برآورد قابليت جريان سنگ ‌آهن و باطله در منطقه تخريب معدن زيرزميني آنومالي 12 سه چاهون

Estimation of Gravity Flowability of Ore and Waste in Caved Zone of Anomaly No. XII of Sechahoon Underground Mine

جريان ثقلي در معادن زيرزميني تخريبي به دليل اثرگذاري آن بر اختلاط و بازيابي داراي اهميت به سزايي است. از اين‌رو ارزيابي و بررسي آن به روش‌هاي مختلف تا كنون به انجام رسيده است. در اين پژوهش قابليت جريان ثقلي ماده معدني و باطله در آنومالي شماره 12 سه چاهون با استفاده از مدلسازي فيزيكي برآورد شده است. به اين منظور ابتدا ابعاد طراحي مورد مطالعاتي انتخاب و بر اساس آن با مقياس 1:10، مدل فيزيكي سه بعدي ساخته شده است. مدل فيزيكي با استفاده از ماده معدني و باطله دانه بندي شده ايجاد شده است. انجام آزمايش روي مدل در ابتدا با مشخص كردن زاويه قرار ماده معدني و باطله و عمق برداشت آغاز و با به دست آمدن عمق برداشت برابر با 11 سانتي متر، فرايند مدلسازي جريان انجام گرفت. نتايج مدلسازي نشان داد كه ميزان بازيابي برابر با 63 درصد است و عمده مواد خروجي در دسته خوب و قابل قبول قرار مي‌گيرد. همچنين با استفاده از روش المان مجزا، مدلسازي عددي جريان انجام گرفت كه با توجه به اعتبارسنجي انجام شده، مي توان از آن مدل براي مدلسازي‌هاي ديگر بهره برد.

Gravity flow in caving underground mining is a key parameter that effects on dilution and ore recovery. In order to have a successful operation in caving mining, it is necessary to evaluate and estimate the gravity flowability of ore and waste. From past to now, several researchers focused on study of gravity flow by different methods like mathematical, physical and numerical methods. In this study, the gravity flowability of ore and waste in caved zone of Sechahoon Anomaly No. XII was estimated by physical modeling. Then by using DEM modeling, a model based on physical model was created to use for future studies. Introduction In recent studies, sublevel caving method was selected for Sechahoon Anomaly No. XII. In sublevel caving method, we encounter with key parameters like cavability, gravity flow, blastability and subsidence. Therefore, gravity flow study is an important parameter that should be estimated. Gravity flow is studied by several researchers from past to now. These studies carried out by different methods like mathematical, physical and numerical methods. Methodology and Approaches In this study, the physical method was selected for gravity flow modeling. Therefore, a model was designed by a 1:10 scaled, tunnel width, ring height, burden and tunnel height equal to 50, 150, 20 and 40 cm, respectively. The model was filled by iron ore and waste that have a size distribution between 0 to 25 mm. Results and Conclusions The physical modeling results shows that: • Recovery of iron ore is equal to 63 percent. • The angle of repose of iron ore and waste are 43 and 38 degree, respectively. • The shape of gravity flow is similar to common model that presents the validity of model. • Digging depth is equal to 11 cm. • Based on Kvapil suggestion, 48 percent of ore was classified as class A and 20 percent as class B. By using the results of physical modeling, a numerical model is created and validated with physical modeling results in order to avoid from physical modeling problems and use for future studies that are useful in gravity flow studies.