عنوان مقاله [English]
Based on a central composite design (CCD), the effect of operational factors as flow rate, froth depth, slurry solids percent, frother/collector dosage, and pH were considered on the flotation column performance in desulfurization process from iron concentrate. Sulfur, total Fe contents, and d80 of the sample were found to be 0.48%, 63.3%, and 90µm, respectively. Based on the results of ANOVA, the optimum values of column operation parameters were 150 gr/t of PAX, 200 gr/t of MIBC, 20 cm froth depth, 1.6 cm/s of airflow rate, pH of 4.9 and a solid concentration of 30%. In optimum conditions, sulfur grade and iron recovery were equal to 0.08% and 98%, respectively.
Column cells in comparison to mechanical cells are used in iron processing to decrease impurities to produce pellets. Column flotation depends on some operating parameters which are effective on mineral processing performance. This study presents an experimental program performed to study the effects of flotation column variables including gas flow rate, froth depth, slurry solids percent, frother/collector dosage, and pH on desulfurization of an iron ore concentrate.
Methodology and Approaches
The iron ore sample employed in this study was supplied from magnetic separators concentrate in a hematite concentrate plant from the Gole-Gohar iron ore complex. The feed sample consisted of 63.3% Fe with a significant amount of sulfur which is equal to 0.48%. Overall, 45 runs were selected to be performed based on a central composite design (CCD) proposed by Statistica software. The commercial software Design Expert version 18.0 was used for the work. The parameters varied were the airflow rate, pH, reagent dosages, pulp density, and froth height. The main and interaction effects of the flotation column variables on the solid and water recovery and concentration and tailing sulfur grades during the desulfurization of iron ore were analyzed using an ANOVA model.
Results and Conclusions
Based on the results of ANOVA, optimum values of column operation parameters were 150 gr/t of PAX, 200 gr/t of MIBC, 20 cm froth depth, 1.6 cm/s of airflow rate, pH of 4.9 and a solid concentration of 30%. By applying operational optimum conditions at a significant level of 95%, concentrate and tailing sulfur grades were equal to 0.08%, 34%, respectively. Results in optimal conditions indicated that column flotation was considerably more efficient than mechanical flotation for iron ore desulfurization with the iron recovery of 98%.
فلوتاسیون یکی از روشهای مؤثر در بازیابی کانیهای با ارزش در ابعاد دانهریز است که بر مبنای خواص شیمی فیزیکی سطوح ذرات جامد در یک محیط سیال شامل حبابهای هوا، بنا شده است. با توجه به نوع ماشین فلوتاسیون و سیستمهای حبابساز، عوامل کنترلی و فرآیندی متعددی در افزایش کارآیی عملیات نقش دارند. این عوامل مانند دور همزن، ارتفاع کف، میزان هوا و ... با استفاده از روشهای مختلف قابل اندازهگیری و کنترل هستند. میزان بهینه این عوامل در کارکرد مؤثر فلوتاسیون نقش بسزایی دارند.