【摘要】：在選礦的浮選工藝中大型礦漿調漿攪拌槽調節(jié)著礦漿和藥劑的快速、均勻混合,為浮選提供良好的條件,是浮選工藝必不可少的調漿攪拌設備。礦漿攪拌效果不僅與攪拌葉輪密切相關,還與攪拌葉輪的工作環(huán)境(即流體介質的種類)、攪拌槽結構和附件等裝置有關�，F階段對礦漿攪拌效果的影響有很多研究,但對擋板附件形狀結構、安裝方式的研究較少。豎直擋板攪拌槽已作為一種經典的攪拌設備,而對傾斜擋板等特殊擋板結構研究相對較少。利用計算流體力學(CFD)理論和計算技術可以獲得攪拌槽內宏觀流動和微觀湍流特性的詳細信息,使得采用CFD方法對過程設備進行模擬設計、放大和優(yōu)化成為可能,能夠預測槽內不同操作條件下和不同構型的流體動力學特性,通用性良好。本文利用CFD有限元計算方法中的多重參考坐標系法(MRF)對攪拌槽內的流場進行模擬,從擋板形狀結構、安裝方式、葉輪轉速等多因素對攪拌槽內的多相流流場進行分析,旨在改進擋板結構設計,改善流場分布特性,以增強葉輪的剪切性能,避免導致攪拌渦流,促進礦漿顆粒充分混合。通過仿真表明:在攪拌過程中葉輪周圍流體會形成兩個旋轉相反的渦流,促進礦漿整體循環(huán),葉輪周圍礦漿攪拌劇烈,葉輪邊緣流速最大。前傾直擋板比標準直擋板結構對多相流攪拌更有利;采用前傾直擋板結構攪拌后的理想混合區(qū)(濃度58%~62%)比例最高,當其前傾角為45°時理想混合區(qū)比例高達到88.48%,達到最優(yōu)攪拌效果。在攪拌槽結構尺寸、礦漿濃度等相同的條件下,葉輪轉速為30~35r/min時礦漿攪拌理想混合區(qū)(濃度58%~62%)比例較高,達到最優(yōu)攪拌效果。礦漿粘度在0.003~0.015kg·s/m2理想礦漿濃度隨著礦漿粘度的升高而升高;粘度在0.015~0.020kg·s/m2時理想礦漿濃度隨著礦漿粘度的升高略微降低。
[Abstract]:In the flotation process of mineral processing, the large slurry mixing tank adjusts the rapid and uniform mixing of pulp and reagent, which provides good conditions for floatation and is an indispensable slurry mixing equipment in flotation process. The mixing effect of slurry is not only closely related to the stirring impeller, but also related to the working environment of the stirring impeller (that is, the type of fluid medium), the structure of the mixing tank and the accessories. At present, there are a lot of studies on the effect of pulp mixing, but there are few studies on the shape and structure of baffle accessories and installation methods. Vertical baffle mixing tank has been used as a classical mixing equipment, but the research on special baffle structure such as inclined baffle is relatively few. The detailed information of macro-flow and micro-turbulence characteristics in stirred tank can be obtained by using computational fluid dynamics (CFD) theory and computational technology, which makes it possible to use CFD method to simulate and design the process equipment, amplify and optimize the process equipment, and can predict the hydrodynamic characteristics of different operating conditions and different configurations in the tank, and has good generality. In this paper, the multi-reference coordinate system method (MRF) in CFD finite element method is used to simulate the flow field in the stirred tank. The multiphase flow field in the stirred tank is analyzed from the shape and structure of the baffle, installation mode, impeller speed and so on. The purpose of this paper is to improve the baffle structure design, improve the flow field distribution characteristics, in order to enhance the shear performance of the impeller, avoid causing mixing vortex, and promote the full mixing of slurry particles. The simulation results show that during the stirring process, the fluid around the impeller will form two rotating vortex currents, which will promote the overall circulation of the pulp, the slurry around the impeller will stir violently, and the velocity at the edge of the impeller will be the largest. The forward tilting straight baffle is more beneficial to multiphase flow stirring than the standard straight baffle structure, and the ideal mixing zone (concentration 58% 鈮，

本文編號：2497924