胶磷矿晶体结构研究

详细叙述了磷灰石的晶体结构,并采用多种方法对磷灰石结构中配位多面体各元素间的化学键力进行计算,分析了磷灰石的表面特性。针对贵州典型磷矿区具有代表性的胶磷矿试样,其主要由微晶磷灰石组成,采用x射线衍射分析了胶磷矿试样的物相组成、结晶度、晶胞参数以及磷灰石晶粒大小。在扫描电子显微镜下,2种胶磷矿多呈集合体形态,两种胶磷矿中磷酸盐矿物主要为氟磷灰石。     

Association of phosphate with rhyolite glass in marine Neogene tuffs from Patagonia,Argentina

The precipitation/replacement of Ca‐phosphate is a complex process that commonly takes place during the early diagenesis in marine sediments. The unusual occurrence of shallow marine, early diagenetic phosphatic deposits associated with glassy tuffs in the Neogene Gaiman Formation, in the Chubut Province, Patagonia, Argentina, constitutes a good case example for the study of replacement and precipitation of Ca‐phosphate on an unstable substrate. Isocon diagrams illustrate that chemical changes during glass diagenesis include gains in loss on ignition and Ca, and losses of K. These changes are the result of glass hydration during sea water–glass interaction, together with adsorption and diffusion of ions into the bulk shard; combined, these represent an incipient process of volcanic glass replacement by Ca‐phosphate. Subsequent early diagenetic P enrichment in the pore solutions led to phosphate precipitation, associated with pitting on the glass shards and pumice. The associated development of a reactive surface promoted the incorporation of P and Ca into their margins. Lastly, precipitation of calcium phosphate filled the vesicles and other open cavities, inhibiting further glass dissolution. The high porosity and reactivity of the volcanic glass provided an appropriate substrate for phosphate precipitation, leading to the development of authigenic apatite concretions in the volcanic‐glass bearing strata of the Gaiman Formation. This research is of significance for those concerned with marine phosphatic deposits and sheds light on the processes of early diagenetic phosphate precipitation by replacement of an atypical, unstable substrate like hydrated volcanic glass.     

中国北方磷矿成矿特征及找矿潜力

中国北方磷矿在华北、东北以岩浆岩型磷矿和海相沉积型磷矿为主 ,在西北则以海相沉积型磷矿为主。海相沉积型磷块岩矿床主要形成于早寒武世 ,受南面和西面海水侵入影响最大、侵入距离最近的已知含磷地区可作为磷块岩矿床重点研究靶区 ;岩浆岩型磷灰石矿床所赋存的岩体类型比较多 ,但矿床规模较大 ,品位较高 ,具有较大的找矿潜力的磷灰石矿床产于超基性碱性碳酸岩杂岩体中 ,这类杂岩体在我国北方有一定的分布 ,对其做详细工作 ,可望找到规模大、品位高的磷灰石矿床     

上扬子区早寒武世黑色页岩磷结核特征及生化淀磷机制

通过野外观察、室内化学分析、矿物学分析、硫同位素分析、光学显微镜和扫描电镜观察,发现磷结核内所观察到的许多现象均与微生物的活动有关,微生物是使磷淀积的重要营力,这为磷结核的生物成矿作用提供了有力的证据.沉积物孔隙水物理化学条件的变化直接影响着磷结核的生长过程.     

磷酸盐现场自动分析仪化学工艺优化研究

本文结合营养盐现场自动分析仪的研制,研究了磷酸盐分析所南各种试剂的用量及其作用,重点研究了低浓度磷酸盐的浓度与吸光值之间的关系以及温度对完全反应时间的影响,给出了０．００６～０．１２０ｍｇ／Ｌ范围内ＰＯ４－Ｐ浓度与吸光值的线性函数关系和较合适的完全反应温度,并且提出了现场自动分析仪的两点定标方法。     

坡缕石粘土的磷吸附机制及其铁负载效果研究

比较了3种天然坡缕石粘土对不同程度磷污染水体的吸附净化能力,通过等温吸附实验和吸附动力学实验探讨了坡缕石粘土的磷吸附机制,并研究了不同形态铁负载对坡缕石粘土吸附净化磷污染水体性能和机制的影响.结果发现,3种天然坡缕石粘土对不同程度磷污染水体均有一定的吸附净化能力,其中含白云石较多的坡缕石粘土的磷吸附能力最强,吸附等温曲线呈S型,且Freundlich方程(R2=0.977 6)比Langmuir方程(R2=0.924 9)拟合效果更好;准一级方程、冥函数方程、抛物线扩散方程、准二级方程均能较好地模拟坡缕石粘土对磷的吸附动力学过程,说明坡缕石粘土对磷的吸附可能属于不均匀介质的多分子层吸附.此外,不同形态铁负载均能显著增强坡缕石粘土对不同程度磷污染水体的吸附净化能力,吸附等温曲线呈L型,Langmnir方程(Fe2 :R2=0.96,Fe3 :R2=0.967 7)比Freundlich方程(Fe2 :R2=0.965 7,Fe3 :R2=0.936 1)能略好地拟合铁负载坡缕石粘土的磷吸附等温结果,说明铁负载坡缕石粘土的磷吸附过程可能是均匀介质的单分子吸附.适量白云石有助于提高坡缕石粘土的磷吸附净化性能,铁负载可能通过改变坡缕石的表面电荷和吸附活性位点来改变其磷吸附机制,从而提高其磷吸附性能.     

Removal of Lead,Copper, Zinc and Cadmium from Water Using Phosphate Rock

Removal of Pb^2＋, Cu^2＋, Zn^2＋ and Cd^2＋ from aqueous solutions by sorption on a natural phosphate rock （FAP） was investigated. The effects of the contact time and initial metal concentration were examined in the batch method. The percentage sorption of heavy metals from solution ranges generally between 50% and 99%. The amount of sorbed metal ions follows the order Cu〉Pb〉Cd〉Zn. Heavy metal immobilization was attributed to both surface complexation of metal ions on the surface of FAP grains and partial dissolution and precipitation of a heavy metal-containing phosphate. The very low desorption ratio of heavy metals further supports the effectiveness of FAP as an alternative and low-cost material to remove toxic Pb^2＋, Cu^2＋, Zn^2＋ and Cd^2＋ from polluted waters.     

离子色谱法同时测定地质样品中氟氯磷硫

本文研究了离子色谱同时测定地质样品中F~-、Cl~-、PO_4~(3-)、SO_4~(2-)的前处理过程,选择了色谱测定最佳条件。在Na_2CO_3全熔的样品溶液中,加入(NH_4)_2CO_3使Si、Al随大多数金属离子同时沉淀;再用预处理柱除去熔剂引入的大量Na~+及CO_3~(2-)消除其干扰;并在流出液中补加相应试剂与淋洗液相匹配,实现了多种地质样品中F~-、Cl~-、PO_4~(3-)和SO_4~(2-)的测定。方法检出限(3s,μg/ml)分别为F~-0.05、Cl~-0.1、PO_4~(3-)0.3、SO_4~(2-)0.5。测定范围为F~-0.05—3μg/ml,Cl~-0.1—6μg/ml,PO_4~(3-)0.3 —30μg/ml,SO_4~(2-)0.5—30μg/ml。     

Study of inorganic ligand-chromium(III)-surface ternary complexes by ESR spectroscopy

Cr(III) sorbed at the solid/water interface of latex and hectorite was studied by ESR spectroscopy in the presence of different inorganic ligands. The ESR spectra of the surface obtained in the presence of selenite, phosphate and fluoride can be explained in terms of ternary surface complex formation. This is contrasted by the behaviour of sulfate and selenate ions which were found to have no effect on the ligand field of Cr(III), either in the adsorbed state or in solution.     

Oxyanion Concentrations in Eastern Sierra Nevada Rivers – 2. Arsenic and Phosphate

Water samples were collected from the Truckee River-Pyramid Lake system, the Walker River-Walker Lake system, and the Carson River, all located in eastern California and western Nevada, U.S.A., at three different times (i.e., summer 1991, spring 1992, and autumn 1992) over a two year period. The concentrations of As, Na, Cl, PO4, and pH were measured in these river samples and the associated terminal lakes. Arsenic values ranged from below 13 nmol/kg near Truckee, California to 160 nmol/kg at Nixon, Nevada in the Truckee River, from 40 nmol/kg in the headwaters of both West and East Walker Rivers to 270 nmol/kg below Weber Reservoir on the main branch of the Walker River, and from <27 nmol/kg to 234 nmol/kg for the lower Carson River system. Arsenic concentrations in Steamboat Creek (0.91 mol/kg–1.80 mol/kg) in the Truckee River catchment are above the U.S. EPA drinking water maximum contaminant level of 0.67 mol/kg, as are the As concentrations in both Pyramid Lake (1.33 mol/kg–1.57 mol/kg ) and Walker Lake (13.7 mol/kg–18.7 mol/kg). Sources of As for all three rivers include weathering of As-rich rocks and/or regolith and input of high-As geothermal spring waters, both processes primarily, although not exclusively, adding As to the headwater regions of these rivers. Steamboat Hot Springs (29 mol/kg As 54.5 mol/kg), for example, is identified as a source of As to the Truckee River via Steamboat Creek. The high As concentrations in Pyramid and Walker Lakes are likely due to (1) desorption of arsenate from aquatic particulate matter in these high pH waters (9.0 pH 9.5), (2) limited biologic uptake of arsenate, and (3) evaporative concentration of the lake waters. Evaluation of molar PO4}/As ratios of river waters and geothermal spring waters (e.g., Steamboat Hot Springs), indicates that phosphate is substantially enriched in Steamboat Creek as well as the mid to lower reaches of the Walker and Carson Rivers. These regions of each river are dominated by agricultural interests and, additionally, in the case of Steamboat Creek, residential areas and golf courses. Our data strongly imply that phosphate-rich agricultural return flow has likely added P to these streams and, consequently, increased their respective P:As ratios.