CN111715393B - Mineral separation method for grading, recleaning and quality improvement of fine-grained magnetite concentrate - Google Patents

Abstract

The invention discloses a beneficiation method for grading, recleaning and upgrading fine-grained magnetite concentrates, and relates to the technical field of beneficiation. The beneficiation method for grading, recleaning and upgrading fine-grained magnetite concentrate is characterized by comprising the following steps: the method comprises the following steps: s1, one-stage elutriation and fine selection operation: and performing primary elutriation and concentration on the magnetite concentrate which is subjected to the purification of the beneficiation operation and has TFe of 62.0-64.0% and the particle size of-0.045 mm 85-95% by using an elutriation magnetic separator, and removing part of poor intergrowths and gangue in the magnetite concentrate. The beneficiation method for grading, re-selecting and upgrading fine-grained magnetite concentrate is characterized in that the fine-grained magnetite concentrate is selected by utilizing the cyclone re-selection principle, a part of elutriation and concentration processes are replaced, the load of subsequent elutriation and concentration operations is reduced, meanwhile, the TFe grade of the common iron concentrate purified by the beneficiation operation can be improved from 62.0% -64.0% to 65.0% -67.0%, the method is simple in process, suitable for large-scale industrial production, chemical agents are not needed in the production process, and the obtained product has a higher added value.

Description

Mineral separation method for grading, recleaning and quality improvement of fine-grained magnetite concentrate

Technical Field

The invention relates to the technical field of mineral separation, in particular to a mineral separation method for grading, recleaning and upgrading fine-grained magnetite concentrates.

Background

The iron concentrates produced at present are mainly magnetite concentrates, and the TFe grade of the iron concentrates is generally 62.0 to 65.0 percent. In recent years, because of the growing environmental trend, the iron ore dressing plant which provides the blast furnace raw material must continuously improve the grade of the iron ore concentrate and reduce the content of impurities in order to provide the blast furnace with the 'concentrate', improve the productivity of the blast furnace iron making and reduce the pollution.

At present, the magnetite beneficiation technology mainly adopts a stage grinding-stage low-intensity magnetic separation beneficiation method of single low-intensity magnetic separation, many magnetite beneficiation plants adopt a common magnetic separation method to hardly obtain high-grade magnetite concentrate, and particularly, the single magnetic separation method cannot be used for obtaining the high-grade magnetite concentrate from various originally high-monomer dissociation degrees (generally 80-90%) magnetite in the magnetic separation process. Because the conventional low-intensity magnetic field drum magnetic separator and the magnetic desliming tank applied to the magnetite concentrating mill cannot effectively overcome the magnetic impurities caused by magnetized magnetic agglomeration and residual magnetized magnetic agglomeration, magnetite intergrowth enters magnetic concentrate and non-magnetic impurities to enable monomer gangue to enter the magnetic concentrate, and further quality improvement and impurity reduction of the iron concentrate are limited. In order to improve the quality of the iron ore concentrate in more than ten years, elutriation and concentration equipment (a magnetic separation column, an elutriation magnetic separator and the like) is added behind a cylindrical magnetic separator for re-upgrading operation. The elutriation and concentration equipment utilizes the principle of combining magnetic force and gravity mineral separation, can remove intergrowths with large particle sizes and light specific gravity from a magnetic chain, reduces intergrowth impurities, has higher mineral separation precision compared with a weak magnetic cylinder magnetic separator, but has small treatment capacity and large water consumption, and a section of elutriation and concentration process is mostly adopted in many concentration plants due to the limitation of treatment capacity and production water capacity.

In some magnetite concentration plants at present, the magnetite has fine embedded particle size, the existing magnetic separation process has low separation precision, and poor intergrowth and impurities are difficult to effectively remove. In order to ensure that high-quality iron ore concentrate is continuously provided for ironmaking, the development of a beneficiation method for grading, recleaning and upgrading fine-grained magnetite ore concentrate, which has the advantages of simple flow, brief introduction of operation, low investment on equipment and capital construction, environmental friendliness and high separation precision, is urgently needed.

In recent years, there are many patent applications related to the method for upgrading magnetite concentrates, for example, chinese patent document CN106378256A discloses a method for upgrading and reducing silicon of mixed type lean iron magnetic concentrates, wherein ore pulp of mixed type lean iron magnetic concentrates is fed into an elutriation magnetic separator to obtain elutriated tailings and elutriated concentrates, the elutriated tailings are reground and re-selected, and the re-selected concentrates and the elutriated concentrates are mixed to obtain upgraded and reduced silicon concentrates. The mixed type lean iron magnetic concentrate is directly fed into the elutriation magnetic separator, the required elutriation magnetic separator is more, and the water consumption is large. CN109127122A discloses a mineral processing method for extracting iron and reducing silicon from magnetite concentrate, high-silicon magnetite concentrate is sieved by a high-frequency fine sieve to obtain two products of undersize and oversize, the undersize product is subjected to a first-stage cation reverse flotation to obtain iron concentrate C1, the product on the high-frequency fine sieve and a first-stage cation reverse flotation tailing are combined and then pumped to a cyclone classification-tower mill-low intensity magnetic separation operation to obtain low intensity magnetic concentrate, and the low intensity magnetic concentrate is subjected to a second-stage cation reverse flotation to obtain iron concentrate C2. The flotation operation process is complex, the flotation reagent consumption is high, the operation is complex, the equipment and capital investment is high, various reagents are needed for flotation, the environment is polluted, the reagents are prepared, the mineral separation cost is increased, and the reagents damage the bodies of operators. CN106269212A patent document discloses a method for preparing super iron ore concentrate by magnetic separation-classification, wherein, the common iron ore concentrate is fed into an electromagnetic concentration machine for pre-separation and discarding tailings, the pre-separated ore concentrate is fed into a first-stage hydrocyclone for classification, a first-stage classification sand settling product is fed into a stirring mill for fine grinding, a first-stage classification overflow product is fed into a drum magnetic separator for wet type low intensity magnetic separation to obtain low intensity magnetic separation ore concentrate, then the low intensity magnetic separation ore concentrate is fed into the electromagnetic concentration machine for concentration, the concentrated ore concentrate is fed into a second-stage hydrocyclone for classification, and the overflow product obtained by the second-stage classification is finally iron ore concentrate. In the method, a two-stage hydrocyclone is adopted for grading, the graded first-stage sand setting product is ground, the second-stage sand setting product is used as middlings for reprocessing, and the sand setting is directly used as concentrate without reprocessing.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a beneficiation method for grading, recleaning and upgrading fine-grained magnetite concentrates, and solves the problems that the existing magnetic separation process is low in separation precision and is difficult to effectively remove poor intergrowths and impurities.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: a beneficiation method for grading, recleaning and upgrading of fine-grained magnetite concentrates comprises the following steps:

s1, one-stage elutriation and fine selection operation: carrying out primary elutriation and concentration on the magnetite concentrate which is purified by mineral separation operation and has TFe of 62.0-64.0% and granularity of-0.045 mm 85-95% by an elutriation magnetic separator, and removing part of poor intergrowths and gangue in the magnetite concentrate to respectively obtain a primary elutriation iron concentrate C1 product and a primary elutriation tailing T1 product; in the step, the TFe grade of a product of the first-stage elutriation iron concentrate C1 reaches over 64.0 percent, the TFe grade of a product of the first-stage elutriation tailings T1 is 15-25 percent, the magnetic field intensity range of the elutriation magnetic separator is 110-140kA/m, and the feeding concentration is 35-45 percent;

s2, cyclone selection: concentrating the first-stage elutriation iron concentrate C1 product obtained in the step S1 through a cyclone, namely obtaining an overflow iron concentrate C2 product and a sand setting iron concentrate C3 product by adopting gravity separation; in the step, the TFe grade of the product of the overflow iron ore concentrate C2 is 60-63 percent, the TFe grade of the product of the sand setting iron ore concentrate C3 is 65-67 percent, the hydrocyclone is a hydrocyclone with the diameter of 200mm, the feeding pressure is controlled to be 0.1-0.15 MPa, and the feeding concentration is 35-45 percent;

s3, two-stage elutriation and fine selection operation: performing second-stage elutriation and fine selection on the overflow iron ore concentrate C2 product obtained in the step S2 through an elutriation magnetic separator, further removing fine-grain poor intergrowth and gangue in the magnetite ore concentrate, and obtaining a second-stage elutriation iron ore concentrate C4 product and a second-stage elutriation tailing T2 product; in the step, the TFe grade of the product of the second-stage elutriation iron concentrate C4 reaches more than 65.0 percent, the TFe grade of the product of the second-stage elutriation tailings T2 is 15-25 percent, the magnetic field intensity range of the elutriation magnetic separator is 110-140kA/m, and the feeding concentration is 35-45 percent;

s4, combining the tailing T1 product obtained in the step S1 and the tailing T1 product obtained in the step S3 into tailing or a middling product;

and S5, combining the iron concentrate C3 product obtained in the step S2 and the iron concentrate C4 product obtained in the step S3 to obtain a final iron concentrate product with TFe grade of 65-67%.

(III) advantageous effects

The invention provides a beneficiation method for grading, recleaning and upgrading fine-grained magnetite concentrate. The method has the following beneficial effects: the beneficiation method for grading, re-selecting and upgrading fine-grained magnetite concentrate is characterized in that the fine-grained magnetite concentrate is refined by utilizing the cyclone reselection principle, a part of elutriation and concentration processes is replaced, the load of subsequent elutriation and concentration operation is reduced, the cyclone is used as concentration equipment, the advantages of small equipment floor area, no noise and low energy consumption are achieved, meanwhile, the grade of TFe of the common iron concentrate purified by the beneficiation operation can be improved from 62.0% -64.0% to 65.0% -67.0%, the method is simple in process, low in cost and suitable for large-scale industrial production, chemical agents are not needed in the production process, the method is green and environment-friendly, the obtained product has higher added value, and considerable economic benefit and social benefit can be created.

Drawings

FIG. 1 is a process flow diagram of a beneficiation method for grading, recleaning and upgrading fine-grained magnetite concentrate according to the present invention;

fig. 2 is a mass flow chart of an embodiment of the beneficiation method for grading, recleaning and upgrading of fine-grained magnetite concentrate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides a technical solution: a beneficiation method for grading, recleaning and upgrading of fine-grained magnetite concentrates comprises the following steps:

s1, one-stage elutriation and fine selection operation: carrying out primary elutriation and concentration on the magnetite concentrate which is purified by mineral separation operation and has TFe of 62.0-64.0% and granularity of-0.045 mm 85-95% by an elutriation magnetic separator, and removing part of poor intergrowths and gangue in the magnetite concentrate to respectively obtain a primary elutriation iron concentrate C1 product and a primary elutriation tailing T1 product; in the step, the TFe grade of a product of the first-stage elutriation iron concentrate C1 reaches over 64.0 percent, the TFe grade of a product of the first-stage elutriation tailings T1 is 15-25 percent, the magnetic field intensity range of the elutriation magnetic separator is 110-140kA/m, and the feeding concentration is 35-45 percent;

s2, cyclone selection: concentrating the first-stage elutriation iron concentrate C1 product obtained in the step S1 through a cyclone, namely obtaining an overflow iron concentrate C2 product and a sand setting iron concentrate C3 product by adopting gravity separation; in the step, the TFe grade of the product of the overflow iron ore concentrate C2 is 60-63 percent, the TFe grade of the product of the sand setting iron ore concentrate C3 is 65-67 percent, the hydrocyclone is a hydrocyclone with the diameter of 200mm, the feeding pressure is controlled to be 0.1-0.15 MPa, and the feeding concentration is 35-45 percent;

s3, two-stage elutriation and fine selection operation: performing second-stage elutriation and fine selection on the overflow iron ore concentrate C2 product obtained in the step S2 through an elutriation magnetic separator, further removing fine-grain poor intergrowth and gangue in the magnetite ore concentrate, and obtaining a second-stage elutriation iron ore concentrate C4 product and a second-stage elutriation tailing T2 product; in the step, the TFe grade of the product of the second-stage elutriation iron concentrate C4 reaches more than 65.0 percent, the TFe grade of the product of the second-stage elutriation tailings T2 is 15-25 percent, the magnetic field intensity range of the elutriation magnetic separator is 110-140kA/m, and the feeding concentration is 35-45 percent;

s4, combining the tailing T1 product obtained in the step S1 and the tailing T1 product obtained in the step S3 into tailing or a middling product;

and S5, combining the iron concentrate C3 product obtained in the step S2 and the iron concentrate C4 product obtained in the step S3 to obtain a final iron concentrate product with TFe grade of 65-67%.

Examples

A beneficiation method for grading, recleaning and upgrading of fine-grained magnetite concentrates comprises the following steps:

s1, subjecting the magnetite concentrate product of a certain concentration plant TFe 62.42%, granularity-0.045 mm 88.73%, concentration 41.96%, ore feeding amount 150-;

s2, selecting TFe 64.77% first-stage elutriation iron concentrate products through 6 FX2050-PU-B cyclones, controlling the feeding pressure of the cyclones to be 0.1-0.13 MPa, and controlling the feeding concentration to be 35-45% to obtain TFe 63.75% overflow iron concentrate products and TFe 65.61% sand-settling iron concentrate products;

s3, performing second-stage elutriation and concentration on TFe 63.75% overflow iron concentrate products by using 2 CH-CXJ2600 elutriation magnetic separators, wherein the field intensity range of the magnetic field is 110-140kA/m, and respectively obtaining TFe 65.43% second-stage elutriation iron concentrate products and TFe 17.90% second-stage elutriation tailing products;

s4, combining a TFe 22.06% first-stage elutriation tailing product and a TFe 17.90% second-stage elutriation tailing product into a TFe 21.66% tailing (middling) product;

s5, TFe 65.61% sand setting iron concentrate product and TFe 65.43% second-stage elutriation iron concentrate product are combined to obtain final iron concentrate product with TFe grade of 65.53%.

As can be seen from the mass flow chart of the embodiment of the beneficiation method for grading, recleaning and upgrading of the fine-grained magnetite concentrate of the invention shown in fig. 2, the fine-grained magnetite concentrate tfe treated in the embodiment is 62.42%. The method provided by the invention improves the quality, obtains the iron ore concentrate with the final iron ore concentrate grade of 65.43 percent, has the iron recovery rate of 92.99 percent, and obtains good economic effect.

The industrial production practice shows that the method has the characteristics of obvious quality improvement effect, stable index, simple process, low equipment and capital investment and the like. The produced TFe 21.66% tailings can be used as middlings to be returned to a dressing plant for regrinding and dressing, and the metal recovery rate of the dressing plant is further improved.

In summary, the fine-grained magnetite concentrate grading, re-selecting and quality-improving beneficiation method utilizes the cyclone reselection principle to carry out concentration on the magnetite concentrate to replace part of elutriation and concentration processes, reduces the load of subsequent elutriation and concentration operations, and the cyclone is used as concentration equipment, so that the method has the advantages of small equipment floor area, no noise, low energy consumption and capability of improving the TFe grade of the common iron concentrate purified by the beneficiation operations from 62.0-64.0% to 65.0-67.0%.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (1)

1. A beneficiation method for grading, recleaning and upgrading fine-grained magnetite concentrate is characterized in that: the method comprises the following steps:

s1, one-stage elutriation and fine selection operation: carrying out primary elutriation and concentration on the magnetite concentrate which is purified by mineral separation operation and has TFe of 62.0-64.0% and granularity of-0.045 mm 85-95% by an elutriation magnetic separator, and removing part of poor intergrowths and gangue in the magnetite concentrate to respectively obtain a primary elutriation iron concentrate C1 product and a primary elutriation tailing T1 product; in the step, the TFe grade of a product of the first-stage elutriation iron concentrate C1 reaches over 64.0 percent, the TFe grade of a product of the first-stage elutriation tailings T1 is 15-25 percent, the magnetic field intensity range of the elutriation magnetic separator is 110-140kA/m, and the feeding concentration is 35-45 percent;

s2, cyclone selection: concentrating the first-stage elutriation iron concentrate C1 product obtained in the step S1 through a cyclone, namely obtaining an overflow iron concentrate C2 product and a sand setting iron concentrate C3 product by adopting gravity separation; in the step, the TFe grade of the product of the overflow iron ore concentrate C2 is 60-63 percent, the TFe grade of the product of the sand setting iron ore concentrate C3 is 65-67 percent, the hydrocyclone is a hydrocyclone with the diameter of 200mm, the feeding pressure is controlled to be 0.1-0.15 MPa, and the feeding concentration is 35-45 percent;

s3, two-stage elutriation and fine selection operation: performing second-stage elutriation and fine selection on the overflow iron ore concentrate C2 product obtained in the step S2 through an elutriation magnetic separator, further removing fine-grain poor intergrowth and gangue in the magnetite ore concentrate, and obtaining a second-stage elutriation iron ore concentrate C4 product and a second-stage elutriation tailing T2 product; in the step, the TFe grade of the product of the second-stage elutriation iron concentrate C4 reaches more than 65.0 percent, the TFe grade of the product of the second-stage elutriation tailings T2 is 15-25 percent, the magnetic field intensity range of the elutriation magnetic separator is 110-140kA/m, and the feeding concentration is 35-45 percent;

s4, combining the tailing T1 product obtained in the step S1 and the tailing T2 product obtained in the step S3 into tailing or a middling product;

and S5, combining the iron concentrate C3 product obtained in the step S2 and the iron concentrate C4 product obtained in the step S3 to obtain a final iron concentrate product with TFe grade of 65-67%.

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