Production of hematite concentrate from hematite-magnetite ore

Abstract

The main useful minerals in composition of hematite-magnetite ore are magnetite and hematite. Magnetite is extracted by wet magnetic separation in weak magnetic field with production of magnetite concentrate and nonmagnetic product. The nonmagnetic product is a feed of the processing circuit for hematite. It is difficult to produce concentrate with iron content of 58-60 mass % if hematite grains are smaller than 0.05 mm. For hematite concentrate production from finely disseminated hematite-magnetite ore, the magnetic-gravitation and magnetic- flotation circuits are designed. This article discusses the magnetic-gravitational separation circuit for hematite grains smaller than 0.05 mm. The first stage of this circuit is fine screening intended to remove large particles. The second stage is high-gradient magnetic separation. The high-gradient separator performance depends on the mineral composition of initial ore and on the rate of mineral dissociation. In finely disseminated hematite-magnetite ore, the associate minerals are mainly represented by quart and amphiboles. Magnetic properties of hematite and amphiboles are similar. For this reason, the high-gradient magnetic separation product contained hematite, amphiboles and quartz-magnetic accretions. The iron content of the magnetic product was 28.9 %. Thus, additional treatment is required, and separation by gravity is applicable in this case. The gravitational separation was carried out on centrifugal concentrator, jigging machine, spiral separator and sluice, and on concentration table. The best results are obtained on the concentration table. The iron content of the final concentrate was 62.3 %.

Processing technology for ferruginous quartzite of Okolovo deposit

“…The grindability tests in stages II and III were performed in a ball mill, re-grinding of stage III concentrate was aimed to produce a high-quality concentrate (at the content of Fe total not less than 70%) [12][13][14][15][16][17]. In this manner, the yield of coarse tailings in stage I varies from 29.1 to 35.6% (relative to initial), and, considering the earlier tailings of DMS, the yield of waste increase to 60%.…”

Comparative technological evaluation of schemes for the enrichment of oxidized ferruginous quartzites

“…In terms of the possibility of obtaining high technological indicators of enrichment, the technology can be arranged in the following row: flotation ĺ magnetic -flotation ĺ magnetic. According to numerous studies [6,7,10,11] enrichment of oxidized quartzites can be carried out by the following schemes: flotation, magnetic with magnetic separation in low-and highintensity fields; combined, including gravity and flotation enrichment, magnetic separation in low-and high-intensity magnetic fields.…”

“…They are polymineral raw materials in which the minerals of the ore phase (martite, hematite, goethite, magnetite, hydrohematite, hydrogetite, limonite) are in close association and in various quantitative ratios with quartz [7][8][9]. These are multi-component systems with certain features of composition, properties and structure, and their difference from unoxidized ferruginous quartzites does not allow to effectively use traditional means of ore dressing and enrichment [6,7,10,11].…”