دانلود ترجمه مقاله کاربرد کوکریجینگ در برآورد رطوبت در یک توده معدنی

فهرست مطالب:

چکیده
مقدمه
منطقه ی مورد مطالعه
تئوری
ژئواستاتیک
کوکریجینگ
مقاومت الکتریکی
روش مطالعه ی ژئوفیزیکی و نتایج

بخشی از ترجمه:

یک توده ی سنگی برای کاربرد بالقوه ی ریکاوری یا بازیابی ثانویه مطالع شد. روش های تعیین و مطالعه شامل داده های سخت از حفاری و داده های ژئوفیزیکی نرم از مقاومت الکتریکی بودند. نمونه های مربوط به حفاری در فواصل ۱٫۵ متر ارتفاعی از ۲۹ مکان چاهی حاصل شدند اما چاه ها فاصله ی خیلی زیادی از هم داشتند تا به این طریق بتوان یک تفکیک پذیری جانبی کافی حاصل کرد. داده های مقاومت در امتداد ۱۲ لاین خط موازی با طول ۴۰۰ متر حاصل شدند و سپس در ۳ بعد تحت مدل سازی معکوس قرار گرفتند.روش کوکریجینگ به عنوان مکمل داده های رطوبت اندازه گیری شده با مقاومت الکتریکی برای تولید نقشه ای از نقاط خشک بالقوه درون توده استفاده شدند.

نتایج کوکریجینگ مزیت های زیادی را نسبت به کریجینگ داده های رطوبت به تنهایی و رگرسیون حداقل مربعات در برابر اسکاتر پلات رطوبت اندازه گیری های هم مختصات نشان داد.طول همبستگی شاخص های اندازه گیری رطوبت کوتاه تر از فاصله ی میانگین چاه ها بود.که باعث شد تا رطوبت کریج شده در دور از نقاط نمونه برداری نسبتا همگن شود. تقریبا درفاصله ی ۴۰ متری از چاه ها رطوبت براورد شده به مقدار میانگین داده های نمونه برداری شده رسید این خود باعث شد تا رطوبت کریج شده در حول چاه ها توزیع یکنواختی به خود بگیرد روش کوکریجینگ میانگین را برای درون یابی های بین چاهی در اختیار گذاشت.

بخشی از مقاله انگلیسی:

INTRODUCTION Modern mining relies on the heap leaching process to extract metal from rock
e.g., Burkin, 2001; Han, 2002. Heap leaching is a method of applying a dilute aqueous ionic solution to the surface of a pile of prepared ore
Juvonen and Kontas, 1999. Ore preparation can include crushing, agglomeration, or run-of-mine
ROM, depending on the geology and amount of fine-grained material. The leachate is allowed to percolate through the pile to solubilize and mobilize the metal
Crundwell and Godorr, 1997; De Andrade Lima and Hodouin, 2005;Bouffard and Dixon, 2007, and the leaching solution is either acidic or basic, depending on the metal. A basic sodium cyanide solution, for example, is used to extract gold by forming aurocyanide
Habashi, 1966; Marsden and House, 1992. Gold extraction can be enhanced also by pretreatment with biological agents or through roasting
Iglesias and Carranza, 1994. Beneath the heap, a liner and drainage pipe network collects the pregnant leach solution
PLS for final processing, including solvent extraction and electrowinning. The application rate of leaching solution to the surface of a heap is approximately 5 to 15 L/h per square meter of surface area, and effective leaching of the ore is impacted greatly by the types of geologic materials used in the construction, how they were placed, and the degree of fines. In general, heaps are large heterogeneous rock piles of differing geologic media taken from various parts of an open pit
see Kennedy, 1990. The heap at the Round Mountain Mine in central Nevada, for example, spans approximately 1600 m by 800 m and is more than 150 m tall, with gold occurring in tuff, limestone, and quaternary alluvium
Mills, 1985. These different types of deposits have their own grain-size distribution and controlling factors for lixiviant flow. Manuscr Ineffective leaching within the heap typically is the result of factors that can include the tendency of finer-grained material to compact into confining zones, wetting front instability, and channeling along “fractures” of well-sorted, coarse-grained material
Kunkel and Arnold, 2008. The creation of confining zones, for example, causes pooling and shading. The pooling of lixiviant occurs when solution accumulates above the confining zone, where the hydraulic conductivity of the zone is sufficiently low that percolation through the zone occurs at very large time scales. The pooling then causes additional water to cascade around the confining zone and create a shading effect immediately below. The shaded region remains relatively dry, reducing the total volume of leached ore. Large confining zones therefore reduce the total effectiveness of the heap and leave large metal inventories in place. Targeting the dry zones with a secondary leaching application, such as Hydro-Jex
Seal, 2004, 2007, increases the yield and effi- ciency of a heap. The secondary leaching process consists of drilling and casing holes within a heap, perforating the casing at specific depth intervals, and injecting leachate at high pressures within each depth interval using a straddle packer. The challenge then becomes the characterization of the heap and effective well siting. Given the cost of well drilling and assaying, indiscriminate well placement could absorb the additional profit gained through secondary recovery. Heap characterization can be conducted through direct and indirect means. Direct characterization includes hard information obtained from assay results during drilling. Indirect characterization can include inexpensive geophysical surveys, and the mining industry has relied traditionally on geophysics, primarily for the initial exploration of mineral resources. Geophysics, however, can be applied to near-surface problems to understand more fully the distribution of resources and moisture in an engineered earth. Examples of geophysics applied to engineered structures include levees
Asch et al., 2008, dams
Osazuwa and Chinedu, 2008, and foundations
Dong et al., 2008. The geophysical data usually are considered soft, as unique relationships between the geophysical property and the desired heap property
water content, gold concentration, and so on are rare. Many competing factors can give rise to similar values of the measured geophysical property, and it is necessary to combine the hard and soft data to form a complete conceptual model of the subsurface. In this study, we present a method of combining hard assay data and soft geophysical data for characterizing an active heap using geostatistics. The assay data include gravimetric water content
mass-based moisture content as defined in Topp and Ferré, ۲۰۰۲, and the geophysical data include electrical resistivity, acquired along transects on the surface of the heap and inverse modeled using a 3D resistivity code. This study follows an approach similar to Parks and Bentley
۱۹۹۶, whereby several geostatistical methods are tested and compared, including kriging of the assay data alone, least-squares regression
LSR of the assay and resistivity data, and cokriging of the assay and resistivity data. Although geophysical characterization of waste rock piles is shown in the literature
e.g., Campos et al., 2003; Gloaguen et al., 2007; Poisson et al., 2009, this study explores an active heap to help increase gold production by providing the means for better well siting for secondary recovery methods.