The Fort Knox Mine, located 25 miles northeast of Fairbanks, Alaska, is operated in a sub-Antic environment. Since process slurry temperatures cycle seasonally with air temperature, the mine presents a unique opportunity to measure the impact of slurry temperature on process performance under full scale plant, conditions. This thesis analyzes an energy balance approach to model the seasonal variations in slurry temperature throughout the Fort Knox mill.; The mill utilizes both gravity concentration and cyanidation for gold recovery. Models were developed to accurately predict the impact of slurry temperature on cyanide leach, carbon adsorption and cyanide destruction kinetics. The energy balance model, combined with the kinetics models, was used to accurately predict the gold recovery and subsequently to justify the installation of a tailings wash thickener to recovery heat from the mill tailings. A substantial portion of this thesis is dedicated to the development of these models, analysis of the post expansion plant performance, and summarizing project economics.; Gold in the Fort Knox deposit is generally less than 100 microns in size and contained in quartz veins and along shears within the host granite, at an average gold grade of 0.8 g/metric ton. In April 2001, the mill began processing ore from a satellite ore deposit, the True North Mine, as a blend with Fort Knox ore. The gold grade in the True North deposit averages 1.5 g/metric ton and can be associated with pyrite, arsenopyrite and stibnite.; An unexpected drop in gold recovery resulted from processing the blended ore and was the subject of an extensive laboratory evaluation. Laboratory results suggested that the leach kinetics of the coarse gold particles were significantly impacted, when the blended ore was processed, and that the impact could be reduced, or eliminated, with the addition of lead nitrate. Subsequently, a lead nitrate addition scheme was implemented at the Fort Knox mill. A portion of this thesis is dedicated to a review of the laboratory program, an evaluation of the environmental impacts and a summary of plant performance, when utilizing lead nitrate at the Fort Knox Mine.
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机译：诺克斯堡矿位于阿拉斯加费尔班克斯东北25英里处，在亚安蒂奇环境下作业。由于工艺浆液温度随空气温度季节性变化，因此矿山提供了一个独特的机会来测量浆液温度对满规模工厂条件下工艺性能的影响。本文分析了一种能量平衡方法，以模拟整个诺克斯堡工厂的矿浆温度的季节性变化。该厂利用重力浓缩和氰化来回收金。建立了模型以准确预测浆料温度对氰化物浸出，碳吸附和氰化物破坏动力学的影响。能量平衡模型与动力学模型相结合，可用于准确预测金的回收率，并随后证明安装尾矿洗涤增稠剂以从工厂尾矿中回收热量是合理的。本文的很大一部分致力于这些模型的开发，扩建后工厂性能的分析以及项目经济学的总结。 Fort Knox矿床中的金通常小于100微米，并且包含在石英脉中以及沿主体花岗岩内的剪切带，平均金品位为0.8 g /公吨。 2001年4月，该工厂开始从卫星矿床True North Mine加工矿石，与Fort Knox矿石混合。 True North矿床的金品位平均为1.5克/公吨，可能与黄铁矿，毒砂和辉辉石有关。加工混合矿石导致金回收率意外下降，这是广泛的实验室评估的主题。实验室结果表明，在加工混合矿石时，粗金颗粒的浸出动力学受到显着影响，并且可以通过添加硝酸铅来减少或消除这种影响。随后，诺克斯堡工厂实施了硝酸铅添加方案。本文的一部分致力于在诺克斯堡矿使用硝酸铅时审查实验室计划，评估环境影响并总结植物性能。
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