鲁奎山铁矿逆冲推覆系与成矿

对鲁奎山向斜东西两翼构造变形、赋矿特征、成矿规律、控矿因素的分析，及在东翼开展地质物探综合找矿中发现，早期鲁奎山裂陷槽中、昆明群大龙口组的含菱铁质矿源层。卷入构造变形变质后已经历不同层间剥滑构造多次错移或碾碎。后期次生淋漓富集，含矿热液交代蚀变和层间滑剥构造再次叠加改造，改变原来沉积变质含菱铁质矿源层或贫矿体的属性，形成类似于原生沉积、又具有热液交代蚀变和构造岩特征的层状富铁矿体。经坑道进一步揭露证实，沿鲁奎山向斜东西两翼断续分布、已经二次富集成矿的各矿床(点)，实际上是在具层间构造性质的环形断裂带控制下所形成的沉积变质后生矿床类型。表～浅部脆性断裂形成的热液交代与充填脉状矿体，局部叠加在沿环形断裂带内“层状”矿体之上，增加了找寻厚大巢状矿体的可能性。这一新的成矿与控矿规律，为重新认识原“鲁奎山式沉积变质铁矿床”提供了实践基础，同时也为在该区域找矿指明方向。     

湘南─粤北铁锰多金属矿床的表生风化作用

湘南─粤北是我国一个重要的铁锰多金属矿化带，该矿化带中重要的铁锰多金属矿床经历了海相沉积、热液改造和表生风化等多种地质作用。由沉积作用和热液改造作用形成的原生铁锰多金属矿化岩石，由于其中的成矿元素Fe、Mn、Pb、Zn和Ag的含量低，有害元素S的含量高，工业价值不大。通过表生风化作用后，原生铁锰多金属矿化岩石中易溶组分发生强烈淋失，矿石矿物组合也发生了根本变化。次生氧化矿石中有害元素S的含量大幅度降低，有用元素铁、锰、铅、锌、银含量明显升高，它们的平均富集系数基本都大于1．22，从而大大提高了矿石的经济价值。因此，表生风化作用对该矿带铁锰多金属矿床形成起到非常重要的作用。     

云南剑川铁腊曲铅银矿矿床地质

铁腊曲铅银矿位于德钦—维西有色金属成矿带内,是三江成矿带中铅、锌、银矿的富集区域之一。初步认为矿床成因受构造破碎带控制,与地下热卤水溶滤作用有关的热液型铅银多金属矿床。     

Mobilization of Ag,heavy metals and Eu from the waste deposit of the Las Herrerias mine (Almería,SE Spain)

We studied the mobility of silver, heavy metals and europium in waste from the Las Herrerías mine in Almería (SE Spain). The most abundant primary mineral phases in the mine wastes are hematite, hydrohematite, barite, quartz, muscovite, anorthite, calcite and phillipsite. The minor phase consisted of primary minerals including ankerite, cinnabar, digenite, magnesite, stannite, siderite and jamesonite, and secondary minerals such as glauberite, szomolnokite, thenardite and uklonscovite. The soils show high concentrations of Ag (mean 21.6 mg kg^–1), Ba (mean 2.5%), Fe (mean 114,000 mg kg^–1), Sb (mean 342.5 mg kg^–1), Pb (mean 1,229.8 mg kg^–1), Zn (mean 493 mg kg^–1), Mn (mean 4,321.1 mg kg^–1), Cd (mean 1.2 mg kg^–1) and Eu (mean 4.0 mg kg^–1). The column experiments showed mobilization of Ag, Al, Ba, Cu, Cd, Eu, Fe, Mn, Ni, Sb, Pb and Zn, and the inverse modelling showed that the dissolution of hematite, hausmannite, pyrolusite and anglesite can largely account for the mobilization of Fe, Mn and Pb in the leaching experiment. The mobility of silver may be caused by the presence of kongsbergite and chlorargyrite in the waste, while the mobility of Eu seems to be determined by Eu(OH)₃, which controls the solubility of Eu in the pH–Eh conditions of the experiments. The mineralogy, pH, Eh and geochemical composition of the mine wastes may explain the possible mobilization of heavy metals and metalloids. However, the absence of contaminants in the groundwater may be caused by the carbonate-rich environment of “host-rocks” that limits their mobility.     

Evaluation of the effects of alteration and leaching on Sm–Nd and Lu–Hf systematics in submarine mafic rocks

Nd and Hf isotope systematics of oceanic basaltic rocks are often assumed to be largely immune to the effects of hydrothermal alteration. We have tested this assumption by comparing Nd and Hf isotope data for acid-leached Cretaceous oceanic basalts from Gorgona and DSDP Leg 15 with unleached data on the same rocks. Hf isotope values and Lu/Hf ratios are relatively unaffected by leaching, but ¹⁴³Nd/¹⁴⁴Nd values of leached samples are significantly higher than those of unleached fractions of the same sample in most cases. Furthermore, the Sm/Nd ratios of the majority of leached samples are 10–40% greater than those of unleached samples. X-ray diffraction studies indicate that selective removal of secondary minerals, such as smectite, during the acid leaching process is responsible for the fractionation of Sm/Nd ratios. These results have implications for interpretation of the Hf–Nd isotope systematics of ancient submarine rocks (older than ~ 50 Ma), as (1) the age-corrected ¹⁴³Nd/¹⁴⁴Nd ratio may not be representative of the primary magmatic signature and (2) the uncertainty of the age-corrected ε_Nd value may exceed the assumed analytical precision.     

Mobilization and loss of elements from roofing tiles

Deposition, leaching and chemical transformation are processes that affect roofing tile and roof runoff water. Leaching experiments, with artificial rainwater in the laboratory, showed the presence of Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃ ⁻, SO₄ ²⁻, with a ratio of Ca²⁺ and SO₄ ²⁻ suggesting gypsum dissolution. X-ray fluorescence (XRF) of the exposed roof tile showed depletion such as Mg, Al, Si, P, Ti and K at the surface of the tile and an enrichment of Fe and Mn which hinted at a process akin to laterite formation. However, calcium appeared to be enriched at the surface as gypsum (confirmed by X-ray diffraction) and to a lesser extent calcite, which is characteristic of deposits on building surfaces in cities.     

云南金平长安金矿矿石类型及分带

应用氧化铁含量变化确定矿石类型,分带界线初定为1 645米中段,但无法确定混合带界线,开发中很难满足生产。通过柱浸试验浸出率确定矿石类型,即可正确分带。     

堆浸提金原理与试验研究

本文介绍了堆浸提金原理和在实验室进行金矿石堆浸可行性研究的方法.以我国辽宁猫岭金矿、四川茶铺子金矿和福建紫金山金矿为研究对象,研究了矿石粒度、氰化钠溶液浓度、浸出时间等因素对金浸出率的影响,从而确定堆浸提金最佳工艺条件.通过对上述三类矿石性质及堆浸性能的比较,认为矿石的物质组成和金的嵌布特性对金的浸出率影响较大.     

Speciation of Cr and V within BOF steel slag reused in road constructions

Basic Oxygen Furnace (BOF) steel slag is a residue from the basic oxygen converter in steel-making operations, which is partially reused as an aggregate for road constructions. It is essentially composed of calcium, silicon and iron but also contains potential toxic elements present as traces, like chromium (Cr, 2600 mg kg^− 1) and vanadium (V, 690 mg kg^− 1), which can be released. The linked results of chemical analysis, XRD and SEM-EDX enabled to identify the main mineral phases composing BOF slag and EDX micro-analyses indicated that V and Cr were associated to dicalciumferrite. A 47-days static leaching test at a laboratory scale with a controlled pH of 5 (pH_stat leaching test) showed that Cr was little released, while V was significantly released. Finally, X-ray absorption near-edge structure (XANES) spectra of 3 BOF slag samples were recorded (“raw”, leached 47 days at pH 5 and aged 2 years in a lysimeter). XANES spectra showed that Cr is present at octahedral coordination in the trivalent form, the less mobile and less toxic one, and that its speciation does not evolve during natural ageing and leaching at pH 5. They also indicated that V is predominantly present in the + 4 oxidation state and seems to become oxidized to the pentavalent form (the most toxic form) during natural ageing.