基于LA-ICP-MS多元素成像技术的早寒武世磷结核成因研究

我国下寒武统底部广泛发育磷结核、磷块岩等富磷沉积,为早寒武世最为重要的化学标志层之一,也代表了隐生宙—显生宙转折期地球表层系统的重大变革。当前对磷来源和富集机制的解释不一。为进一步明确该时期富磷沉积的形成机制,本文利用激光剥蚀电感耦合等离子体质谱联用技术(LA-ICP-MS)对贵州金沙地区牛蹄塘组黑色页岩中的磷结核进行多元素原位微区成像研究。结果表明:磷结核中各元素富集情况清晰地记录了磷结核形成过程中微环境的变化趋势。其中,磷结核内部Ca、P共富集以及Si亏损,指示P富集缘于自生磷灰石生成,P则来自于有机质含氧或厌氧降解释放;Mn、Zn与P共富集于磷结核内部,指示结核形成时的底部水体为含氧水体;As、Mo、V等元素主要富集于围岩或黑色页岩,指示缺氧含H_2S水体形成终止了结核生长。本研究显示,LA-ICP-MS原位多元素成像技术能够获取微区内丰富的地球化学信息,并提供高精度可视化证据,未来将在地质勘探和古环境研究等领域得到更广泛应用。     

湖北钟祥莲花山矿段第一磷矿层分布的制约因素及找矿意义

湖北钟祥莲花山矿段为大型磷矿床,其第一磷矿层(Ph1)的矿体分布不均匀。通过研究矿层顶底板的岩石,探讨了矿体分布的规律性。研究认为,底板岩石(页岩和含锰白云岩)的厚度与Ph1厚度相关性很高,并严格制约着Ph1的分布,表明在莲花山矿段因沉积时地势的起伏导致古海水深度不同,水体较深的区域一般沉积有含矿层位,水体较浅的区域含矿层变薄甚至缺失。这一规律可指导成矿预测及矿床深边部的找矿工作。     

Distribution of Dissolved Inorganic Phosphate in Nansha Islands Sea Area,Southern South China Sea

Based on the survey data from the program Multidisciplinary Expedition to Nansha Islands Sea Area, the distribution of dissolved inorganic phosphate ( PO4^3--P ) in the sea water of Nansha Islands Sea Area is comprehensively analyzed in this paper. The results show that PO4^3--P concentration in the sea water of southeastern Nansha Islands Sea Area is commonly higher than that in the other sea areas; the vertical distribution of PO4^3--P concentration varies inconspicuously in different seasons; the concentration of PO4^3--P increases with water depth and changes most greatly in the layer of 50-100m. The diurnal variation of PO4^3--P concentration differs in different seasons and at different observation stations. The distribution and variation of PO4^3--P concentration result from the physical and biological processes together.     

Physical and thermal treatment of phosphate ores — An overview

The annual consumption of phosphate rock approached 150 million tons. The marketable phosphate is usually 30% P₂O₅ or higher. The run-of-mine material is mostly of lower grade which needs processing or upgrading. The processing techniques of phosphate ores depend mostly on the type of associated gangue minerals present in the mined rock. In some cases, simple, inexpensive techniques are enough to produce the required grade. For example, crushing and screening is used to get rid of the coarse hard siliceous material, and attrition scrubbing and desliming is used to remove the clayey fine fraction. If silica is the main gangue material, single-stage or double-stage flotation is the conventional mineral processing technique used in this case. If the ore is igneous carbonatitic alkaline or ultra basic phosphate deposit, crushing, grinding, scrubbing, and flotation associated with other steps such as magnetic and/or gravity separation is proved to be successful in upgrading this type of ore. The sedimentary phosphate ores having carbonate-apatite as the main phosphate minerals and containing carbonates (calcite and/or dolomite) represent a challenge in the field of phosphate concentration due to similarity in the physico-chemical properties of surfaces of the ore constituents. Also, if considerable amount of organic matter constitutes the main gangue material, upgrading of the ore becomes difficult. New flotation systems (techniques and reagents) are being developed to treat these challenging phosphate ores. Furthermore, calcination is another solution for upgrading these difficult-to-treat types of ores. However, calcination is indicted with some controversial drawbacks. This overview discusses and summarizes the State-of-the-Art and the existing efforts to overcome these problems and to produce a high-grade phosphate product suitable for fertilizers and other phosphate compounds.     

贵州某磷矿矿石物质组分及部分工艺矿物学特征

中低品位磷矿床的物质组成及工艺矿物学特征是合理利用磷矿资源重要的研究内容。本文通过对贵州某磷矿三个层位物质组成、产出特征、解离性以及粒度分析等方面的研究,提出了胶磷矿中包裹物对磷回收的影响以及在现有研究基础上,通过磨矿到＋0．104mm时可最大限度地实现胶磷矿与其共生脉石矿物的解离。     

长江口理化因子影响初级生产力的探索Ⅱ.磷不是长江口浮游植物生长的限制因子

1985年8月至1986年8月在长江口及其附近海域的50个大面观测站进行了磷酸盐和初级生产力逐月调查。通过分析磷酸盐的水平分布特征,发现长江口海域的磷酸盐浓度没有明显的季节变化,几乎不受长江流量变化的影响,因此认为,长江输送磷酸盐浓度不能由丰水期与枯水期决定;磷酸盐浓度与初级生产力的断面分布和时间变化的分析表明,磷酸盐浓度并不一定离岸越远越低,也没有周期性的季节变化;初级生产力的值几乎不受磷酸盐浓度变化的影响。根据营养盐限制的判断方法和法则,在长江口及其附近海域,磷并不是浮游植物生长的限制因子,仅靠氮磷比值来得到磷限制或氮限制的结论是不完善的。     

旅游活动对黄龙景区磷酸盐浓度和水藻生长的影响

由于其独特的钙华景观,黄龙风景区从1992年被联合国教科文组织列入世界自然遗产名录以来,每年吸引数以十万甚至百万计的国内外游客前来游览;然而,可能由于旅游活动的影响,近年来黄龙钙华景观出现了诸多形式的退化,水藻加速生长钙华黑化即是其表现形式之一。为了阐明这一退化现象是否与旅游活动有关,从2010年5月底到11月初的丰水时段,采用野外自动监测和室内分析相结合的方法,对溪流水藻叶绿素含量和水中的磷酸盐浓度变化进行了研究。结果发现,随着景区游客人数的增减,水中磷酸盐浓度呈现出与之一致的变动趋势;同时,叶绿素与磷酸盐间也呈现出明显一致的变动趋势。因此,我们认为,旅游活动增加了黄龙景区的磷酸盐浓度,并促进了水藻的生长,这很可能是黄龙水藻近年来加速生长的重要原因,值得引起有关方面的高度关注。     

Recycled insular phosphates and coated grains: Case study from Little Cayman,British West Indies

Phosphatic limestones on the west end of Little Cayman, at an elevation of 3 to 4 m above sea level and ca 320 to 550 m inland of the coast, lie on top of a phytokarst surface that defines the upper boundary of the Pedro Castle Formation (Pliocene). These phosphatic limestones are formed of phosphatic lithoclasts, detrital phosphate grains, coated grains (glaebules), composite coated grains, biofragments and phosphate rafts that are held in a matrix that is formed of micrite, calcite cement, and non-crystalline masses formed of P, Al, Si and Fe. The phosphate in these limestones is primarily hydroxylapatite, whereas the overlying soils, found in some areas, are formed of hydroxylapatite, crandallite and minor amounts of boehemite, kaolinite and quartz. Textures in the lithoclasts and detrital phosphate grains indicate that they were derived from older insular phosphates that that were largely removed by mining in 1890 to 1895. The coated grains (glaebules) typically have nuclei formed of a detrital phosphate grains that are encased by non-crystalline cortical laminae that are composed primarily of Al with their variable red colour reflecting the variable Fe content. The phosphatic limestones developed in a low-lying coastal area where the guano produced by a large seabird colony that was close to or mixed with terra rossa and marine carbonates that were washed onshore during storms/hurricanes. The Al, Fe, Si and rare earth elements found in the phosphatic limestones came from the terra rossa. Critically, this study documents the complex depositional regimes and diagenetic processes that can exist at the interface of marine carbonates, coastal phosphates and terrestrial soils as sea-level fluctuations control phases of sediment accumulation that were periodically interrupted by periods of non-deposition.     

磷酸盐水泥注浆浆液的试验研究

针对工程实际的要求,筛选了以磷酸盐为缓凝剂的３种类型的注浆浆液,采用正交法进行试验研究,并介绍了它们各自的性能特点。     

Dissolved Nutrient Distributions in Groundwater in the Mediterranean Coastal Plains – the Case of Silifke,Turkey

Total carbon, nitrogen, and phosphate parameters were studied for the first time in the groundwater in the Silifke coastal plain, which is a RAMSAR site in Turkey. Seasonal variations of these parameters in the plain were examined based on groundwater data collected from 21 wells during the winter, spring, summer, and fall seasons. Total dissolved organic carbon (DOC), inorganic carbon (DIC), inorganic phosphate (DIP), inorganic nitrogen (DIN), and total alkalinity (TAlk) average values in the groundwater were low in all seasons (<2.2 mg/L for DOC; <54 mg/L for DIC; <0.06 mg/L for DIP; <1.5 mg/L for DIN; <232 mg/L for TAlk). The results showed a strong relationship between DIC and as expected. The results indicate that the content of these parameters in the groundwater of Silifke coastal plain pose no or little risk at present. However, computed Langelier Saturation Index (LSI) values indicated that the groundwater has a tendency to form scale and CaCO₃ precipitation may occur.