、1000℃煅烧石膏对C2S浆体强度的影响，结果表明：石膏的掺入，能提高C2S浆体的强度；煅烧石膏比二水石膏更能提高C2S浆体的强度。证明了石膏不仅对硅酸盐水泥中C3A的水化产生影响，同时亦对硅酸盐矿物的水化有促进作用。     

热活化非高岭石质粘土制备水泥混合材的探索研究

以欧洲某国储量丰富的非高岭石质粘土为原料,研究了其煅烧活化制度,并以热活化非高岭石质粘土和石灰石作为混合材制备了复合水泥。研究结果表明：非高岭石质粘土以石英、绿泥石和白云母等矿物为主,其最佳活化制度为850℃煅烧3 h,获得的热活化非高岭石质粘土28 d活性指数为83%,以其与石灰石共同作为混合材可配制熟料含量50%～70%且力学性能等级32.5 MPa及以上的复合水泥。复合水泥水化进程和水化产物与石灰石煅烧粘土水泥相类似,均含有碳铝酸盐、Ca(OH)₂等水化产物。     

金属尾矿代黏土配料煅烧水泥熟料试验研究

为获取金属尾矿代黏土配料用于水泥熟料生产的工艺参数以及分析金属尾矿对不同品位石灰石的适应性，选取6种金属尾矿，在实验室高温炉不同温度下进行尾矿代黏土配中、高钙石灰石煅烧水泥熟料的试验研究.对试验所得熟料样品分别进行了游离氧化钙质量分数的测定和矿物组成X射线衍射（XRD）分析.试验结果表明，金属尾矿代黏土与中钙、高钙石灰石配料均能烧制出合格熟料；熟料的烧成温度较黏土配料1 450 ℃的烧成温度降低了100～150 ℃；当金属尾矿配中钙石灰石时在1 300 ℃即可完成熟料烧成，与金属尾矿配高钙石灰石时1 350 ℃的煅烧温度相比，金属尾矿配中钙石灰石更适合水泥熟料烧成.     

Physical Properties and Hydration of Cementitious Materials Prepared from Vanadium Slag and Phosphate Slag

The physical properties and hydration of a cementitious material, which prepared mainly from the vanadium slag and phosphate slag, were investigated. These slags were investigated can be reused as original resources to prepare cement clinker based on the fact that they mainly comprise silicon and calcium phases, respectively. In this research, a batch of cement having various grades was prepared by mixing the clinker with gypsum, tailings, and fly ash. X-ray diffraction(XRD), differential thermogravimetric(DTG) as well as scanning electron microscopy(SEM) were applied to test and analyze the physical properties and hydration of the prepared cement. Experimental results suggest that the performances of the cement meet the requirements of national standards in all aspects. Its hydration process is similar to that of common Portland cement, whose hydrates were mainly composed of C-S-H, ettringite and CH. Moreover, the addition of fine particles would accelerate cement hydration, as it provided additional surfaces to help the nucleating and growing of hydrates.     

镁渣硅酸盐水泥的性能

用2种不同来源的镁渣作为水泥混合材配制镁渣硅酸盐水泥。研究了其标准稠度用水量、凝结时间、强度等基本性能,考察了镁渣对水泥干燥收缩的影响,并通过XRD、DSC/TG、SEM等微观手段研究了镁渣在水泥中的作用效应。结果表明：镁渣作为水泥的混合材具有一定的减水缓凝效果;镁渣掺量在10%～30%范围内时,水泥样品符合通用硅酸盐水泥42.5R级的标准,掺量为35%～40%符合32.5R型复合硅酸盐水泥的要求;镁渣掺量为30%～40%时对水泥砂浆的干燥收缩有抑制作用;镁渣与水泥熟料水化产物发生反应,使水泥浆体结构更加致密。     

Early hydration of composite cement with thermal activated coal gangue

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca(OH)₂ content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis (TG-DSC), X-ray diffraction(XRD), scanning electronic microscopy (SEM) and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca(OH)₂ and AFt. The cement with 30% (in mass) the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 °C displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.     

Optimization of Blended Mortars Using Steel Slag Sand

A new kind of mortar made of ground granulated blast-furnace slag （GGBFS）, gypsum, clinker and steel slag sand （〈4.75 mm） was developed. The ratio of steel slag sand to GGBFS was 1 ： 1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development. Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined. The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.     

Analysis of Hydration Mechanism and Microstructure of Composite Cementitious Materials for Filling Mining

To obtain the compositions and microstructure of hydration products of cementitious material in different hydration ages and its growth law of filling strength, the optimal proportion of composite cementitious material was determined according to the chemical composition of cement clinker which was composed of the Portland cement 32.5R, CSA 42.5 sulphoaluminate cement and two gypsum(CS). The characterization of composite cementitious materials in different hydration ages was conducted by NMR, XRD and SEM techniques. The mechanism of hydration was explored. It is shown that the compressive strength of the test block increases gradually with the increase of hydration age. The microstructure of composite cementitious material can be changed from Al-O octahedron into Al-O tetrahedron in the hydration process. The hydrated alkali alumi niumsilicate formed with Si-O tetrahedron and Al-O tetrahedron. The degree of polymerization of Si-O tetrahedron gradually increased, and the structural strength of cementitious materials continued to increase. The diffraction peak of clinker minerals gradually decreased with the extension of hydration age. The CaSO_4 completely hydrated to produce Aft during hydration which resulted in high early strength of cementitious material. The early hydration product of composite cementitious materials was Aft with a needle bar structure. The main middle and last hydration products were CSH gel and CH gel with dense prismatic shape. The microscopic pore of composite cementitious material gradually decreased and improved the later strength of filling block. The strong support was provided for mined-out area.     

Resource utilization of slag from desulphurization and slag skimming: A comprehensive recycling process of all components

In order to make the slag from desulphurization and slag skimming (SDSS) to be comprehensively recycled and utilized, a combined process of beneficiation and building materials preparation was proposed to recover iron from SDSS, meanwhile to apply the remaining slag tailings as cement admixture. From this process, three iron-rich products were recovered in stages by clean gravity - magnetic separation, slag tailings were left. Slag powder was prepared by ultrafine grinding of slag tailings. The stability, setting time and cement mortar strength of the slag tailings cements (STC) which were mixed with Portland cement and slag powder were studied respectively. The results showed that a proper overall performance still could be obtained at the slag powder content of 30%. Chemical composition analysis, X-ray diffraction (XRD) analysis, metallographic microscope and scanning electron microscope (SEM) analysis were employed to assess the characteristics of the SDSS and the products obtained from the whole process. The results indicated that the three iron-rich products could be used as a raw material for steelmaking and ironmaking and the relatively large amount of calcium silicate (C₂S) and tricalcium silicate (C₃S) in the slag tailings make the addition of slag powder into the Portland cement feasible.     

镁渣等工业废渣应用现状的研究及前景分析

镁渣矿物属于介稳的高温型结构,结构中存在活性的阳离子,所以,镁渣本身具有很高的水化活性,水化后生成水化硅酸钙凝胶,镁渣作为破胶凝材料是可行的,镁渣中的[SiO4]4-更易丢失,链断裂,形成类似于有机-无机杂化物的结构,在镁渣中掺入一定的硅酸盐水泥或磨细硅酸盐水泥熟料和磨细矿渣,以提高镁渣胶凝材料的耐久性,镁渣作为砂浆的胶结材料是非常理想的,镁渣不但可以提高砂浆的和易性,而且还可以提高砂浆的强度和耐久性,镁渣中掺入一定量的轻骨料,可制作轻质保温墙体材料或制成屋面材料。     

Strength of limestone-based non-calcined cement and its properties

A new type of cement was prepared with ground limestone powder, blastfurnace slag, steel slag and gypsum without calcination. The fraction of ground limestone powder in the cement was as high as 40 wt%–60 wt% without Portland clinker. All of its physical properties can meet the requirements of masonry cement standards. The impact of limestone content on physical properties of the cement and determined its impact on law was investigated. The steel slag can excit the aquation activity of this cement effectively, and the influence of its quantity on the strength of the materials was studied, which shows that the optimum quantity of mixing is 10%. By way of changing the different content of the lime stone by quartzy sample, the law of the compression strength and the PH value was determined, confirming that the lime stone can promote the early aquation of the slag and improve the early strength. The main hydration product of this cement is calcium aluminate hydrate, ettringite and calcium silicate hydrate, as indicated by XRD and SEM analysis.     

Model Analysis of Initial Hydration and Strueture Forming of Portland Cement

The auto efficiently hydration heat arrangement and the non-contacting electrical resistivity device were used to test the thermology effect and the resistivity variation of Portland cement hydration. The structure forming model of Portland cement initial hydration was established through the systematical experiments with different cements,the amount of mixing water and the chemical admixture.The experimental results show that,the structure forming model of cement could be divided into three stages,i e,solution-solution equilibrium period,structure forming period and structure stabilizing period.Along with the increase of mixing water,the time of inflexion appeared is in advance for thermal process of cement hydration and worsened for the structure forming process.Comparison with the control specimen,adding Na_2SO_4 makes the minimum critical point lower,the flattening period shorter and the growing slope after stage one steeper.So the hydration and structure forming process of Portland cement could be described more exactly by applying thc thermal model and the structure-forming model.     

Long-term Performance of Moderate Heat Portland Cement with Double-expansive Sources

The long-term performance of moderate heat Portland cement with double-expansive sources （DE cement） in the system of high MgO clinker and gypsum was studied by XRD, SEM/EDAX and test methods for strength and expansion of cement. Results indicate that the periclase particle, whose size was 5-7.5μm in DE cement clinker containing 4.8 % MgO, existed individually. The periclase hydration in hardened DE cement paste started at about 60 days and completed up to 2 000 days, and ettringite in the paste was stable from 3 days to 2 000 days. Under the conditions of 4.5%-5.0 % MgO in clinker and 2.8%-3.4 %SO3 in cement, ettringite expansion and brucite expansion in DE cement paste had a continuity, entirety and stability. At the ages of 90, 365,730 and 2 000 days the expansion of the paste reached 0.07%-0.11%, 0.16%-0.21%, 0.21%-0.27 %, and 0.29%-0.38%, respectively. The results suggest that by using this cement in mass concrete it may compensate its temperature shrinkage and autogenous shrinkage to some extent.