Development Of A Centrifugal High-gradient Magnetic Separator And Research On Its Sorting Mechanism

In China there are extremely abundant weakly magnetic ores such as titanium,oxidation of iron ore and tungsten resources,for instance,both titanium and tungsten resources rank first in the world.At present,high gradient magnetic separation is one of the important technologies to utilize these resources.High gradient magnetic separation is mainly suitable for roughing,which create favorable conditions for following up cleaning methods to produce a qualified magnetic product.Our research found,centrifugal separation has the advantage of environmental pollution,and it can effectively separate fine grained and high density mineral,which mainly used to concentrate the rough concentrates after high gradient magnetic separation.In summary,high gradient magnetic field and centrifugal field separation have different characteristics;high gradient magnetic separator has large processing capacity,high efficiency,but poor selectivity;centrifugal separator is suitable for cleaning operation,it has high selectivity in process,but the capacity is too small.Thus,the development of new separation method with compound force field,which based on high gradient magnetic field and centrifugal field,has profound significance and great research value.In order to explore the application of centrifugal high gradient magnetic separation technology,CenMag-100 centrifugal high gradient magnetic separation(CHGMS)separator developed in this paper,and carries out theoretical analysis and experimental verification.This separator mainly consists of magnet,driving device and lifting device,and the magnetic field measurement and theoretical analysis show that:(1)The average magnetic induction is 0.5T,showed a stable and regular distribution.(2)In the process of CHGMS,the magnetic particles are mainly subjected to magnetic force,centrifugal force,fluid resistance and friction,and the minimum critical magnetic force required for the effective capture is written as:(?)The rotation of matrix has good effect on the agitation of ore particle group,which can significantly improve the selectivity of separating process.(4)The rotation of matrix can significantly increase the number of particles passing through the layers of matrix,and improve the collision probability between particles and matrix,thereby significantly improving the recovery rate.(5)For CenMag-100 CHGMS separator,the main factors affecting the separation results are magnetic induction,centrifugal acceleration,matrix diameter and feed slurry flow.CenMag-100 CHGMS separator was used to separate typical weak magnetic minerals in China under the optimum experimental condition,the experimental results are consistent with the theoretical results,and the excellent separation index was obtained.Details are as follows:(1)Xichang Taihe Iron Ore ilmenite in Chongqing.According to its industrial production process(One stage high gradient magnetic separation roughing-one stage scavenging-grinding classification-high gradient magnetic separation)through centrifugal high gradient magnetic separation,it can produce a concentrate assaying 28.30%TiO2 and recovery of 58.76%from the material assaying 9.17%TiO2;under the same magnetic induction,follow this process through laboratory pulsating high gradient magnetic separation(PHGMS),which produced a concentrate assaying 15.82%TiO2 and recovery of 70.76%;and in industrial production separation,it is can produced a concentrate assaying 19.73%TiO2 and recovery of 59.86%,(2)CenMag-100 CHGMS separator was adopted to separate the rough concentrate of ilmenite after one stage high gradient magnetic separation in Panzhihua Iron and Steel Plant,the material assaying 18.93%TiO2,it produced a magnetic product with TiO2 grade approaching 26.92%and the recovery of 89.39%in accordance with its industrial production process(cleaning and scavenging with high gradient magnetic separation),and with the same magnetic induction,the pilot-scale PHGMS process produced a concentrate assaying 31.44%TiO2 and recovery of 64.98%.(3)For the low-grade titanium sand assaying 7.12%TiO2 from Yunnan province,with a primary separation,the titanium concentrate assaying 36.67%TiO2 and recovery of 49.70%(the theoretical separable TiO2 is 62.92%);(4)For the tailing assaying 31.53%Fe of second stage weak magnetic separation in Dahongshan iron ore plant,with a primary separation,the magnetic product with Fe grade of 48.93%at recovery of 53.12%was obtained.After one roughing and one scavenging,it produced a concentrate assaying 48.82%Fe and recovery of 76.31%,the result is better than that of PHGMS process with the same magnetic induction,and similar to industrial process performance on the basis of reducing one cleaning.The results of these experiments show that CenMag100 CHGMS separator has the advantage of high selectivity in concentration for weakly magnetic ore,and it has important guiding significance to simplify the existing production technology.To summarize,centrifugal high gradient magnetic separation technology is advanced and fully proved to be able to effectively separate typical domestic weak magnetic ores,and it has certain directive significance for the development of new technology of short flow process and the efficient utilization of weak magnetic mineral resources.