Short-Term Linear Production scheduling for Mineral Reserves with Severe Geological Variability

Document Type : Research Article

Authors

1 Mining and Metallurgical Engineering Department, Yazd University

2 Ph.D. Student at Yazd University

3 Yazd university

Abstract

The characteristics of fire clay soil mines are their High Geologic Variable Reserves. This article presents a model for scheduling such mines. The objective function is defined by minimizing costs. For the first time, constraints were added to the model to explore new minerals. Slope constraints were also defined by cost. To execute the model, one of the working face in the mine was considered. Standard scheduling model was used to evaluate the validity of the obtained results and the material layers were considered as hypothetical blocks. These models were solved for 8 time periods (weeks) by CPLEX software. The results showed that the assumed model was able to reduce costs by 4% compared to the standard model. Extract rate increased by 18.5% and transferring to stockpile by 17% compared to standard model. But the rate of material reclaiming from the stockpile was 90% lower than the standard model. The results of the sensitivity analysis of the parameters also showed that the extraction cost per ton of minerals is currently at a turning point in the graph. The cost of transporting each ton of minerals to the stockpiles has two minimum points, which is currently at the local minimum. Mining costs were not sensitive to the cost of reclaiming. Slope creating costs are not optimal in the second bench of the mine, and with a bit of optimization these costs can reduce overall mine costs. The costs of developing slopes in the third and fourth levels also follow a rational procedure, and as these costs increase, overall mine costs also increase.

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Full Text

عملیات معدنکاری به‌صورت معمول مبتنی بر مدل بلوکی حاصل از عملیات اکتشاف و مدل‌سازی ذخیره است. ازاین‌رو مدل کانسار آرایه‌ای سه‌بعدی از بلوک‌های منظم است که هر بلوک مفهوم یک واحد را برای معدنکاری دارد. مشخصات هر بلوک به‌منظور تنظیم عملیات مورداستفاده قرار می‌گیرد. مجموعه بلوک‌ها در سه بعد، ورودی فرآیند برنامه‌ریزی تولید را تشکیل می‌دهد. به‌منظور عملکرد صحیح یک معدن، معدنکاری بلوک‌ها باید در زمان صحیح، کارآمد و سودآور صورت گیرد. برنامه‌ریزی تولید معدن روباز به معنی استخراج توالی مواد معدن به سودآورترین شکل ممکن است، به‌نحوی‌که محدودیت‌های فیزیکی و عملیاتی نیز برآورده شوند.

بلوک‌ها به دودسته تقسیم‌بندی می‌شوند: بلوک‌های ماده معدنی که می‌توان آن‌ها را به نحو سودآوری استخراج و فرآوری نمود؛ و بلوک‌های باطله که شامل باقی بلوک‌ها خواهد بود. ارزش اقتصادی هر بلوک به معنای سود خالص حاصل از آن بلوک است. فرایند برنامه‌ریزی تولید در هر دوره زمانی مبتنی بر مجموعه‌ای از بلوک‌ها است که با استخراج آن‌ها، ارزش خالص فعلی معدنکاری در انتهای عمر معدن بیشینه می‌شود؛ بنابراین می‌توان گفت که مسئله برنامه‌ریزی تولید به دنبال انتخاب بلوک‌هایی برای استخراج، در دوره‌های زمانی مشخص استخراج آن‌ها و گزینه‌های فراوری آن‌ها، در عین برآورده کردن محدودیت‌های توالی در میان بلوک‌ها است. این فرایند باید بر اساس محدودیت‌های منابع عملیاتی و بیشینه و/یا کمینه بودن عیار مجاز ماده معدنی یا آلاینده‌ها انجام می‌شود، به‌نحوی‌که ارزش خالص فعلی بیشینه شود [1].

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Journal of Analytical and Numerical Methods in Mining Engineering
Volume 11, Issue 27
July 2021
Pages 67-77

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History

  • Receive Date: 25 September 2019
  • Revise Date: 12 August 2020
  • Accept Date: 12 August 2020

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