The breakdown of diopside to(Ca,Mg)SiO_(3)perovskite–(Mg,Ca,Fe)SiO_(3)glass–(Mg,Ca)SiO_(3)glass–(Mg,Ca)SiO_(3)majorite in a melt vein the Suizhou L6 chondrite

The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite.It contains a minor amount of diopside with a(Ca_(0.419)Mg_(0.466)Fe_(0.088))SiO_(3)composition,and a shock-metamorphosed diopside grain associated with ringwoodite and lingunite was found in a melt vein of this meteorite.Our electron microprobe,transmission electron microscopic and Raman spectroscopic analyses revealed four silicate phases with different compositions and structures inside this shock-metamorphosed diopside grain,termed phase A,B,C and D in this paper.Phase A is identified as orthorhombic(Ca_(0.663)-Mg_(0.314))SiO_(3)-perovskite which is closely associated with phase B,the vitrified(Mg_(0.642)Ca_(0.290)Fe_(0.098))SiO_(3)perovskite.Phase D is assigned to be(Mg_(0.578)Ca_(0.414))SiO_(3)majorite which is associated with phase C,the vetrified Carich Mg-perovskite with a(Mg_(0.853)Ca_(0.167))SiO_(3)composition.Based on high-pressure and high-temperature experiments,the diopside grain in the melt vein of the Suizhou meteorite would have experienced a P–T regime of 20–24GPa and 1800–>2000℃.Such P–T conditions are high enough for the decomposition of the diopside and the formation of four different silicate phases.The orthorhombic(Ca_(0.663)Mg_(0.314))SiO_(3)perovskite found in the Suizhou L6 chondrite might be considered as the third lower-mantle silicate mineral after bridgmanite and davemaoite after the detailed analyses of its crystal structure and physical properties being completed.

Photocatalytic activity of Fe-doped diopside

UV-visible light induced photocatalytic degradation of methylene blue (MB) over Fe-doped diopside was investigated. The structure, composition, morphology and absorption property of UV-visible light of as-prepared samples were characterized using XRD, SEM, FTIR and UV-vis DRS. The experimental results show that doping Fe3+ induced the formation of some new species in diopside, and promoted light adsorption property of diopside in UV-visible region. Photochemical reactivity of Fe-doped diopside obviously depended on the content of doping Fe3+. The diopside with 1.848% Fe3+ exhibited the superior photocatalytic activity with 95% degradation of MB under UV-visible light for 3 h. The photocatalytic degradation kinetics of MB over all samples showed the first-order reaction nature.

Exsolutions of Diopside and Magnetite in Olivine from Mantle Dunite,Luobusa Ophiolite,Tibet,China

The exsolutious of diopside and magnetite occur as intergrowth and orient within olivine from the mantle dunite, Luobusa ophiolite, Tibet. The dunite is very fresh with a mineral assemblage of olivine （〉95%） ＋ chromite （1%-4%） ＋ diopside （〈1%）. Two types of olivine are found in thin sections： one （Fo = 94） is coarse-grained, elongated with development of kink bands, wavy extinction and irregular margins; and the other （Fo = 96） is fine-grained and poly-angied. Some of the olivine grains contain minor Ca, Cr and Ni. Besides the exsolutions in olivine, three micron-size inclusions are also discovered. Analyzed through energy dispersive system （EDS） with unitary analytical method, the average compositions of the inclusions are： Na20, 3.12%-3.84%; MgO, 19.51%-23.79%; Al2O3, 9.33%-11.31%; SiO2, 44.89%-46.29%; CaO, 11.46%-12.90%; Cr2O3, 0.74%-2.29%; FeO, 4.26%- 5.27%, which is quite similar to those of amphibole. Diopside is anhedral f＇dling between olivines, or as micro-inclusions oriented in olivines. Chromite appears euhedral distributed between olivines, sometimes with apparent compositional zone. From core to rim of the chromite, Fe content increases and Cr decreases; and A! and Mg drop greatly on the rim. There is always incomplete magnetite zone around the chromite. Compared with the nodular chromite in the same section, the euhedral chromite has higher Fe3O4 and lower MgCr2O4 and MgAI2O4 end member contents, which means it formed under higher oxygen fugacity environment. With a geothermometer estimation, the equilibrium crystalline temperature is 820℃-960℃ for olivine and nodular chromite, 630℃-770℃ for olivine and euhedral chromite, and 350℃-550℃ for olivine and exsoluted magnetite, showing that the exsolutions occurred late at low temperature. Thus we propose that previously depleted mantle harzburgite reacted with the melt containing Na, Al and Ca, and produced an olivine solid solution added with Na^＋, Al^3＋, Ca^2＋, Fe^3＋, Cr^3＋. With temperature decreasing, the olivine solid solution decomposed; and Fe^3＋, Cr^3＋ diffused into magnetite and Ca^2＋ and Na^＋ into clinopyroxene, both of which formed intergrowth textures. A few Fe^3＋ and Cr^3＋ entered interstitial chromite. Through later tectonism, the peridotite recrystallized and formed deformational coarse grained olivine, fine grained and poly-angled olivine, and euhedral grained chromite. Due to the fast cooling rate of the rock or rapid tectonic emplacement, the exsolution textures in olivine and compositional zones of chromite are preserved.

EFFECT OF SILANE COUPLING AGENT ON THE MECHANICAL,THERMAL PROPERTIES AND MORPHOLOGY OF TREMOLITE/PA1010 COMPOSITES

Tremolite,a kind of inorganic filler,was modified with a silane coupling agentγ-methacryloxypropyl trimethoxy silane (MPS) in ethanol/ammonia solution.The graft of MPS on tremolite was confirmed by X-ray photoelectron spectroscopy (XPS),IR and thermogramitric analysis (TGA) measurements.In addition,contact angle analysis showed that particle surface property was changed from hydrophilicity to hydrophobicity after the modification.Modified tremolite and pure tremolite were blended respectively with PA1010 (p...

FLOTATION SEPARATION OF WOLLASTONITE FROM DIOPSIDE

The floatabilities of single mineral samples of Tvollas-tonite and diopside have been studied with addition of a cationic collector , dodecylamine hydrochloride (DDA ?HC1) , and modifiers. A mixture of two minerals was successfully separated , when DDA ?HC1 and tannic acid (as depressant)were used together . The interaction between tannic acid and wollastonite and diopside in the pulp and the adsorption of tannic acid on the surface of the two minerals was sttidide with the help of ultra-violet (UV) spectroscopy and X-ray photoelectron spectroscopy (XPS) , re-spectively.

ANALOG STUDY ON THE DEPRESSING MECHANISM OF TANNIN TO DIOPSIDE

The depression mechanisms of tannin on the diopside surface have been studied by the rise of Infrared spectroscopy (IR), simulated pulp and mixed solution tests, It is found that the first order hydroxy completes of calcium are able to interact with tannin, and to form chemical complexes. es. The functional groups in tannin molecules participating in the chemical complexation are the hydroxyl groups, and carboxyl groups derived from the hydrolysis of hydroxyl groups.

STUDY ON SOLUTION CHEMISTRY BETWEEN TANNIC ACID AND THE FLOTATION PULP OF WOLLASTONITE AND DIOPSIDE

The mechanisms of interaction between tannic acid and calcium ions either added externally to or inherently present in the (?)olution ( dissociated from mineral surface ) , are studied by the use of Inductively Coupled Plasma Atomic Emission Spectroscopy ( ICP-AES ) , Ultraviolet Spectroscopy (UV). It is found that wollastonite has a high solubility in the concentration of calcium ions, calcium ions are able to interact with tannic acid.

Rare-earth Cerium Additives for Sinterability of Anorthite-Diopside Ceramics

Anorthite -diopside ceramics were prepared by sintering iron ore railings, calcium carbonate, and silicon dioxide. Rare-earth cerium nitrate was evaluated as a sintering additive for the ceramics, whose mass percentage was 3% , 5%, 7% , 9% , and 11% , respectively. The sinterability of anorthite - diopside ceramics during heat treatment was confirmed hy X-ray diffiaction, transmission^scanning electron micrascopy, thermogravi- metric analysis- differential thermal analysis, and hotstage microscopy, respectively. The obtained results show that the density of ceramics gradnally increases, while the sintering temperature and sintering activation energy of anorthite -diopside ceramics are notably decreased with the increasing cerium content. Rare-earth cerium not only is beneficial to the complete reaction of raw materials, but a/so can accelerate the mass transfer process through forming eutectic phase with aluminum.

Elastic Properties of Clinopyroxene Based Glasses along Diopside (CaMgSi₂O₆)-Jadeite (NaAlSi₂O₆) Join

The elastic properties of glasses along Diopside (CaMgSi2O6)-Jadeite (NaAlSi2O6) join (Dix - Jd1-x where x=20, 40, 60, 80, 100 mole %), were obtained by the ultrasonic echography technique, at room temperature. The correlation of elastic moduli with the atomic packing density of these glasses was discussed. The derived experimental values of Young’s modulus, bulk modulus, shear modulus and Poisson’s ratio for investigated glasses were compared with those theoretically calculated values in terms of the Makishima–Mackenzie model and the modified model presented by Rocherulle.

古代玉石白化机理解析——以三星堆遗址出土部分玉器为例

中国古代出土玉器常伴有白化现象,此现象在三星堆遗址出土玉石器中较为常见。本研究采用X射线衍射仪、激光共聚焦显微拉曼光谱仪、傅里叶变换红外光谱仪、同步热分析仪等分析三星堆遗址出土白化玉器。结果显示三星堆遗址出土白化玉器主要物相为方解石及透辉石——透辉石可由透闪石受热转化而成,玉器白化与受热有关。透闪石玉由高温热液流经镁质碳酸岩通过交代作用而形成,镁质碳酸盐岩中富含晶包有机质,推测透闪石玉中同样含有晶包有机质。本研究中玉石的荧光光谱及加热、溶出等模拟试验均证明了这一推论。方解石与透闪石玉内均含有分散有机质,玉石白化不仅取决于玉石结构变化,还与玉内分散有机质流失有关。

广西大化县透闪石玉矿床地球化学、锶同位素特征及成因

广西大化县透闪石玉矿床产自贫镁碳酸盐岩中,是一种新型透闪石玉矿床,其成矿物质来源及成因研究较为薄弱。对该矿床中围岩、蚀变岩、侵入岩和透闪石玉进行主微量元素和锶同位素对比研究,结果表明:透闪石玉的微量元素和稀土元素配分模式与石灰岩和大理岩相似,且微量元素和稀土元素含量与大理岩相关性较强(相关系数0.931),说明Ca的来源与大理岩有关;透闪石玉^(87)Sr/^(86)Sr与1000/Sr呈线性负相关关系,说明透闪石玉^(87)Sr/^(86)Sr(0.7070)主要受大理岩(0.7075)和辉绿岩(0.7061)两个端元控制,外推1000/Sr=0得到的^(87)Sr/^(86)Sr值与辉绿岩一致,说明成矿流体为岩浆热液;透闪石玉Y/Ho值(均值49.10)高于大理岩和辉绿岩(均值分别为44.53、24.30),说明其受岩浆热液作用较强烈。结合大化透闪石玉成矿特点,推测其成矿物质Ca来自大理岩,Si和Mg来自辉绿岩。采用稀土元素配分、δCe、δEu、Zr/Hf、Nb/Ta、Sr/Ba、U/Th、W、V、Cu等指标判断,其氧逸度较高,成矿环境为碱性。广西大化透闪石玉矿床的成矿过程分为4个阶段:基性岩浆侵入→石灰岩变质为大理岩→富含Mg和Si的基性岩浆热液形成→热液交代大理岩形成透闪石玉。

染色透闪石玉仿墨玉的宝石学特征及其鉴定方法研究

采用拉曼光谱、紫外-可见光谱、红外光谱、X射线荧光光谱、激光剥蚀电感耦合等离子体质谱等现代测试方法,对市面上销售的称之为“墨玉”的黑色玉石与贵州罗甸透闪石玉、广西大化透闪石玉以及新疆墨玉进行了对比研究。结果表明,此种黑色透闪石玉样品经过了染色处理以仿制天然墨玉。通过与天然透闪石玉样品的对比研究,染色处理透闪石玉样品的透明度较低,部分样品横截面可见颜色分带,长波紫外光下呈特殊荧光现象,部分样品具有水草状花纹。拉曼光谱证实其主要成分为透闪石,在处理部位可见团块状、浸染状及不规则条带状石墨的1580 cm^(-1)振动;紫外-可见吸收光谱则表明,天然透闪石玉样品具有270 nm和950 nm附近的吸收峰,而染色样品则无该吸收;红外光谱表明染色部位中的结构水占比减少。XRF及LA-ICP-MS测试表明染色透闪石玉样品与广西大化透闪石玉具有相似的化学成分,二者均具有较高的Mn含量及相似的稀土元素配分模式。根据染色透闪石玉样品颜色观察、成分、拉曼光谱等特征,结合笔者对大化及罗甸透闪石玉染色处理实验结果,基本确定本文研究染色样品为大化透闪石玉经糖酸处理产物。

Hydro-uvarovite from Mantle Peridotites of Naga Hills Ophiolite: A Mineral Tracer for Neo-Tethyan Mantle Wedge Metasomatism

Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydrous uvarovite garnet having Cr_(2)O_(3) upto 19.66 wt% and CaO of 32.12–35.14 wt% in the serpentinized mantle peridotites of Naga Hills Ophiolite(NHO), India. They occur in association with low-Cr diopsides. They are enriched in LILE(Ba, Sr), LREEs, with fractionating LREE-MREE [avg.(La/Sm)_(N) = 2.16] with flat MREE/HREE patterns [avg.(Sm/Yb)_(N) = 0.95]. Raman spectra indicate the presence of hydroxyl(OH^(–)) peaks from 3500 to 3700 cm^(-1). Relative abundances in fluid mobile elements and their close association with clinopyroxenes are suggestive of the formation of uvarovite garnets through low temperature metasomatic alteration of low-Cr diopsides by hydrothermal slab fluids. The high LREE concentration and absence of Eu anomaly in the garnet further attest to alkaline nature of the transporting slab dehydrated fluid rather the involvement of low-p H solution. The chemical characteristics of the hydroxyl bearing uvarovite hosted by the mantle peridotite of NHO deviate from the classical features of uvarovite garnet, and their origin is attributed to the fluid-induced metasomatism of the sub arc mantle wedge in a suprasubduction zone regime.

烧结温度及机械活化时间对陶瓷固废制备陶瓷砖的影响

陶瓷的生产、使用和废弃过程会产生大量的固体废物,这些陶瓷固废大多只能露天堆放或填埋处置,其资源化利用程度很低。本文以陶瓷固废为主要原料,在三乙醇胺和毫米级氧化锆球的协同作用下对陶瓷废弃物机械活化处理,探究不同机械活化时间和烧结温度对废瓷粉烧结性能的影响。结果表明:机械活化6 h后能将废瓷粉的中位粒径D_(50)从4.329μm减小到0.141μm,打破了废瓷粉中有序的Si—O四面体结构,使其无定形化程度加深,进而提高粉体的烧结活性。烧结温度的升高不仅能增加液相的生成量,使其填充颗粒间的孔隙,提高样品的致密度,还能促进透辉石的生成,优化样品物理性能。在烧结温度950℃、保温0.5 h后,样品抗折强度为51.63 MPa,吸水率为0.386%,体积密度为2.342 g/cm^(3),符合《陶瓷砖》(GB 4100—2016)中BIa类标准(平均抗折强度≥35 MPa,吸水率≤0.5%)瓷质砖要求。本文提供了一种“以废制新”的新方法,实现了废陶瓷的有效回收利用。

配方组成对抗菌无光白釉釉面性能的影响

以石英、烧滑石、高岭土、钾长石、氧化锌、碳酸钡、硅灰石、硅酸锆和抗菌粉为原料,经1230℃保温30 min制备抗菌无光白釉,并通过XRD、XRF、SEM等表征手段研究了石英、烧滑石、高岭土和硅酸锆的添加量对釉面白度、光泽度和抗菌性能的影响。结果表明:当石英、烧滑石、高岭土和硅酸锆的添加量分别为25 wt.%、22 wt.%、10 wt.%和18 wt.%时,样品综合性能最佳,此时釉面的白度为86.4%、光泽度为8.9 GU,对大肠杆菌、金黄色葡萄球菌的抗菌率分别为97.06%和96.77%,具备良好的抗菌效果。釉层的晶相组成为锆英石和透辉石。

氟化钙对脱硫渣提铁和制备透辉石微晶玻璃的影响研究

作为一种铁水预处理方法,KR搅拌法可以通过机械搅拌实现脱硫。试验以KR脱硫渣为材料,采用NH4Cl对其进行浸出,得到铵浸脱硫渣,并通过碳热还原反应提取金属铁和制备微晶玻璃,以研究氟化钙对提铁和微晶玻璃制备的影响。结果表明,随着CaF_(2)添加量的增加,碳热还原所得铁块由整块向不完整的多块转变,还原渣由非晶相向透辉石、透辉石与钙长石的混合晶相转变,而微晶玻璃由透辉石主晶相逐步转向钙长石。结合主晶相和析晶生长指数,当CaF_(2)添加量为1%时,微晶玻璃性能最佳,此时析晶生长指数为2.75,接近体积析晶。

陕西省宝鸡市上刃集沟透辉石矿床地质特征及开发利用前景分析

透辉石作为新兴的陶瓷材料,是一种很好的新型节能添加剂和陶瓷原料。本文结合相关地质工作成果,对陕西省宝鸡市上刃集沟透辉石矿床地质特征、矿床成因及开发利用前景进行分析。结果表明:矿区内共圈定2条矿体,矿体赋存于中元古界四岔口岩组下段;矿床为区域变质加接触热变质型矿床;矿床矿石质量优良,适合作为陶瓷原料进行开发利用,也可以用作微晶玻璃原料、冶金保护渣、基料以及橡胶、塑料和油漆的填料等,市场需求大,开发利用前景广阔。

中国古代受热玉器无损鉴别方法研究

透闪石-阳起石是中国古代最重要的制玉材料,其在古代社会承载着装饰、礼仪、丧葬等多种功能。除了在自然状态下的应用之外,玉器也在非自然状态下被应用,如燎祭、热处理等。然而,当透闪石-阳起石玉器的受热程度低,现有的快速鉴别方法常无法有效鉴别。本文据此通过模拟加热实验对便携式红外反射光谱方法进行探讨,结果显示通过二阶导数的处理方法可以方便地鉴别出受热温度低的透闪石-阳起石玉器。该项研究既有助于玉器文物考古研究,也有助于从入土前的人类行为和入土后的自然作用两方面探讨玉器的劣化机制,进而有助于玉器文物保护研究。

河南省南召县老庄透辉石–透闪石矿床地质特征及其成因分析

南召县老庄透辉石–透闪石矿是河南省唯一的透辉石–透闪石矿床。矿区位于区域性栾川–明港大断裂的北侧,大地构造位置处于华北陆块南缘。矿区有2个透辉石–透闪石矿体,呈似层状赋存于青白口系栾川群南泥湖组上段中,矿体形态简单。围岩蚀变为透闪石化和透辉石化,次为钾长石化和金云母化等。矿石自然类型主要为金云母透辉石透闪石矽卡岩型、金云母透闪石透辉石矽卡岩型和金云母透闪石矽卡岩型。矿物成分主要为透闪石和透辉石,次为钾长石和金云母,方解石少量。矿石化学成分主要为SiO_(2)、CaO、MgO和Al_(2)O_(3),其次是FeO、K_(2)O、Na_(2)O和CO_(2)等。透闪石+透辉石(Tl+Di)品位较高、较稳定,矿床平均品位(Tl+Di)为68.25%。透辉石–透闪石原矿代替硅灰石用于生产釉面砖。初步试验表明,制品性能稳定,节能效果明显。矿床属矽卡岩型矿床,成矿时代为早白垩世。矿床形成受早白垩世竹园石英正长斑岩体与南泥湖组上段中的白云石大理岩及层间破碎带的多重控制。矽卡岩期为主成矿期,干矽卡岩阶段形成透辉石,湿矽卡岩阶段形成透闪石,氧化阶段形成钾长石、金云母和方解石等。

白云鄂博矿渣制备微晶玻璃制备工艺的优化

以包钢高炉渣和白云鄂博萤石尾矿为主要原料,采用烧结法制备矿渣微晶玻璃,通过正交试验优化微晶玻璃的抗折强度.结果表明:影响微晶玻璃抗折强度的因素主次顺序为原料粒度、烧结温度、制样压强、烧结时间.最优工艺条件为烧结温度975℃、烧结时间0.5 h、制样压强6 MPa、原料粒度过200网目筛;抗折强度达到104.76 MPa;制备的矿渣微晶玻璃主晶相为透辉石,晶粒形貌较为规整,呈树枝状,晶粒约1~2μm,分布较为均匀;尾矿和炉渣固废利用率达58%;试样达到B类装饰装修材料的放射性限制水平.