Abstract:

The iron grade of raw ore from a concentrator in Anhui is 20.65%，the sulfur content of

harmful elements is 3.80%，and the phosphorus content is 0.21%. The distribution rate of magnetite，the

main iron-bearing mineral in the raw ore，is 63.13%. It also contains a small amount of pyrite and iron car⁃

bonate. In order to improve the grade of the abrasive，reduce the selection ratio and the operation cost of the

plant，the pre-discarding test was carried out on the finely crushed products of the plant. The results show

that the optimal process parameters for the discarding of fine products (-16 mm) by dry magnetic separation

are as follows: the magnetic field strength is 278.66 kA/m，the separation plate distance is 22 cm，and the

belt line speed is 2.0 m/s.Under these conditions，the total iron grade of concentrate is 22.58%，the tailings

yield is 24.42%，and the magnetic iron content in the tailings is 2.92%. By simulating the production status，

the dry rough concentrate was rolled to -5 mm to carry out the tailings discarding test of wet coarse magnetic

separation. The test results show that after the tailings discarding of dry concentrate by wet magnetic separa⁃

tion，the grinding grade can be increased to 29.77%，and the abrasive grade can be significantly improved.

The test results can provide technical basis for process transformation.

Key words:

finely crushing, dry magnetic separation, pre-disposal, magnetic field intensity