吉林省硬质高岭(土)岩的开发及利用

吉林省地矿信息中心与白山市八道江区煤管局合作 ,对白山市砟子煤矿竖井矿区石炭、二叠系煤系地层中的硬质高岭 (土 )岩进行了详查及评价。该类型矿石过去人们称其为“夹矸”、“黑砂石” ,日本人称其“焦宝石”。岩石学术语为高岭石粘土岩 ,由于这类矿石大多产自煤系夹层或煤系顶、底板 ,故我们称其为硬质高岭 (土 )岩。白山地区石炭、二叠系煤系地层中硬质高岭 (土 )岩资源极其丰富 ,矿物组分与我国北方地区硬质高岭 (土 )岩相当 ,高岭石含量在 90 %以上。有益化学组发ＳｉＯ2 含量为 4 0 %左右 ,Ａｌ2 Ｏ3含量在 36 %左右 ,有害组分Ｆｅ2…     

北方煤系高岭岩矿床中高岭岩的有序度研究

高岭岩的结晶有序度除了受物源和成岩强度的影响外,还与显微结构和高岭岩的纯度有关。高岭岩有4种显微结构：同一剖面的高岭岩中,假象结构高岭岩的结晶有序度最高;隐晶高岭岩、隐晶团块状高岭岩的结晶有序及相差不大;蠕晶高岭岩的结晶有序度最低。高岭岩中混入的其他矿物越多,其结晶有序度越低。高岭岩中高岭石的结晶有序度有不同的表示方法,不同表示方法所表示的结晶有序度有不同的物理意义,且相互间存在着一定的对应关系。     

北宿井田高岭岩矿床特征研究有结果

最近 ,兖州矿业 (集团 )公司地质工程公司开展了对北宿井田高岭岩矿床特征的研究。北宿井田的高岭石赋存在上石炭统太原组底部、煤 18夹矸及其底板。根据岩性特征可划分为夹矸高岭岩及 N1、N2和N3高岭岩三个分层。据 5 7个勘探钻孔统计 ,高岭岩矿层厚0 .74～ 4 .85 m,平均 3 .0 5 m,大致呈西部厚、东部薄、北部厚、南部薄的趋势。 N2及局部夹矸、N1和 N3高岭岩的有益矿物高岭石和有益组分 Al2 O3含量比较高 ,为用途较广的矿物 ,但其有害杂质 Fe2 O3和 Ti O2 含量亦较高 ,降低了矿石的质量。N2矿层的质量相对较好 ,高岭石含量高 ,颗粒…     

准格尔煤田官板乌素6号煤层中煤矸石的矿物学特征研究

运用X射线衍射、红外光谱、热重-热流和扫描电镜等手段对准格尔矿区官板乌素煤矿主采6号煤层下部层位中煤矸石的矿物组成和微观形貌进行了系统研究。结果表明,煤矸石在官板乌素煤矿6号煤层下部层位中分布广泛,呈薄层状产出,主要矿物组成为高岭石,其次含有极少量的勃姆石等矿物。样品中SiO_2/Al_2O_3(摩尔比值)在2.00~2.10之间,接近高岭石族矿物理论比值,有害组分铁、钛含量相对较低。在扫描电镜下,可见煤矸石样品中高岭石单晶形态主要为六方片状,叠片状聚晶,晶片的片径多在5μm以下。该矿区煤矸石中的高岭石为结晶度较高的优质高岭岩,可用于生产陶瓷。     

淮北闸河矿区高岭岩特征及其利用途径

用差热、X射线衍射及红外光谱等方法,对淮北闸河矿区下石盒子组底部5#、6#煤层间一层高岭岩矿层进行了研究。结果表明:矿层平均厚3.8m,矿石几乎全部是由高岭石组成的单矿物岩,有益组分Al₂O₃含量一般在36%~39%;主要有害组分Fe₂O₃含量变化在0.78%~1.71%之间;TiO₂含量多在0.4 9%~0.97%。为矿物组成纯净,有益组分含量高但有害组分亦较高的高岭岩。这种岩石是生产化工产品,以及煅烧高岭土的良好原料。      

陕西韩城矿区11#煤层中高岭岩矿研究

通过野外调查和室内研究,查明韩城矿区11#煤层底板（南区）和煤层中、下部（北区）有一层厚0.60～1.30m的高岭岩矿层。其厚度稳定,储量丰富,为一大型高岭岩矿床。矿石成分纯,高岭石含量在95%以上,Al₂O₃含量高,SiO₂含量低,TiO₂含量较高,Fe₂ O₃含量低至较高。可作为生产超细煅烧高岭土及4A分子筛等产品的原料,有较广阔的开发利用前景。      

陕西渭北、陕北石炭二叠纪煤系共伴生高岭岩赋存规律及利用方向

陕西省渭北、陕北石炭二叠纪煤系共伴生高岭岩资源极其丰富。渭北高岭岩质纯，矿石中高岭石自形程度差，但结晶有序；府谷高岭岩质量纯，杂质少，粒度细、结晶好，是一种优质高岭土矿。渭北高岭岩可用作“双90”、莫来石、4A沸石等的原料，广泛用于陶瓷工业、造纸工业；府谷高岭岩可用作生产纸张涂布、高级日用细瓷原料。高岭岩的赋存具有平面和剖面上的规律性，这些规律又受区域构造背景、古气候、母岩、沉积环境、成煤植物、成岩后生作用等控制。针对不同的资源特征，可以合理利用，节省投资，化资源优势为经济优势。     

黔西北玄武岩风化壳稀土地球化学特征

黔西北玄武岩风化壳中的稀土矿是一个分布广泛、稀土含量较高的新类型稀土矿。本文主要通过岩相学、矿物学和地球化学的方法,系统研究了该稀土矿层的岩石组构、矿物组合及地球化学特征,探讨了该地区稀土迁移富集机理。结果显示该风化壳稀土矿层厚度大(单层厚度0.1～0.5 m,总厚度约5～15 m)。矿石中主要矿物为高岭石(60%～80%),次要矿物为蒙脱石(2%～8%)、赤铁矿(5%～20%)。稀土总量较高(144～2288×10-6),具轻稀土富集特征,并且稀土含量高的样品均为高岭石粘土岩。稀土配分模式图中显示明显负铕异常(0.22～0.85),铈异常变化较大(0.86～1.63)。综合分析认为玄武岩风化壳中的稀土元素的富集和高岭石的含量密切相关,稀土元素可能在偏还原的环境中被高岭石颗粒吸附。     

安徽宣城红土剖面中粘土矿物过渡相及其意义

为研究长江中下游红土剖面中粘土矿物的特征及其成因意义, 对安徽宣城红土剖面中粘土矿物进行深入、系统的X射线衍射分析.结果表明, 宣城剖面各土壤层中粘土矿物成分基本一致, 主要为蛭石、伊利石、高岭石, 以及粘土矿物过渡相. 由采自剖面上部样品的X射线衍射图可知, 经乙二醇饱和后7 ?衍射峰可分解为7.15、7.60和7.92 ?三部分, 表明除了高岭石(7.15 ?)外, 还存在高岭晶层含量分别为~80%和~95%的2种高岭-蒙脱石过渡相, 并以前者为主; 剖面下部样品在乙二醇饱和后, 7 ?衍射峰可分解为7.16、7.79和8.35 ?等3个衍射峰, 其中8.35 ?峰衍射强度很小, 表明除了高岭石外, 样品中存在高岭晶层含量为~90%和~43%的高岭-蒙脱石过渡相, 后者含量甚少.甲酰胺饱和结果表明, 高岭-蒙脱石混层粘土矿物相中高岭晶层为埃洛石相.加热试验的衍射图中10 ?衍射峰强度明显增强, 证实高岭相中含有一定数量的来源于绿泥石风化的蒙脱石间层; 而10 ?衍射峰的低角度一侧没有出现拖尾现象, 则指示高岭-蒙脱石混层矿物中的蒙脱石不是简单的羟基间层蒙脱石.此外, 红土剖面中还普遍出现过渡性粘土矿物伊利石-蒙脱石混层和伊利石-蛭石混层粘土矿物.大量过渡性粘土矿物相的出现, 从成土作用的角度上说明红土沉积物经历了沉积-风化、以及多期风化作用叠加, 而且在沉积-风化成土过程中, 气候环境变化于强烈化学风化的温暖、季节性干旱和强烈风化淋滤的温暖而更加潮湿的条件.蛭石-伊利石混层粘土矿物仅发育于红土剖面上部, 表明总体上剖面上部的化学风化程度低于剖面下部.      

广西钦州_防城地区次生氧化锰矿床矿物学和地球化学研究及矿床成因意义

钦州-防城锰矿带是中国次生氧化锰矿的重要产地之一,其含锰岩系为上泥盆统榴江组含锰硅质岩。锰矿床主要赋存在以腐岩带为主的风化壳中,矿石的主要矿物为软锰矿、锰钡矿、隐钾锰矿、锂硬锰矿、钙锰矿等,与之伴生的其他表生矿物有赤铁矿、针铁矿、石英、高岭石和其他粘土矿物。矿石多呈葡萄状、块状、网脉状构造。与原生含锰硅质岩相比,次生氧化锰矿矿石的品位明显提高,Mn含量平均达到42.6%。矿石化学分析和单矿物电子探针成分分析表明,氧化锰矿石中还普遍出现Co、Ni、Cu、Zn等元素的富集,其平均含量分别为0.05%(最高0.40%)、0.09%(最高0.53%)、0.08%(最高0.53%)和1%(最高2.2%);它们主要以类质同象和吸附的形式赋存在锂硬锰矿及隐钾锰矿中。氧化锰矿石和锰氧化物的Mn/Fe比值均较高,一般大于6～10,说明该区化学风化强烈,铁、锰分离显著,有利于形成高品位的优质锰矿。有害杂质元素P主要存在于针铁矿等铁的氧化物中。氧化锰矿的形成和空间分布受气候、构造、含锰岩系及地形地貌等多种因素的影响和控制。     

华北盆地东南部下石盒子组高岭岩的成因及研究意义

介绍了高岭岩的岩石、矿物、化学和物理测试特征,根据马氏链对沉积序列的模拟、高岭岩的厚度分布以及微量元素分布和古盐度分析结果,认为华北盆地东南部的高岭岩属沉积成因。      

The mineralogy and geochemistry of two copper-rich weathering profiles in Burkina Faso, West Africa

Two weathering profiles developed over disseminated Cu mineralization hosted by granodiorites (porphyry type) and felsic volcanics respectively, in a savannah tropical environment (Burkina Faso) have been studied in detail. A mineralogical and geochemical study was carried out in order to determine the characteristics of both profiles and the behaviour of Cu in such deeply weathered environments. Our investigation was focused on the upper part of the weathering profile, respectively 4.0 and 10.5 m below the surface.The mineralogical study reveals that in the first case (profile A) the predominant clay minerals are smectites and kaolinite while in the second (profile B) a more kaolinitic composition is indicative of more severe leaching. In fact, field observations seem to demonstrate that the latter situation is more clearly related to an ancient lateritic-type weathering while the first one results from more recent processes.In both cases the Cu contents through the profiles are high (several thousands of ppm) and in good agreement with the grades obtained in depth, in the mineralized rock. Nevertheless, some leaching can be observed in the upper soil horizons, but the contents still remain highly anomalous, in the 1000 ppm range.It is shown that Cu is distributed in the main secondary minerals constituting the weathering products, whether they are silicates (smectites, phyllites, kaolinites) or oxides (goethite, hematite, Mn oxides).The main stable Cu-bearing mineral seems to be the kaolinite: indeed, smectites turn into kaolinite in the upper part of the profiles while goethite seems to be depleted in Cu under the same conditions.As concerns geochemical exploration, two observations can be noted. Firstly, Cu is very stable in such supergene environments, and secondly, the best size fraction in which to detect the Cu secondary dispersion haloes in soil or stream sediment samples is the <63 μ fraction, in terms of anomaly intensity or contrast.     

Petrographic-microchemical studies and origin of the Agbaja Phanerozoic Ironstone Formation, Nupe Basin, Nigeria: a product of a ferruginized ooidal kaolin precursor not identical to the Minette-type

The Campanian-Maastrichtian Agbaja Ironstone Formation of the Nupe basin, Nigeria, forms a major part of the about 2 billion tons of iron ore reserves of the Middle Niger Embayment. The ironstone deposits were previously reported to be similar to the Minette-type ironstones because of their depositional patterns, composition and inferred origin. Four rock-types are recognized within the Agbaja Ironstone Formation: ooidal pack-ironstone, pisoidal pack-ironstone, mud-ironstone and bog iron ore. In the ironstones, kaolinite of both the groundmass and the ooids/pisoids is of lateritic origin, whereas the associated quartz, mica and heavy minerals are of detrital origin. Ooids and pisoids were formed by mechanical accretion of platy kaolinite crystals by rolling on the sea floor in a near-shore environment, and were subsequently transported and deposited together with a fine-grained kaolinitic groundmass. Pyrite (mainly framboidal) and siderite (both exclusively occurring as pseudomorphs of goethite and/or hematite) are diagenetic whereas goethite is post-diagenetic in origin, resulting from the ferruginization of the kaolinitic precursor. Crandallite-gorxeicite-goyazite, bolivarite and boehmite are also post-diagenetic in origin. Hematite was formed from the dehydration of goethite, whereas gibbsite (restricted to the upper part of the deposit) is of recent and in situ lateritic origin. The presence of newly formed authigenic pyrite and siderite (now replaced by hematite and goethite) are indicators of a reducing environment during diagenesis. The absence of diagenetic chamositic clay minerals, evidently caused by a low Mg concentration, suggests that fully marine conditions were not established during sedimentation. This is supported by the lack of fossils, brecciated shell materials and bioturbation features in the deposit. Reworking and redeposition of the primary constituents are inferred from broken pisoids, nuclei of pisoidal/ooidal fragments in pisoids and high iron concentrations present in the pisoids and ooids compared to that of the groundmass. These observations indicate that the Agbaja ironstone deposits of the Lokoja study area exhibit some environmental and mineralogical characteristics that are markedly different from other known deposits of Minette-type, where primary chamositic clay minerals generally form the protore for the ironstones. The recognition of kaolinite as the precursor constituent and the occurrence of similar deposits of the same age (Late Cretaceous) in Nigeria, Sudan and Egypt have implications for the paleoenvironmental interpretations of Phanerozoic ironstone deposits. Received: 16 February 1998 / Accepted: 8 July 1998     

淄川-博山地区伊利石化高岭石粘土岩地质特征及其应用

论述了淄川-博山一带的伊利石化高岭石粘土岩的区域地质概况及成矿地质条件,按自然分布结合地质情况,划分为3个成矿带,叙述了各成矿带分布及含矿层特征。以南坡矿区为例,详细论述了矿层赋存特征,矿体的规模、厚度及其质量,研究了矿石类型、化学成分及主要物理性能指标,类比研究了加工技术性能,经简单水选即可达到较为理想的选矿指标,具有高效、低成本优势;结合有关研究,认为该类粘土岩是在较高温度条件下由高岭石粘土岩加钾水化转变而成。山东省该类矿床总体勘查程度低,具有较好的找矿潜力,但优质粘土资源找矿难度大。     

砚山县梭落底地区碳酸锰矿地质特征及找矿方向

梭落底地区碳酸锰矿是云南省砚山地区近年来新发现产于中三叠统法郎组碎屑岩中的重要碳酸锰矿,在滇东南具有代表性.该类锰矿以矿层厚度大,出现多层而且相互平行产出为特征,与相邻的斗南、老乌锰矿进行对比,该碳酸锰矿沉积的氧化—还原界面深度比斗南、老乌锰矿更深,该类锰矿的形成很大程度上受下伏地层个旧组碳酸盐岩基底古地理的控制.     

Properties and origin of a very fine-grained kaolinitic lacustrine deposit

The Rosebrook Member of the Miocene Bunyan Formation is a highly kaolinitic clay-rock of lacustrine origin. It is ultra-fine grained, plastic and of high cation exchange capacity (CEC) of 20–33 c mol(+)kg^?1 of clay. Fabrics observed optically and by transmission electron microscopy (TEM) indicate significant post-depositional consolidation and localized shear failure. Sedimentation and TEM analyses confirm its very fine grain size which is consistent with the relatively high CEC. Tertiary soils and weathering profiles in the catchment of Lake Bunyan developed under relatively moist and cool conditions. Some were gibbsitic with kaolinite and smectite clay minerals. Highly weathered soils (oxisols) on basalt under modern high rainfall environments in the region are dominated by gibbsite and kaolinite. These and other highly weathered soils in the region, formed on a range of parent rocks, have high proportions of very fine grained kaolinite in their subsoils. Such materials are likely to have been abundant in the catchment of Lake Bunyan during the Miocene and would have contributed very fine grained kaolinite directly to the lake by sedimentation. However, the unusually high proportion of kaolinite in the Rosebrook Member and its euhedral crystal form suggest that some of its features developed diagenetically.     

Mineralogical characterization of the Nkamouna Co–Mn laterite ore, southeast Cameroon

The Nkamouna property is an oxide laterite deposit developed on serpentinized peridotite in southeast Cameroon. It is enriched in Co and Mn, has sub-economic Ni grades and will be mined primarily for Co. The ore zone is ca. 10 m thick and comprises the lower breccia (～3 m thick) and ferralite (7–8 m thick) units sandwiched between an 8-m-thick ferricrete overburden and a barren hydrated Mg–silicate saprolite. The ore mineral assemblage includes Mn oxyhydroxides, magnetite, maghemite, ferritchromite, goethite, hematite, kaolinite and gibbsite. Lithiophorite is the most common Mn mineral and is the main host of Co, Mn and a significant proportion of Ni. It occurs as coatings in pores and on other mineral grains and as concretions and impregnations in the matrix. It is invariably associated with gibbsite in the lower breccia and with magnetite and ferritchromite in the ferralite. Although ore in the lower breccia is volumetrically less important than the ferralite, it has the highest grade and Co/Ni ratio. The lithiophorite in the ore zone is authigenic, and its formation was enhanced by influx of Al³⁺ from the overlying ferricrete. Magnetite and ferritchromite in the ferralite are relicts and contributed to mineralization by enhancing the permeability of the ferralite and providing substrates for the precipitation of the Mn oxyhydroxides. The structure and mode of occurrence of the lithiophorite makes Nkamouna ore amenable to physical beneficiation, producing a concentrate with Co grades 2.3–4.5 times higher than the run-of-mine ore.     

西昆仑北缘主乌鲁克锰矿床地质特征及成因探讨

主乌鲁克锰矿床位于西昆仑北缘晚古生代陆缘裂谷恰尔隆弧盆系的北部,含锰层位为下石炭统他龙群细碎屑岩夹碳酸盐岩,锰矿层为黑色泥质碳质页岩夹铁锰质泥晶灰岩。锰矿体严格受地层的控制,呈NWW向展布,延伸较为稳定,规模较大,共见有13条锰矿体,其中有3个矿体较大构成主矿体;锰矿石以原生菱锰矿为主体,氧化矿石不多。该矿床与近年发现的玛尔坎苏地区锰矿床既有相似之处,又有明显不同,矿床类型为在深海-半深海陆缘裂谷环境中形成的与黑色碳质页岩有关的沉积型锰矿床,锰矿的成矿时代为早石炭世。由于下石炭统他龙群是西昆仑地区新发现的含锰层位,具有较大的找矿潜力,应加强矿床外围及深部的找矿工作。     

Genesis of the Hussainiyat ironstone deposit, Western Desert, Iraq

The Hussainiyat ironstone deposit (Jurassic) is mainly pisolitic, intraclastic and concretionary in texture, associated with kaolinite mudstones and/or with quartzose sandstone. The ironstone consists mainly of goethite, hematite, kaolinite and quartz. The deposits were derived from a variety of parent rocks that included low- and medium-rank metamorphics, intermediate igneous rocks and pre-existing sediments of the Nubio-Arabian Shield. The source rocks suffered deep chemical weathering in the hinterland, and the products (Fe-oxyhydroxides, kaolinite and quartz) were later transported by rivers to the depositional site. Iron was mostly carried in association with the clay fraction and organic matter. Several genetic processes were involved in the ironstone formation. Iron concretions were mostly formed by bacterial build-up in swamps and marshes, and were subsequently embedded in kaolinitic mud. Large-scale development of groundwater laterite blanket (ferricrete) occurred later in the overbanks and floors of wadis, under oxidizing pedogenic conditions. During this stage iron was mobilized from the kaolinitic deposits and migrated upward in dry seasons and, to a lesser extent, downward in wet seasons. Pisolites and oolites grew in situ in the kaolinitic soil at the upper limit of the fluctuating water table. This ferricrete blanket had a wide and continuous extension within an elongated paleodepression. Seasonal heavy rain periods resulted in the flow of ephemeral streams and rivers, where major parts of this ferricrete was reworked and deposited with quartz sand and mud clasts as channel deposits. The original pisolitic-colloform ironstone was reworked continuously to form a semi-continuous sheet. In such wet seasons, additional Fe-enrichment took place as cementing materials or overgrowths. Received: 28 April 1995 / Accepted: 10 July 1997     

Geology and geochemistry of bauxite deposits in Lushoto District, Usambara Mountains, Tanzania

Bauxite deposits in the Usambara Mountains of north eastern Tanzania occur as remnants of residual deposits on two geomorphologically related plateaus of Mabughai-Mlomboza and Kidundai at Magamba in Lushoto, Usambara Mountains. The parent rocks for the deposits are mainly granulites and feldspathic gneisses of Neoproterozoic Mozambique belt. The plateaus represent a preserved Late Cretaceous–Lower Tertiary old land surface (African surface). Other parts of the Usambara Mountains and the neighbouring Pare Mountains are covered mostly by red–brown lateritic soils and impure reddish-brown kaolinitic clays. The bauxite deposits contain mainly Al₂O₃ (40–69 wt.%), Fe₂O₃ (3–10 wt.%), SiO₂ (0.16–7 wt.%) and other elements occur in quantities not substantial to affect the quality or processing of the bauxite, and are attributed to the presence of relic minerals. Gibbsite makes up to 98 vol.% of the bauxite ore in special cases. Gibbsite is accompanied by goethite in the ore. Boehmite occurs in small amounts and is usually accompanied by hematite. Impurities include goethite, hematite, kaolinite, and minor relic quartz and microcline. Kaolinite is the sole clay mineral encountered in the bauxite ore, suggesting mature soil profiles and a development of the bauxite deposits on a well-drained peneplanation. Ore reserve estimates from the drilling data and surface geological mapping of the deposits yielded bauxite reserves of about 37 million tonnes.