Study Of Hydrocyclone Substituted For Spiral Classifier And Its Turbulent Field Numerical Simulation

Hydrocyclone is a classification and separation equipment which is widely used to the liquid and non-homogeneous compound. Compared with gravity classification and separation equipment , hydrocyclone relying on centrifugal force displays a number of outstanding merits such as simple structure, occupying little area, investing little money, low cost operation, easy installation and manipulation. And hydrocyclone is propitious to the classification and separation of the solid phase grains for the higher cutting force pruduced in the hydrocyclone will effectively destroy the reunite force between the grains. And hydrocyclone has a widely use, it can not only use to the classification , separation and elutriate of the solid phase grains ,but also use to liquid classification, gas and sand removed in the liquid, non-dissolution liquid separation.Hydrocyclone has been applied and pratised in our mineral processing plant for many years, and anciently it was mainly used to the classification, pulpconcentration, desliming and dewatering of granule materiel, and separation equipment in the primary grinding phase is the spiral classifier. While the new big mineral processing plants which adhibit overseas technics are prevalently adopted hydrocyclone as the separation equipment at single-stage grinding, for hydrocyclone has used widely abroad at single-stage grinding and can see little of spiral classifier..The key problem of hydrocyclone used at single-stage grinding is that the Grinding mill discharge granularity is very uneven and the content of bold grains is high ,even mill discharge contains some broken steel balls..As a result, Hydrocyclone, pump , pipe are seriously abrased and jammed. Because of the appearance of the high quality abrasion-resistant material, abrasion is not a big problem but jam. The new big mineral processing plant which adhibit overseas technics solve the jam problem through the elimination mineral dregs system, setting after the mill discharge flowsheet, which get rid of bold grains and broken steel balls and then return it to the grinding mill.For the old mineral processing plant., the most diffcult problem of hydrocyclone substituted for spiral classifier is that there is no room for the elimination mineral dregs. With this problem, we cooperated with PANZHIHUA and JIUQUAN mineral processing plants to study the feasibility of hydrocyclone substituted for spiral classifier without elimination mineral dregs system.The result of experiment in the PANZHIHUA and JIUQUAN mineralprocessing plants demonstrates that:(l)industry experiment and pratice Shows that hydrocyclone can substitute for spiral classifier in the old mineral processing plant at single-stage grinding operation without elimination mineral dregs system and reconstruction to the grate discharge ball mill. After hydrocyclone substituted for spiral classifier, it could not only make a large room for other technology improvements, but also greatly abate the maintain work of the classification operation and reduce production cost.(2)classification effectiveness of hydrocyclone is fully concerned with grindability of the ore.(3)For the easy grinded and low hardness ore, the content of regular size fraction in the ball milling discharge is high. As soon as hydrocyclone substituted for spiral classifier, it shows high classification efficiency and outstanding alteration effect which improve grinding technology target.(4)For the hard grinded and high hardness ore, the content of regular size fraction in the ball milling discharge is low, the fluctuant feeding condition will influence classification effect of hydrocyclone so as to the fluctuation of overflow granularity. Therefore, the simple controlled classification device which get rid of a small amount of bold grains in the overflow of the hydrocyclone is necessary.The real close numerical simulation of large solid-liquid hydrocyclone has great value to confirm the advisable technology parameter, solve classification technics and its design, study theory and develop new type of hydrocyclone.