Beneficiation method for reducing zinc in zinc-containing magnetite concentrate

Abstract

The invention belongs to the technical field of iron ore beneficiation, and particularly relates to a beneficiation method for reducing zinc in zinc-containing magnetite concentrate, which is suitable for treating the zinc-containing magnetite concentrate with the TFe grade of 65-66% and the Zn content of 0.10-0.20%. Comprising the following steps: (1) carrying out zinc-sulfur bulk flotation on the zinc-containing magnetite concentrate; (2) the zinc-sulfur bulk concentrate is subjected to zinc-sulfur separation roughing; and (3) zinc-sulfur separation and concentration are conducted on the zinc rough concentrate obtained in the step (2), and zinc concentrate is obtained. According to the technical scheme, the yield can be effectively guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of iron ore beneficiation, and in particular relates to a beneficiation method for reducing zinc content in zinc-containing magnetite concentrate. Background Art

[0002] Excessive Zn content in iron ore concentrate is detrimental to smelting. Approximately 10% of the zinc in iron ore concentrate is removed during the sintering process. The remainder exists primarily as ZnO, with a small amount as ferrite compounds, entering the blast furnace with the sintered ore. Due to its high melting point, Zn is difficult to melt directly in the blast furnace, posing a risk to the blast furnace and subsequent smelting. Generally, the Zn content in iron ore concentrate should be reduced to below 0.1%.

[0003] Harmful impurities like zinc in iron concentrate generally exist in the form of sphalerite and iron sphalerite. Sphalerite and iron sphalerite often exhibit poor flotation properties and sensitivity to the medium, with floatability much lower than other sulfides. Therefore, flotation of unactivated sphalerite and iron sphalerite is extremely difficult. In rare cases, zinc may also be present in magnetite minerals due to zinc atoms isomorphously replacing iron atoms in the magnetite lattice; this portion of zinc cannot be removed by physical beneficiation methods.

[0004] The following process is usually used to reduce zinc content in magnetite concentrate:

[0005] (1) Grinding-single magnetic separation process. Chinese patent CN 110947516 A discloses a method for reducing zinc content in iron concentrate: by subjecting zinc tailings to weak magnetic roughing-grinding-weak magnetic concentration 1-weak magnetic concentration 2, and grinding to -400 mesh 80%, the zinc content in the iron concentrate is reduced from 0.09% to 0.068%, which is a small reduction. Moreover, the zinc content in the iron concentrate of 0.09% meets the smelting requirement of zinc content in the iron concentrate of <0.1%, so it seems unnecessary to reduce the zinc content to 0.068%.

[0006] (2) Single flotation process. Chinese patent CN 113477405 B discloses an activator for the beneficiation of sphalerite and sphalerite and a method for flotation reduction of zinc in iron concentrate: amino acids containing multiple ligands are preferably used as activators to increase the depth of zinc removal. Although deep zinc removal in iron concentrate can be achieved, strict requirements are also placed on the zinc grade (<0.1%), making it unsuitable for iron concentrates with high zinc content.

[0007] (3) Combined flotation-magnetic separation process: Chinese patent CN 115582209 A discloses a method for improving the quality of high-zinc iron concentrate and reducing silicon content to prepare high-purity iron concentrate: the high-zinc iron concentrate is ground and then subjected to a closed-circuit flotation process of flotation, coarse, fine, and sweeping, followed by weak magnetic separation of the zinc tailings, to obtain a low-zinc, high-purity iron concentrate. This patent is intended to obtain high-purity iron concentrate and is not suitable for reducing zinc content in ordinary iron concentrates. In Example 1, a certain weak magnetic separation iron concentrate has a zinc content of 0.416%, an iron content of 65.05%, and an SiO2 content of 4.56%. Using the method of this patent, although the zinc content in the iron concentrate is significantly reduced, the iron concentrate yield is also reduced by 7.65%. In Example 2, a certain weak magnetic separation iron concentrate has a zinc content of 0.356%, an iron content of 64.05%, and an SiO2 content of 5.56%. Using the method of this patent, the iron concentrate yield is reduced by 8.95%. The iron concentrate yield loss in the two embodiments is very large, which means that the output of iron concentrate will be greatly reduced. Under the premise that iron ore mining and processing companies generally maintain production, it is almost unacceptable to significantly reduce production in order to reduce zinc. Moreover, general iron ore mining and processing companies do not need to produce high-purity iron concentrate. As far as the domestic market is concerned, the market demand for both high-purity iron concentrate and ultra-pure iron concentrate is small, and blindly pursuing high-quality iron concentrate is not meaningful. Summary of the Invention

[0008] In order to ensure the yield, the present application provides a beneficiation method for reducing zinc in zinc-containing magnetite concentrate.

[0009] To achieve the above technical objectives, the technical solution adopted in this application is as follows: a beneficiation method for reducing zinc content in zinc-bearing magnetite concentrate, suitable for processing zinc-bearing magnetite concentrate with a TFe grade between 65% and 66% and a Zn content between 0.10% and 0.20%; comprising the following steps:

[0010] (1) Zinc-sulfur mixed flotation of zinc-containing magnetite concentrate;

[0011] Zinc-containing magnetite concentrate was subjected to zinc-sulfur mixed flotation to obtain magnetite concentrate with Zn content <0.08% and zinc-sulfur mixed concentrate with zinc content of 2.5% to 3.5%; the flotation adopted a single roughing flotation; copper sulfate was used as activator, BK606, BK608 and butyl xanthate were used as collectors, and No. 2 oil was used as frother;

[0012] (2) Zinc-sulfur mixed concentrate is subjected to zinc-sulfur separation roughing;

[0013] The zinc-sulfur mixed concentrate with a Zn content of 2.5%–3.5% was subjected to zinc-sulfur separation roughing to obtain a zinc rough concentrate with a Zn content of 9.0%–11.0% and bottom product with a zinc content of <0.20%. The zinc-sulfur separation roughing was carried out in a single roughing process. Activated carbon was used for dechemical treatment, lime was used as a depressant, copper sulfate was used as an activator, and MK-306 was used as a collector.

[0014] (3) The zinc concentrate in step (2) is subjected to zinc-sulfur separation and selection to obtain zinc concentrate; the zinc concentrate is subjected to three-stage selection to obtain a zinc concentrate with a zinc grade greater than 30.0%, and lime is used as an inhibitor.

[0015] As an improved technical solution of this application, the reagent dosage in step (1) flotation is as follows: based on the dry ore quantity of the flotation feed, the reagent dosage is: copper sulfate 100-300g / t, BK606 100-200g / t, BK608 100-200g / t, butyl xanthate 25-75g / t, and No. 2 oil 40-60g / t.

[0016] As an improved technical solution of this application, the reagent dosage for flotation in step (2) is as follows: based on the dry ore quantity of the flotation feed, the reagent dosage is: activated carbon 200-400 g / t, lime 3000-5000 g / t, copper sulfate 200-400 g / t, and collector MK-306 40-60 g / t.

[0017] As an improved technical solution of this application, the reagent dosage for flotation in step (3) is as follows: based on the dry ore quantity of the flotation feed, the reagent dosage is as follows: 800-1200 g / t of lime for fine selection 1, 400-600 g / t of lime for fine selection 2, and 200-300 g / t of lime for fine selection 3.

[0018] Beneficial effects

[0019] (1) Considering the large fluctuation of zinc content in zinc-containing iron concentrate during production, the flotation process of this application adopts a fully open-circuit process (fully open-circuit process: the products of each operation in the mineral processing are directly output as the final product and are not returned to the previous operation for reprocessing), which avoids the impact of middlings return on the beneficiation index, is conducive to the stability of the mineral processing process, and makes it more convenient to adjust the operation of the production position.

[0020] (2) By adopting a fully open-circuit process for fine separation, the zinc content in the iron concentrate is reduced to below 0.10% (by testing the zinc content in the iron concentrate, a zinc content below 0.1% is considered acceptable), thus minimizing the loss of iron concentrate yield. The loss of iron concentrate yield is controlled at around 0.20%, which solves the contradiction between reducing zinc content in iron concentrate and losing iron concentrate yield to the greatest extent, achieving unexpected technical results.

[0021] (3) The process has strong adaptability. When the zinc concentrate market situation is good, the zinc concentrate with a zinc grade of about 30.0% can be sold as a product. When the situation is not good, it can be directly used as tailings for filling.

[0022] (4) During zinc-sulfur mixed flotation, three collectors are used in combination to exert a “synergistic effect” and minimize the Zn content of the product at the bottom of the mixed flotation tank; the selective collector MK 306 is used for separation roughing to maximize the grade of zinc concentrate. Attached Figure Description

[0023] Figure 1 This is a flow chart of the beneficiation process for reducing zinc content in zinc-containing magnetite concentrate, as described in this application.

[0024] Figure 2 This is a full-process flow chart illustrating an embodiment of a zinc-containing magnetite concentrate zinc reduction beneficiation method according to this application. Detailed Implementation

[0025] To describe the technical solution of this application, the following detailed description of a zinc-containing magnetite concentrate zinc reduction beneficiation method is provided in conjunction with the accompanying drawings and embodiments.

[0026] Definition: All terms “content” in this article refer to mass percentage.

[0027] like Figure 1 As shown, a beneficiation method for reducing zinc content in zinc-bearing magnetite concentrate is suitable for processing zinc-bearing magnetite concentrate with a TFe grade between 65% and 66% and a Zn content between 0.10% and 0.20%; it includes the following steps:

[0028] (1) Zinc-sulfur mixed flotation of zinc-containing magnetite concentrate;

[0029] Zinc-containing magnetite concentrate was subjected to zinc-sulfur mixed flotation to obtain magnetite concentrate with Zn content <0.08% and zinc-sulfur mixed concentrate with zinc content of 2.5% to 3.5%; the flotation adopted a single roughing flotation; copper sulfate was used as activator, BK606, BK608 and butyl xanthate were used as collectors, and No. 2 oil was used as frother;

[0030] (2) Zinc-sulfur mixed concentrate is subjected to zinc-sulfur separation roughing;

[0031] The zinc-sulfur mixed concentrate with a Zn content of 2.5%–3.5% was subjected to zinc-sulfur separation roughing to obtain a zinc rough concentrate with a Zn content of 9.0%–11.0% and bottom product with a zinc content of <0.20%. The zinc-sulfur separation roughing was carried out in a single roughing process. Activated carbon was used for dechemical treatment, lime was used as a depressant, copper sulfate was used as an activator, and MK-306 was used as a collector.

[0032] (3) The zinc concentrate in step (2) is subjected to zinc-sulfur separation and selection to obtain zinc concentrate; the zinc concentrate is subjected to three-stage selection to obtain a zinc concentrate with a zinc grade greater than 30.0%, and lime is used as an inhibitor.

[0033] As an improved technical solution of this application, the reagent dosage in step (1) flotation is as follows: based on the dry ore quantity of the flotation feed, the reagent dosage is: copper sulfate 100-300g / t, BK606 100-200g / t, BK608 100-200g / t, butyl xanthate 25-75g / t, and No. 2 oil 40-60g / t.

[0034] As an improved technical solution of this application, the reagent dosage for flotation in step (2) is as follows: based on the dry ore quantity of the flotation feed, the reagent dosage is: activated carbon 200-400 g / t, lime 3000-5000 g / t, copper sulfate 200-400 g / t, and collector MK-306 40-60 g / t.

[0035] As an improved technical solution of this application, the reagent dosage for flotation in step (3) is as follows: based on the dry ore quantity of the flotation feed, the reagent dosage is as follows: 800-1200 g / t of lime for fine selection 1, 400-600 g / t of lime for fine selection 2, and 200-300 g / t of lime for fine selection 3.

[0036] Example 1

[0037] The zinc-containing magnetite concentrate used in this embodiment was obtained from an iron mine in Anhui Province. The results of multi-element chemical analysis of the zinc-containing magnetite concentrate are shown in Table 1, and the results of zinc phase analysis are shown in Table 2.

[0038] Table 1. Results of multi-element chemical analysis of zinc-bearing magnetite concentrate

[0039]

[0040]

[0041] Table 2 Zinc phase analysis results of zinc-containing magnetite concentrate

[0042] Zinc phase name Zinc content Distribution rate Zinc in zinc sulfide 0.073 48.67 Zinc oxide zinc 0.009 6.00 Other forms of zinc 0.068 45.33 total 0.150 100.00

[0043] Depend on Figure 1 The diagram shows the principle process flow chart of a zinc-containing magnetite concentrate zinc reduction beneficiation method. Figure 2 The flowchart illustrating the entire process of zinc reduction in zinc-containing magnetite concentrate, as shown in the embodiment, illustrates the following process and steps employed in this application's method for reducing zinc in zinc-containing magnetite concentrate:

[0044] (1) Zinc-sulfur mixed flotation of zinc-containing magnetite concentrate;

[0045] First, zinc-bearing magnetite concentrate is subjected to zinc-sulfur mixed flotation to obtain magnetite concentrate with Zn content <0.08% and zinc-sulfur mixed concentrate with zinc content of 2.92%. Zinc-bearing magnetite concentrate refers to iron concentrate with TFe grade between 65% and 66% and Zn content between 0.10% and 0.20%.

[0046] Step (1) Flotation adopts primary roughing flotation; copper sulfate is used as activator, BK606, BK608 and butyl xanthate are used as collectors, and No. 2 oil is used as frother.

[0047] Step (1) The reagent dosage for flotation is as follows: Based on the dry ore quantity of the flotation feed, the reagent dosage is as follows: 200g / t of copper sulfate for mixed flotation roughing, 150g / t of BK606, 150g / t of BK608, 50g / t of butyl xanthate, and 50g / t of frother 2# oil.

[0048] (2) Zinc-sulfur mixed concentrate is subjected to zinc-sulfur separation roughing;

[0049] The zinc-sulfur mixed concentrate with a Zn content of 2.92% was subjected to zinc-sulfur separation roughing to obtain a zinc rough concentrate with a Zn content of 10.84% ​​and bottom product with a zinc content of about 0.2%.

[0050] Step (2) Zinc-sulfur separation roughing adopts a single roughing process; activated carbon is used for de-drug removal, lime is used as an inhibitor, copper sulfate is used as an activator, and MK-306 is used as a collector.

[0051] Step (2) The reagent dosage for flotation is as follows: Based on the dry ore quantity of the flotation feed, the reagent dosage is: 300g / t of activated carbon, 4000g / t of lime, 300g / t of copper sulfate, and 50g / t of collector MK-306.

[0052] (3) The zinc crude concentrate from step (2) is subjected to zinc-sulfur separation and beneficiation.

[0053] The zinc crude concentrate from step (2) is separated and refined to obtain zinc concentrate.

[0054] Step (3) Zinc concentrate zinc-sulfur separation and beneficiation: Three beneficiation processes were used to obtain zinc concentrate with a zinc grade of 30.26%, and lime was used as an inhibitor.

[0055] Step (3) The reagent dosage for flotation is as follows: Based on the dry ore quantity of the flotation feed, the reagent dosage is as follows: 1000g / t of lime for fine selection 1, 500g / t of lime for fine selection 2, and 250g / t of lime for fine selection 1.

[0056] Since the raw ore processed in this application is zinc-containing iron concentrate (iron grade 65.00%, zinc content 0.16%), the bottom product (residual product) of the zinc-sulfur mixed flotation, zinc-sulfur separation roughing, and zinc-sulfur separation cleaning (three cleaning processes) in this application process is still iron concentrate (iron grade 65.08%, zinc content 0.086%), and the zinc content no longer exceeds the standard, and will be directly combined as iron concentrate.

Claims

1. A method for reducing zinc in zinc-containing magnetite concentrate, characterized in that: The method is suitable for processing zinc-containing magnetite concentrate with a TFe grade of 65% to 66% and a Zn content of 0.10% to 0.20%; and comprises the following steps: (1) Zinc-sulfur mixed flotation of zinc-containing magnetite concentrate; The zinc-containing magnetite concentrate is subjected to zinc-sulfur mixed flotation to obtain a magnetite concentrate with a Zn content of <0.08% and a zinc-sulfur mixed concentrate containing 2.5% to 3.5% zinc; the flotation adopts a flotation primary roughing method; copper sulfate is used as an activator, BK606, BK608 and butyl xanthate are used as collectors, and 2# oil is used as a frother; (2) Rough separation of zinc and sulfur from zinc-sulfur mixed concentrate; The zinc-sulfur mixed concentrate with a Zn content of 2.5% to 3.5% is subjected to zinc-sulfur separation roughing to obtain a zinc rough concentrate with a Zn content of 9.0% to 11.0% and a bottom product containing zinc <0.20%; the zinc-sulfur separation roughing adopts a primary roughing; activated carbon is used for dedoping, lime is used as an inhibitor, copper sulfate is used as an activator, and MK-306 is used as a collector; (3) The zinc concentrate in step (2) is subjected to zinc-sulfur separation and concentration to obtain zinc concentrate; the zinc concentrate is subjected to zinc-sulfur separation and concentration by three concentrations to obtain a zinc concentrate with a zinc grade of >30.0%, and lime is used as an inhibitor.

2. A method for reducing zinc in a zinc-containing magnetite concentrate as claimed in claim 1, characterized in that: The dosage of the reagents for flotation in step (1) is as follows: based on the amount of dry ore fed to the flotation ore, the dosage of the reagents is as follows: 100-300 g / t of copper sulfate, 100-200 g / t of BK606, 100-200 g / t of BK608, 25-75 g / t of butyric acid, and 40-60 g / t of 2# oil.

3. A method for reducing zinc in a zinc-containing magnetite concentrate as claimed in claim 1, characterized in that: The dosage of the reagents for flotation in step (2) is as follows: based on the dry ore amount of the flotation feed, the dosage of the reagents is: 200-400 g / t of activated carbon, 3000-5000 g / t of lime, 200-400 g / t of copper sulfate, and 40-60 g / t of collector MK-306.

4. A method for reducing zinc in a zinc-containing magnetite concentrate as claimed in claim 1, characterized in that: The dosage of the reagent for flotation in step (3) is as follows: based on the dry ore amount of the flotation feed, the dosage of the reagent is as follows: 800-1200 g / t of lime for selection 1, 400-600 g / t of lime for selection 2, and 200-300 g / t of lime for selection 3.

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