Collaborative Research: Thermodynamic Properties of Solutions Generated by Acid Rock Drainage: Fe2O3-SO3-H2O systems

合作研究：酸性岩石排水产生的溶液的热力学性质：Fe2O3-SO3-H2O 系统

• 批准号: 0230172
• 负责人: Moira Ridley
• 金额: $ 11.1万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0230172&HistoricalAwards=false
• 关键词: Collaborative; Research; Thermodynamic; Properties; Solutions

0230172Ridley The oxidation of metal sulfide minerals can generate solutions that have pH values as low as -3.6 and contain less than 190 g H2O per liter of solution. Such acid rock drainage can be generated in any locality where sulfides are exposed to the weathering process, including mine workings and wastes, exposed coastal sediments, and exposures of ancient marine sedimentary rocks. These solutions have a high environmental impact that is estimated to be in the billions of dollars in North America alone. Acid rock drainage has also generated large ore deposits, makes possible the economic recovery of copper and other metals from disseminated mineralization, and hosts some unusual microbial communities. The ability to model the chemistry of these systems accurately would aid greatly in efforts to remediate environmentally sensitive sites, improve the recovery of metals by hydrometallurgic processes, and better understand the processes that control diurnal and seasonal variations in the chemistry of acid rock drainage. Such detailed modeling is currently impossible for many systems: activity coefficients are lacking for strongly acidic ferric sulfate brines as are some basic equilibrium constants needed to model the aqueous and mineral species effectively. This project will take three steps to remove some of those obstacles. 1)Osmotic coefficients of ferric sulfate and mixed ferric-ferrous sulfate brines will be measured. The data will be modeled to retrieve interaction parameters necessary to calculate activity coefficients using the specific ion interaction model. 2)The association constants for ferric sulfate complexes will be measured using a mercury/mercurous sulfate concentration cell. These association constants will be necessary to complete the activity modeling. 3)The solubility of jarosite will be measured over a range of temperatures and ionic strength and in different ionic media. This research will improve significantly the ability to accurately model natural acid-sulfate waters.

0230172 Ridley金属硫化物矿物的氧化可产生pH值低至-3.6且每升溶液含有少于190 g H2O的溶液。 这种酸性岩石排水可以在硫化物暴露于风化过程的任何地方产生，包括矿井和废物，暴露的沿海沉积物和古海洋沉积岩的暴露。 这些解决方案对环境的影响很大，仅在北美估计就达数十亿美元。 酸性岩石排水也产生了大量的矿床，使得从浸染型矿化中经济地回收铜和其他金属成为可能，并容纳了一些不寻常的微生物群落。 准确模拟这些系统的化学性质的能力将大大有助于对环境敏感地点进行补救，通过水文过程提高金属的回收率，并更好地了解控制酸性岩石排水化学性质的昼夜和季节变化的过程。 这种详细的建模是目前不可能的许多系统：缺乏强酸性硫酸铁盐水的活度系数是一些基本的平衡常数需要有效地模拟水和矿物物种。 该项目将采取三个步骤来消除其中一些障碍。 1)将测量硫酸铁和混合硫酸亚铁盐水的渗透系数。 将对数据进行建模，以检索使用特定离子相互作用模型计算活度系数所需的相互作用参数。 2)硫酸铁络合物的缔合常数将使用汞/硫酸亚汞浓差电池测量。 这些关联常数将是完成活动建模所必需的。 3)黄钾铁矾的溶解度将在温度和离子强度的范围内以及在不同的离子介质中测量。 该研究将显著提高天然酸性硫酸盐沃茨的精确模拟能力。