Titanium Magnetite Formation Mechanism Of Magnetic Behavior And Flux

The researches and advances in titanomagnetite at home and abroad are reviewed.it introduces,in detail,the researches of titanomagnetite resource in Panzhihua-Xichang mining area.In view of the different magnetic characteristics of coarse and fine fractions of titanomagnetite,the new craft that coarse and fine fractions should been separated in different type of magnetic separators is proposed which thoroughly solves the problem of low concentrate iron grade of Panzhihua Midi plant,the concentrate grade exceeds 54% with the recovery of 74%.In the same time,the model of a single particle and the model of magnetic chain made of magnetic particles have been established according to the different magnetic separation behavior of particles size-by-size.It well explains the influence of magnetic agglomerates to the concentrate grade and recovery of magnetic separation using the magnetic chain model.The new craft and the novel theory of which the coarse and fine fractions should been separated in different type of magnetic separators have been proposed and proved for the first time.The main work and conclusions are as follows:Ⅰ,Systematic studies on the magnetic separation behavior of the titanomagnetite.1.Results of the experimental studies on the magnetic separation behavior of particles size-by-size show that the middle coarse particles(-0.10+0.045mm)are easy to process by the magnetic separation,but the coarse particles(-0.40+0.25mm)and the fine particles (-0.045mm)are difficulty to process.Because the conditions adapted to magnetic separation of particles size-by-size are different obviously,if the material is being separated without classification,it is very difficult to satisfy the magnetic separation conditions of particles of different sizes,also is impossible to achieve the highest grade and recovery of magnetic separation concentrate,therefore,the concentrate grade and recovery of the fine fraction(-0.045mm)of titanomagnetite with magnetic separation increase along with the enhancement of the magnetic field strength,which is the one of the most important discoveries in the experimental study.2.Results of the experimental studies on the behavior of magnetic separation without classification show that fineness of grind is the key factor that restricts the grade and recovery of magnetic separation concentrate,the concentrate grade could achieve a breakthrough to 55%with recovery of 72.21%by reducing the fineness of grind without classification.However,the concentrate grade could be improved not very obviously by changing of the magnetic field strength and rotational speed of drum that could not make the concentrate grade achieved a breakthrough to 54%.Therefore,it is the key method to enhance the grade and recovery of concentrate by reducing the fineness of grind without classification.3.The results of experimental studies on the different magnetic separation behaviors of the coarse and fine fractions show that the magnetic field strength is the key factor affected the concentrate grade and recovery of fine fractions,moreover,which including period of time detained in slurry and shearing force and rotational speed of the magnetic drum are all important factors to improve the concentrate grade and recovery.The desirable concentrate: the grade of -0.074mm fraction is 54.82%with recovery of 71.68%,the grade of -0.045mm fraction is 54.47%with the recovery of 72.21%,the grade of +0.074mm fraction is 52.63% with recovery of 75.63%,the grade of +0.045mm fraction is 53.96%with the recovery of 74.88%.While the key factor that affects the grade and recovery of magnetic separation concentrate of the coarse fractions is the fineness of grind,If the two coarse fractions (+0.074mm and +0.045mm)should be reground to fineness as small as 0.15mm,then the final concentrate grade and recovery could achieve a breakthrough that the concentrate grade exceeds 55%with the recovery of 75%.4.In view of the experimental studies on the magnetic separation behavior of particles size-by-size and the different magnetic separation behaviors of the coarse and fine fractions, we can obtain the conclusion as follows:if the coarse and fine fractions be processed individually and the fine fractions be processed in the transformed magnetic separator,the desirable concentrate could achieved with the grade of 54.12%and the recovery of 74.06%. If the coarse fraction would be reground as small as 0.15mm and the fine fraction would be separated using the transformed magnetic separator,the iron concentrate grade could achieve to 55.26%with recovery of 75.40%.Therefore,regardless of regrinding or not,the concentrate grade and recovery of magnetic separation achieved by the coarse and fine fractions being processed separately is better than the concentrate grade and recovery achieved without classification.Ⅱ,Establishment and using in theoretical calculation of magnetic chain model of titanomagnetite particles.1.Model of a magnetic particle's movement in magnetic field of magnetic separator has been represented.According to the analysis of forces on a particle and movement if it is in the magnetic field of theφ1050mm×3000mm magnetic separators in Panzhihua Midi plant,Magnetic characteristics and widest gap of the magnetic field that particles of different sizes needed have been calculated in detail,the conclusion was drawn out that the magnetic separator on the plot couldn't suit the separation of fine fraction(as small as 0.12mm)of titanomagnetite.2.Magnetic chain model on the foundation of magnetic dipole model is proposed and proved.Through detailed calculation and analysis of the characteristics of the magnetic field formed by a titanomagnetite particle and magnetic action energy and force between magnetic particles in slurry,we can obtain that the magnetic action force between the particles is far stronger than magnetic force,gravity and fluid resistance,which is direct propelling force in the formation of magnetic chain.The results of analysis on formation mechanism of magnetic chain show that magnetic chains are formed with the coarse particles as the center instantaneously as soon as the particles enter the magnetic field,the magnetic unions may be formed with magnetic wraps primarily as the particles' size is different very much or may be formed with magnetic chains primarily as the particles' size is similar.Because the magnetic chain opposite to the magnetic wrap is easier to destroy by shear force,it is easier to discharge the non-magnetic mixture in order to improve the grade of concentrate.The magnetic chain model not only explains the universal phenomenon of magnetic unions,but also provides the theory support for the scenes that many problems caused by magnetic unions can solve and then the development and manufacture of the new type of magnetic separator.3.Magnetic chain model application in the theoretical calculation of titanomagnetite.The relation obtained with theoretical analysis of magnetic chain model of the iron recovery and particle sizes shows that the magnetic separators on the plot could only satisfy the separation of coarse particle as big as 0.045mm,but it could not get the desirable grade and recovery of concentrate if the particle size as small as 0.045mm without the advanced type magnetic separator.The conclusion has been confirmed thoroughly in the experimental studies on fine fractions.In summary,the article proposes a novel magnetic separation craft that is the coarse and fine fractions processed separately.The craft not only could solve the difficult problem of the Panzhihua Iron and Steel Co.that the iron concentrate grade is low and enhance the concentrate recovery,but also it is very advantageous to recycle the other useful elements in material.Moreover,the magnetic chain model on the foundation of magnetic dipole model is presented and proved which not only well explains the phenomenon of the magnetic agglomerates to the concentrate grade and recovery of magnetic separation using the magnetic chain model and gets the conclusion that the magnetic agglomerates is formed more easily by fine fraction than by coarse fraction.Therefore,the fine fraction should be processed separately which could be named coarse and fine fractions be processed separately.So,it provides the theory support for that the coarse and free fractions are processed separately.