magnetite ore mining solution - mineral processing
Most of the iron minerals in a single magnetite are magnetite. Because the single magnetite is simple in composition, strong in magnetism, and easy to grind and sort, the weak magnetic separation method is often used for selection.
When the particle size of grinding is greater than 0.2mm, most iron ore magnetic separation plants often adopt a process of grinding and magnetic separation; When the grinding particle size is less than 0.2mm, the two-stage grinding-magnetic separation process is used; If qualified tailings are separated in the rough grinding stage, the magnetite magnetic separation plant should adopt the stage grinding-magnetic separation process; For dry and water-scarce areas, the magnetite ore dressing plant may consider using dry grinding-dry magnetic separation process; For the depleted magnetite-rich ore or magnetite-rich ore, the gangue can generally be removed by dry magnetic separation process, and then the lump-rich ore is obtained, and then the concentrate is obtained through the grinding-magnetic separation process.In order to obtain high-grade concentrate, magnetite concentrate can be treated by reverse flotation or high-frequency fine screen. In addition, in order to further improve the recovery rate, processes such as tailings gravity separation may also be considered to further recover magnetic minerals.
The gangue containing polymetallic magnetite often contains silicate or carbonate minerals, associated with cobalt pyrite, chalcopyrite and apatite, etc. Generally, the combined process of weak magnetic separation-flotation is used, that is, weak magnetic separation process recovers iron, and flotation process recovers sulfide or apatite.In general, the combined processes of weak magnetic separation-flotation process of polymetallic magnetite can be divided into weak magnetic separation-flotation and flotation-weak magnetic separation, the difference of which lies in the different direction of the continuum of magnetite and sulfide.For the weak magnetic separation-flotation process flow, the contiguous body mainly enters the iron concentrate; for the flotation-weak magnetic separation process flow, the conjoined body mainly enters the sulfide concentrate. Therefore, under the same grinding particle size, the first float and then magnetic process process can obtain iron concentrate with lower sulfide content and sulfide concentrate with higher recovery rate.
According to the types of iron-bearing minerals, common iron ore can be divided into magnetite, hematite, vanadium-titanium magnetite, limonite, siderite and mixed ore consisting of two or more of these iron bearing minerals. Among them, magnetite-hematite is a common mixed ore, and its beneficiation usually adopts a combined process flow composed of multiple beneficiation methods.
The single magnet-hematite is mostly fine-grained; the gangue mineral is mainly quartz, and some of it contains iron silicate. The proportion of magnets in the ore is gradually increases from the surface of the deposit to the deep part. The following two beneficiation methods are commonly used for selection:Weak magnetic separation, gravity separation/flotation/strong magnetic separationThe combined process of using weak magnetic separation to recover magnetite and then gravity separation, flotation or strong magnetic separation process to recover weak magnetic iron mineral.Production practice shows that for the weak magnetic separation-flotation process, the flotation method can be placed after the weak magnetic separation according to the nature of the ore and the actual conditions of the beneficiation plant, so as to ensure stable production indicators and save costs.
The iron minerals in polymetallic magnetite are mainly magnetite and hematite or siderite, medium and fine-grained; gangue minerals are mainly silicate and carbonate minerals or fluorite, etc., and the accompanying components include apatite , pyrite, chalcopyrite and rare earth minerals.The sorting of polymetallic magnetite is relatively complicated. Generally, the combined process consisting of weak magnetic separation and other mineral separation methods is used, that is, the weak magnetic separation method is used to recover the magnetite first, and then the gravity separation, flotation or strong magnetic separation method is used to recover weak magnetic iron minerals, and the associated components are final recovered by flotation.The above is the common magnetite beneficiation method. For magnetite beneficiation, it is recommended to tailor the process to suit your own through the beneficiation test, and rationally select the appropriate magnetite beneficiation method according to the final beneficiation test report.
the role of gravity concentration in modern processing plants - sciencedirect
Next to hand picking, gravity concentration is the oldest of all forms of mineral processing. While, in the twentieth century gravity concentration has been partially replaced by other processes, notably flotation and magnetic separation, they have not made it obsolete.
That such an ancient and inherently simple process has not only survived, but thrived, is in part due to its very simplicity. Not only is gravity concentration the process of choice in small, remote, artisanal plants, it also continues to play a major role in larger, modern plants for the concentration of many minerals, literally from A (andelusite) to Z (zircon).
This paper will review some of the advances in gravity concentration equipment and technology, that has allowed it to keep pace with, and grow, in what is becoming an increasingly competitive world. Various examples of modern equipment, and their potential application will be given.
a new method for gravity separation: vibrating table gravity concentrator - sciencedirect
A recently developed gravity concentration equipment was studied.Geometrical and operational parameters were disclosed in detail.Separation performance was investigated with distinct chromite ore tests.Effect of particle size, ore type, liberation, and desliming were discussed.Up to 93.22% recovery and 50.20% grade values were achieved.
This paper discusses recently developed gravity concentration equipment, namely vibrating table, and reports detailed descriptions of the equipment in terms of principles of design and their effects on operational parameters. Vibrating table originally combines the known physical phenomena of a teetered bed, resistance to water flow, vibration, and density differences. The resulting effect of these combined forces can also be manipulated by integrated settings of feed rate, solid %, plate inclination, and water rate. Following the detailed description of the equipment, mineral separation tests with two different chromite ores obtained from industrial applications were performed in order to investigate the performance of the laboratory scale vibrating table. While former chromite ore had low grade with complex mineralogy and inadequate liberation, the latter had high grade consisting of liberated lumpy chromite particles. Experimental studies were focused on investigating the effect of plate inclination, removal of slimes, ore type, size classification, and particle size on separation performance. Within the tests performed with 600m, 800m, and 1000m high grade chromite ores under certain conditions, it was observed that increase in particle size results in a dramatic increase in recovery, while % grade decreases slightly. In another test with high grade chromite ore, sustainable product qualities were achieved up to a recovery of 93.22% in comparison with the 66.08% achieved with a conventional shaking table, within and approx. 4748% final grade level. Additionally, product grades and recoveries up to 50.20%58.36% with deslimed 400m low grade chromite feed and 53.68%67.45% with deslimed 200m low grade chromite feed were obtained, respectively.