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1.
A study has been made of the adsorption of sodium silicate by calcite, fluorite and barite and the effect that this adsorption has on the flotation of these minerals with oleic acid. The results show that sodium silicate depresses these minerals by preventing oleate species from reacting with surface sites. This effect is independent of the total silica concentration. Aged sodium silicate solutions do not produce markedly different results to those obtained with fresh solutions.The concentration of the sodium silicate solutions was generally such that the total silica concentration was below that in equilibrium with amorphous silica. Under these conditions the solutions contained no polymeric silica species and the mechanism of silica adsorption can be generally attributed to interactions of monosilicate ion and monosilicic acid with surface sites.  相似文献   

2.
萤石重晶石方解石共生非金属矿物分析方法研究   总被引:1,自引:0,他引:1  
王峰  倪海燕 《岩矿测试》2013,32(3):449-455
萤石、方解石、重晶石是自然界中普遍共生的非金属矿,具有十分重要的经济价值.目前对于该类共生矿物中不同矿物含量的分离测定,尚未建立较系统、准确的方法.本文通过条件试验,选用10%冰醋酸作为溶剂溶解分离方解石和萤石,硝酸-高氯酸溶解分离萤石和重晶石,制定了一套适用于方解石、萤石、重晶石共生矿物的分离分析方法流程.应用该实验流程对三类矿石组合样品及实际样品进行分析,内外检的测定结果准确可靠;对GBW 07250 ~ GBW 07254五个萤石国家一级标准物质和一个重晶石管理样品进行分析,方法精密度(RSD)<0.4%,证明该方法流程也适用于萤石或重晶石含量较高的样品分析.与国家标准方法GB/T 5195.1-2006(萤石氟化钙含量测定)比较,本流程更加连续简便,可指导方解石、萤石、重晶石共生矿物资源评价、选矿及回收试验,有利于提高该类非金属矿物的综合利用价值.  相似文献   

3.
The influence of an ultrasonic field frequency of 22 kHz and intensity of 0.5 W/cm2 has been examined on the flotation of barite, fluorite and quartz as well as on their ability to adsorb dodecyl- and cetylsulphates. The tests affected the flotation of pure minerals in a Hallimond tube as well as the flotation of a natural barite-fluorite ore. It has been found that ultrasonic pretreatment of minerals causes an increase in the flotation rate of barite and a decrease in the flotation rate of fluorite. Ultrasonic pretreatment of the natural barite-fluorite ore before its flotation is the most advantageous. In this case it is possible to obtain concentrates of barite composed of a low amount of CaF2. This may be explained by the different effects of ultrasonic vibrations on barite and fluorite which cause some improvement of the selectivity of their flotation separation.For a full explanation of these results the effects of ultrasonic pretreatment of the minerals on their adsorption properties and surface topography have been investigated, as well as the direct influence of ultrasound on the adsorption process.  相似文献   

4.
包裹体地球化学研究表明,四川冕宁稀土矿床中存在着岩浆成因的萤石、重晶石和方解石,它们的微量元素地球化学特征与热液成因对应矿物有明显差别:岩浆成因重晶石相对富集亲石元素,贫亲硫元素;无论是岩浆成因重晶石,还是萤石均明显富集挥发分。稀土元素地球化学研究显示,不同成因萤石、重晶石在稀土元素总量、LREE/HREE、(La/Yb)N、δEu及δCe等一系列稀土元素地球化学参数上都存在明显的差异。该项研究还揭示了岩浆成因萤石、重晶石是在相对还原和酸性体系内结晶而成的。  相似文献   

5.
Calcite is generally associated with apatite minerals in phosphate deposits. To explore the possibility of separating these minerals by a soap flotation technique, their electrokinetic properties and flotation behaviour were studied in the presence of sodium oleate.Microelectrophoresis data indicate oleate adsorption on these minerals, and from Hallimond-tube flotation tests it has been noted that in a controlled pH environment and for a certain sodium oleate concentration range, separation of these minerals is possible.The study of apatite/calcite-sodium metasilicate-sodium oleate systems indicates the preferential adsorption of silicate at the calcite surface. This suggests the potential use of sodium metasilicate as the modifying agent for the separation of apatite from calcite by depressing calcite when using sodium oleate as collector.  相似文献   

6.
The maximum flotation response for three naturally occurring calcium minerals, apatite, calcite and fluorite with sodium oleate collector correlated directly with the minimum interfacial tension of the air/solution interface. For fluorite and apatite the minimum surface tension occurred about the mid-pH region and was attributed to the formation of pre-micellar associated species in solution. In the case of calcite the minimum was observed at high pH since the presence of high concentrations of calcium ions in solution appeared to reduce the concentration of amphililic species in the low and mid-pH regions.Microelectrophoresis data demonstrated that the three minerals acquired a negative charge in sodium oleate solution, resulting from adsorption of oleate species on the mineral surfaces.The flotation behaviour of the systems were shown to be related to the species distribution diagrams suggesting that the role of the acid soap dimer, soap dimer, molecular and lattice species could make a significant contribution to the character and composition of the interfacial films.High flotation response was explained by strong adhesion between the hydrophobic particle and bubble. It was suggested that the reduction in surface tension may not be the major factor contributing to the flotation efficiency but indicated the presence of associated surfactant species in solution which could also synergistically adsorb at the solid/liquid interface, increasing the hydrophobic character of the mineral surface. This would maximize the magnitude of the contact angle and hence the strength of the adhesion between particle and bubble. This adsorption behaviour is not in general agreement with conventionally non-hydrolyzable collector theory which is usually based on electrostatic models.  相似文献   

7.
重庆酉阳坝竹坨汞、铅锌矿床地质特征及成因分析   总被引:1,自引:0,他引:1  
酉阳坝竹坨汞、铅锌矿叠生并主要呈似层状和脉状产于中寒武统高台组、石冷水组白云岩中,矿石矿物组合简单,主要有辰砂、方铅矿、闪锌矿、方解石、白云石、石英、重晶石、萤石等。矿床主要受地层、岩性及构造的控制。矿床为多期热液成矿。  相似文献   

8.
Spherical calcium dioleate particles (∼ 10 μm in diameter) were used as AFM (atomic force microscope) probes to measure interaction forces of the collector colloid with calcite and fluorite surfaces. The attractive AFM force between the calcium dioleate sphere and the fluorite surface is strong and has a longer range than the DLVO (Derjaguin–Landau–Verwey–Overbeek) prediction. The repulsive AFM force between the calcium dioleate sphere and the fluorite surface does not agree with the DLVO prediction. Consideration of non-DLVO forces, including the attractive hydrophobic force, was necessary to explain the experimental results. The non-DLVO interactions considered were justified by the different interfacial water structures at fluorite– and calcite–water interfaces as revealed by the numerical computation experiments using molecular dynamics simulation. The density of interfacial water at the fluorite surface is low and the fluorite surface is not strongly wetted by water molecules. In contrast to the water at the fluorite surface, water molecules at the calcite surface form tightly packed monolayer structures and the calcite surface is extensively hydrated by water molecules. The interfacial water structure agrees with the AFM force measurements and the flotation recovery data. The strong attraction between the calcium dioleate colloid and the fluorite surface, and the moderately wetted fluorite surface by water molecules explain the better flotation response of fluorite with the oleate collector colloid.  相似文献   

9.
矿物流体包裹体中的羧酸曾贻善刘家齐(北京大学地质系,北京100871)(地矿部宜昌地质矿产研究所,宜昌443003)关键词矿物包裹体浸取液羧酸离子色谱分析分子中含有羧基官能团(—COOH)的物质称为羧酸。Fein[1]和Shock[2]曾概述羧酸在自...  相似文献   

10.
潘彦宁  董国臣  刘铭初  张虹 《地质通报》2014,33(12):1933-1940
在丰富的自然重砂数据资料基础上,对全国各省37个典型重晶石矿床中的自然重砂矿物报出结果进行了相关研究,发现2种成因类型的重晶石矿床具有特定的自然重砂矿物组合,沉积型重晶石矿床的自然重砂矿物组合为重晶石+黄铁矿+褐铁矿,热液型自然重砂矿物组合为重晶石+铅族矿物+黄铜矿+萤石+黄铁矿+闪锌矿+辉锑矿+孔雀石。同时,对此特征性自然重砂矿物组合进行了相关分析,为重晶石的找矿矿物学发展提出相关建议。  相似文献   

11.
《Ore Geology Reviews》2003,22(1-2):133-141
A mineralogical and geochemical (fluid inclusion, stable and radiogenic isotopes) study of the Berta F–(Pb–Zn) vein system has identified the source and temperature of the fluid reservoirs involved and proved the existence of two separate hydrothermal events at the mine scale, which reflect distinct periods of regional fluid circulation. Main stage minerals (fluorite I, sulphides, calcite I and barite I) precipitated by mixing between a polysaline H2S bearing (δ34S=11‰) brine (up to 23% NaCl eq salinity) and a more dilute fluid (δ18O from −3.2‰ to 0‰), at temperatures between 80 and 150°C. The progressive increase in 87Sr/86Sr ratio from the early precipitated minerals (0.71242 in calcite I) to the late ones (0.71894 in fluorite II) is mainly (but not exclusively) due to a difference in age separating the two hydrothermal events. The assumed genetic model for the main stage fluorite (I) is based on a convective circulation of surficial waters leaching the crystalline basement rocks acquiring a high salinity, high 87Sr/86Sr ratios and a high temperature. These fluids then mixed with low salinity–low temperature waters, having a low 87Sr/86Sr ratio. An at least Jurassic age is suggested for the main period of vein filling, contemporaneous with the extensional regime during the Mesozoic, when fluid circulation was probably enhanced by crustal thinning. During the early Burdigalian (lower Miocene), a new period of important extension in this area took place. Hydrothermal activity related to this new and younger extensional regime is geochemically different and produced a distinctive mineralogical record, developing a set of veinlets filled with green octahedral fluorite (fluorite II), calcite (II) and barite (II). The Sr isotope compositions of these late stage vein minerals are compatible with leaching the granodiorite host-rocks during recent times. The existence of successive hydrothermal events in the same area is not surprising as geothermal systems, like La Garriga–Samalus, are still active and currently precipitating fluorite.  相似文献   

12.

Six minor sulphide occurrences hosted by the Lower Devonian Buchan Group have been investigated. Sulphide minerals and associated phases are hosted by both dolostone and limestone lithologies along stylolitized bedding planes, cross‐cutting fractures, low angle minor faults and in cavities. Mineralization was closely associated with minor structures of inferred Tabberabberan age (Middle Devonian), which it appears to have post‐dated, but was largely strata‐bound in nature. The mineralogy of the occurrences is simple and characterized by the following generalized paragenesis which reflects the increasing oxidation state and pH of the mineralizing fluids: pyrite (pseudomorphous after marcasite)‐galena ± sphalerite ± pyrite‐dolomite ± barite‐calcite ± fluorite ± dolomite.

The sulphur isotope composition of sulphide minerals varies from ‐32.1 to +4.1‰, with iron and base metal sulphide minerals forming two distinct populations around ‐25‰ and 0‰, respectively. A single barite sample gives a sulphur isotope composition of +22.4‰, which is similar to that estimated for Early Devonian seawater. Fluid inclusions in fluorite and calcite homogenize at temperatures in the range 160 to 212° C and have average salinities of approximately 10 wt% NaCI eq. Sphalerite contains up to 1.81 wt% iron which correlates with colour, and up to 1.43 wt% cadmium. The Pb isotopic pattern of galena suggests a source region with U/Pb(= μ) lower than the crustal average, and a high Th/U.

A genetic hypothesis is proposed which involves the circulation of saline fluids through the Snowy River Volcanics, which directly underlie the Buchan Group, during or at some time after the Tabberabberan Orogeny. Although the Buchan occurrences show features characteristic of both Mississippi Valley‐type and stratiform ore deposits, they are most directly comparable to the epigenetic zones of Irish carbonate‐hosted base‐metal deposits. However, Pb‐Zn sulphide mineralization at Buchan appears to have been associated with minor compressional structures, suggesting that a simple correlation with the Irish deposits is not directly applicable.  相似文献   

13.
A compilation and comparison of fracture mineral studies from the Canadian and Fennoscandian Shields and the French Massif Central shows many similarities indicating larger external control over fracture mineral deposition, with different rock types exerting local controls. The sites investigated represent a wide range of geological settings, and host rock types ranging from felsic intrusive and extrusives to ultramafic intrusives and volcanics that span an age range from 2.5 to 0.36 Ga. Typical fracture minerals found at Canadian Shield sites include calcite, quartz, chlorite and clays, and these do not appear to be dependant on age, erosional depth or geological environment. The Fennoscandian Shield has a much larger variety of fracture filling minerals with epidote, zeolites, prehnite, fluorite, pyrrhotite, Fe oxides, serpentine, graphite, magnesite and barite in addition to the minerals typically found at Canadian Shield sites. The major control on fracture mineral type is most likely variations in rock type, and fluid chemistry and temperature.  相似文献   

14.
The Xiangquan Tl deposit, located in the northern part of the Middle–Lower Yangtze Valley metallogenic belt, eastern China, is the only known Tl-only deposit. It is hosted in micritic limestone, marl and mudstone of the Lower Ordovician Lunshan Formation. The orebodies are controlled by the Xiao–Xiaolongwang–Dalongwang anticline and two reverse faults, and are generally stratabound and lenticular. Tl is only ore metal contained in disseminated, massive, brecciated and banded ores. The ore is composed of Tl-bearing pyrite, and gangue minerals quartz, fluorite, barite and carbonate. Alteration minerals include fluorite, barite, fine grained quartz and carbonate. Tl occurs isomorphously replacing iron in the lattice of pyrite, and less commonly as tiny independent Tl-bearing minerals which may be lafossaite (TlAsS2) or lorandite (TlCl) appearing as 0.1–1 μm-sized cubic crystals. Xiangquan is a submarine sedimentary deposit and demonstrates that Tl, as a normally dispersed element, can form not only part of poly-metallic deposits but also as independent Tl deposits.  相似文献   

15.
The geological and mineralogical data on the Chailag-Khem F-Ba-Sr-REE occurrence in the Western Sayan Range, Russia, are discussed. The chemical compositions of rocks, ores, and minerals (ICP-MS, Link) are reported. The occurrence is localized in a tectonic crush zone composed of Cambrian quartz-sericite slates intruded by quartz syenite porphyry. Ore mineralization occurs as veins, cement of tectonic breccia, and metasomatic disseminations in host rocks. Massive ore consists of calcite, strontianite, and quartz; impregnations of euhedral fluorite, ankerite, and bastnaesite crystals; and fine-grained barite aggregate. Accessory minerals include parisite, synchysite, barytocelestine, sulfides, rutile, and uraninite. Late metasomatic calcite and strontianite segregations and veinlets are abundant. In genetic, mineralogical, and geochemical features, the Chailag-Khem occurrence is similar to the Late Mesozoic carbonatite deposits of Central Tuva, of which the Karasug Fe-F-Ba-Sr-REE deposit is the largest and best known. All carbonatite deposits and occurrences are located within a longitudinal zone transverse to the major tectonic elements of the region.  相似文献   

16.
The effects of Na2SiO3, Na3PO4, Na4P2O7, (NaPO3)6, quebracho, tannic acid and S 808 (sulphonated product of rough phenantrene) on the floatability of the following five pure minerals: scheelite, calcite, fluorite, garnet and quartz, with sodium oleate as collector were investigated in detail as well as the role of pH on these effects. The results obtained indicate that Na4P2O7 and (NaPO3)6 were effective modifiers for the selective flotation of scheelite. The results of the batch flotation tests on mixtures of these minerals showed that the recovery of scheelite from scheelite-silicate mixtures (31% WO3) with (NaPO3)6 or Na4P2O7 increased by 20% as compared with sodium silicate and the WO3 grade of the concentrate by 5%. At room temperature, the scheelite-calcium mineral mixtures could not be separated with sodium silicate. In the separation of these mixtures with the phosphate modifiers, a concentrate grade of 47–60% WO3 was obtained at 70–90% recovery. This showed that the flowsheet of the selective flotation of scheelite with phosphate modifiers may replace the conventional Petrov's process.  相似文献   

17.
The Monakoff iron oxide–Cu–Au (IOCG) deposit, located to the north east of Cloncurry within the Eastern Succession of the Mount Isa Inlier, Queensland, Australia, is characterised by high concentrations of F and Ba, with a host of other enriched elements including Co, Ag, Mn, REE, U, Pb, Zn and Sr. This gives the deposit a characteristic gangue assemblage dominated by fluorite, barite and calcite. The nearby E1 deposit, located 25 km to the NNE of Monakoff, and the large Ernest Henry deposit, 3 km to the west of E1, also contain abundant fluorite, barite and calcite in late stage assemblages. The three deposits, therefore, constitute a distinct group of IOCG deposits within the district, based on their F-rich geochemical and mineralogical affinities.The Monakoff ore zone is hosted in dilational openings along a shear zone developed within metasediments and metavolcanic rocks at the boundary between competent hangingwall rocks of the Toole Creek Volcanics and footwall rocks of the Mount Norna Quartzites. Four stages of alteration and mineralisation are recognised: Stage 1 garnet–biotite alteration; Stage 2 biotite–magnetite alteration; Stage 3 main F–Ba-ore mineralisation; and a Stage 4 pyrite–alloclasite Au–Co–As overprint. The E1 deposit has a more complex history, but Stage 5 has veins of fluorite–barite–carbonate that are comparable to Monakoff's main stage. The Stage 3 assemblage at Monakoff comprises a sheared groundmass of fluorite, barite, manganoan calcite, magnetite, chalcopyrite, pyrite, galena and sphalerite, with coarser grained pods of the same mineralogy interpreted to be dilational structures infilled during syn-ore deformation. Accessory minerals include U–Pb-oxides, REE–F-carbonates and Ag–Pb–Bi-sulfosalts, with no discrete Au minerals. The sulfosalts are interpreted to have formed from an immiscible Bi-melt within the mineralising fluid at temperatures higher than the melting point of Bi. The Stage 4 overprint at Monakoff contains pyrite and alloclasite. Laser ablation analyses of the sulphide minerals at Monakoff reveal that Stage 3 sulphides contain only trace amounts of Au (0.04 ppm in pyrite), although galena and chalcopyrite contain significant concentrations of Ag. Stage 4 pyrite and alloclasite, however, contain ~ 1 ppm Au in solid solution and mass balance calculations indicate the majority of bulk rock Au to be present in these minerals, although the majority of bulk Ag is present in Stage 3 sulphides. The Stage 5 veins at E1 have an identical gangue and accessory mineralogy to Stage 3 at Monakoff and differ in the sulphide mineralogy only in the lack of galena and sphalerite.Four fluid inclusion populations are identified within the fluorite at Monakoff: Group 1 is CO2 rich; Group 2 is complex solid–liquid–vapour inclusions, with two groups based on homogenisation temperature (> 450 °C and 300–375 °C). Laser ablation-ICP-MS analyses indicate that these inclusions contain Cu, Pb, Zn, Fe, Mn, Mg, Ag, REE, U and Ba, but significantly no S, Se or Au; Group 3 are solid–liquid–vapour inclusions with a Th of 200–275 °C, and contain Ba, Na, Mg, K and Br; and Group 4 are low salinity liquid–vapour inclusions. Group 1, 2 and 4 inclusions are also present in fluorite at E1. The REE geochemistry of fluorite from Monakoff and E1 is comparable and is characterised by a distinct positive Eu anomalies in all analyses, interpreted to indicate oxidising conditions at the time of high temperature ore deposition. The presence of abundant fluorite and barite is indicative of fluid mixing due to the insolubility of barite and fluorite and thus Ba and S, and Ca and F must have been introduced via different fluids. We propose that the oxidised fluid represented by the Group 2 inclusions and containing F, Ba, REE, U and base metals, mixed with a reduced, S-bearing fluid in a zone of dilation in the host shear zone that acted as a conduit for fluid flow during D3 deformation. The source of the metal and F-rich fluid is likely to be the nearby granitic intrusions of the Williams–Naraku batholith, probably the Malakoff granite. This granite is also likely to be the source of the CO2 represented by Group 1 fluid inclusions, and the REE, U, base metals and possibly Au, although the high Pb and Zn content of Monakoff and not E1 may suggest a local input of those elements at Monakoff. Stage 4 mineralisation overprints the F–Ba stage and is characterised by a Co–As–Au signature. At present it is unclear if this is a late stage, more reduced, evolution of the main ore fluid, or a separate mineralising event entirely.The presence of this F–Ba-metal-rich fluid has produced a distinctive style of IOCG mineralisation in the area to the north of Cloncurry. The probable link to the Malakoff granite implies that similar deposits may be present within several kilometres of the granite in suitable structural traps. Monakoff illustrates that although structurally controlled, the presence of Na–Ca alteration and ‘red rock’ K-alteration and brecciation are not key exploration criteria for these deposits. In addition, the presence of the overprinting As–Co–Au assemblage may indicate that this is a separate mineralising episode that may be present at other localities in the district. This study has also shown that fluorite can provide a powerful tool for determining ore forming conditions in F-rich IOCG systems.  相似文献   

18.
查明流体包裹体中稀有气体的保存能力,对于判断其初始组分特征是否因后生作用而发生改变具有重要意义.文章以Ar为例,从扩散动力学角度对稀有气体地球化学研究中常用的矿物中流体包裹体稀有气体的保存能力进行了定量分析和系统比较,计算了Ar在这些矿物中的封闭温度以及不同温度条件下的保存时间,得出相同条件下各矿物对Ar、He等保存能...  相似文献   

19.
茂租铅锌矿床位于扬子地台西南缘,是滇东北矿集区内的一个大型矿床,矿体主要呈似层状产于震旦系灯影组白云岩中;矿石矿物以闪锌矿为主,次为方铅矿;脉石矿物主要为白云石、方解石和萤石。本文对该矿床中与铅锌矿密切共生的团块状白云石、方解石和萤石以及围岩灯影组白云岩的REE地球化学特征和C、O、Sr同位素进行了对比研究。结果表明:团块状白云石和方解石的稀土配分模式、C同位素和Sr同位素比值与围岩灯影组白云岩比较接近,表明形成团块状白云石和方解石的成矿流体主要来源于围岩灯影组白云岩的溶解;但这两种矿物的稀土总量ΣREE高于灯影组白云岩,说明成矿流体除了主要由围岩提供REE外,还有部分其他富含REE流体的加入。萤石则具有LREE亏损和分配曲线相对平缓的稀土配分模式特征,表明萤石形成于成矿的晚阶段,有更多的外部流体的加入。团块状白云石、方解石和萤石表现出明显的Eu正异常,且团块状白云石和方解石的O同位素低于灯影组白云岩,反映了存在较高温度的流体活动,这3种脉石矿物是由高温热液流体形成的。灯影组白云岩和3种脉石矿物都具有明显的Ce负异常,说明成矿流体可能主要来源于地层循环水,继承了围岩的Ce负异常特征。方解石和萤石的Sr同位素比值高于围岩震旦系灯影组白云岩和峨眉山玄武岩,但小于基底岩石昆阳群和会理群,说明成矿流体主要由赋矿围岩等沉积地层中的循环流体与流经了基底岩石的深部流体混合形成。  相似文献   

20.
黔东北(沿河)-渝东南(酉阳)一带广泛发育萤石、重晶石及铅锌(汞)矿化,关于其成矿时代,一直缺少直接的同位素年龄证据。黔东北大竹园萤石矿床位于上扬子地块东南缘,矿体赋存于下奥陶统桐梓组和红花园组碳酸盐岩内,受NW向断裂控制,是本区热液脉型萤石矿床的代表。本文以该矿床为研究对象,利用单矿物Sm-Nd等时线方法进行了成矿年龄测定,获得萤石Sm-Nd等时线年龄为436±15 Ma(MSWD=0. 85),萤石与共生方解石Sm-Nd等时线年龄为430±13 Ma(MSWD=1. 02),两者在误差范围内一致,表明矿床形成于加里东期,该年龄与湘西-黔东MVT铅锌矿床成矿时代(477~410 Ma)一致。本区萤石-重晶石矿床与区内产出的主要铅锌(汞)矿床关系密切,推测它们有相近的物质来源,是在同一构造运动时期形成的一个有亲缘关系的成矿系列。研究结果指示加里东期是区内重要的萤石-重晶石-铅锌(汞)中低温热液成矿期。  相似文献   

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