硅酸盐水泥熟料显微结构分析

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,第七章 硅酸盐水泥熟料的显微结构分析,1,、硅酸盐熟料岩相（显微结构）分析的作用,2,、硅酸盐水泥熟料的矿物组成,3,、硅酸盐水泥熟料岩相分析样品制备,4,、硅酸盐水泥熟料的岩相形态,4,、硅酸盐水泥熟料岩相形态的变化,一、熟料岩相分析的作用,1,、鉴定,熟料矿物相组成,、,煅烧,过程、,均匀,性；,2,、直接观察到各个矿相的形状、尺寸以及其分布状态，,快速判断生产工艺过程中存在的问题,；,3,、根据岩相分析对,水泥性能和生产工艺实现系统优化,：,提高熟料活性、减少水泥中的混合材用量；,优化窑内煅烧工艺制度，降低烧成热耗；,改善熟料的易磨性，降低水泥生产的粉磨电耗；,分析鉴定水泥质量存在的问题,二、硅酸盐水泥熟料的矿物组成,硅酸盐水泥熟料主要由以下四种矿物组成：,硅 酸 三 钙,-,3CaO SiO,2,，,可简写为,C,3,S,；,硅 酸 二 钙,-,2CaO SiO,2,，,可简写为,C,2,S,；,铝 酸 三 钙,-,3CaO Al,2,O,3,，,可简写为,C,3,A,；,铁相固溶体,-,通常以铁铝酸四钙,4CaOAl,2,O,3, Fe,2,O,3,作为其代,表式，可简写为,C,4,AF,；,玻璃体、方镁石、游离氧化钙,Figure 4-1. Modes of sample preparation:,(1),single clinker, impregnated with epoxy resin, cut, and polished; (2,) crushed clinker fragments, encapsulated and impregnated with epoxy, cut, and polished; (3,),whole clinkers impregnated with epoxy and mounted on a thin film of epoxy on a glass microscope slide, cut and polished; (4,),millimeter-size crushed clinkers, embedded in epoxy, ground, and polished;,三、硅酸盐水泥熟料的矿物组成,(5) cement, size graded by sedimentation in an alcohol-mineral spirits mixture in a glass vial, dried, impregnated with epoxy, cut, and polished;,(6) drilled holes in an epoxy plug,filled individually with cement (a) extracted with a potassium hydroxide-sugar solution, (b) extracted with maleic acid, and unextractedthe plug has been cut and polished;,(7) thin section of whole clinkers;,section thickness is approximately 22 mm;,(8) crushed clinker,45- to 75- mm fraction, in Hyrax, for determination of the kiln parameters with the Ono Method. Scale divisions in mm. (S#A7094),四、硅酸盐水泥熟料的岩相形态,从岩相分析的角度看，硅酸盐水泥熟料是多矿物组成的集合体。,因此，水泥熟料实际上是一种多矿物组成的结晶细小的人造岩石。,主要包括,:,Alite,（简称阿利特或,A,矿,）；,Belite,（简称贝利特或,B,矿,）；,黑色中间相,（,C,3,A,）；,白色中间相,Celite,（简称才利特或,C,矿,，,C,4,AF,）；,少量的,游离氧化钙,（,f,-CaO,）、,方镁石,、,玻璃相,等。,1. A矿 （Alite）,A矿是含有少量MgO、Al,2,O,3,和Fe,2,O,3,的硅酸三钙（C,3,S ）固溶体。,纯的硅酸三钙属于,三斜晶系,；,A矿晶体最常见的是,单斜晶系。,晶体外形为假,六方片状或板状，有时出现短柱状,等，图,8-1-1,、,7-2,、,7-3,。,（,为几何轴率,，,为晶体长度与宽度之比，一般为,2,）。,正常煅烧熟料中A矿晶体的大小约20,-,30,m，呈边棱平直，六角板，柱状的自形晶（图9-3）。,A,矿晶体中常可发现包裹着其他晶体的包裹结构（图,9-4,，图,8-1-8,，图,3,，图,4,）。,图,3,包晶结构的阿里特晶体,图,4,阿里特包裹,f,-CaO,、,C,3,A,结构,1%,硝酸酒精,图,9-5,是慢冷熟料,A,矿分解，周围环绕着析出的小颗粒,C,2,S,晶体的花环状结构。,花环状结构,A,矿和片状,C,3,A,图,9-6,是受酸性溶液浸蚀后形成的港湾状结构；,图,9-7,是内外成份不同出现的环带结构，等等。,在反光显微镜下，,用,1%,的,NH,4,Cl,水溶液浸蚀光片后,A,矿呈兰色；,用,1%,硝酸酒精浸蚀光片后，,A,矿呈棕色。,Euhedral to subhedral, zoned, yellowish tan alite; dark, round belite with typical multidirectional lamellae; and a well-differentiated matrix of aluminate (C3A) and ferrite (C4AF). Small belite inclusions in alite. Epoxy-filled pore at bottom of photo. Coal-fired kiln, wet-process, 1000 tons/day, 38 MPa; coarse seashell feed (30% greater than 75 mm).,Polished section,Nital etch,Uniform silicate distribution in polished clinker thin section showing angular, equant to elongated alite; round, clear belite with typical multidirectional lamellae; and a finely microcrystalline matrix of aluminate (C3A) and ferrite (C4AF).,plane-polarized light,Section thickness = 15 mm,Same field of view as previous photograph. Different shades of gray on silicates indicate different crystallographic orientations in partially cross-polarized light. High maximum temperature, long burning time, slow heating rate, quick cooling, 42 MPa. Dry-process, coal- and cokefired kiln, 2145 tons/day.,Clinker thin section (approximately 15 mm thick) showing relatively large angular alite; smaller, round belite; and normal ferrite with its short slender intersecting crystals, between which the aluminate occurs (not visible at this magnification).,Transmitted, plane-polarized light,Same field of view as previous photograph except in partially crossed polars. Various interference colors due, in large part, to different crystallographic orientations.,Same field as previous photograph but with reflected light and nital etch. Euhedral, brown alite; round belite with multidirectional lamellae; welldifferentiated matrix (almost invisible in the photograph). High maximum temperature, long burning time, slow heating rate, quickly cooled. Coalfired, dry-process kiln, 2000 tons/day,.,2,、,B,矿（Belite）,B,矿,是含有,FeO,、,MgO,、,Fe,2,O,3,、,Al,2,O,3,、,Mn,2,O,3,等微量组分的硅酸二钙（C,2,S ）固溶体，有多种晶型。,工厂水泥熟料中的B矿大部分为,型的，属单斜晶系,。,一般,B,矿,呈,圆粒状,，常具有,两组相互交叉的双晶纹或一组平行的晶纹,（,图,7-4，图9-8，图8-1-2，,图,7-5，图9-9）,因窑内还原气氛或其他工艺因素的影响，还会呈现手指状（图,7-8,，图,9-10,），树叶状（图,9-11,），花蕾状（图,7-6,）和脑状（图,7-7,，图,9-12,）,B,矿。,B,矿显微结构,B,矿群,手指状、树叶状,B,矿,B,矿矿巢及发育不完整的,A,、,B,矿,B,矿矿巢及发育不完整的,A,矿,具有爪状结构的,B,矿和麻面、,形状不规则的,B,矿矿巢,具有交叉双晶纹的,B,矿矿巢,Crushed clinker in refractive-index oil showing large, clear to pale yellow, round belite (arrow) with typical,internal cross lamellae,. Moderately high maximum temperature, long burning time, slow heating rate, quickly cooled. Dry-process kiln with flash calciner, 5000 tons/day.,plane-polarized light,当烧成温度高于,1400,并急冷时，可见,相互交叉的细密双晶纹,，见图9-8；,当温度度在,1400,以上，但冷却较慢时，,双晶纹变得粗,短，见,图8-1-2,；,当温度低于,1400,（约,1350,）时，冷却速度又慢，会出现,平行双晶纹,，见,图,7-5，图9-9。,当煅烧温度低于,1300,时，晶体一般不具有,双晶,。,根据,-C,2,S的形态和双晶的变化，可以推断窑内的煅烧温度及热工制度。,当,- C,2,S 转变为,- C,2,S 时，体积要增大10%左右，大量转变时常会使熟料崩裂呈粉状（图7-9）,。,- C,2,S 在反光显微镜下，,用 1NH,4,Cl 水溶液或 1% 硝酸酒精浸蚀光片后，都呈现棕色或棕黄色,。,Polished section,Nital etch,Ragged belite crystals and belite coating on alite, one of which is twinned. Note abundant dotlike impurities in alite. Coarsely crystalline matrix with gray aluminate and relatively bright ferrite. Slowly cooled clinker.,Polished section,Nital on KOH etch,Slowly cooled kiln buildup from the transition zone containing, for the most part, polysynthetically twinned belite (Type II, Insley) in lower left and slightly splintery gamma belite (upper right) in matrix of coarsely microcrystalline ferrite and aluminate.,Thin section,Crossed polars,Polished section,Nital etch,Zoned euhedral to subhedral alite; ragged, round, internally disorganized belite; welldifferentiated matrix; and round pore (upper center) with peripheral alkali sulfate. Coal- and coke-fired, dryprocess kiln, 900 tons/day. High maximum temperature, moderately long burning time, slow heating rate, slow to moderately slow cooling rate.,(S#A6649),Polished section,Nital etch,Field dimensions = 0.21x0.21 mm,Ragged belite from very slow cooling. Extension of “fingers” into matrix. Note dotlike impurities. Kiln coating. Coal-fired, dry-process kiln, 2350 tons/day. (S#A6650),Thin section,Transmitted, plane-polarized light,Field dimensions = 0.21x0.21 mm,Clear belite ring around central pore formed by silica mobilization during sintering of coarse quartz in feed. (S#A6655),Thin section,Thickness = approximately 20 mm,Field dimensions = 0.53x0.53 mm,Dendritic belite in ferrite-rich matrix of clinker containing fragments of refractory brick (not shown). Brightly reflecting ferrite in plane-polarized light is unusually pleochroic, suggesting compositional change from refractory brick consumption.,Polished section,Nital etch,3,、中间体,中间体是水泥中介于,A,矿和,B,矿之间物质的总称，其中有结晶相和玻璃相。,中间体按反射率大小分为黑色中间体和白色中间体两大类。,（,1,）黑色中间体,黑色中间体是反射率低的一类，通常是,铝酸盐类矿物,。,主要有铝酸三钙（,C,3,A,）、七铝酸十二钙（,C,12,A,7,）、氟铝酸钙等，属于等轴晶系。,当铝氧率高，并在缓慢冷却的条件下，,C,3,A,晶体呈四方片状,或叶片状（图,7-10,，图,9-14,，图,8-1-16,）。,当铝氧率低，冷却速度快时，,C,3,A,晶体则呈点滴状、点线状和骨骼状,（图,7-11,，图,9-15,），也有呈针状或纤维状析晶的（图,7-12,）。,当熟料烧成带急冷时，,C,3,A,来不及析晶，形成玻璃相物质,。,在反光显微镜下，,用,1% NH,4,Cl,水溶液或,1%,硝酸酒精溶液浸蚀光片后，,C,3,A,呈暗色或灰色；,用蒸馏水浸蚀光片后，,C,3,A,呈兰灰色。,（,2,）白色中间体,主要是铁铝酸四钙（,C,4,AF,），又称为,C,矿，它是水泥熟料中间体中反射率较大，色泽浅的部分（图,7-14,）。,C,4,AF,属斜方晶系,当熟料铝氧率较高（,P1.38,）而又快冷时，以他形晶填充于,A,矿和,B,矿之间，或因来不及析晶而成玻璃相；,当熟料的铝氧率较低（,P1.38,）而又慢冷时，它可呈棱柱状半自形晶出现（图,7-15,，图,9-13,，图,8-1-17,）。,Thin, typical lath-form crystals of ferrite and extremely finely microcrystalline crevicefilling aluminate (C3A). Clear, angular alite crystals stacked on the basal pinacoid (001). Coal- and cokefired, semidry-process kiln, 1850 tons/day. High maximum temperature, long burning time, slow heating rate, quick to moderately quick cooling, 44 MPa.,Ultrathin section. Thickness = approximately 10 mm,Transmitted, plane-polarized light,Same field of view as previous photograph but in,partially cross polars,. Note relatively high interference colors of some ferrite crystals.,4,、游离氧化钙,又称游离石灰，常用,f-CaO,表示 。,它是没有与熟料中其它成份化合的氧化钙，属等轴晶系。,按成因可分为一次游离氧化钙和二次游离氧化钙,f-CaO,A,矿与游离钙,游离钙,（,1,）一次游离氧化钙,又称残存游离氧化钙，是生料中残留下来的氧化钙，残存的原因大致有以下几种。, 生料细度没有达到要求，石灰石（或混入的方解石）颗粒太粗，在煅烧过程中反应不完全，这种残留下来的氧化钙在镜下呈,圆形或卵形，粒径较大，而且成堆聚集形成矿巢型分布,（图,7-16,，图,9-16,）。, 生料的饱和系数过高，硅酸率太低，在镜下能见到未化合的游离氧化钙以圆粒状分布于,A,矿和,B,矿之间，或包裹于,A,矿中间（,7-17,，图,7-18,）。, 煅烧温度过低，液相量少，粘度大，,CaO,没有被充分地吸收生成,C,3,S,，而呈游离状态残存下来。,（,2,）二次游离氧化钙：,又称次生游离氧化钙。它是,A,矿中分解出来的,CaO,，大致有以下两种。, 熟料在高温下慢冷，,A,矿在,1250 ,左右停留的时间过长，将分解为,B,矿和游离氧化钙，此时,A,矿边缘往往出现许多小粒,B,矿，形成花环结构,A,矿,，同时出现一些极细小的游离氧化钙溶入液相或聚集成团形成蠕虫状结构（图,8-1-23,）, 发生阳离子置换，,Fe,2+,离子进入,A,矿使,A,矿由不稳定到分解，同时置换出游离氧化钙，形成所谓蠕虫状结构的,B,矿和,f-CaO,。,在反光显微镜下，用蒸馏水浸蚀光片,35,秒钟，游离氧化钙呈现彩虹色，极易辨认。,Multicolored, round free lime crystals in aluminate-rich matrix (dull gray) from coarse marl particle. Estimated C3A = 14% to 18%. Anhedral to subhedral, tan to bluish red alite. High maximum temperature, long burning time, moderately slow heating rate, moderately fast cooling rate, 40 MPa. Coal-fired, dry-process kiln, 1600 tons/day.,Polished section,Nital etch,Free-lime nest colored by water etch in polished section. Chemical analysis gave clinker free-lime value of 2.69%. High maximum temperature, moderately long burning time, moderately slow heating rate, moderately slowly cooled, 31 MPa. Gas-fired, dry-process kiln, 3000 tons/day.,5,、方镁石,是单独析晶的游离氧化镁（,MgO,），属等轴晶系。,方镁石在反光显微镜下突起高，一般呈三角形或多角形小晶体，其表面略显粉红色。,当熟料中,MgO,的成份高达一定数量时，,MgO,便会从中间体中单独析晶出来（图,7-20,，图,8-1-14,）。,高镁熟料中形成的游离氧化镁,不规则多角形的方镁石,6,、玻璃相,成份不定，含有多量的,Al,2,O,3,和,Fe,2,O,3,组分。,在偏光显微镜下玻璃相与结晶相不易识别，但在反射光下用,10%KOH,水溶液及,1%,硝酸酒精溶液腐蚀后，玻璃相呈暗黑色的包裹体。,7,、孔洞,是,熟料中的气相在冷却过程中形成的；,反光显微镜下可见，在视域中孔洞呈凹下去的圆形、三角形或不规则多角形等。由于光线漫反射的原因，孔洞部分显得较为黯淡，当提升或下降镜筒时，孔洞大小也随之变化。,孔洞在镜下呈现的颜色主要决定于光片抛光粉的颜色。,煅烧正常的熟料中的孔洞大小为80100,m，呈圆形，而且分布较均匀。,四、硅酸盐水泥,熟料岩相形态的变化,1,、熟料矿物形态特征的描述,见表,7-1,，水泥熟料常见矿物形态。,2,、几种矿物集合体形态的术语,（,1,）矿巢：,是一种矿物的不规则堆聚，且在矿物颗粒间有明显界线。,B,矿巢,：由原料中粗粒长石、石英或矿渣形成，粗大的,B,矿几乎紧紧连在一起，见图,9-26,，图,8-1-12,。,游离氧化钙矿巢,：是由粗粒石灰石在煅烧中,CaO,没有被完全吸收形成的，图,7-22,，图,9-21,。,当生料中有粗粒白云石时，还会形成方镁石与游离氧化钙的等粒结构矿巢，见图,7-23,，图,9-27,由于煤粉颗粒较粗及煤灰不均匀沉降形成的包裹液相的,B,矿矿巢结构,保留石灰石粗颗粒外形的游离钙矿巢,由粗颗粒石英在熟料结构形成的粗大的,B,矿矿巢,（,2,） 共析晶体：,固溶体的组分在一定条件下分离出来，形成几种独立的晶体。,如析出的二次,B,矿小粒（图,7-47,）。,（,3,）孔隙率,镜下的孔隙率是指孔洞的面积,S,孔,与熟料矿物的总面积,S,矿,之比（,S,孔,/S,矿,100%,）。,煅烧良好的熟料孔隙率一般在,25%,30%,，容重为,1450 g/L,左右。,3,、硅酸盐水泥熟料的岩相结构类型,构造类型：,是指,矿物集合体、玻璃体及孔洞的之间的排列、充填方式,。,块状,构造：熟料中矿物大小相似、排布均匀、孔洞较少、形状规则，正常煅烧的熟料有此构造。, 多孔,构造：镜下孔洞较多、孔径较大，部分正常煅烧的多孔状熟料及欠烧熟料有此构造。,层状,构造：熟料中分层，各层矿物的组成、颗粒大小不同。旋窑中的圈料、窑皮料及轻烧、急烧熟料有此构造。,结构类型,是指矿物结晶程度，颗粒大小、形状及其相互间的关系。, 均齐结构,：,A,矿和,B,矿清晰，结晶大小均齐，分布均匀，彼此被,20%30%,的中间体隔开。,A,矿晶形完整、边棱整齐光洁、包裹物少，含量约,50%60%,。,B,矿晶体圆度较好，有清晰的双晶纹，含量约,20%30%,。,孔洞较少，形状规则，大小在,80m,左右。,这是正常煅烧的优质熟料岩相结构，图,7-24,，图,9-25,，见表,7-2,。, 斑状结构：,A,矿和,B,矿结晶清晰，但大小不均齐，分布不均匀。,A,矿边棱不光洁，已有部分分解和溶蚀现象。,B,矿圆度不好，有时还能见到大堆的,f,-CaO,矿巢。,这种熟料的岩相结构见图,7-25,，图,9-37,，见表,7-3,。, 多孔结构：,A,矿晶体发育不良，颗粒细小，边棱不光洁，有严重的分解和溶蚀现象，体内有包裹物。,B,矿晶形不规则，无双晶纹，含量多，分布不均。,中间体数量少。孔隙率高达,50%60%,。,镜下常见到大堆的,f-CaO,矿巢。,这是配方不良，煅烧不足的岩相结构，见图,7-26,，表,7-4,。,Extremely heterogeneous clinker containing large concentrations of loosely packed yellow-amber belite and alite with a wide range of crystal sizes and, like the belite, a nonuniform distribution. Free lime is abundant (dark, round crystals). Sandy, silica-rich raw feed with coarse quartz. Gas-fired dry-process kiln, 3000 tons/day.,Polished section,Nital etch,Streak of belite crystals in sulfate resisting cement clinker, suggesting nonuniformity in feed. Gas-fired, dry-process kiln, 770 tons/day.,Polished section,Nital etch,Euhedral to subhedral, zoned, yellowish tan alite; dark, round belite with typical multidirectional lamellae; and a well-differentiated matrix of aluminate (C3A) and ferrite (C4AF). Small belite inclusions in alite. Epoxy-filled pore at bottom of photo. Coal-fired kiln, wet-process, 1000 tons/day, 38 MPa; coarse seashell feed (30% greater than 75 mm).,Polished section,Nital etch,4,、 熟料岩相结构类型与强度的关系,（,1,）一级熟料：,外观为黑色或绿黑色，料球粒径,1-5cm,（多为,1cm,）；,岩相特征为均齐结构，图,7-27,，图,9-25,，见表,7-8,。,（2,）,二级熟料：,外观灰黑色，部分出现黄心，球粒径比一级大，大小不均,岩相结构基本上与斑状结构接近。,孔隙率比一级熟料高，且大而不规则。,图7-28，见表7-9 。,（,3,） 三级熟料：,外观,灰色或灰黑色，有较严重的黄心，料球大小不匀（,1-20cm,。,岩相结构类似于多孔结构。,孔洞多而大（孔径达100,-,200 m ，孔隙率高达50%60%）,见图7-29 。,熟料岩相结构与强度的关系总是遵循下列规律变化：,强度由高到低，熟料矿物岩相结构的变化规律为：, A矿形态由规则的长柱状、板状依次到不规则状；, A矿大小由均齐到不均齐，晶体尺寸依次变小，并至细晶成堆；, A矿和B矿之间分布依次由均匀变为不均匀；, B矿是圆形且具清晰的二组双晶纹，依次到小圆粒无双晶纹，手指状，树枝状；, B矿数量由少到多，由均匀到成堆分布；, 中间相含量逐渐减少；, 黑色中间体由点滴状、点线状、骨骼状依次到叶片状、板状；, 白色中间体的反射率由高到低；, 游离氧化钙的数量依次递增，由少量到小堆，直到形成f,-,CaO矿巢；, 孔洞由少到多，由圆形到不规则，分布由均匀到不均匀，孔隙率由小到大。,