Baizhongobei middle lean oxidized heap leaching ore efficient recovery of iron, rare earth beneficiation process

Abstract

The application discloses a beneficiation process for efficiently recovering iron and rare earth from poor oxidized and piled ore in Baiyunebo, and comprises the following steps: S1, directly dry selecting after crushing the raw ore; S2, using a ball mill to coarsely grind the dry selected concentrate, using a weak magnetic separation on the coarse grinding product, using a strong magnetic separation on the weak magnetic tailings, using a fine grinding on the mixture of the weak magnetic concentrate and the strong magnetic concentrate after mixing, using a weak magnetic separation on the fine grinding product, using a strong magnetic separation on the weak magnetic tailings, using a reverse flotation on the strong magnetic concentrate to obtain iron concentrate, and using one roughing and three cleaning rare earth flotation on the first and second strong magnetic tailings to obtain rare earth concentrate. The dry selection-stage grinding selection-iron reverse flotation-rare earth direct flotation process can finally obtain comprehensive iron concentrate with TFe grade of 64.5% or above and recovery rate of 65% or above, and comprehensive rare earth concentrate with REO grade of 60% or above and recovery rate of 45% or above, and the effect is outstanding.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of middle-lean oxidized stockpile ore in Baiyunebo high-efficiency recovery of iron, rare earth dressing process. BACKGROUND

[0002] The existing middle-lean oxidized stockpile ore in Baiyunebo is the lean ore stacked in the mine when the rich ore was directly smelted in Baotou Steel from 1959 to 1964. The ore contains 20%-30% iron, with an average grade of 25%-27%, 5.5% rare earth oxides, and more than 20% fluorite. The ore type is complex, the oxidation degree is high, the particle size is fine and easy to be slimed. In the past production process, it has entered the existing beneficiation plant weak magnetic-strong magnetic-reverse flotation process. However, due to the characteristics of the ore, it cannot be produced stably. The ore stacking amount is ten million tons, and the resource amount is large. If a reasonable process is adopted for industrialization, it can greatly alleviate the problem and improve the resource utilization rate in Baiyunebo area.

[0003] Using dry separation-stage grinding separation-reverse flotation iron-positive flotation rare earth process, laboratory has achieved success. For middle-lean oxidized ore with fine particle size and high oxidation degree, it has promotional significance and far-reaching significance for resource green development.

[0004] In the paper "Beneficiation Test Research on Middle-lean Stockpile Ore in Baiyunebo Iron Ore", the process is stage grinding separation-reverse and positive flotation process. Under the condition that the iron grade of raw ore is only 26.17%, the comprehensive iron concentrate grade of 64.53% and the iron recovery rate of 67.98% are obtained. Compared with the process of the present application, ① the process design does not use positive flotation to recover part of the iron, and the index is more ideal, with a comprehensive iron concentrate grade of 64.92% and an iron recovery rate of 68.94%. ② The grinding particle size can be relaxed to 95% of -200 mesh. For the characteristics of fine particle size and easy sliming of raw ore, the particle size in the paper is 92% of -325 mesh, which is too fine and will have a great impact on the flotation process. ③ The reverse and positive flotation PH in the paper process is different, which will cause the adjustment of slurry PH to consume a large amount of reagents, and the cost of reagents is high. At the same time, the positive flotation has poor stability for on-site operation, especially for sliming ore samples, the separation effect will be greatly discounted. ④ Only iron is selected in the paper, and rare earth is not separated.

[0005] The paper "Application Research of New Type Collector FC9502 in Flotation of Baotou Medium Lean Oxidized Ore", aiming at the Baotou medium lean oxidized ore, the strong magnetic scanning concentrate (containing TFe 30.31%) after weak magnetic-strong magnetic separation is selected, the new type collector FC9502 and the conventional adjusting agent are combined to obtain the comprehensive iron concentrate containing TFe 62.90% and the iron recovery rate 77.00% through the industrial separation stable test after the operation of reverse flotation once roughing, twice cleaning and positive flotation once roughing, twice cleaning. The paper mainly carries out reverse and positive flotation agent research, develops FC9502 agent, which can improve the recovery rate of separate separation operation, but from the process design, ① in the paper, the closed-circuit test only obtains the iron concentrate with the grade 59.55% and the iron recovery rate 68.57%, which is worse than the application. ② in the industrial experiment, the positive flotation agent is only used for the strong magnetic scanning concentrate, the TFe recovery rate is 7%, but it needs to increase the once reverse flotation, the one roughing and two cleaning positive flotation, the reverse and positive flotation combination, and the production cost is high, and the technical index of the whole process iron concentrate is worse than the application. ③ the paper only selects iron and does not separate rare earth. The paper "High-pressure roller mill beneficiation test research of a magnetite ore in Anhui" adopts the process flow of dry magnetic separation-high pressure roller mill-coarse wet separation-stage grinding separation, and finally obtains the iron concentrate with the yield 22.83%, the total iron content 65.55% and the magnetic iron recovery rate 93.38% under the condition that the original ore iron grade is 24.10% and the magnetic iron is 15.8%. Compared with the technology, the original ore grade is about 5% lower than that in the paper, but the concentrate recovery rate is high, which indicates the advancement of the process.

[0006] The paper "Iron and rare earth beneficiation test research of Baiyunebo medium lean oxidized ore" adopts the weak magnetic-strong magnetic-flotation process to test the medium lean oxidized ore, and finally can obtain the iron concentrate with the grade 60.54% and the iron recovery rate 79.17%, and the rare earth concentrate with the grade 49% and the rare earth recovery rate 35.51%. Compared with the application, the economic efficiency of the process is not as good as the application, the technical index of the iron concentrate is about 4.5% lower than that of the application, and the comparison is not comparable. Under the condition that the comprehensive rare earth grade is about 10% lower than that of the application, the recovery rate of the application is still 4% higher than that of the application, and the separation effect is worse than that of the application. SUMMARY

[0007] The application aims to provide a Baiyunebo medium lean oxidized ore stacking ore high-efficiency iron and rare earth recovery beneficiation process, which can effectively improve the beneficiation process of iron and rare earth resource utilization rate of Baiyunebo medium lean oxidized ore stacking ore, and finally can obtain the comprehensive iron concentrate with the TFe grade more than 64.5% and the recovery rate more than 65%, and the comprehensive rare earth concentrate with the REO grade more than 60% and the recovery rate more than 45% through the dry separation-stage grinding separation-iron reverse flotation-rare earth positive flotation process, and the effect is outstanding.

[0008] To solve the above technical problems, the present application adopts the following technical solutions:

[0009] The present application is a kind of Baiyunebo lean oxidized stockpiled ore efficient recovery of iron, rare earth beneficiation process, comprising the following steps:

[0010] S1. The raw ore is directly dry selected after crushing;

[0011] S2. The dry selection concentrate is used for coarse grinding by ball mill, weak magnetic separation of coarse grinding product, strong magnetic separation of weak magnetic tailings, and fine grinding of the mixture of weak magnetic concentrate and strong magnetic concentrate by Aixi mill, weak magnetic separation of fine grinding product, strong magnetic separation of weak magnetic tailings, and reverse flotation of strong magnetic concentrate to obtain iron concentrate. The first and second strong magnetic tailings are respectively subjected to one roughing and three cleaning rare earth flotation to obtain rare earth concentrate.

[0012] Further, the field strength of dry selection is 3600 Oe.

[0013] Further, the coarse grinding product is 70% of -0.074 mm size fraction.

[0014] Further, the magnetic field strength of weak magnetic separation is 1800 Oe.

[0015] Further, the magnetic field strength of strong magnetic separation is 8000 Oe.

[0016] Further, the fine grinding product is 95% of -0.074 mm size fraction.

[0017] Further, the magnetic field strength of strong magnetic separation of weak magnetic tailings is 12000 Oe.

[0018] Further, the raw ore is directly dry selected after crushing to 2 mm.

[0019] Compared with the prior art, the present application has the beneficial technical effects:

[0020] Dry selection of raw ore can improve grinding efficiency, reduce overgrinding phenomenon, make the already dissociated iron minerals achieve the effect of early and complete separation, reduce subsequent grinding amount by about 10%, increase production capacity while reducing production cost, and create a better particle size distribution environment for the next rare earth selection. The Aixi mill is used as the fine grinding equipment in the second stage fine grinding, which has higher grinding efficiency and uniform particle size, and reduces overgrinding and mud phenomenon. The first and second strong magnetic tailings are respectively subjected to one roughing and three cleaning rare earth flotation, which is designed for flotation under different particle size conditions. The particle size of the second strong magnetic tailings is fine, and part of the fine mud is removed by desliming, reducing the influence on the subsequent flotation process. The present process is designed for the easy mudification characteristics of Baiyunebo oxidized ore, uses pre-separation to improve separation efficiency, optimizes stage grinding process, improves grinding efficiency, reduces overgrinding, and does not need excessive fine grinding, which avoids the influence on flotation operation and has good separation effect and ideal indicators.

[0021] Ultimately, it yields a comprehensive iron concentrate with a TFe grade of over 64.5% and a recovery rate of over 65%, as well as a comprehensive rare earth concentrate with a REO grade of over 60% and a recovery rate of over 45%, demonstrating outstanding results. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 This is a process flow diagram of the present invention;

[0024] Figure 2 X-ray analysis spectrum of the raw ore;

[0025] Figure 3 This is a microscope photograph of the raw ore, showing iron mineral grains intercalated with silicates and fluorite. Detailed Implementation

[0026] like Figure 1 As shown, a high-efficiency iron and rare earth beneficiation process for recovering iron from the Bayan Obo medium-lean oxide stockpile ore is described. The process flow is as follows: raw ore is crushed to 2mm and directly dry-separated (dry separation field strength 3600 Oe) - dry separation concentrate is coarsely ground using a ball mill - coarse grinding product (70% of -0.074mm particle size) is weakly magnetically separated (magnetic field strength 1800 Oe) - weak magnetic tailings are strongly magnetically separated (magnetic field strength 8000 Oe) - the weak magnetic concentrate and strongly magnetic concentrate are mixed and then finely ground using an abrasive mill - fine grinding product (95% of -0.074mm particle size) is weakly magnetically separated (magnetic field strength 1800 Oe) - weak magnetic tailings are strongly magnetically separated (magnetic field strength 12000 Oe) - the strongly magnetic concentrate is reverse-flotated to obtain iron concentrate. The first and second strong magnetic tailings are respectively subjected to a roughing and finishing rare earth flotation to obtain rare earth concentrate.

[0027] Case

[0028] In 2021, Baogang Group Mining Research Institute (Limited Liability Company) conducted research on the recovery of iron and rare earth resources from the Bayan Obo medium-lean oxide stockpile ore. This patented research process was developed. Through process experiments, the raw ore was crushed from over 300mm to below 2mm. After crushing, the ore was mixed and reduced in size, and a 500g sample was obtained using a point sampling method for physicochemical analysis and process mineralogical studies. The multi-element results of the raw ore are shown in Table 1, the mineral composition of the raw ore is shown in Table 2, the sieve analysis results of the raw ore are shown in Table 3, and the X-ray diffraction analysis results of the raw ore are shown in Table 4. Figure 2 See the microscopic photograph. Figure 3 .

[0029] Table 1. Multi-element results of the raw ore

[0030] Element TFe FeO mFe K2O Na2O CaO F Zn Content % 27.8 3.85 13.5 0.62 0.90 16.76 7.99 0.094 Element SiO2 MgO Al2O3 TiO2 P S REO Content % 9.44 4.52 0.73 0.49 0.89 0.865 4.48

[0031] Table 2 Mineral Composition of Raw Ore

[0032] Dolomite Fluorite Rare earths Aegirine Amphibole Mica Iron minerals Others 13.94 14.95 6.4 8.32 6.12 8.47 37.12 4.68

[0033] Table 3 raw ore screening results

[0034]

[0035]

[0036] From the data in the chart, iron minerals are distributed in each particle size, and the largest share in the +200 mesh particle size reaches 80.14%, and the iron minerals and gangue minerals are complexly embedded, the main gangue minerals are dolomite, fluorite and silicate minerals, and the iron minerals are mainly magnetite and hematite.

[0037] From the analysis of the microscope image of the raw ore, the iron mineral particles and gangue minerals are complexly embedded, and there are many intergrowths. Fine grinding should be performed during separation to dissociate the gangue minerals and iron minerals. The ore contains magnetite, which can be separated by weak magnetic separation. The ore also contains a lot of hematite, which needs to be separated by strong magnetic separation. The iron minerals are more intergrown with fluorite and silicate minerals, and it is appropriate to use reverse flotation operation to remove impurities and improve the concentrate grade.

[0038] The iron separation test was carried out using the patented process, in which the first stage grinding used a ball mill and the second stage grinding used an Isa mill. The test results are shown in Table 4.

[0039] Table 4 raw ore dry separation-dry separation concentrate stage grinding (second stage Isa mill grinding) full process results

[0040] Product name TFe yield % TFe grade % TFe recovery % Dry tailings 12.13 12.10 5.13 Low intensity concentrate 21.08 67.40 49.69 Flotation concentrate 9.28 59.30 19.25 Flotation tailings 7.29 29.50 7.53 High intensity middlings 13.90 14.60 7.10 High intensity tailings 36.32 8.90 11.31 Total 100.00 28.59 100.00 Comprehensive concentrate 30.36 64.92 68.94

[0041] The iron separation process using raw ore dry separation-dry separation concentrate, using a ball mill for coarse grinding-weak magnetic separation of coarse grinding products-strong magnetic separation of weak magnetic tailings-fine grinding of the mixture of weak magnetic concentrate and strong magnetic concentrate using an Isa mill-weak magnetic separation of fine grinding products-strong magnetic separation of weak magnetic tailings-reverse flotation of strong magnetic concentrate can obtain an iron concentrate with a yield of 30.36%, a TFe grade of 64.92%, and a TFe recovery rate of 68.94%. The process has good stability and good separation effect.

[0042] Rare earth flotation tests were carried out on the first and second stage strong magnetic tailings, the depressor was water glass, the collector was XT4, and the frother was 2# oil. The first stage strong magnetic tailings were directly subjected to one roughing-three cleaning flotation to obtain a rare earth concentrate with a REO grade of 60.12% and a REO overall process recovery rate of 14.47%. The second stage strong magnetic tailings were first subjected to desliming and then directly subjected to one roughing-three cleaning flotation to obtain a rare earth concentrate with a REO grade of 60.04% and a REO overall process recovery rate of 31.98%. The comprehensive first and second stage strong magnetic tailings flotation rare earth concentrate obtained a rare earth comprehensive concentrate with a REO grade of 60.06% and a REO overall process recovery rate of 46.45%, and the separation indexes were good. The second stage strong magnetic tailings were designed to be deslimed, because the medium-poor oxidized heap ore was easy to be slimed after fine grinding, and if the desliming treatment was not carried out, the subsequent flotation would be affected.

[0043] The above-described embodiments are merely preferred modes of the present application, and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A high-efficiency iron and rare earth beneficiation process for recovering iron from medium-lean oxide stockpiled ore in Bayan Obo, characterized in that: Includes the following steps: S1. Dry separation is performed directly after crushing of the raw ore; S2. The dry concentrate is coarsely ground using a ball mill - the coarsely ground product is separated by weak magnetic separation - the weak magnetic tailings are separated by strong magnetic separation - the weak magnetic concentrate and strong magnetic concentrate are mixed and then finely ground using an abrasive mill - the finely ground product is separated by weak magnetic separation - the weak magnetic tailings are separated by strong magnetic separation - the strong magnetic concentrate is then subjected to reverse flotation to obtain iron concentrate. The first stage strong magnetic tailings and the second stage strong magnetic tailings are respectively subjected to one roughing and three finishing rare earth flotation to obtain rare earth concentrate. Dry separation field strength 3600 Oe; coarse grinding product -0.074mm particle size 70%; weak magnetic separation field strength 1800 Oe; strong magnetic separation field strength 8000 Oe; fine grinding product -0.074mm particle size 95%; weak magnetic tailings strong magnetic separation field strength 12000 Oe; raw ore crushed to 2mm directly dry separation.

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