Preconcentration and sulfur flotation process for high-sulfur magnetite ore

Abstract

The invention discloses a pre-concentration and sulfur flotation process for high-sulfur magnetite ore, and belongs to the technical field of iron ore beneficiation. Comprising the following steps: 1, crushing and screening the high-sulfur magnetite ore; 2, carrying out first-stage ore grinding-grading on the undersize product; thirdly, sulfur flotation is conducted on the first-section graded overflow product, sulfur concentrate is obtained, and sulfur separation tailings are discharged to enter subsequent iron separation operation; in the step, secondary roughing, secondary concentration and primary scavenging are adopted in the flotation process, middlings are intensively returned to the closed-loop flotation process, and BK 608 and MK 306 are adopted as a collecting agent A and a collecting agent B in the flotation process respectively. According to the method, the reagent unit consumption in the flotation process can be reduced, and meanwhile the effective sulfur grade of the sulfur concentrate is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of iron ore beneficiation, and more specifically, relates to a high-sulfur magnetite ore pre-selection and sulfur flotation process. Background Art

[0002] Pre-selection is an important part of iron ore beneficiation, and pre-selection tailings discarding is an important means to achieve "more crushing and less grinding" and "discarding as early as possible". For single magnetite, the application of pre-selection is becoming more and more mature, but there has been no successful application and ideal effect of pre-selection of high-sulfur magnetite ore. It is mainly manifested in that it is difficult to take into account both the tailings discarding yield and the magnetic iron content in the tailings. If too much is discarded, the magnetic iron grade in the tailings is high, which affects the magnetic iron recovery rate and iron concentrate output of the whole process; if less is discarded in order to ensure the magnetic iron grade in the tailings, it is difficult to ensure the magnetic iron grade of the ore entering the mill, which increases the burden of subsequent grinding and selection operations and affects the quality of the iron concentrate.

[0003] In addition, for high-sulfur magnetite ores, in order to ensure that the sulfur content in the iron concentrate does not exceed the standard, the principle process of first flotation and then magnetization is often adopted. At present, collectors and frothers are usually added for flotation and sulfur selection, such as a one-rough, two-fine and one-sweep process, to obtain qualified sulfur concentrate products (effective sulfur grade greater than 40.0%) while reducing the effective sulfur content in the floating tail to avoid affecting the quality of the iron concentrate in subsequent iron selection operations. However, there are often problems of high reagent unit consumption and high cost. In recent years, new collectors have also appeared, which do not require the addition of frothers, which can greatly reduce the reagent unit consumption, but there are also large fluctuations in indicators. The effective sulfur grade in the original ore has increased significantly, and the amount of reagents needs to be increased, which will lead to flotation tank running and production being difficult to control. Summary of the invention

[0004] 1. Problems to be solved

[0005] Aiming at the problem that the existing high-sulfur magnetite preselection and sulfur flotation processes have poor effects, the present invention provides a high-sulfur magnetite preselection and sulfur flotation process, which can reduce the reagent consumption in the flotation process and improve the effective sulfur grade of sulfur concentrate.

[0006] 2. Technical solution

[0007] To solve the above problems, the present invention adopts the following technical solutions.

[0008] A high-sulfur magnetite ore pre-selection and sulfur flotation process comprises the following steps:

[0009] 1. Crushing and screening high-sulfur magnetite ore;

[0010] 2. Grinding and classifying the product under the screen;

[0011] 3. Carry out sulfur flotation on the overflow product of the first stage classification to obtain sulfur concentrate, and discharge the sulfur tailings for subsequent iron selection operations; in this step, the flotation process adopts secondary roughing, secondary cleaning, and primary scavenging, and the middlings are concentrated and returned to the closed-circuit flotation process. BK 608 and MK 306 are used as collectors A and B in the flotation process, respectively.

[0012] As a further improvement of the technical solution, the specific process of step one is: crushing the high-sulfur magnetite ore from -250mm to -60mm, and then screening the crushed product to obtain three particle sizes of +50mm, -50+10mm and -10mm.

[0013] As a further improvement of the technical solution, step one also includes: directly putting the obtained -10mm particle size product into the ball grinding ore bin; performing dry selection, coarse selection and sweeping to discard the tailings of the obtained -50+10mm particle size product, retaining the dry selection tailings, combining the dry selection concentrate with the obtained +50mm particle size for fine crushing and then returning to the screening equipment to form a closed circuit.

[0014] As a further improvement of the technical solution, the dry roughing selection adopts LCT1014 permanent magnetic dry bulk magnetic separator with a magnetic field strength of 0.3T; the dry sweeping selection adopts CTX0820 dry magnetic separator with a magnetic field strength of 0.4T.

[0015] As a further improvement of the technical solution, the undersize product in step 2 refers to the -10 mm particle size product obtained in step 1, and the grinding particle size in this step is controlled at -0.076 mm particle size, accounting for 50% to 55%.

[0016] As a further improvement of the technical solution, in the step three, the dosage of the reagents for the first rough selection is: collector A is 40-60 g / t, and collector B is 20-40 g / t; the dosage of the reagents for the second rough selection is: collector A is 20-40 g / t, and collector B is 10-30 g / t; the dosage of the reagents for the first scavenging selection is: collector A is 10-30 g / t, and collector B is 5-15 g / t.

[0017] As a further improvement of the technical solution, the screening equipment in step 1 adopts a double-layer circular vibrating screen, with the upper layer sieve hole size of 20×50 mm and the lower layer sieve hole size of 10×30 mm.

[0018] As a further improvement of the technical solution, the ore grinding in step 2 adopts an MQY 4060 overflow ball mill.

[0019] As a further improvement of the technical solution, a Φ500×6 hydrocyclone group is used for classification in step 2.

[0020] 3. Beneficial effects

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention discloses a high-sulfur magnetite preselection and sulfur flotation process. The medium-crushed products of the high-sulfur magnetite ore are subjected to double-layer screening and grading. The -10mm particle size products are directly sent to the ball grinding ore bin to eliminate the influence of the fine particle size on the large-block dry selection. The +50mm particle size products are directly returned to the fine crushing without dry selection. Because the particle size is large, the useful minerals are not fully dissociated, and the dry selection operation easily leads to excessive loss of magnetic iron, effective sulfur and copper elements in the dry selection tailings. The -50+10mm particle size is dry selected, and some of the block tailings are discarded. The tailings can be sold as building aggregates, and the amount of ore entering the fine crushing is reduced, which is beneficial to reducing the load of the fine crushing cone crusher and achieving energy saving and efficiency improvement.

[0023] (2) The present invention provides a high-sulfur magnetite pre-selection and sulfur flotation process, wherein the dry selection adopts a one-roughing and one-sweeping process and uses different types of equipment. The dry selection roughing adopts an LCT1014 permanent magnetic dry bulk magnetic separator, and the dry selection scavenging adopts a CTX0820 dry magnetic separator, which is conducive to giving full play to the respective advantages of different types of dry selection equipment;

[0024] (3) The present invention provides a high-sulfur magnetite ore pre-selection and sulfur flotation process, wherein the sulfur flotation process adopts a two-roughing, two-fine and one-sweeping closed-circuit flotation process, and adopts two roughing selections, which is beneficial to improving the roughing effect and increasing the recovery rate;

[0025] (4) The present invention provides a high-sulfur magnetite preselection and sulfur flotation process, in which two different types of collectors are used in combination as flotation reagents, thereby eliminating the need for a frother and giving full play to the synergistic effect between the two collectors, thereby reducing reagent consumption per unit and reducing the production cost of the ore dressing plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a process flow chart of the preselection and sulfur flotation process of high-sulfur magnetite ore. DETAILED DESCRIPTION

[0027] Exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention, it should be understood that other embodiments may be implemented and various changes may be made to the present invention without departing from the spirit and scope of the present invention. The more detailed description of the embodiments of the present invention below is not intended to limit the scope of the claimed invention, but is merely for illustration and does not limit the description of the features and characteristics of the present invention, in order to propose the best mode for performing the present invention, and is sufficient to enable those skilled in the art to implement the present invention. Therefore, the scope of the present invention is limited only by the appended claims.

[0028] Example 1

[0029] like Figure 1 As shown, a high-sulfur magnetite ore pre-selection and sulfur flotation process comprises the following steps:

[0030] 1. Crushing and screening the high-sulfur magnetite ore, specifically: crushing the high-sulfur magnetite ore from -250mm to -60mm, and then screening the medium-crushed product to obtain three particle sizes of +50mm, -50+10mm and -10mm. Then the obtained -10mm particle size product is directly put into the ball mill ore bin; the obtained -50+10mm particle size product is subjected to dry selection, roughing and sweeping, and the dry selection tailings are retained. The dry selection concentrate is combined with the obtained +50mm particle size for fine crushing and then returned to the screening equipment to form a closed circuit.

[0031] In this embodiment, the dry roughing selection adopts LCT1014 permanent magnetic dry bulk magnetic separator with a magnetic field strength of 0.3 T; the dry sweeping selection adopts CTX0820 dry magnetic separator with a magnetic field strength of 0.4 T. The screening equipment adopts a double-layer circular vibrating screen with an upper sieve hole size of 20×50 mm and a lower sieve hole size of 10×30 mm.

[0032] In this step, the medium-crushed products of high-sulfur magnetite ore are subjected to double-layer screening and grading. The -10mm particle size products are directly sent to the ball grinding ore bin to eliminate the influence of the fine particle size on the large-block dry selection. The +50mm particle size products are directly returned to the fine crushing without dry selection. Because of their large particle size, the useful minerals are not fully dissociated, and entering the dry selection operation is likely to cause excessive losses of magnetic iron, effective sulfur and copper elements in the dry selection tailings. The -50+10mm particle size is dry selected and some of the block tailings are discarded. They can be sold as building aggregates and reduce the amount of ore entering the fine crushing, which is beneficial to reducing the load of the fine crushing cone crusher and achieving energy saving and efficiency improvement.

[0033] The dry separation adopts a one-roughing and one-sweeping process, and uses different types of equipment. The dry separation roughing adopts the LCT1014 permanent magnetic dry bulk magnetic separator; the dry separation sweeping adopts the CTX0820 dry magnetic separator, which is conducive to giving full play to the advantages of various types of dry separation equipment. After the implementation of this method, the dry separation tailings discarding rate increased by 7.5 percentage points compared with before (from 8.5% to 16.0%, an increase of 88.24%), and the magnetic iron grade in the dry tailings dropped from 1.96% to 1.34% (a decrease of 31.63%). While the dry tailings yield increased significantly, the magnetic iron grade in the tailings was also greatly reduced, which greatly exceeded expectations (the expected indicator is to increase the tailings discarding yield when the magnetic iron grade of the tailings does not increase or slightly increases), and has achieved unexpected technical effects.

[0034] Second, the product under the screen is subjected to a first-stage grinding and classification. Specifically, the -10mm particle size product obtained in step 1 is subjected to a first-stage grinding and classification, and a first-stage classification overflow product is discharged. The grinding particle size is controlled at a -0.076mm particle size accounting for 50% to 55%.

[0035] In this embodiment, MQY 4060 overflow ball mill is used for grinding, and Φ500×6 hydrocyclone group is used for classification.

[0036] 3. Carry out sulfur flotation on the overflow product of the first stage classification to obtain sulfur concentrate, and discharge the sulfur tailings for subsequent iron selection operations; in this step, the flotation process adopts secondary roughing, secondary cleaning, and primary scavenging, and the middlings are concentrated and returned to the closed-circuit flotation process. BK 608 and MK 306 are used as collectors A and B in the flotation process, respectively.

[0037] In step three, the dosage of reagents for the first roughing selection is: collector A is 40-60g / t, and collector B is 20-40g / t; the dosage of reagents for the second roughing selection is: collector A is 20-40g / t, and collector B is 10-30g / t; the dosage of reagents for the first scavenging selection is: collector A is 10-30g / t, and collector B is 5-15g / t.

[0038] Step 3 uses two roughing operations, which is beneficial to improving the roughing effect and increasing the recovery rate. The flotation reagent uses two types of collectors in combination, which not only saves the frother, but also brings into play the synergistic effect between the two collectors, reduces the reagent consumption per unit, and reduces the production cost of the ore dressing plant.

[0039] Before the implementation of this method, the collector A was used alone with the frother to select sulfur. Under the conditions of effective sulfur grade of 5.67% in the feed ore and total dosage of 250 g / ton of collector A, the yield of sulfur concentrate was 12.54%, the effective sulfur grade of sulfur concentrate was 40.55%, and the effective sulfur recovery rate was 89.68%. Under the conditions of effective sulfur grade of 5.96% in the feed ore and total dosage of 100 g / ton of collector B (no frother required), the yield of sulfur concentrate was 13.22%, the effective sulfur grade of sulfur concentrate was 40.35%, and the effective sulfur recovery rate was 89.50%.

[0040] After the implementation of this method, the mixed use of collector A and collector B for sulfur selection, the frother was eliminated, and under the conditions of effective sulfur grade of 5.32% in the feed, total dosage of collector A and collector B of 160 g / ton, the yield of sulfur concentrate was 11.29%, the effective sulfur grade of sulfur concentrate was 41.77%, and the effective sulfur recovery rate was 88.64%. It can be seen that the mixed use of the two collectors has played a synergistic effect, greatly improved the selection index, and the effective sulfur grade of sulfur concentrate was increased by 1.22 percentage points, which has achieved an unexpected technical effect of 1+1>2. At the same time, it also reduces the unit consumption of reagents, which is conducive to reducing the production cost of the ore dressing plant.

[0041] In summary, the high-sulfur magnetite ore preselection and sulfur flotation process of this embodiment can reduce the reagent consumption in the flotation process and improve the effective sulfur grade of the sulfur concentrate.

[0042] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A process for preselection and sulfur flotation of high-sulfur magnetite ore, characterized in that: The following steps are involved:

1. Crushing and screening high-sulfur magnetite ore; 2. Grinding and classifying the product under the screen; 3. Carry out sulfur flotation on the overflow product of the first stage classification to obtain sulfur concentrate, and discharge the sulfur tailings for subsequent iron selection operations; in this step, the flotation process adopts secondary roughing, secondary cleaning, and primary scavenging, and the middlings are concentrated and returned to the closed-circuit flotation process. BK 608 and MK 306 are used as collectors A and B in the flotation process, respectively.

2. The process for preselection and sulfur flotation of high-sulfur magnetite ore according to claim 1, characterized in that: The specific process of step one is: crushing the high-sulfur magnetite ore from -250mm to -60mm, and then screening the crushed product to obtain three particle sizes of +50mm, -50+10mm and -10mm.

3. The process for preselection and sulfur flotation of high-sulfur magnetite ore according to claim 2, characterized in that: The step 1 also includes: directly putting the obtained -10mm particle size product into the ball grinding ore bin; performing dry selection, coarse selection and sweeping and discarding of the obtained -50+10mm particle size product, retaining the dry selection tailings, combining the dry selection concentrate with the obtained +50mm particle size for fine crushing and then returning to the screening equipment to form a closed circuit.

4. The process for preselection and sulfur flotation of high-sulfur magnetite ore according to claim 2, characterized in that: The dry roughing selection adopts LCT1014 permanent magnetic dry bulk magnetic separator with a magnetic field strength of 0.3T; the dry sweeping selection adopts CTX0820 dry magnetic separator with a magnetic field strength of 0.4T.

5. The process for pre-selection and sulfur flotation of high-sulfur magnetite ore according to claim 1, characterized in that: The undersize product in step 2 refers to the -10 mm particle size product obtained in step 1. The grinding particle size in this step is controlled at -0.076 mm particle size, accounting for 50% to 55%.

6. The process for pre-selection and sulfur flotation of high-sulfur magnetite ore according to claim 1, characterized in that: In the step 3, the dosage of the reagents for the first roughing selection is: collector A is 40-60 g / t, and collector B is 20-40 g / t; the dosage of the reagents for the second roughing selection is: collector A is 20-40 g / t, and collector B is 10-30 g / t; the dosage of the reagents for the first scavenging selection is: collector A is 10-30 g / t, and collector B is 5-15 g / t.

7. A high-sulfur magnetite ore pre-selection and sulfur flotation process according to any one of claims 1 to 6, characterized in that: In the step 1, the screening equipment adopts a double-layer circular vibrating screen, the size of the upper sieve hole is 20×50 mm, and the size of the lower sieve hole is 10×30 mm.

8. A high-sulfur magnetite pre-selection and sulfur flotation process according to any one of claims 1 to 6, characterized in that: In the step 2, the ore is ground using an MQY 4060 overflow ball mill.

9. A high-sulfur magnetite ore pre-selection and sulfur flotation process according to any one of claims 1 to 6, characterized in that: In the step 2, a Φ500×6 hydrocyclone group is used for classification.

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