A beneficiation method for magnetite concentrate resource utilization

Abstract

The present application relates to the technical field of iron ore dressing, and particularly relates to a beneficiation method for resource utilization of magnetite concentrate, the present application discloses a beneficiation method for resource utilization of magnetite concentrate, which comprises the following steps: ordinary magnetite concentrate raw materials are divided into first-grade magnetite concentrate raw materials and second-grade magnetite concentrate raw materials; the sorting process of the first-grade magnetite concentrate raw materials comprises the following steps: water cyclone grading, tower mill tower grinding, rough magnetic separation, one-stage magnetic separation and two-stage magnetic separation; the sorting process of the second-grade magnetite concentrate raw materials comprises the following steps: water cyclone grading, tower mill tower grinding, one-stage magnetic separation and two-stage magnetic separation; the sorting process of the present application is simple, the process does not use flotation or chemical beneficiation, and the one-stage magnetic separation and the two-stage magnetic separation do not need to be subjected to demagnetization treatment, so that the process flow is simple, the cost is low, and the process is environmentally friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of iron ore dressing, in particular to a beneficiation method for resource utilization of magnetite concentrate. BACKGROUND

[0002] At present, in response to the national double carbon policy, all walks of life are looking for ways to reduce carbon emissions. The steel industry accounts for 13%-15% of China's total carbon emissions, so carbon-free metallurgical process is a problem that the steel industry needs to solve urgently. Studies have shown that high-grade pellet with hydrogen-based reduction has good metallurgical properties and can effectively reduce carbon dioxide emissions. Therefore, the demand for high-grade pellet in China is increasing, and the preparation of high-grade iron concentrate, as the raw material of high-grade pellet, is particularly important. However, the iron ore resources in China have low ore grade, fine ore dissemination size, and many impurity minerals, which need to be finely ground and deeply selected to reduce impurity content and improve concentrate grade.

[0003] The Chinese invention patent with publication number CN112090578A points out a beneficiation method for preparing ultra-pure iron concentrate from magnetite concentrate, which puts the magnetite concentrate with TFe in the range of 66.5%-68.9% into a one-stage grinding-classification operation. The grinding adopts a ball mill, and the classification-one-stage low-intensity magnetic separation, one-stage low-intensity magnetic separation concentrate dewatering, two-stage grinding-classification, two-stage low-intensity magnetic separation rough separation-demagnetization-two-stage low-intensity magnetic separation cleaning, two-stage low-intensity magnetic separation cleaning concentrate demagnetization-concentration operation: the obtained two-stage low-intensity magnetic separation cleaning concentrate is subjected to demagnetization treatment, and then concentration and reverse flotation operation, finally obtaining ultra-pure iron concentrate with TFe>72.0%, SiO2 content≤0.20%, acid-insoluble substance≤0.17%, and high-purity iron concentrate with TFe>70.7%. However, the beneficiation process is relatively complex, and the magnetic separation must be preceded by demagnetization treatment, and the magnetic separation concentrate also needs to be subjected to reverse flotation operation.

[0004] The Chinese invention patent with publication number CN110193423B points out a beneficiation method for obtaining high-grade iron concentrate from iron ore, which can increase the iron ore without magnetic iron or with less than 5% magnetic iron to an iron grade of more than 65% high-grade iron concentrate. Mainly using an external magnetic high-intensity magnetic separator to pre-recover high-grade iron concentrate with TFe grade of more than 65% at coarse particle level, and then using a vertical ring pulsating high-intensity magnetic separator or a flat ring high-intensity magnetic separator to recover iron concentrate with TFe grade of more than 60%, and the mixture of the two kinds of iron concentrate can achieve iron concentrate with TFe grade of more than 63% and recovery rate of more than 85%.

[0005] The Chinese invention patent with publication number CN115155799A points out a beneficiation method for grading and reselecting high-grade iron concentrate from iron ore tailings, which combines the cleaning concentrate and the one-stage magnetic separation concentrate for flotation, and finally obtains concentrate product with iron grade of more than 60%.

[0006] The Chinese invention patent with announcement number CN112892847B states "A mineral processing technology for reducing impurities in cassiterite-impregnated iron ore to prepare high-grade iron concentrate", which obtains high-grade iron concentrate through a process of raw ore crushing-magnetic separation-magnetic concentrate reverse flotation.

[0007] Chinese invention patent CN1920066 discloses a method for producing ultrapure iron concentrate powder, which can increase the iron content of low-grade iron concentrate (60-66%) to about 71%. The method involves grinding low-grade iron concentrate powder (60-66%) with a particle size of 160-180 mesh, separating it into 260-mesh powder using a separator; adding a water mixture composed of a strong alkaline reagent, allowing it to react fully, and then discharging the material. The discharged material is placed in a settling tank for sedimentation. The upper part of the sediment is a sodium silicate solution (a byproduct), and the lower part is ultrapure iron concentrate powder.

[0008] Comprehensive analysis shows that the preparation of high-grade iron concentrate often requires grinding the raw materials to liberate the monomers. However, over-grinding is prone to occur during grinding, leading to mud formation in the grinding product and affecting subsequent separation indicators. Furthermore, conventional flotation, chemical leaching, microbial leaching, and combined separation processes suffer from complex processes, high beneficiation costs, and potential environmental pollution. With the continuous development of mineral processing technology, the requirements for full utilization of mineral resources and efficient separation are constantly increasing. Therefore, there is an urgent need for a simple, efficient, and environmentally friendly separation method that can efficiently utilize minerals, protect the environment, and produce high-grade iron concentrate with a grade higher than 70%. Summary of the Invention

[0009] To overcome the above problems, the purpose of this invention is to provide a mineral processing method for the resource utilization of magnetite concentrate. The method is simple and low-cost, and can not only separate high-grade magnetite concentrate, but also obtain a variety of magnetite concentrate by-products, thereby maximizing the added value of concentrate products and the utilization of resources.

[0010] To achieve the above objectives, the present invention provides a beneficiation method for the resource utilization of magnetite concentrate, comprising the following steps:

[0011] 1) Classification of common magnetite concentrate raw materials:

[0012] Ordinary magnetite concentrate raw materials are classified according to their grades of 50% < TFe ≤ 60% and 60% < TFe ≤ 68%. The grade of 50% < TFe ≤ 60% is classified as Grade 1 magnetite concentrate raw material, and the grade of 60% < TFe ≤ 68% is classified as Grade 2 magnetite concentrate raw material.

[0013] 2) Sorting of primary magnetite concentrate raw materials:

[0014] 2.1), the primary magnetite concentrate raw material is fed into a hydrocyclone for cyclone classification operation, the underflow product of cyclone classification is fed into a tower mill for grinding operation, and the tower mill product after grinding is returned to the hydrocyclone for cyclone classification operation to obtain an overflow product;

[0015] 2.2), the overflow product is subjected to rough magnetic separation to obtain a rough concentrate and a rough tailing;

[0016] 2.3), the rough concentrate is subjected to one-stage magnetic separation to obtain a one-stage concentrate and a one-stage tailing;

[0017] 2.4), the one-stage concentrate is subjected to two-stage magnetic separation to obtain a two-stage concentrate and a two-stage tailing, the two-stage concentrate is collected to obtain high-grade magnetite concentrate with a TFe grade of >70.5%, and the two-stage tailing is collected to obtain ordinary magnetite concentrate with a TFe grade of 62-68%;

[0018] 2.5), the one-stage tailing in step 2.3) is subjected to magnetic scavenging to obtain a scavenging concentrate and a scavenging tailing, and the scavenging concentrate is collected to obtain medium-low grade magnetite concentrate with a TFe grade of 53-59%;

[0019] 2.6), the scavenging tailing in step 2.5) and the rough tailing in step 2.2) are combined to obtain final tailing with a TFe grade of ≤15%;

[0020] 3), separation of secondary magnetite concentrate raw material:

[0021] 3.1), the secondary magnetite concentrate raw material is fed into a hydrocyclone for cyclone classification operation, the underflow product of cyclone classification is fed into a tower mill for grinding operation, and the tower mill product after grinding is returned to the hydrocyclone for cyclone classification operation to obtain an overflow product;

[0022] 3.2), the overflow product is subjected to one-stage magnetic separation to obtain a one-stage concentrate and a one-stage tailing;

[0023] 3.3), the one-stage concentrate is subjected to two-stage magnetic separation to obtain a two-stage concentrate and a two-stage tailing, and the two-stage concentrate is collected to obtain high-grade magnetite concentrate with a TFe grade of >70.5%;

[0024] 3.4), the one-stage tailing is subjected to magnetic scavenging to obtain a scavenging concentrate and a scavenging tailing, and the scavenging concentrate and the two-stage tailing in step 3.3) are combined to obtain medium-low grade magnetite concentrate with a TFe grade of 53-59%, and the scavenging tailing is collected to obtain final tailing with a TFe grade of ≤10%.

[0025] As a preferred solution, the high-grade magnetite concentrate with TFe grade > 70.5% obtained is used as raw material for hydrogen-based reduced pellets; the ordinary magnetite concentrate with TFe grade of 62-68% obtained is used as raw material for oxidized pellets; and the medium-low grade magnetite concentrate with TFe grade of 53-59% obtained is used as raw material for sintering.

[0026] As a preferred solution, the step 2.1) and the step 3.1) are realized by a closed-circuit device for staged grinding, which comprises a feeding conveying device, a hydrocyclone and a tower mill; the feeding port of the hydrocyclone is connected with the feeding conveying device, the underflow outlet of the hydrocyclone is connected with the inlet of the tower mill, and the outlet of the tower mill is connected with the tower grinding material inlet of the hydrocyclone, and the tower grinding material flows out from the overflow outlet of the hydrocyclone through cyclone classification.

[0027] As a preferred solution, the volume concentration of the feeding of the tower mill is 25%-50%, and the mass percentage of the material with particle size of-0.034 mm in the overflow product of the hydrocyclone is 70-90%.

[0028] As a preferred solution, the high-efficiency impurity-removing belt magnetic separator or wet magnetic drum is used for the rough magnetic separation in the step 2.2).

[0029] As a preferred solution, the high-efficiency impurity-removing belt magnetic separator is used for the first-stage magnetic separation in the step 2.3) and the step 3.2), the field strength is 500-1200 GS, the slope is 22-25°, the belt speed is 0.5-0.7 m / s, and the water pressure is 0.3-0.7 MPa.

[0030] As a preferred solution, the high-efficiency impurity-removing belt magnetic separator is used for the second-stage magnetic separation in the step 2.4) and the step 3.3), the field strength is 500-1200 GS, the slope is 22-25°, the belt speed is 0.6-0.7 m / s, and the water pressure is 0.3-0.7 MPa.

[0031] The present application has the following advantages compared with the conventional magnetite concentrate beneficiation method:

[0032] (1) The ordinary magnetite concentrate raw material is fed into the hydrocyclone for cyclone classification operation, the underflow product of the cyclone classification is fed into the tower mill for grinding operation, and the tower mill product is returned to the hydrocyclone for cyclone classification operation to obtain the overflow product, and the hydrocyclone and the tower mill form a closed circuit process, which can reduce the amount of ore entering the mill, reduce overgrinding, reduce the grinding energy consumption, and improve the separation effect.

[0033] (2), the present application classifies the ordinary magnetite concentrate raw material according to the grade 50% < TFe <= 60% and 60% < TFe <= 68%, obtains the first grade magnetite concentrate raw material and the second grade magnetite concentrate raw material, the first grade magnetite concentrate raw material is increased in the rough magnetic separation process in the sorting process, and the second grade magnetite concentrate raw material cancels the rough magnetic separation process in the sorting process, according to the grade of the ordinary magnetite concentrate raw material, the corresponding sorting process can reduce the cost of sorting.

[0034] (3), the sorting process of the first grade magnetite concentrate raw material of the present application is hydrocyclone classification, tower mill tower grinding, rough magnetic separation and one-stage magnetic separation and two-stage magnetic separation; the sorting process of the second grade magnetite concentrate raw material is hydrocyclone classification, tower mill tower grinding, one-stage magnetic separation and two-stage magnetic separation; the sorting process of the present application is simple, the process does not use flotation or chemical beneficiation, and does not need to be demagnetized before one-stage magnetic separation and two-stage magnetic separation, the process flow is simple, the cost is low, and the environment is friendly.

[0035] (4), the present application not only obtains high-grade magnetite concentrate with TFe grade > 70.5% which can be used for hydrogen-based reduced pellets, but also obtains ordinary magnetite concentrate with TFe grade of 62-68% which can be used for oxidized pellets, medium-low grade magnetite concentrate with TFe grade of 53-59% which can be used for sintering ore matching, and final tailings with TFe grade <= 10%, realizing the maximization of the added value of concentrate products and the resource utilization. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The sorting flow chart of the first grade magnetite concentrate raw material is shown in the figure;

[0037] Figure 2 The sorting flow chart of the second grade magnetite concentrate raw material is shown in the figure. DETAILED DESCRIPTION

[0038] In order to better understand the present application, the application will be described in detail in combination with the drawings and specific examples.

[0039] Example 1

[0040] Combined with the drawings Figure 2 As shown in the figure, the beneficiation method for magnetite concentrate resource utilization includes the following steps:

[0041] 1), classification of ordinary magnetite concentrate raw material:

[0042] After detection, the grade of the ordinary magnetite concentrate raw material to be treated is 65.34%, which is the second grade magnetite concentrate raw material.

[0043] 2), sorting of the second grade magnetite concentrate raw material:

[0044] 3.1), the secondary magnetite concentrate raw material is fed into a hydrocyclone for cyclone classification operation, the underflow product of cyclone classification is fed into a tower mill for grinding operation, and the tower mill product is returned to the hydrocyclone for cyclone classification operation to obtain an overflow product; wherein the ore feeding volume concentration of the tower mill is controlled at 40%, and the particle size of the overflow product of the hydrocyclone reaches 80% of -0.034 mm; the classification-tower milling operation is realized through a classification-tower milling closed circuit device, which includes a feed conveying device, a hydrocyclone and a tower mill; the feed inlet of the hydrocyclone is connected with the feed conveying device, the underflow outlet of the hydrocyclone is connected with the inlet of the tower mill, and the outlet of the tower mill is connected with the tower feed inlet of the hydrocyclone, and the tower feed is discharged from the overflow outlet of the hydrocyclone through cyclone classification.

[0045] 3.2), the overflow product is subjected to one-stage high-efficiency impurity removal belt magnetic separation to obtain one-stage concentrate and one-stage tailings; the field strength of the one-stage high-efficiency impurity removal belt magnetic separator is 800 GS, the slope is 20°, the belt speed is 0.6 m / s, and the water pressure is 0.4 MPa.

[0046] 3.3), the one-stage concentrate is subjected to two-stage high-efficiency impurity removal belt magnetic separation to obtain two-stage concentrate and two-stage tailings, and the two-stage concentrate is collected to obtain high-grade magnetite concentrate with TFe grade of 70.65% and recovery rate of 84.89%; the field strength of the two-stage high-efficiency impurity removal belt magnetic separator is 600 GS, the slope is 22°, the belt speed is 0.6 m / s, and the water pressure is 0.6 MPa.

[0047] 3.4), the one-stage tailings are subjected to magnetic separation scavenging to obtain scavenging concentrate and scavenging tailings; the scavenging concentrate and the two-stage tailings in step 3.3) are combined and collected to obtain medium-low grade magnetite concentrate with TFe grade of 55.95% and recovery rate of 14.46%; the scavenging tailings are collected to obtain final tailings with TFe grade of 9.25% and recovery rate of 0.65%.

[0048] The obtained high-grade magnetite concentrate with TFe grade of 70.65% is used as raw material for hydrogen-based reduced pellets, and the medium-low grade magnetite concentrate with TFe grade of 55.95% is used as raw material for sintering.

[0049] Example 2

[0050] In combination Figure 1 As shown in the figure, the beneficiation method for magnetite concentrate resource utilization includes the following steps:

[0051] 1), classification of ordinary magnetite concentrate raw material:

[0052] After detection, the grade of the ordinary magnetite concentrate raw material to be treated is 55.30%, which is a first-stage magnetite concentrate raw material.

[0053] 2), sorting of first-stage magnetite concentrate raw material:

[0054] 2.1), the primary magnet concentrate raw material is fed into a hydrocyclone for cyclone classification operation, the underflow product of cyclone classification is fed into a tower mill for grinding operation, and the tower mill product is returned to the hydrocyclone for cyclone classification operation to obtain an overflow product; wherein the ore feeding volume concentration of the tower mill is controlled at 35%, and the particle size of the hydrocyclone overflow product reaches 75% of -0.034mm; the classification-tower milling operation is realized through a classification-milling closed circuit device, which includes a feed conveying device, a hydrocyclone and a tower mill; the feed inlet of the hydrocyclone is connected with the feed conveying device, the underflow outlet of the hydrocyclone is connected with the inlet of the tower mill, and the outlet of the tower mill is connected with the tower feed inlet of the hydrocyclone, and the tower feed is discharged from the overflow outlet of the hydrocyclone through cyclone classification.

[0055] 2.2), the overflow product is subjected to rough magnetic separation through a wet magnetic drum magnetic separator to obtain rough concentrate and rough tailings; the field strength of the wet magnetic drum magnetic separator is 1300GS;

[0056] 2.3), the rough concentrate is subjected to one-stage magnetic separation through a one-stage high-efficiency impurity removal belt magnetic separator to obtain one-stage concentrate and one-stage tailings; the field strength of the one-stage high-efficiency impurity removal belt magnetic separator is 1000GS, the slope is 23°, the belt speed is 0.55m / s, and the water pressure is 0.5MPa.

[0057] 2.4), the one-stage concentrate is subjected to two-stage magnetic separation through a two-stage high-efficiency impurity removal belt magnetic separator to obtain two-stage concentrate and two-stage tailings, and the two-stage concentrate is collected to obtain high-grade magnetite concentrate with a TFe grade of 70.53% and a recovery rate of 61.14%; the two-stage tailings are collected to obtain ordinary magnetite concentrate with a TFe grade of 62.52% and a recovery rate of 28.04%; the field strength of the two-stage high-efficiency impurity removal belt magnetic separator is 600GS, the slope is 23°, the belt speed is 0.65m / s, and the water pressure is 0.6MPa.

[0058] 2.5), the one-stage tailings in step 2.3) are subjected to magnetic separation scavenging to obtain scavenging concentrate and scavenging tailings, and the scavenging concentrate is collected to obtain medium-low grade magnetite concentrate with a TFe grade of 58.69% and a recovery rate of 5.50%;

[0059] 2.6), the scavenging tailings in step 2.5) and the rough tailings in step 2.2) are combined to obtain final tailings with a TFe grade of 13.03% and a recovery rate of 5.32%.

[0060] The TFe grade of 70.53% high-grade magnetite concentrate is used as raw material for hydrogen-based reduced pellets;

[0061] The TFe grade of 62.52% ordinary magnetite concentrate is used as raw material for oxidized pellets;

[0062] TFe grade 58.69% low grade magnetite concentrate is used as raw material for sintering.

[0063] The above-described embodiments only express several embodiments of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation to the scope of the patent of the present application. It should be noted that, for ordinary skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A beneficiation method for resource utilization of magnetite concentrate, characterized in that, The method comprises the steps of: 1) classifying common magnetite concentrate raw materials according to the grade 50% < TFe ≤ 60% and 60% < TFe ≤ 68%, wherein the grade 50% < TFe ≤ 60% is the first-grade magnetite concentrate raw material, and the grade 60% < TFe ≤ 68% is the second-grade magnetite concentrate raw material; 2) sorting the first-grade magnetite concentrate raw material: 2.1) feeding the first-grade magnetite concentrate raw material into a hydrocyclone for cyclone classification, feeding the underflow product of the cyclone classification into a tower mill for grinding, returning the tower mill product to the hydrocyclone for cyclone classification, and obtaining the overflow product; 2.2) performing rough magnetic separation on the overflow product to obtain rough concentrate and rough tailings; 2.3) performing one-stage magnetic separation on the rough concentrate to obtain one-stage concentrate and one-stage tailings; 2.4) performing two-stage magnetic separation on the one-stage concentrate to obtain two-stage concentrate and two-stage tailings, collecting the two-stage concentrate to obtain high-grade magnetite concentrate with a TFe grade > 70.5%, and collecting the two-stage tailings to obtain common magnetite concentrate with a TFe grade of 62-68%; 2.5) performing magnetic scavenging on the one-stage tailings in step 2.3) to obtain scavenging concentrate and scavenging tailings, and collecting the scavenging concentrate to obtain medium-low-grade magnetite concentrate with a TFe grade of 53-59%; 2.6) combining the scavenging tailings in step 2.5) and the rough tailings in step 2.2) to obtain final tailings with a TFe grade ≤ 15%; 3) sorting the second-grade magnetite concentrate raw material: 3.1) feeding the second-grade magnetite concentrate raw material into a hydrocyclone for cyclone classification, feeding the underflow product of the cyclone classification into a tower mill for grinding, returning the tower mill product to the hydrocyclone for cyclone classification, and obtaining the overflow product; 3.2) performing one-stage magnetic separation on the overflow product to obtain one-stage concentrate and one-stage tailings; 3.3) performing two-stage magnetic separation on the one-stage concentrate to obtain two-stage concentrate and two-stage tailings, and collecting the two-stage concentrate to obtain high-grade magnetite concentrate with a TFe grade > 70.5%; 3.4) performing magnetic scavenging on the one-stage tailings to obtain scavenging concentrate and scavenging tailings, and combining the scavenging concentrate and the two-stage tailings in step 3.3) to obtain medium-low-grade magnetite concentrate with a TFe grade of 53-59%; and collecting the scavenging tailings to obtain final tailings with a TFe grade ≤ 10%. The obtained high-grade magnetite concentrate with a TFe grade > 70.5% is used as raw material for hydrogen-based reduced pellets, the obtained common magnetite concentrate with a TFe grade of 62-68% is used as raw material for oxidized pellets, and the obtained medium-low-grade magnetite concentrate with a TFe grade of 53-59% is used as raw material for sintering.

2. The beneficiation method for resource utilization of magnetic iron ore concentrate according to claim 1, characterized in that, ​ 3. The beneficiation method for resource utilization of magnetic iron ore concentrate according to claim 1, characterized in that, Said step 2.1) and said step 3.1) are achieved by a closed-circuit device of stage grinding, which comprises a feed conveying device, a hydrocyclone and a tower mill; the feed inlet of the hydrocyclone is connected with the feed conveying device, the underflow outlet of the hydrocyclone is connected with the inlet of the tower mill, the outlet of the tower mill is connected with the tower feed inlet of the hydrocyclone, and the tower feed is discharged from the overflow outlet of the hydrocyclone through cyclone classification.

4. The beneficiation method for resource utilization of magnetic iron ore concentrate according to claim 3, characterized in that, The volume concentration of the feed of the tower mill is 25%-50%, and the mass percentage of the material with particle size of-0.034 mm in the overflow product of the hydrocyclone is 70-90%.

5. The beneficiation method for resource utilization of magnetic iron ore concentrate according to claim 3, characterized in that, In said step 2.2), the high-efficiency impurity removal belt magnetic separator or wet magnetic drum is used for rough magnetic separation.

6. The beneficiation method for resource utilization of magnetic iron ore concentrate according to claim 3, characterized in that, In said step 2.3) and step 3.2), the high-efficiency impurity removal belt magnetic separator is used for one-stage magnetic separation, the field strength is 500-1200 GS, the slope is 22-25°, the belt speed is 0.5-0.7 m / s, and the water pressure is 0.3-0.7 MPa.

7. The beneficiation method for resource utilization of magnetic iron ore concentrate according to claim 3, characterized in that, In said step 2.4) and step 3.3), the high-efficiency impurity removal belt magnetic separator is used for two-stage magnetic separation, the field strength is 500-1200 GS, the slope is 22-25°, the belt speed is 0.6-0.7 m / s, and the water pressure is 0.3-0.7 MPa.

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