Low-cost method for magnetic separation, iron extraction and fluorine reduction of bruninite concentrate

Abstract

The invention discloses a low-cost method for magnetic separation, iron extraction and fluorine reduction of bailinite concentrate, which comprises the following steps: taking bailinite concentrate products as feedstock, obtaining iron concentrate 5 by adopting a first-section magnetic suspension classificator, regrinding tailings (tailings 5) of the first-section magnetic suspension classificator, and obtaining iron concentrate 6 by adopting a second-section magnetic suspension classificator, tailings of the second-section magnetic suspension classificator serve as final tailings, iron ore concentrate 5 and iron ore concentrate 6 are mixed and fed into a third-section magnetic suspension classificator, obtained magnetic separation iron ore concentrate 7 serves as final concentrate, and the magnetic separation tailings 7 are returned to be reground together with the tailings 5. The iron ore concentrate indexes of the obtained magnetic separation iron ore concentrate 7 meet the conditions that the TFe content is larger than or equal to 68%, and the F content is smaller than or equal to 0.30%, and the method for increasing iron and reducing fluorine of the brunin iron ore concentrate is low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of mining engineering, and in particular relates to a low-cost method for magnetic separation of Barun iron concentrate to extract iron and reduce fluorine. Background Art

[0002] my country's mineral resources are characterized by low grade, complex composition, and many paragenetic and associated minerals, some of which contain harmful elements and cannot be used directly, cannot be used directly for smelting, or are difficult and costly to smelt directly. For the sake of national resource security, this part of the ore must be used. With the rapid development of the steel industry in recent years, the consumption of iron ore resources has increased year by year, and the problem of the increasing depletion of high-grade and well-sorted iron ore resources has become increasingly obvious. Therefore, how to reasonably develop and utilize low-grade iron ore is particularly important.

[0003] The TFe content of the low-grade dolomite iron ore in the Bayan Obo West Mine is 20.55%, and iron is mainly found in magnetite, with a share of 70.02%. In order to fully develop and utilize the ore, the ore is pre-treated by magnetic drum dry magnetic separation and tailings to reduce the ore processing volume, and then the sectional grinding process, coarse grinding-weak magnetic separation, fine grinding-weak magnetic separation and regrinding-magnetic separation process are used for separation to improve the grade of the iron concentrate, and an iron concentrate with a TFe grade of 68.09%, a TFe recovery rate of 56.90%, and an MFe recovery rate of 79.84% can be obtained. Baosteel's self-produced iron ore concentrate index requires TFe content greater than 65% and F content less than 0.4%. However, the actual production of Barun's iron concentrate index is TFe greater than 65%, but F content greater than 0.4 (it is Barun's stage grinding, that is, three-stage grinding and four-stage weak magnetic separation to obtain four-stage concentrate, its index is TFe content greater than 65%, F content greater than 0.4, three-stage ball mill discharge particle size -325 mesh 85%, iron mineral dissociation degree has reached 90%), which does not meet the company's iron concentrate smelting standards. In production, the three-stage grinding particle size -325 mesh content has reached 85%. If all fine grinding is continued, the cost will be high, and the grinding effect will be poor. If the concentrate is not finely ground, the concentrate will be unqualified. Therefore, it is urgent to provide a method to treat Barun's iron concentrate to achieve the purpose of increasing iron and reducing fluorine. Summary of the invention

[0004] Considering that the dissociation degree of a small part of the iron mineral monomers in the Barun Sijing concentrate does not meet the requirements, which is an important factor affecting the quality of the iron ore, the present invention provides a method for magnetic separation of the Barun iron concentrate to achieve the purpose of increasing iron and reducing fluorine. The technical solution adopted by the present invention to solve its technical problem is: using the Barun four-fine concentrate product as feed, using the first section magnetic suspension concentrator to obtain iron concentrate 5, the first section magnetic suspension concentrator tailings are regrinded, and using the second section magnetic suspension concentrator to obtain iron concentrate 6, the second section magnetic suspension concentrator tailings are used as the final tailings (tailings 6), the iron concentrate 5 and the iron concentrate 6 are mixed and fed into the third section magnetic suspension concentrator to obtain magnetically separated iron concentrate 7 as the final concentrate, and the magnetically separated tailings 7 are returned to the Ai sand mill for grinding, and the Barun four-fine concentrate is subjected to the magnetic suspension separator-grinding-magnetic suspension separator process flow, and the process flow parameters are optimized and controlled, which solves the problem that the dissociation degree of a small part of the iron mineral monomers in the four-fine concentrate does not meet the requirements and affects the quality of the iron concentrate, thereby achieving the purpose of iron enhancement and fluorine reduction, and the method is low in cost. The specific technical solution of the present invention is as follows.

[0005] One aspect of the present invention provides a low-cost method for magnetic separation of Barun iron concentrate to extract iron and reduce fluorine, which comprises using the Barun four-fine concentrate product as feed, using the first-stage magnetic suspension concentrator to obtain iron concentrate 5, regrinding the tailings (tailings 5) of the first-stage magnetic suspension concentrator and using the second-stage magnetic suspension concentrator to obtain iron concentrate 6, the tailings of the second-stage magnetic suspension concentrator are used as the final tailings, the iron concentrate 5 and the iron concentrate 6 are mixed and fed into the third-stage magnetic suspension concentrator to obtain magnetically separated iron concentrate 7 as the final concentrate, and the magnetically separated tailings 7 are returned to be regrinded together with the tailings 5;

[0006] The iron concentrate indexes of the magnetically separated iron concentrate 7 meet the following requirements: TFe content ≥ 68%, F content ≤ 0.30%.

[0007] In some embodiments, the Barun four-concentrate concentrate product is a four-concentrate concentrate obtained by Barun Company's stage grinding, that is, three-stage grinding and four-stage weak magnetic separation, with indicators such as TFe content greater than 65%, F content greater than 0.4%, three-stage ball mill discharge particle size -325 mesh accounting for 85%, and iron mineral dissociation degree reaching 90%.

[0008] In some embodiments, in the first stage of magnetic levitation concentration, the Barun Si concentrate product is configured to have a concentration of 10%-20%, and is fed to the first stage magnetic levitation concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 350-400 GS, and an upward water flow of 20-50 L / min to obtain iron concentrate 5 and tailings 5.

[0009] In some embodiments, the tailings are regrinded using an abrasive mill with a feed rate of 100kg-1000kg and a grinding time of 400s-500s to obtain a mill discharge product.

[0010] In some embodiments, in the second stage magnetic suspension concentration, the mill discharge product is configured to have a concentration of 10%-20%, and is fed to the second stage magnetic suspension concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 350-400 GS, and an upward water flow of 20-50 L / min to obtain iron concentrate 6 and tailings 6.

[0011] In some embodiments, in the third stage magnetic levitation concentration, the mixture of iron concentrate 5 and iron concentrate 6 is configured to have a concentration of 10%-20%, and is fed to the third stage magnetic levitation concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 200-300 GS, and an upward water flow of 40-50 L / min to obtain iron concentrate 7 and tailings 7.

[0012] Another aspect of the present invention provides a Barun iron concentrate obtained by the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a process flow chart of one embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention is described in detail below through specific examples. The examples are intended to help understand the present invention but are not intended to limit the present invention.

[0015] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0016] The present invention aims to provide a low-cost method for magnetic separation of Barun iron concentrate to extract iron and reduce fluorine. Figure 1 As shown, it includes using the Barun four-concentrate concentrate product (Barun Company's stage grinding concentrate, that is, the four-concentrate concentrate obtained by three-stage grinding and four-stage weak magnetic separation, with indicators of TFe content greater than 65%, F content greater than 0.4, three-stage ball mill discharge particle size -325 mesh accounts for 85%, and the iron ore dissociation degree has reached 90%) as feed, using the first stage magnetic suspension concentrator to obtain iron concentrate 5, the first stage magnetic suspension concentrator tailings (tailings 5) are re-grinded and the second stage magnetic suspension concentrator is used to obtain iron concentrate 6, the second stage magnetic suspension concentrator tailings are used as the final tailings, the iron concentrate 5 and the iron concentrate 6 are mixed and fed into the third stage magnetic suspension concentrator to obtain magnetically separated iron concentrate 7 as the final concentrate, and the magnetically separated tailings 7 are returned and re-ground together with the tailings 5; the iron concentrate indicators of the obtained magnetically separated iron concentrate 7 meet the following requirements: TFe content ≥ 68%, F content ≤ 0.30%. Specifically, the method provided by the present invention includes the following operations:

[0017] (1) First stage magnetic suspension concentrator: The Barun Si concentrate product is configured to have a concentration of 10%-20%, and is fed to the first stage magnetic suspension concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 350-400 GS, and an upward water flow of 20-50 L / min to obtain an iron concentrate 5 and a tailing 5;

[0018] (2) Tailings regrinding: The tailings regrinding adopts an Aisha mill with a feed rate of 100kg-1000kg and a grinding time of 400s-500s to obtain the mill discharge product;

[0019] (3) Second stage magnetic suspension concentration: the mill discharge product is configured to have a concentration of 10%-20%, and is fed to the second stage magnetic suspension concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 350-400 GS, and an upward water flow of 20-50 L / min to obtain iron concentrate 6 and tailings 6;

[0020] (4) The third stage magnetic suspension concentration: the mixture of the iron concentrate 5 and the iron concentrate 6 is prepared into a concentration of 10%-20%, and is fed to the third stage magnetic suspension concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 200-300 GS, and an upward water flow of 40-50 L / min to obtain an iron concentrate 7 and tailings 7; wherein the iron concentrate 7 is used as the final iron concentrate, and the tailings 7 is returned for regrinding together with the tailings 5.

[0021] Example

[0022] The Barun four-fine concentrate product used in the embodiment is the Barun Company's stage grinding concentrate, that is, the four-fine concentrate obtained by three-stage grinding and four-stage weak magnetic separation. The indicators are TFe content of 65.16%, F content of 0.64%, three-stage ball mill discharge particle size of -325 mesh accounting for 85%, and the iron ore dissociation degree has reached 90%. As a feed, the following operations are performed.

[0023] 1. The first stage of magnetic suspension concentrator: The Barun Sijing concentrate product was configured to have a concentration of 15%, and fed to the first stage of magnetic suspension concentrator under the conditions of 0.60 kg / min of feed rate, 350 GS of magnetic field intensity, and 30 L / min of rising water flow to obtain iron concentrate 5 and tailings 5. The separation results of the first stage of magnetic suspension concentrator are shown in Table 1.

[0024] Table 1: Sorting results of the first stage magnetic suspension concentrator

[0025]

[0026] 2. Second stage magnetic suspension concentrator: The mill discharge product was configured to have a concentration of 15%, and fed to the second stage magnetic suspension concentrator under the conditions of a feed rate of 0.60 kg / min, a magnetic field strength of 350 GS, and an upward water flow of 40 L / min to obtain iron concentrate 6 and tailings 6. The separation results of the second stage magnetic suspension concentrator are shown in Table 2.

[0027] Table 2: Sorting results of the second stage magnetic suspension concentrator

[0028]

[0029] 3. The third stage magnetic suspension concentrator: The mixture of iron concentrate 5 and iron concentrate 6 is prepared to have a concentration of 15%, and is fed to the third stage magnetic suspension concentrator under the conditions of ore feeding amount of 0.60 kg / min, magnetic field strength of 200 GS, and rising water flow of 40 L / min to obtain iron concentrate 7 and tailings 7; wherein iron concentrate 7 is used as the final iron concentrate. The separation results of the third stage magnetic suspension concentrator are shown in Table 3.

[0030] Table 3: Sorting results of the third stage magnetic suspension concentrator

[0031]

[0032] From the results shown in Table 3 above, it can be seen that the TFe content of the iron concentrate 7 after sorting by the third-stage magnetic suspension concentrator can reach 68.40%, and the F content is only 0.28%. Therefore, the method provided by the present invention can effectively reduce the impurities in the original iron ore, and then effectively increase the iron and reduce the fluorine content of the Barun Si concentrate product, and the method has the characteristics of low cost.

[0033] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-cost method for magnetic separation of Barun iron concentrate to extract iron and reduce fluorine, comprising: using the Barun four-fine concentrate product as feed, using the first-stage magnetic suspension concentrator to obtain iron concentrate 5, regrinding the tailings of the first-stage magnetic suspension concentrator (tailings 5) and using the second-stage magnetic suspension concentrator to obtain iron concentrate 6, the tailings of the second-stage magnetic suspension concentrator are used as the final tailings, the iron concentrate 5 and the iron concentrate 6 are mixed and fed into the third-stage magnetic suspension concentrator to obtain magnetically separated iron concentrate 7 as the final concentrate, and the magnetically separated tailings 7 are returned to be regrinded together with the tailings 5; The iron concentrate indexes of the magnetically separated iron concentrate 7 meet the following requirements: TFe content ≥ 68%, F content ≤ 0.30%.

2. The method according to claim 1, wherein the Barun four-fine concentrate product is the four-fine concentrate obtained by Barun Company's stage grinding, that is, three-stage grinding and four-stage weak magnetic separation, with indicators such as TFe content greater than 65%, F content greater than 0.4%, three-stage ball mill discharge particle size -325 mesh accounting for 85%, and iron ore dissociation degree reaching 90%.

3. According to the method described in claim 1 or 2, in the first stage of magnetic suspension concentration, the Barun Sijing concentrate product is configured to have a concentration of 10%-20%, and is fed to the first stage magnetic suspension concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 350-400 GS, and an upward water flow of 20-50 L / min to obtain iron concentrate 5 and tailings 5.

4. According to the method described in any one of claims 1 to 3, the tailings are regrinded using an argon sand mill with a feed rate of 100kg-1000kg and a grinding time of 400s-500s to obtain a mill discharge product.

5. According to the method described in claim 4, in the second stage magnetic suspension concentration, the mill discharge product is configured to have a concentration of 10%-20%, and is fed to the second stage magnetic suspension concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 350-400 GS, and an upward water flow of 20-50 L / min to obtain iron concentrate 6 and tailings 6.

6. According to the method described in any one of claims 1 to 5, in the third stage of magnetic levitation concentration, the mixture of iron concentrate 5 and iron concentrate 6 is configured to have a concentration of 10%-20%, and is fed to the third stage magnetic levitation concentrator under the conditions of a feed rate of 0.45-0.80 kg / min, a magnetic field strength of 200-300 GS, and an upward water flow of 40-50 L / min to obtain iron concentrate 7 and tailings 7.

7. A Barun iron concentrate obtained by the method according to any one of claims 1 to 6.

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