低品位硫铁矿烧渣生产复合硅酸盐水泥工艺优化

这是一篇矿物材料领域的论文。为因地制宜寻求低品位硫铁矿烧渣的综合利用途径，解决硫铁矿烧渣大量堆存的问题，并缓解土壤及水质污染，进行了低品位硫铁矿烧渣生产复合硅酸盐水泥工艺优化研究。利用硫铁矿烧渣具有铁含量高的特点，作为外加剂，将其掺入水泥熟料、脱硫石膏、粉煤灰等，混合磨细，制备复合硅酸盐水泥，以强度为指标，确定适宜的硫铁矿烧渣掺量。通过对不同硫铁矿烧渣掺量制备的水泥试块进行物理性能检测，利用正交实验对工艺条件进行优化。结果表明，较佳工艺条件为，水泥熟料掺量为55%，钙硅比为2.5，灰渣比为1，水灰比为0.4，在此条件下，实验制得的水泥28 d抗压强度为43.9 MPa，强度等级为42.5。     

低品位硫铁矿烧渣生产复合硅酸盐水泥研究

以硫铁矿烧渣为外加剂,水泥熟料、脱硫石膏、粉煤灰为原料,制备复合硅酸盐水泥,以强度为评价指标,确定硫铁矿烧渣最佳掺量为13.5%,此掺量下制备的复合硅酸盐水泥试块初凝时间为75min,终凝时间为330min,安定性合格;28d抗压强度为48.7MPa,28d抗折强度为7.20MPa,符合GB175-2007《通用硅酸盐...     

响应曲面法优化硫铁矿烧渣生产水泥工艺条件

以硫铁矿烧渣为外加剂,水泥熟料、脱硫石膏、粉煤灰为原料,制备复合硅酸盐水泥。以28 d抗压强度为评价指标,选取硫铁矿烧渣掺量、水泥熟料掺量、灰渣比为影响因素,运用Minitab软件进行试验设计,建立响应曲面回归模型,进行响应曲面分析,优化配合比。结果表明,最佳工艺条件为:硫铁矿烧渣掺量为14%,水泥熟料掺量为70%,灰渣比为1.2。在此条件下,试验制得的水泥28 d抗压强度可达48.66 MPa。     

以铅锌尾矿为原料煅烧水泥熟料

以广西河池富源铅锌选矿厂尾矿为主要原料煅烧制备水泥熟料,从不同煅烧温度下熟料成分的差异,水化产物的微观相貌和组成,煅烧过程中重金属的固化与熟料净浆试块的毒性浸出情况,以及熟料净浆试块的力学性能等方面探讨了用该铅锌尾矿制备水泥熟料的适宜工艺条件。试验结果表明:掺有35.4%广西河池富源铅锌尾矿的生料煅烧制备水泥熟料的最佳烧成温度为1 350℃,此时可生成大量有利于熟料强度的C2S和C3S。该水泥熟料的主要水化产物为C—S—H和钙矾石,试块前期强度的主要来源是钙矾石,后期强度的主要来源是C—S—H,C—S—H填满试块内部空隙,增大试块密实度,使试块28 d龄期的抗压强度达到43.68 MPa,与普通硅酸盐水泥P.O 42.5的28d抗压强度指标相当。煅烧过程中Pb的固化率较低,仅为21.16%,而As和Zn的固化率则高达87.61%和91.43%。养护龄期为3 d和28 d的水泥净浆试块浸出液中As、Pb、Zn的含量远低于浸出毒性标准。这种水泥熟料在生产地下胶结充填料的胶结剂方面具有一定潜力。     

钨尾矿在水泥工业中的应用

用钨尾矿作生产水泥熟料的原料之一,既可提高水泥熟料的产量和质量,节省能耗,又可减少水泥窑氟硫污染,具有较好的经济效益和社会效益。但钨尾矿掺量应适当,在一定范围内可取得满意效果,过量反而会产生副作用。     

新型绿色水泥的制备

以铬铁渣为主要原料，采用较低的石灰饱和系数、较高的硅率和铝率、引入适量的复合矿化剂的配料方案，可锻烧出质量合格、性能良好的绿色硅酸盐水泥熟料。本文在合理确定水泥生料配方的基础上，着重讨论了锻烧温度和复合矿化剂对熟料中ｆ－ＣａＯ含量的影响，研究了锻烧过程中铬铁渣的物相变化，分析了熟料的冷却速率对水泥强度的影响，为绿色水泥生产和铬铁渣综合利用开辟了一条新的途径。     

脱硫石膏无熟料钢渣水泥物理力学性能研究

以钢渣、脱硫石膏为主要原料,掺入适量矿渣和复掺少量激发剂,配制了无熟料钢渣水泥。试验结果表明所配制的无熟料钢渣水泥达到了42.5标号水泥的技术要求。探讨了矿渣掺量、激发剂复掺比例和脱硫石膏掺量对无熟料钢渣水泥强度和安定性的影响,以及配料的不同粉磨方式对无熟料钢渣水泥力学性能影响,通过微观分析进一步探究水化产物的结构和组成。     

贵州某磷渣矿物学特征及作水泥掺合料可行性研究

采用ICP-AES、XRD、SEM-EDS、FTIR等方法,对贵州某磷渣矿物学特征进行了研究,并考察了磷渣用作水泥掺合料时水泥的活性、凝结时间和标准稠度用水量。试验结果表明,磷渣掺量越大,水泥凝结时间越长,标准稠度用水量越高,活性指数越低。磷渣掺量为45%时,水泥的初、终凝结时间分别为502 min和572 min,满足GB 175-2007普通硅酸盐水泥凝结时间的要求;磷渣掺量为40%的水泥3 d的抗压、抗折活性指数均大于50%,满足GB/T 26751-2011规定的水泥和混凝土中的粒化电炉磷渣粉要求。     

脱硫灰在水泥工业中的应用

研究了脱硫灰在水泥工业中的应用。研究结果表明:亚硫酸钙含量较多的脱硫灰可用作水泥的调凝剂,并且与二水石膏复掺后的效果更好。通过控制脱硫灰与二水石膏复合掺入到水泥中的比例可有效地调节水泥的凝结时间,不仅不影响水泥的安定性,而且还可以提高水泥的胶砂强度,降低水泥的标准稠度用水量。     

粉煤灰少熟料水泥的制备和水化机理研究

以粉煤灰为原料,添加少量水泥熟料,并以电厂脱硫石膏和NaOH为激发剂研制出一种少熟料水泥,物理性能实验和XRD分析表明,粉煤灰在硫酸盐和强碱叠加等多重激发手段下活性大大提高,充分参与了水化反应,其主要水化产物为无定形三维网状聚合铝硅酸盐凝胶、钙矾石以及水化硅酸钙(C-S-H)凝胶,该水泥中粉煤灰掺量为65％,28 d抗压强度可达到53.9 MPa,凝结时间和安定性均符合通用硅酸盐水泥现行规范,为粉煤灰的高效利用找到了新途径.     

水泥回转窑结圈问题的初步探讨

对水泥回转窑结圈情况及其危害、产生的原因、处理方法及预防措施进行了分析和讨论。     

水泥混凝土路面在厂矿道路中的应用与发展前景

对水泥混凝土路面在厂矿道路中的应用现状进行了介绍。详述了厂矿道路采用水泥混凝土路面的有利因素,即完整的设计理论、成熟的设计方法、可靠的参数、实用的施工方法和配套的施工机具、可靠的材料供应、低廉的价格、显著的经济效益和良好的社会效益等。结合多年厂矿道路设计工作实践, 建议厂矿道路多采用水泥混凝土路面。     

改性钢渣制备水泥的基础性能研究

摘要:以钢渣、铁尾矿为主要原料,将钢渣掺加三种铁尾矿并在高温下熔融,熔融后得到的改性钢渣用于制备钢渣水泥。研究钢渣掺加三种铁尾矿制备的钢渣水泥的凝结时间、安定性、抗折抗压强度等性能。通过物理性能和XRD检测分析三种改性钢渣水泥的各项基础性能。结果表明,此改性钢渣水泥具有良好的物理力学性能。钢渣掺加铁尾矿改性之后能缩短钢渣水泥的初凝时间,有效提高钢渣水泥的早期强度;改性钢渣水泥中f-CaO含量低于2%,钢渣掺加铁尾矿能有效降低f-CaO含量,提高水泥的安定性;抗折抗压强度分别达到P?SS42.5和P?SS32.5R等级。本项目利用当地工业废渣和尾矿研制的改性钢渣复合硅酸盐水泥,铁尾矿掺量达到了10%,对废弃资源进行了有效利用,增加了钢渣的高附加值,减少了环境污染。      

Elimination of the adverse effect of cement filling on the flotation of a nickel ore

In China, most of the nickel sulphide deposit is spatially related to ultrabasic rocks and the cementation filling method is used in the process of mining. However, the cement filling from the mine back fill often gets into the ore and interferes with the pentlandite flotation. In this work, the effect of the cement filling on the flotation performance of a nickel ore was studied and ammonium sulphate was used to eliminate this adverse effect. The flotation result shows that the pentlandite recovery decreased from 87% to 65% with the increase of the content of cement filling from 0% to 8%. The addition of ammonium sulphate was shown to improve the flotation performance of pentlandite that depressed by cement filling. This result points out a problem often encounter in the flotation of a nickel sulphide ore and finds a solution to it.     

Analysis of grinding media effect on specific breakage rate function of particles in a full-scale open circuit three-compartment cement ball mill

A full-scale three-compartment FLSmidth® cement grinding ball mill with dimensions of Ø3.5 × L10 operating in open circuit was sampled to analyse the grinding media effect on specific breakage rate function of particles. Size reduction performance of the ball mill was evaluated with respect to the applied grinding media size. Samples from the circuit and inside the mill were collected. Mass balance of the circuit was done using JKSimMet Steady State Mineral Processing Simulator. Specific discharge and breakage rate functions of particles were estimated using perfect mixing modeling approach (Whiten, 1972) on the basis of the proposed open circuit three-compartment ball mill model structure (Genç and Benzer, 2015). Maximum specific breakage rate was related to maximum grinding media size in the grinding compartments. An exponential correlation was found to exist between maximum grinding media size and maximum specific breakage rate. Relationship between maximum grinding media size and maximum particle size was also fitted to an exponential function. Findings indicated that, grinding performance of cylpebs applied in the third compartment did not improved the size reduction performance as compared to the grinding performance of the first and second compartment.     

Effect of High Pressure Grinding Rolls (HPGR) pre-grinding and ball mill intermediate diaphragm grate design on grinding capacity of an industrial scale two-compartment cement ball mill classification circuit

Effect of High Pressure Grinding Rolls (HPGR) pre-grinding and two-compartment ball mill intermediate diaphragm grate design on grinding capacity of an industrial scale conventional two-compartment ball mill cement grinding and classification circuit was investigated. For this purpose, cement clinker was crushed in an industrial scale HPGR in open circuit and fed to a Polysius® two-compartment ball mill and air classifier closed circuit. Two-compartment ball mill intermediate diaphragm middle grate design was changed when HPGR crushed clinker was fed to the circuit to obtain optimum flow of material from the first compartment into the second compartment. Modifications on the diaphragm design were required due to the increased throughput when processing HPGR product. Two sampling campaigns were performed at the steady state conditions of the circuit. Raw clinker (uncrushed clinker) was fed to the conventional two-compartment ball mill air classifier circuit in sampling campaign-1 whereas HPGR crushed clinker was fed to the same circuit with modifications on the intermediate diaphragm middle grate design in sampling campaign-2. Mass balanced tonnage and particle size distributions were estimated by using JKSimMet Steady State Mineral Processing Simulator in both sampling campaigns. Polysius® two-compartment ball mill was modeled by using perfect mixing modeling approach (Whiten, 1974). Specific discharge and breakage rates in the grinding compartments were estimated by using the two-compartment ball mill model structure proposed by Genç and Benzer (2015). Specific discharge rates were found to increase at coarse size ranges when raw clinker was fed to the circuit in compartment-1. However, specific discharge rates of particles were increased slightly at coarse size ranges in the second compartment at higher mill capacity condition. Specific breakage rates were increased when the circuit was fed with HPGR crushed clinker. Modifications in the circuit and the ball mill intermediate diaphragm grate design enabled the optimization of the grinding capacity of the conventional two-compartment ball mill cement grinding and classification circuit. Ball mill grinding and classification circuit capacity was increased by 10% and specific energy consumption of the ball mill was decreased by 9.1%.     

Cement hydration and durability of low sulfide tailings-based renders: A case study in Moroccan constructions

Appropriate tailings management is one of the main requisites for sustainable development in the mining industry. This research study aims to assess the use of low sulfide or sulfide free tailings (LST) as aggregates for rendering mortars, focusing on their cement hydration and durability. An authentic case study in Moroccan constructions is additionally used to assess long term behavior of LST-based renders in actual field conditions. To address such needs, renders sampled from wall constructions and laboratory-made specimens were firstly characterized by means of thermo gravimetric analysis (TGA), X-ray diffraction analysis (XRD), scanning electron microscopy investigation (SEM) and mercury intrusion porosimetry (MIP). Renders were then exposed to standard detrimental agents (moisture, sulfate water and acid rain) to assess their long term behavior. Experimental results confirmed that LST-based renders seem to involve different cement hydration processes, which lead to larger pore size distribution and lower CSH and portlandite content. These observations significantly influence their susceptibility to cracking and sulfate attack resistance.     

“多孔硅质岩”开发应用的初步研究

本文介绍了湖北京山“多孔硅质岩”的资源状况及物化性能，探讨了其在水泥、陶瓷、耐火保温材料及啤酒助滤剂等工业领域开发应用的可能性。     

海南首次发现水泥用硬质千枚岩矿

首次在海南省发现一种水泥用硬质千枚岩矿，产于下石炭统中部，矿层巨厚，经水泥工艺试验得到的各项指标，表明为优质水泥粘土质原料矿。