Trona resources in southwest Wyoming

Bedded trona (Na₂CO₃·NaHCO₃·2H₂O) in the lacustrine Green River Formation of Eocene age in the Green River Basin, southwest Wyoming, constitutes the largest known resource of natural sodium carbonate in the world. In this study, 116 gigatons (Gt) of trona ore are estimated to be present in 22 beds, ranging from 1.2 to 11 meters (m) in thickness. Of this total, 69 Gt of trona ore are estimated to be in beds containing less than 2 percent halite and 47 Gt in beds containing 2 or more percent halite. These 22 beds underlie areas of about 130 to more than 2,000 km² at depths ranging from about 200 m to more than 900 m below the surface. The total resource of trona ore in the basin for which drilling information is available is estimated to be about 135 Gt.Underveloped trona beds in the deeper southern part of the basin may be best developed by solution mining. Additional unevaluated sodium carbonate resources are present in disseminated shortite (Na₂CO₃·2CaCO₃) in strata interbedded with the trona and in shallow sodium carbonate brines in the northeast part of the basin. Estimates of the shortite and brine resources were not made.     

The chemical composition including the Rare Earth Elements of the three major glass types of Europe and the Orient used in late antiquity and the Middle Ages

Sets of 20 soda ash glasses, 16 soda lime glasses and 23 wood ash glasses mainly from excavations in Europe (additional soda ash glasses from Egypt) were analysed on 61 chemical elements. Average SiO₂ is about 62% in soda glasses and 50% in wood ash glasses. The three groups of glasses contain on average 13% Na₂O, 18% Na₂O and 13% K₂O as fluxes to lower the melting temperature of quartz at their production. The starting materials beside quartz were halophytic plant ash for soda ash glass, trona (Na₃H(CO₃)₂·2H₂O) and lime (clamshells) for soda lime glass and beech ash for wood ash glass. Each of the three major glass types contains specific Rare Earth Element (REE) concentrations mainly contained in quartz and its intergrown minerals. 50 Paleozoic and Mesozoic sandstones from Central Europe represent the quartz composition. The REE pattern of these glasses apparently indicates major compositional stages of the Continental Earth's Crust. The boron to lithium and sodium to potassium ratios as in seawater suggest reactions of materials for soda glass with seawater. Negative Ce anomalies in the three glasses are caused by reactions of quartz with seawater.     

土耳其卡赞天然碱矿溶采对接井工程HSE管理

HSE管理是现代企业走出国门、承揽国际大型项目的必备条件,并且在现代工程管理中具有越来越重要的地位。土耳其卡赞天然碱矿水溶开采对接井工程的实施过程中,在借鉴国内外相关行业经验的基础上,结合项目自身特点,成立了HSE管理机构,加强了人员安全培训和机械设备的升级改造,使之符合当地的行业安全标准。引入了JSA工作安全分析工具,建立了切实可行的HSE管理体系,并强调了现场监督,从而实施了行之有效的HSE管理,为该项目的顺利运行提供了有力的安全保障。     

土耳其卡赞天然碱溶采对接井堵井原因分析及修复

土耳其卡赞天然碱矿由于地质条件复杂,首采层不溶物含量高,矿层倾角大,在商业开采过程中易发生堵井事故。本文以P078水平对接井组为例,介绍了其施工工艺和注采井史,分析了引起井组堵塞的原因。遵循“先易后难、降低风险、控制成本”的原则,先后进行了直井单井循环、固井泵车压井和循环泥浆清理井底等各种尝试,最后提出了分支侧钻重新连通的技术方案,并成功修复了溶采通道,恢复了井组的正常生产。并在钻井施工组织、修井设计与施工和溶采作业等方面提出了建议。该技术对类似故障井组的修复具有一定的指导作用和借鉴意义。     

土耳其卡赞碱矿对接井水溶开采技术创新综述

土耳其卡赞碱矿钻井项目主要利用高精度中靶技术使定向水平井与垂直井在碱层中对接后进行水溶开采的方法。该项目通过长期大量的钻井工作,在已有的钻井技术与地质条件基础上,改进完善了与地层相适应的钻井技术,建立了矿区三维地质模型,设计应用了水平分支对接井,优化了钻井轨迹设计,建立起非矿层与矿层的基准物探测井响应曲线,探索出矿区地层致斜机理及相应钻井防斜措施,研究并应用了各种井底钻具组合与设备,采用了提高水平钻井轨迹控制精度的技术方法。上述多种水溶采矿钻井技术创新措施的应用,提高了矿山规划能力、降低了施工成本、提高了资源回采率、缩短了施工工期、降低了劳动强度、提高了钻进效率、减少了施工用地以及对环境的破坏。可为天然碱矿及可溶性矿产的整体矿山规划,以及钻井水溶采矿技术的提高提供借鉴。     

土耳其贝帕扎里天然碱矿钻井工程MWD实地校核

土耳其贝帕扎里天然碱矿采卤工程是目前世界范围内采用对接井水溶开采方法进行采矿的最大规模的天然碱采矿工程。在对接井施工过程中，由于出现了地磁变化异常和地质条件变化，致使MWD导向系统出现了一定偏差。为减少仪器偏差，设计并对仪器进行了实地校核。校核结果表明，探管的安装条件对其数据精度有较大的影响。其校核结果被应用于实际生产中，起到了良好的指导作用。     

土耳其卡赞碱矿对接井分层同时开采设计方案探讨

土耳其卡赞天然碱矿采用了对接井水溶开采的方法,目前已成功完成了100余组对接井组,创造了显著的社会与经济效益。为了提高矿山的利用率,根据现有情况和地质条件,本文针对卡赞碱矿四期钻井工程,提出了3种分层同时开采碱层的可选方案进行探讨。在总体方案已基本确定的情况下,提出了分层同时开采的布井原则,并对3种方案进行了简要阐述及各项指标对比。本文选择了具有钻井工作量少、工期较短及投资费用较低等优点的可选方案C（1口水平井+2口垂直井）,详细阐述了垂直井施工、水平井施工及溶采操作,并提出了一些技术问题与建议。该分层同时开采方案对于天然碱矿的多层同时开采及回采率提高具有一定的指导作用和借鉴意义。     

Adsorption of carbonate and bicarbonate salts at the air–brine interface

Previous research has shown that the flotation of soluble salt is determined by interfacial water structure, thermal stability, and viscosity. These salts include alkali halide and alkali oxyanion salts. Of particular interest are the carbonate salts such as those associated with the great trona deposit of the Green River basin in Wyoming. In this study, we investigated the adsorption of carbonate and bicarbonate salts at the air–brine interface and correlated the adsorption behavior with water structure. Specifically, the equilibrium and dynamic surface tensions of sodium carbonate and sodium bicarbonate salts have been measured as a function of the salt concentration up to saturation and compared with the model prediction using the Gibbs–Langmuir adsorption theory. The results show that the negative adsorption of sodium carbonate leads to a significant increase in surface tension of the brine solution. For sodium bicarbonate, both the negative adsorption and the increase in surface tension are significantly lower when compared with the sodium carbonate case. The negative adsorption is correlated with the water structure making/breaking character of carbonate and bicarbonate solutions. In particular, sodium ions are significantly more hydrated than carbonate and bicarbonate ions, and, therefore, tend to be excluded from the air–brine interface. On the other hand, carbonate and bicarbonate ions are accommodated at the air–brine interface. In any event, the balance between sodium exclusion and carbonate/bicarbonate accommodation results in an increase in the surface tension of these solutions with an increase in salt concentration.     

Modeling of lithology induced chemical anomalies in the aquifer systems of the Kazan Trona deposit area, Ankara, Turkey

The study was carried out in order to investigate existing hydrogeochemical relationships between groundwater environment and geological units in the Kazan trona deposit area, Ankara, Turkey. Evaluations indicate that concentrations of alkalinity, boron, chloride and sodium in the upgradient groundwater of the Eocene sedimentary units gradually increase toward downgradient by the interactions of saline minerals (searlesite, shortite, northupite and pyrite) present in the secondary structures (microfractures and irregular voids) at various levels. Inverse modeling calculations suggest that the range of dissolved mass amounts in millimoles per kilogram of water for searlesite, shortite and northupite minerals are 0.05–28.67, 2.62–24.39 and 0.01–24.19, respectively, in the aquifer between the upgradient and downgradient locations. The ranges of accompanying calcite and dolomite precipitations are 4.54–48.71 and 2.16–24.08 mmol per kg of water, respectively. Chemical composition of the groundwater in the overlying Neogene sedimentary unit includes also higher concentrations of the major ions as measured in groundwater of the underlying units. However the lack of saline mineral zones in the Neogene unit indicates that upward groundwater mixing takes place from the underlying aquifer as also suggested by the measured upward gradient. The mixing percentage of the underlying groundwater as determined from the nested wells ranges from 2.7 to 48.3%, from upgradient to downgradient, respectively. The unconfined alluvium aquifer overlying the Neogene unit includes relatively dilute groundwater except in two locations, where high-ion concentrations detected in groundwater of the underlying units are also high in these locations, suggesting upward groundwater mixing from the underlying aquifer due to upward gradient. However, groundwater input investigations from the alluvium aquifer to the nearby Ova stream indicate that the detected high concentrations in these locations are diluted or sorbed by the aquifer material toward downgradient (Ova Stream).     

土耳其卡赞天然碱矿溶采对接井质量控制措施

土耳其卡赞天然碱矿水溶采卤对接井施工项目技术规范中对工程质量的要求非常严格。由于矿区地质构造复杂、地层倾角大、含水层多等原因,易出现直井易斜、岩心采取率低、固井质量差,水平对接井轨迹控制难等问题。针对这些问题,在前期施工经验的基础上,通过调查研究、方案优选等手段,分别提出了针对性的措施,有效地解决了这些钻井难题,优化了钻井工艺,从而保证了施工质量,加快了施工进度。该项目钻井质量控制成果对于今后类似工程的施工具有一定的借鉴意义。