Study On Combined Rod Media With High Gradient Magnetic Separation Process

Rod matrix, as carrier for magnetic particles in pulsating high gradient magnetic separators (PHGMS), is effectively applied to separate fine weakly magnetic particles in PHGMS, due to its reliable operation, simple combination, resistance to mechanical entrainment, stabilization of separation index and high efficiency. They are now used to beneficiate oxidized iron ores, ilmenite, manganese and wolframite, etc., and to purify non-metallic ores, to purify wastewater. The single-diameter of matrix has a high collecting capability to capture narrow size particles, but is not effective in capturing the other particle size fractions in the material. Combinative rod matrix of different rod elements is investigated that combinative rod matrix increases size-by-size recovery of concentrate and improves separation performance on PHGMS.In the investigation, the matching theory of magnetic field gradient and the theory of magnetic capture radius are used to design combinative rod matrix, to study the effect of combinative rod matrix on the separation performance of the separator with typical fine hematite, by Slice Matrix-Analysis method (SAM). In the method, the matrix is artificially considered to consist of a number of slice matrices, so that the magnetic capture of rod elements to magnetic particles is visible and measurable while the matrix is detached.The experimental investigations indicate that,2/3mm combinative rod matrix improves iron concentrate grade, but decreases iron recovery compared with the single diameter rod matrix;3/2mm combinative rod matrix improves iron recovery, which is higher10.96%, but iron concentrate grade lower about4.34%Fe, compared with2/3mm combinative rod matrix. Also,3/2mm combinative rod matrix achieves a higher iron recovery than those of the2and3mm single diameter rod matrix; apparently, this is resulted from the improved size-by-size recovery of+0.037mm and-0.037mm. Meanwhile, it is a general trend that the different fraction of wide size feed can be captured synchronously by the combinative rod matrix. At the same time, it is found that with the small diameter rod elements improves, the capture area of particles with matrix increases, it has a mainly influence to the recovery of-0.037mm particles.3/1.5mm combinative rod matrix achieves a higher concentrate weight than3/2mm combinative rod matrix in the same filling ratio. Becanse the magnetic force of1.5mm rod element is stronger than2mm rod elment to the magnetic particles.It is therefore concluded that the use of a combinative rod matrix, corresponding to characteristics of material, improves the separation performance of pulsating high gradient magnetic separation, and it is beneficial to optimization design of rod matrix on high gradient magnetic separator, both on the theory and practice.