بررسی فرآیند خود رقیق‌کنی در تیکنرها با استفاده از دینامیک سیالات محاسباتی

تیکنرها از واحدهای کلیدی در کارخانه‌های فرآوری مواد معدنی هستند و برای جداسازی جامد از مایع استفاده می‌شوند. در پژوهش حاضر الگوی اختلاط فازهای پالپ و آب زلال در کانال مخلوط کننده موسوم به ایداک و تاثیر تغییر دبی بر فرآیند رقیق‌سازی قبل از ورود به چاهک خوراک در تیکنرهای مس میدوک با استفاده از دینامیک سیالات محاسباتی بررسی شده است. مطالعه رفتار سیالات با استفاده از مدلسازی معادلات پیوستگی و ناویر- استوکس توسط نسخه 14.5 نرم‌افزار فلوئنت انجام شده است. برای اعمال شرایط جریان آشفته از تابع کتابخانه‌ای k- ϵو برای مطالعه جریان چند فازی از مدل اختلاط استفاده شده است. در این مطالعه رقت ورودی به چاهک خوراک توسط شبیه‌سازی صورت گرفته در شرایط عملیاتی کارخانه با دبی متوسط 605.45 مترمکعب بر ساعت، 19.51 درصد به دست آمده که تخمین قابل قبولی از وضعیت موجود است. در ادامه با تغییر دبی، نحوه اثرگذاری این پارامتر بر رقت پالپ ورودی به چاهک خوراک تعیین شده است. در شرایط افزایش دبی به 700 مترمکعب بر ساعت، میزان رقت به 28.51 درصد افزایش می‌یابد.

Study the Process of Self Dilution in Thickeners by Computational Fluid Dynamics

SummaryThickeners are the critical units in the hydrometallurgical processing operations and are used to separate solids from liquids. In the present study, the mixing pattern of pulp and clear water phases in the mixing duct known as EDUC was calculated through computational fluid dynamics (CFD) and the effect of flow rate changes and solids content of the input feed on dilution before entering the feed well in Midouk copper thickener was studied. The flow rate and solids content of the feed under the operational conditions were 605.45 m3/h and 25%, respectively. Under these operational conditions, dilution of the feed flowing into the feed well was calculated 19.51 using simulations, which was an acceptable estimate of the actual dilution. Then, by changing the flow rate of the feed, the effect of this parameter on dilution of the pulp input to the feed well was determined. By increasing the flow rate to 700 m3/h, dilution levels rose to 28.5, respectively. IntroductionOne of the main methods of dewatering in mineral processing units is to settle the materials in the thickeners. Since studies have shown that reducing the concentration of the inlet pulp to the thickener is effective in improving its performance, often a mechanism has been used to increase the dilution of the inlet pulp, including the selfdilution system of the pulp using the clear water section at the top of the thickener. Given the powerful processors and the many advances that have been made in computational fluid dynamics, it is possible to simulate the performance of these structures in a thickener numerically. Methodology and ApproachesThe dynamic behavior of fluid was studied by modeling the continuity and NavierStokes equations in Fluent version 14.5. The kε library function was used to apply turbulent flow conditions and the mixture model was used to study multiphase flows. Results and ConclusionsThe simulation of the plant operating conditions by the model showed that due to the pressure drop around the nozzle, water enters the EDUC channel. The dilution of pulp increases as a result of mixing the two phases of the pulp and water before entering the feed well. The result is in excellent compliance with the conditions in the thickener, which may indicate the accuracy of the obtained model. The simulation showed that with increasing the inlet feed flow, the dilution of the inlet pulp raised more than the current situation.