The role of spiral chutes in the selection of joint processes
The spiral chute is used for sorting purposes by means of the density difference of the minerals. At the same time, the iron minerals separated by the monomer can be recovered in time at a coarser particle size level (generally not affected by iron mineral type and magnetic properties, surface chemistry). Effects of characteristics, etc.) or the disposal of monomeric gangue minerals. Therefore, it can be widely used in the weak magnetic-fine screening process for treating magnetite (including roasting magnetite), weak magnetic-re-selection (centrifuge) for processing imaginary hematite, and weak magnetic-strong magnetic-flotation Various joint processes are used to supplement, assist, improve, and improve the processes or operations such as magnetic separation, flotation, centrifuge re-election, and fine screening. The spiral chute is applied to the weak magnetic-fine screening process of the magnetite ore in the Gongchangling plant, which can sort out the concentrate with a yield of 14-15% and a grade of 65-66%, thus ensuring the final concentrate grade. and concentrate to obtain a coarse fraction, had the purpose of reducing wear and metal loss, to simplify the process, energy efficiency and reduce production costs. Compared with magnetic separation, the spiral chute has higher sorting efficiency and the function of recovering coarse-grained monomeric iron minerals. It is said that the spiral chute plays a role that the magnetic separation device can't, and achieves the sorting effect that the magnetic separation process cannot achieve. (2) The spiral-slot is used to process the magnetic-heavy process of weak magnetic iron ore (3) The spiral chute is used to treat the magneto-floating process of hematite. The spiral chute application and the magnetic-floating process constitute the combined gravity-magnetic-floating process of stage grinding, which is a successful attempt to treat the Anshan-type lean hematite. . The function of the spiral chute is to sort out the coarse final concentrate C with a yield of 15-20% and an iron grade of 65-67% after a period of grinding and pass a rough selection, a selection and a sweep. The selected three-stage spiral chute is sorted, and the middle mine with a yield of nearly 50% is sorted into the regrind process, thereby greatly reducing the amount of grinding of the secondary mill. The whole process also selects the final concentrate with a yield of about 5-10% through the weak magnetic machine, and discards the tailings with a yield of about 50-55% through the medium magnetic machine and the strong magnetic machine, so that the ore content of the flotation operation is only It is about 20% of the original ore, which simplifies the sorting process and reduces the consumption of flotation chemicals and production costs. Air Condenser Unit,Freezer Condenser,Dimroth Condenser,Condenser Refrigeration Wuxi Dingfeng pressure vessel Co., Ltd , https://www.wuxidingfeng.com
(I) Spiral chute for weak magnetic-fine screening process One of the characteristics of Anshan-type iron ore is the uneven grain size of iron minerals and gangue minerals. 51.24% of iron minerals and 67.54% of quartz are present in the grade of +0.074 mm, that is, under rough grinding conditions, a large amount of monomeric iron minerals and quartz are dissociated. Such coarse-grained grinding products are suitable for processing with spiral chutes. The grain size analysis of the concentrate obtained from the treatment of the Gongchangling magnetite by the spiral chute shows that the coarse-grained concentrate with a particle size of 0.045-0.25 mm can reach more than 65% of the iron grade.
On the basis of a large number of experimental research work, the magnetic separation workshop of Gongchangling Plant has carried out the transformation of the phase grinding-magnetic separation-re-election combined process. The principle flow is shown in Figure 1. That is, a primary overflow is roughly selected by a magnetic separator, and a tailings with a yield of about 47% is thrown. The magnetic separation coarse concentrate is graded by two successive fine sieves. Subdivision selection: The fine grade products under a fine sieve screen are sorted by three-bar magnetic separator to obtain the final concentrate and tailings; the medium-grain grade products under the second-stage fine sieve are sorted by spiral chute. The final concentrate is produced; the coarse-grained product on the second-stage fine sieve is returned to the original process after concentration and second-stage grinding. 
Both the test and the production practice have proved that the spiral chute is used for the magnetic separation and fine screening process of the roasting magnetite in the Qidashan plant, and the final concentrate with a yield of nearly 20% and a grade of 64% can also be sorted.
The five production series of Qi Dashan roasting magnetic separation workshop originally used two continuous grinding and single magnetic separation processes. Later, the fine screening and self-circulation operation was added. By 1982, the concentrate grade was 62.39% and the recovery rate was 78.33%. Better indicator. [next]
In order to further improve the selection index and achieve the purpose of energy saving and income increase, with the introduction of the spiral chute in the 4th and 5th series of 1983, the technical transformation of the process of coarse and subdivided selection was carried out. After the transformation, the production practice in the past few years shows that although the selection index has not been significantly improved, the ratio of the first and second mills has basically reached 2:1, and the effect of energy saving and income increase has been achieved to some extent.
The spiral chute plays a role in early recovery of monomer-separated iron minerals, ensuring final concentrate grade and overall process metal recovery, both in the weak magnetic-grading re-election or the weak magnetic-strong magnetic-grading re-election process.
In 1979, on the basis of a large number of experimental research work, Gongchangling was selected, and a second-selection workshop for the treatment of the poor hematite in the mining area was technically transformed. The whole centrifuge process of the original re-election operation was a spiral chute and centrifuge. The sorting process of coarse and fine grain grades is separately processed. The middle ore after separation of the magnet concentrate by three-stage weak magnetic and two-stage fine sieve is classified by a cyclone, and the cyclone overflow, that is, the fine-grain grade product is fed into the centrifuge; the cyclone is sanded and coarse The graded product is sorted using a two-stage spiral chute. The examination shows that although the ore body shape of the arch bearing area of ​​Gongchanglingling East Mine is complex and disorderly distributed, and the ore is subjected to complex mixed lithification hydrothermal oxidation, the degree of oxidation is extremely uneven and transitions to each other, magnetite and hematite. the fluctuation in the ratio of 1: 5.3 to 1: 0.32, resulting in a dressing stone into extremely unstable nature, but the spiral chute greater adaptability to different types of ore. [next]
In 1986, the second workshop of Gongchangling Plant was carried out for the second technical transformation. In the weak magnetic-grading re-election process, the strong magnetic Kai was introduced, and the stage grinding-weakening-strong magnetic-bifurcation was formed. Re-election process. The system flow of No. 7 and No. 8 in which the transformation and industrial tests were carried out in advance is shown in Figure 3. Compared with the pre-retrofit process, it is characterized by weak magnetics only as a preparation for strong magnetism, instead of obtaining the final concentrate. The coarse-grained products with narrower particle size range after sorting by cyclone and fine sieve can be sorted out by a spiral chute to select the final concentrate with a yield of about 20% and a grade of more than 65%. The obtained concentrate has a yield of only about 11% and a grade of more than 63%. It can be seen that in the new process, the spiral chute has become the main operation for obtaining high-grade concentrate.
In the joint process of processing Qi Dashan hematite, spiral chute re-election has become the main operation to ensure the final concentrate grade, and constitutes many processes such as gravity-magnetic-floating, magnetic-heavy-floating, and the number of segments used in the spiral chute. And configuration methods are also different. If the test procedure is after weakening, the weak magnetic concentrate is treated with two-stage spiral chute to obtain the final concentrate with a yield of 7.29% and a grade of 65.32%. After the weak magnetic separation tailings is de-slurried by a cyclone, a section is used. Rough selection, a selection and a sweeping three-stage spiral chute treatment, the final concentrate with a yield of 6.90% and a grade of 65.69% was obtained, and the final tailings with a yield of 24.43% and a grade of 6.69% were discarded. The remaining yield of 50.17%, grade 31.05% of the various spiral chutes selected in the middle of the mine, re-grinding and weak magnetic-strong magnetic-flotation, the final process can reach 65.50% concentrate grade, recycling A preferred rating indicator with a rate of 80.00%.
In short, in the various joint processes for processing weak magnetic iron ore, the spiral chute can better sort and recover the ore of 0.25-0.03mm grade in the ore with uneven grain size, which can obtain the grade. High qualified concentrates; and the ability to reject qualified tailings with lower grades to improve the sorting of the entire process.