易磨硅酸盐水泥熟料的研究

研究了一种容易粉磨硅酸盐水泥熟料的组成、粉磨特性与物理性能。这种容易粉磨硅酸盐水泥熟料可以在假烧温度低于1400℃的条件下烧成。其矿物组成与普通硅酸盐水泥熟料相同，但具有C3S含量高(＞70％)的特点。在水泥熟料粉磨至比表面积320m^2/kg条件下，容易粉磨硅酸盐水泥熟料需要粉磨4．5min，而普通硅酸盐水泥熟料需要粉磨8min。容易粉磨硅酸盐水泥熟料的3d抗压强度可达37MPa，28d抗压强度可达60MPa。     

改善熟料特性提高水泥易磨性

0前言 在水泥生产中,粉磨电耗占总电耗一半以上,长期以来人们都在探索和研究各种降低粉磨能耗的途径。我厂针对熟料特性的改善,逐步提高水泥熟料易磨性,从而达到提高粉磨效率的目的。采用提高熟料C3S、薄料快烧的操作方式,在1年多的试验、分析、实践中,有了一定的效果,现将其方法及体会简介如下。     

水泥熟料易磨性试验方法评述

在简要介绍粉磨理论三大粉碎学说的基础上,总结分析了六种常见熟料易磨性试验方法、试验设备和适用条件。这六种试验方法都可以用来评价熟料易磨性的好坏;邦德功法、粉磨时间法（T3000）和Zeisel法与目前工业生产实际偏差较大,通过修正后可用于设备的选型;小磨时间法和相对易磨性试验法多用于生产企业指导生产实践;TRM立式辊磨试验法基于料床粉磨原理,采用半工业化粉磨设备,试验结果可以直接用于水泥辊磨设备选型和指导生产实践。     

锰对硅酸盐水泥熟料燃烧的影响

通过高温差热分析,ＸＲＤ,高温显微镜分析,ＳＥＭ,ＥＰＭＡ以及测定ｆＣａＯ等方法研究了ＭｎＯ２对硅酸盐水泥熟料煅烧的影响。试验结果表明,锰主要分布在中间相,随着ＭｎＯ２外掺量的增多,熟料中铁相含量增多,Ｃ３Ａ及Ｃ３Ｓ含量减少,液相量大量出现的温度升高。     

水泥原料易磨性试验及其方法的讨论

水泥原料易磨性试验及其方法的讨论罗帆合肥水泥研究设计院（２３００５１）１粉磨功指数与水泥原料的易磨性以邦德（Ｂｏｎｄ）粉磨功指数表征的物料易磨性，已广泛用于我国水泥生产和设计。按邦德原理确定的物料粉磨功指数Ｗｉ为：式中：Ｗｉ──物料由粒度Ｆ粉磨至Ｐ所...     

新型干法水泥熟料易磨性概论

基于国外的研究论点,对新型干法水泥熟料及配料进行试验实测对比。结果表明：熟料热工形成过程影响易磨性的主要因素是C2S含量,其他矿相、液相含量以及密度/升重的影响不明显;快冷熟料优于慢冷;水泥粉磨过程的影响取决于熟料及其配料原料的易磨性,挤压终粉磨、联合粉磨等工艺可以忽略所有影响易磨性的因素,易磨性试验可节能30%~60%以上。     

水泥原料易磨性的影响及其改善

《水泥》１９９７年第１２期载文,从易烧性角度论述了水泥生产原料的选择〔１〕。其中许多观点如原料的品质、晶体构造、理化组成以及配料比等等对易磨性的影响也有共同之处。因此,水泥厂的“两磨一烧”均存在一个原料的合理选择问题。从综合效应考虑,若两者兼顾,即通...     

高贝利特水泥熟料与硅酸盐水泥熟料复合体系的性能研究

实验研究了不同高贝利特水泥(HBC)和硅酸盐水泥(PC)配合比,不同缓凝剂掺量以及不同粉磨细度对HBC-PC复合体系水泥的物理性能的影响。结果表明,HBC与PC混合时,HBC的适宜比例为50%～80%,以50%为最佳。在最佳HBC掺量下,采用二水石膏作缓凝剂,水泥中w(SO3)控制在2.0%～3.0%时水泥具有较好的早期和后期强度;采用硬石膏作缓凝剂,水泥w(SO3)控制在2.0%～3.5%时综合效果较好。当HBC掺量为50%,w(SO3)为2.6%±0.2%时,其复合体系水泥的适宜粉磨细度为320～400m2蛐kg。     

对粉碎过程的划分与易磨性试验的几点看法

１　引言　　　　为了恰当地设计和改造粉碎系统,最重要的一点是了解物料的易碎性和易磨性。在这方面国内外专家学者都作了大量工作,得出许多经验和实测数据。例如一般煤比石灰石易磨,石灰石比水泥熟料易磨。但试验表明［１］,石灰石比熟料和标准砂都难磨,这与人们的一般认识相差很大。由此引出一些问题,如物料的易磨性应如何测试？破碎与粉磨、易碎性与易磨性是否有所区别？本文对此发表一些个人看法,愿与同行探讨。２　破碎与粉磨的区分　　　　矿物质物料由大块变成细粉的过程通称为粉碎过程,人们常常又将其划分为破碎和粉磨两大…     

浅谈改善熟料易磨性的措施

从原材料化学成分、生料细度、熟料的化学分析、配料的稳定性、煤料的匹配以及出窑熟料的结粒与温度方面分析了影响熟料易磨性的原因,并采取了相应的生产管控措施,效果很好.熟料易磨性得到明显改善,小磨试验时间下降3 min,P·O42.5水泥混合材掺量提高了2.3%,水泥磨台时产量上升15t/h、电耗下降0.7 kWh/t,水泥综合成本下降2.6元/t,达到了降本增效的目的.     

铝酸盐水泥熟料对粉煤灰硅酸盐水泥性能的影响

以铝酸盐水泥熟料、硅酸盐水泥熟料和粉煤灰为原料,探讨了掺加少量铝酸盐水泥熟料对硅酸盐水泥及粉煤灰硅酸盐水泥复合体系水化、凝结和硬化性能的影响。结果表明,在硅酸盐水泥及粉煤灰硅酸盐水泥中掺加铝酸盐水泥熟料,可以明显缩短水泥的初、终凝时间,但复合体系的需水量增加;掺加少量铝酸盐水泥熟料(≤3%)可明显提高硅酸盐水泥的早期强度,但后期强度(28d)有所降低;当铝酸盐水泥熟料的掺量达5%时,水泥的各龄期强度均明显降低。少量铝酸盐水泥熟料掺加到粉煤灰硅酸盐水泥中,复合体系的各龄期强度都明显提高,且早期强度的提高幅度较大。     

掺硫铝酸盐水泥熟料的富硅酸盐水泥体系的性能研究

研究了硫铝酸盐水泥熟料对复合硅酸盐水泥性能的影响。研究表明,当复合水泥中掺入少量硫铝酸盐水泥熟料后,再配以适量的石膏,可以提高其早期强度,且随着硫铝酸盐水泥熟料掺量的增加,其凝结时间明显缩短。运用XRD等测试方法探讨了硫铝酸盐水泥熟料改善复合水泥性能的机理。硫铝酸盐水泥熟料水化形成的钙矾石和铝胶,对硅酸盐水泥熟料矿物水化有促进作用,这是水泥凝结加快、强度增加的主要原因。     

高C3S含量硅酸盐水泥熟料极限石灰率值选择及控制方法的探讨

分析了不同C3S含量硅酸盐水泥熟料的矿物形成过程、易烧性及矿相结构差异,对高C3S含量硅酸盐水泥熟料适宜的极限石灰率值选择及控制方法进行了探讨。分析表明,高C3S含量硅酸盐水泥熟料的配料,宜采用李和派克石灰饱和系数LSF控制极限石灰数量,无论硅酸率及铝氧率如何变化,LSF值必须<1。对于低硅酸率高C3S含量熟料,LSF应偏低控制,对于高铁配方熟料,LSF宜偏低控制;视硅酸率不同,熟料LSF低限值可至0.96附近。     

Microwave-promoted burning of Portland cement clinker

A new method of burning Portland cement clinker is studied. The microwave sintering is adopted after the raw meal is heated to certain temperature in an electric furnace. The experimental results show that after the raw meal is heated at a low electric heating temperature (1000-1200 °C) and then further sintered with microwave for 1 to 2 min, Portland cement clinkers can be formed. The f-CaO contents of the clinkers are 1-2%. It has also been found that the higher the temperature of the samples put into the microwave cavity, the shorter the time needed for microwave burning. When the temperature is up to 1300 °C, the sample needs to be heated by microwave for only 40 s, and the f-CaO content decreases to 0.65%. It has been proved by the experiments that (1) the new burning technique can greatly increase the forming speed of Portland cement clinkers, (2) Fe₂O₃ can enhance the microwave clinkering. XRD patterns of the clinkers show that their mineral compositions and the characteristic XRD peaks are similar to those of clinkers by conventional burning method.     

Examination of the jarosite-alunite precipitate addition in the raw meal for the production of portland cement clinker

The aim of the present research work was to investigate the possibility of adding a jarosite-alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low grade nickel oxides ores, in the raw meal for the production of Portland cement clinker. For that reason, two samples of raw meals were prepared, one with ordinary raw materials, as a reference sample ((PC)_Ref) and another with 1% jarosite-alunite precipitate ((PC)_J/A). Both raw meals were sintered at 1450 °C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite-alunite precipitate did not affect the mineralogical characteristics of the so produced Portland cement clinker. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of jarosite-alunite precipitate did not negatively affect the quality of the produced cement.     

一种低温烧成的高阿利特硅酸盐水泥熟料的试验研究

实验室低温烧制了一种高阿利特硅酸盐水泥熟料并测试了其性能。该熟料中的阿利特含量高于70％，烧成温度≤1400℃。其3d抗压强度可达42．8MPa，28d抗压强度可达65．8MPa。同时这种水泥熟料的易磨性优于普通硅酸盐水泥熟料：在相同条件下，磨细到比表面积320m^2／kg时，这种熟料需要4．5min，而普通硅酸盐水泥熟料则需要8．0min。同时对该熟料进行了岩相检验分析。     

浅谈利用磷渣生产水泥熟料

为降低生产成本,提高企业经济效益,西昌航天水泥有限责任公司对磷渣配料生产水泥熟料进行了试生产,试生产中磷渣的掺入量定为6.0%,熟料三率值定为:KH=0.92±0.02,SM=2.7±0.1,IM=1.6±0.1。试生产成功后实施了全面生产,生产中配料方案和熟料三率值基本不变,磷渣掺入量通过摸索定为5.0%。结果表明,在生料中掺入一定比例的磷渣,可以降低生产成本,提高熟料质量,获得较好的经济效益和社会效益。     

预分解窑煅烧高抗硫酸盐硅酸盐水泥熟料的 生产体会

为了满足高抗硫酸盐硅酸盐水泥的市场需求,通过筛选优质的原燃材料和精心设计配料方案,得以在1 000 t/d生产线上批量生产。其生产控制的关键主要掌握其熟料的技术特点,并在实际生产中进行工艺参数的调整,且需加强回转窑的煅烧控制。对生产出的高抗硫酸盐硅酸盐水泥熟料性能分析,已证明了采用预分解窑煅烧优质的高抗硫酸盐硅酸盐水泥熟料是完全可行的。     

Laboratory investigation of portland cement concrete containing recycled asphalt pavements

Recycled asphalt pavement (RAP) is the removed and/or reprocessed pavement material containing asphalt and aggregate. The use of RAP in asphalt pavement has become a common practice in the construction of new, and reconstruction of old, hot mix asphalt (HMA) pavements. But little research has been done to examine the potential of incorporating RAP into concrete. Since RAP contains asphalt, it is very likely that the toughness of concrete made with RAP could be improved. In the present study, the mechanical properties of RAP-incorporated Portland cement concrete were investigated through laboratory experiments. Two types of RAP (coarse and fine RAP) materials were considered. The results from this study indicated that RAP could be incorporated into Portland cement concrete without any modification to the conventional equipment or procedures. Without any treatment, there was a systematic reduction in the compressive and split tensile strengths with the incorporation RAP in concrete. Notably, the energy absorbing toughness for the RAP incorporated concrete has been significantly improved.