Iron mineral recovery in iron tailings - Kunming Steel Shangchang Iron Ore Concentrator

Currently the plant Iron Mine tailings are piled nearly 10 million tons of tailings, iron content greater than 20%, the loss of huge amounts of iron metals. The useful minerals in the tailings are mainly composed of hematite and limonite, and a small amount of magnetite, iron carbonate, iron sulfide and iron silicate. In addition, the tailings have a large amount of slime. The multi-element analysis of tailings, the chemical phase analysis of iron and the mineral composition of tailings and their monomer dissociation are shown in Table 1 and Table 2, respectively.

Table 1 Multi-element analysis of tailings (%)

Table 2 Results of chemical phase analysis of iron (%)

3 Determination of main mineral content and dissociation degree in tailings (%)

In order to recover the iron minerals in the tailings, Shangtie Iron Mine installed three Slon-1500 vertical ring pulsating high gradient magnetic separators in its washing workshop in May 1999 for tailings re-election, and in 1999 It was put into production in July for industrial production trials. The production process is shown in Figure 1.

Figure 1 Production process

The original production process of the Shangtie Iron Mine Test Washing Workshop (handling the trestle ore) is washed by a two-stage tank washing machine to separate the slime. +2mm returning sand is classified by vibrating screen, +11mm enters large grain jig; -11mm passes φ1200mm single spiral classifier, overflow is discarded, returning sand is classified by small vibrating screen, -6mm enters CS-1 induction roller type strong magnetic separator Rough selection, one sweep selection; +6mm into the CS-2 induction roller type strong magnetic separator for rough selection and one sweep. The overflow of a tank washing machine (-2mm) enters the φ1500mm double spiral classifier, and the overflow is discarded. The sand is returned to the φ1200mm single spiral classifier, overflowed and discarded, and returned to the fine grain jig. Now the production process of Slon-1500 vertical ring pulsation high gradient magnetic separator is the overflow of φ1500mm double spiral classifier overflow and φ1200mm single spiral classifier in the original production process of washing workshop. After removing some mud by φ15m thickener, it is fed. Slon-1500 vertical ring pulsating high gradient magnetic separator.

Operating conditions: rough stroke 16mm, select 20mm; pulsation rough selection 220 times / min, select 270 times / min; background field strength rough selection 0.94T, select 0.74T.

The production test results show that for the ore with about 22% Fe, the Slon-1500 vertical ring pulsation high gradient magnetic separator is selected once, and one selected full magnetic separation process can be selected to obtain more than 55% of the iron concentrate grade. The concentrate yield is over 13%, the recovery rate is over 34%, and the economic benefits are considerable.