Beneficiation method for reducing zinc in zinc-containing iron ore concentrate and recovering sulfur ore concentrate

Abstract

The invention belongs to the technical field of iron ore beneficiation, particularly relates to a beneficiation method for reducing zinc in zinc-containing iron ore concentrate and recovering sulfur ore concentrate, and is particularly suitable for treating the zinc-containing iron ore concentrate with the TFe grade ranging from 65% to 66%, the Zn content ranging from 0.10% to 0.15% and the S content ranging from 0.30% to 0.50%. The method comprises the following steps of: (1) performing dezincification flotation on the zinc-containing iron ore concentrate to obtain zinc-sulfur bulk concentrate; copper sulfate is adopted as an activating agent, BK606, BK608 and butyl xanthate are adopted as collecting agents, and 2 # oil is adopted as a foaming agent; (2) regrinding the zinc-sulfur bulk concentrate; and (3) the zinc-sulfur bulk concentrate is subjected to bulk flotation, sulfur concentrate and mixed flotation tailings are obtained, and the mixed flotation tailings are merged into iron concentrate. According to the technical scheme, the contradiction between zinc reduction of the iron ore concentrate and yield loss of the iron ore concentrate is basically solved, and meanwhile the sulfur ore concentrate can be sold as a product.

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 in zinc-containing iron concentrate and recovering sulfur concentrate. Background Art

[0002] Excessive zinc content in iron ore is not conducive to smelting. About 10% of the zinc in the iron ore concentrate in the blast furnace is removed during the sintering process, and the rest exists mostly in the state of ZnO, and a small amount is ferrite compounds, which enter the blast furnace with the sintered ore. Due to its high melting point, it is difficult to be melted directly in the blast furnace, which has certain harm to the blast furnace and subsequent smelting. It is generally required to reduce the Zn content in the iron ore concentrate to less than 0.1%.

[0003] In the prior art, the following process is usually used to reduce zinc in iron concentrate:

[0004] Grinding-single magnetic separation process: For example, Chinese patent CN 110947516 A discloses a method for reducing zinc in iron concentrate, which reduces the zinc content in iron concentrate from 0.09% to 0.068% by performing weak magnetic roughing-grinding-weak magnetic concentration 1-weak magnetic concentration 2 on zinc tailings and grinding to -400 mesh 80%. However, the reduction of zinc in this method is small, and the zinc content of iron concentrate of 0.09% has met the smelting requirements, so further reducing zinc to 0.068% is of little significance.

[0005] Single flotation process: For example, 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. An amino acid containing multiple ligands is used as an activator. Although deep removal of zinc can be achieved, it has strict requirements on the zinc grade (<0.1%) and is not suitable for iron concentrates with higher zinc content.

[0006] Combined flotation-magnetic process: For example, Chinese patent CN 115582209 A discloses a method for improving the quality of high-zinc iron concentrate and reducing silicon to prepare high-purity iron concentrate. After grinding the high-zinc iron concentrate, it is subjected to a closed-circuit flotation process of flotation, coarse, fine and sweeping, and zinc tailings weak magnetic separation to obtain low-zinc high-purity iron concentrate. However, the iron concentrate yield loss of this method is large (7.65% to 8.95%), and the market demand for high-purity iron concentrate is small, and the actual application value is limited. In particular, under the premise that iron ore mining and selection enterprises generally maintain production, it is almost unacceptable to significantly reduce production in order to reduce zinc, and general iron ore mining and selection enterprises do not need to produce high-purity iron concentrate. In terms of the domestic market, whether it is high-purity iron concentrate or ultra-pure iron concentrate, the market demand is small, and blindly pursuing high-quality iron concentrate is not meaningful.

[0007] In summary, the prior art has the following problems:

[0008] The zinc reduction effect is limited, and it is difficult to simultaneously meet the requirements of zinc content <0.1% and sulfur recovery; the iron ore concentrate yield loss is large and the economic benefits are poor; the process flow is complex and the scope of application is limited. Summary of the invention

[0009] The present application provides a beneficiation method for reducing zinc in zinc-containing iron concentrate and recovering sulfur concentrate, which basically solves the contradiction between zinc reduction in iron concentrate and loss of iron concentrate yield. At the same time, the sulfur concentrate can also be sold as a product, achieving an unexpected technical effect.

[0010] In order to achieve the above technical purpose, the technical solution adopted in this application is a beneficiation method for reducing zinc in zinc-containing iron concentrate and recovering sulfur concentrate, which is used to process zinc-containing iron concentrate with a TFe grade of 65% to 66%, a Zn content of 0.10% to 0.15%, and a S content of 0.30% to 0.50%, comprising the following steps:

[0011] (1) dezincifying the zinc-containing iron concentrate by flotation to obtain an iron concentrate with a Zn content of less than 0.08% and a zinc-sulfur mixed concentrate containing 20.0% to 25.0% sulfur and 3.0% to 3.5% zinc;

[0012] (2) grinding the zinc-sulfur mixed concentrate obtained in step (1) to a grinding particle size of -0.076 mm accounting for 95%;

[0013] (3) subjecting the zinc-sulfur mixed concentrate after grinding in step (2) to mixed flotation to obtain a sulfur concentrate with an S grade of 43.0% to 45.0% and a mixed flotation tailing containing 0.5% to 0.7% zinc;

[0014] The mixed flotation adopts one roughing selection, three cleaning selections and one scavenging selection, and the middlings are returned in a "semi-centralized-semi-sequential" manner:

[0015] The concentrate obtained from the roughing in the mixed flotation is provided to the concentrator 1, and the tailings obtained are provided to the scavenger;

[0016] The tailings from the concentration 1 and the concentrate from the scavenging are sequentially returned to the roughing;

[0017] The concentrate from Concentrator 1 goes to Concentrator 2;

[0018] The scavenged tailings are the mixed flotation tailings, which are incorporated into the iron concentrate obtained in step (1);

[0019] The concentrate from Concentrated 2 enters Concentrated 3, and the tailings from Concentrated 2 are concentrated and returned to Concentrated 1;

[0020] The concentrate of Concentrator 3 is sulfur concentrate, and the tailings of Concentrator 3 are concentrated and returned to Concentrator 1;

[0021] Among them: Selection 1 is the first selection; Selection 2 is the second selection; Selection 3 is the third selection.

[0022] As an improved technical solution of the present application, the dezincification flotation in step (1) adopts a primary roughing, and the reagents include:

[0023] Activator: copper sulfate, dosage is 150-250g / t;

[0024] Collector: BK606 dosage is 100-200g / t, BK608 dosage is 100-200g / t, and butyl xanthocyanate dosage is 40-60g / t;

[0025] Foaming agent: 2# oil, dosage is 40-60g / t.

[0026] As an improved technical solution of the present application, the grinding in step (2) adopts a laboratory Φ240×90 conical ball mill.

[0027] As an improved technical solution of the present application, the roughing agent in step (3) comprises:

[0028] Activator: copper sulfate, the rough amount is 400-500g / t;

[0029] Collector: MK-306, the rough usage amount is 200~400g / t.

[0030] As an improved technical solution of the present application, the reagent used in the selection 2 in step (3) is: MK306 in an amount of 20 to 40 g / t.

[0031] As an improved technical solution of the present application, the reagent used in the selection 3 of step (3) is: MK306 in an amount of 20 to 40 g / t;

[0032] As an improved technical solution of the present application, the agent used for the scanning in step (3) is: MK306 in an amount of 80 to 120 g / t.

[0033] Beneficial Effects

[0034] It can be seen from the above technical scheme that the technical scheme of this application adopts the "semi-concentrated-semi-sequential" return method for the middlings in the mixed flotation operation (one roughing, three finishing, and one scavenging closed-circuit flotation process). The middlings of the selected 2 and 3 in the selected section are concentrated and returned to the selected 1, avoiding the sequential return of the middlings affecting the grade of the sulfur concentrate; the tailings of the selected 1 and the scavenging concentrate are sequentially returned to the roughing to ensure the sulfur recovery rate. During the dezincification flotation, the three collectors are mixed and used to exert the "synergistic effect" to minimize the zinc content of the product at the bottom of the mixed flotation tank; the mixed flotation operation uses the selective collector MK 306 to improve the grade of the sulfur concentrate.

[0035] Through the aforementioned measures, the present application obtains a sulfur concentrate product with a sulfur grade greater than 44.0% under the condition that the sulfur content of the iron concentrate is only 0.39%, with an enrichment ratio of more than 110 times, and reduces the zinc content in the iron concentrate to below 0.10%, and the loss of iron concentrate yield is only 0.45%, which basically solves the contradiction between zinc reduction in iron concentrate and loss of iron concentrate yield. At the same time, the sulfur concentrate can also be sold as a product, which has an unexpected technical effect.

[0036] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent.

[0037] The foregoing and other aspects, embodiments and features of the present application can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present application, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned through practice of the specific embodiments according to the teachings of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present application provides a flow chart of a mineral processing method for reducing zinc in zinc-containing iron concentrate and recovering sulfur in concentrate.

[0039] Figure 2 This is a full-process quality flow chart of an embodiment of a mineral processing method for reducing zinc in zinc-containing iron concentrate and recovering sulfur in concentrate. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which this application belongs.

[0041] definition:

[0042] Selection 1 is the first selection.

[0043] Selection 2 is the second selection.

[0044] Selection 3 is the third selection.

[0045] A method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur concentrate, which is used for a method for beneficiating zinc from zinc-containing iron concentrate and obtaining a by-product sulfur concentrate, is particularly suitable for processing zinc-containing iron concentrate with a TFe grade of 65% to 66%, a Zn content of 0.10% to 0.15%, and a S content of 0.30% to 0.50%. The following processes and steps are used:

[0046] Step (1) dezincification flotation of zinc-containing iron concentrate;

[0047] Firstly, the zinc-containing iron concentrate is subjected to dezincification flotation to obtain an iron concentrate with a Zn content of less than 0.08% and a zinc-sulfur mixed concentrate containing 20.0% to 25.0% sulfur and about 3.0% to 3.5% zinc.

[0048] Step (1) dezincification flotation adopts flotation primary roughing; copper sulfate is used as activator, BK606, BK608, and butyl xanthate are used as collectors, and 2# oil is used as frother.

[0049] According to the amount of dry ore fed to the flotation ore, the dosage of the flotation reagents in step (1) is as follows: the dosage of copper sulfate for mixed flotation roughing is 100-300 g / t, the dosage of BK606 is 100-200 g / t, the dosage of BK608 is 100-200 g / t, the dosage of butyric acid is 25-75 g / t, and the dosage of foaming agent 2# oil is 40-60 g / t.

[0050] Step (2) grinding the zinc-sulfur mixed concentrate;

[0051] The grinding in step 2 is carried out using a laboratory Φ240×90 conical ball mill, and the grinding particle size is -0.076mm 95%.

[0052] Step (3) grinding the zinc-sulfur mixed concentrate product and performing mixed flotation concentration;

[0053] The zinc-sulfur mixed concentrate grinding product of step (1) is subjected to mixed flotation to obtain a sulfur concentrate with an S grade of 43.0% to 45.0% and a mixed flotation tailings containing 0.5% to 0.7% zinc (i.e., iron concentrate, the raw material is an iron concentrate containing zinc and sulfur, so the remaining product after dezincification and obtaining the sulfur concentrate is still iron concentrate, and the contents of impurities sulfur and zinc in the iron concentrate are reduced).

[0054] In step 3, a mechanical stirring flotation machine is used, specifically, one roughing selection, three cleaning selections and one scavenging selection are used, and the middling ore is returned in a "semi-centralized-semi-sequential" manner:

[0055] The concentrate obtained from the roughing in the mixed flotation is provided to the concentrator 1, and the tailings obtained are provided to the scavenger;

[0056] The tailings from the concentration 1 and the concentrate from the scavenging are sequentially returned to the roughing;

[0057] The concentrate from Concentrator 1 goes to Concentrator 2;

[0058] The scavenged tailings are the mixed flotation tailings, which are incorporated into the iron concentrate obtained in step (1);

[0059] The concentrate from Concentrated 2 enters Concentrated 3, and the tailings from Concentrated 2 are concentrated and returned to Concentrated 1;

[0060] The concentrate of Concentrator 3 is sulfur concentrate, and the tailings of Concentrator 3 are concentrated and returned to Concentrator 1;

[0061] Among them: Selection 1 is the first selection; Selection 2 is the second selection; Selection 3 is the third selection.

[0062] According to the amount of dry ore fed to the flotation feed, the roughing reagent in step (3) comprises: activator: copper sulfate, the roughing amount is 400-500 g / t; collector: MK-306, the roughing amount is 200-400 g / t.

[0063] The reagent used in the selection 2 of step (3) is: MK306 in an amount of 20 to 40 g / t.

[0064] The reagent used in the step (3) of selecting 3 is: MK306 in an amount of 20-40 g / t;

[0065] The reagent used for the scanning in step (3) is: MK306 in an amount of 80 to 120 g / t.

[0066] The following is a detailed description of a method for reducing zinc in zinc-containing iron concentrate and recovering sulfur in the concentrate according to the present application in conjunction with the accompanying drawings and examples.

[0067] The results of the multi-element analysis of the zinc-containing magnetite used in this example are shown in Table 1, and the results of the zinc phase analysis are shown in Table 2.

[0068] Table 1 Chemical multi-element analysis results of zinc-containing iron concentrate

[0069]

[0070] Table 2 Zinc phase analysis results of zinc-containing iron concentrate

[0071] Zinc phase name Zinc content Distribution rate Zinc in zinc sulfide 0.053 41.67 Zinc in zinc oxide 0.007 5.83 Zinc in other forms 0.060 52.50 Total 0.120 100.00

[0072] Figure 1 The principle process flow chart of a beneficiation method for reducing zinc in zinc-containing iron concentrate and recovering sulfur concentrate is shown; Figure 2 The full process flow chart of an embodiment of a method for reducing zinc in a zinc-containing iron concentrate and recovering sulfur concentrate is shown. The method for reducing zinc in a zinc-containing iron concentrate and recovering sulfur concentrate of the present application adopts the following processes and steps:

[0073] (1) Dezincification flotation of zinc-containing iron concentrate;

[0074] First, the zinc-containing iron concentrate with the analysis results in Table 1 and Table 2 is subjected to dezincification flotation to obtain an iron concentrate with a Zn content of <0.08% and a zinc-sulfur mixed concentrate containing 20.0% to 25.0% sulfur and 3.0% to 3.5% zinc.

[0075] In step (1), flotation is carried out by primary roughing; copper sulfate is used as an activator, BK606, BK608 and butyl xanthate are used as collectors, and 2# oil is used as a frother.

[0076] According to the dry ore content of the flotation feed, the dosage of the flotation reagents in step (1) is: 200 g / t of copper sulfate for dezincification flotation, 150 g / t of BK606, 150 g / t of BK608, 50 g / t of butyl yellow medicine, and 50 g / t of frother 2# oil.

[0077] (2) Grinding the zinc-sulfur mixed concentrate;

[0078] The grinding in step 2 is carried out using a laboratory Φ240×90 conical ball mill, and the grinding particle size is -0.076mm 95%.

[0079] (3) The zinc-sulfur mixed concentrate grinding products are subjected to mixed flotation and concentration;

[0080] The zinc-sulfur mixed concentrate grinding product of step (1) is subjected to mixed flotation to obtain a sulfur concentrate with an S grade of 43.0% to 45.0% and a mixed flotation tailings containing 0.5% to 0.7% zinc (i.e., iron concentrate, the raw material is an iron concentrate containing zinc and sulfur, so the remaining product after dezincification and obtaining the sulfur concentrate is still iron concentrate, and the contents of impurities sulfur and zinc in the iron concentrate are reduced).

[0081] The (step 3) adopts a mechanical stirring flotation machine, and the mixed flotation operation adopts one roughing, three cleaning, and one scavenging. The middling ore adopts a "semi-concentrated-semi-sequential" return, that is, the tailings of cleaning 1 and the concentrate of scavenging 1 are sequentially returned to the roughing, and the concentrate of cleaning 1 enters cleaning 2; the tailings of scavenging are the mixed flotation tailings, which are incorporated into the iron concentrate obtained in step (1); the concentrate of cleaning 2 enters cleaning 3, and the tailings of cleaning 2 are concentrated and returned to cleaning 1; the concentrate of cleaning 3 is sulfur concentrate, and the tailings of cleaning 3 are concentrated and returned to cleaning 1. In this process, copper sulfate is used as the sulfur-containing mineral activator; MK-306 is the collector.

[0082] According to the dry ore content of the flotation feed, the dosage of the mixed flotation roughing reagent in step (3) is: 450 g / t of copper sulfate and 300 g / t of collector MK306.

[0083] The dosage of mixed flotation selection reagent in step (3) is: 30 g / t of MK306 for selection 2 and 30 g / t of MK306 for selection 3.

[0084] Step (3) The dosage of mixed flotation and scavenging agent is: MK306 dosage 100g / t.

[0085] It can be seen from the above embodiments that, compared with the prior art, the ore dressing method of the present application for reducing zinc in zinc-containing iron concentrate and recovering sulfur concentrate has the following advantages:

[0086] (1) Considering that the sulfur and zinc grades of the zinc-sulfur mixed concentrate obtained by dezincification flotation in production fluctuate greatly, the intermediate ore of the mixed flotation operation (one roughing, three finishing, one scavenging closed-circuit flotation process) of this application adopts a "semi-centralized-semi-sequential" return method. The intermediate ore of the selection 2 and selection 3 in the selection stage is concentrated and returned to the selection 1, thereby avoiding the influence of the sequential return of the intermediate ore on the grade of the zinc concentrate; the tailings of the selection 1 and the scavenging concentrate are sequentially returned to the roughing to ensure the sulfur recovery rate.

[0087] (2) During dezincification flotation, three collectors are mixed and used to exert a "synergistic effect" to minimize the zinc content of the product at the bottom of the mixed flotation tank; mixed flotation uses a selective collector MK 306 to improve the grade of sulfur concentrate.

[0088] (3) Under the condition that the sulfur content in the iron concentrate is only 0.39%, a sulfur concentrate product with a sulfur grade greater than 44.0% is obtained, with an enrichment ratio of more than 110 times. At the same time, the zinc content in the iron concentrate is reduced to below 0.10%, and the loss of iron concentrate yield is only 0.45%, which basically solves the contradiction between the reduction of zinc in the iron concentrate and the loss of iron concentrate yield. At the same time, the sulfur concentrate can also be sold as a product, which has an unexpected technical effect.

[0089] Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. A person with ordinary knowledge in the technical field to which the present application belongs can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be determined by the definition of the claims.

Claims

1. A method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur from the concentrate, which is used to process zinc-containing iron concentrate with a TFe grade of 65% to 66%, a Zn content of 0.10% to 0.15%, and a S content of 0.30% to 0.50%, characterized in that: The following steps are involved: (1) dezincifying the zinc-containing iron concentrate by flotation to obtain an iron concentrate with a Zn content of less than 0.08% and a zinc-sulfur mixed concentrate containing 20.0% to 25.0% sulfur and 3.0% to 3.5% zinc; (2) grinding the zinc-sulfur mixed concentrate obtained in step (1) to a grinding particle size of -0.076 mm accounting for 95%; (3) subjecting the zinc-sulfur mixed concentrate after grinding in step (2) to mixed flotation to obtain a sulfur concentrate with an S grade of 43.0% to 45.0% and a mixed flotation tailing containing 0.5% to 0.7% zinc; The mixed flotation adopts one roughing selection, three cleaning selections and one scavenging selection, and the middlings are returned in a semi-centralized and semi-sequential manner: The concentrate obtained from the roughing in the mixed flotation is provided to the concentrator 1, and the tailings obtained are provided to the scavenger; The tailings from the concentration 1 and the concentrate from the scavenging are sequentially returned to the roughing; The concentrate from Concentrator 1 goes to Concentrator 2; The scavenged tailings are the mixed flotation tailings, which are incorporated into the iron concentrate obtained in step (1); The concentrate from Concentrated 2 enters Concentrated 3, and the tailings from Concentrated 2 are concentrated and returned to Concentrated 1; The concentrate of Concentrator 3 is sulfur concentrate, and the tailings of Concentrator 3 are concentrated and returned to Concentrator 1; Among them: Selection 1 is the first selection; Selection 2 is the second selection; Selection 3 is the third selection.

2. The method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur concentrate according to claim 1, characterized in that: The dezincification flotation in step (1) adopts a primary roughing process, and the reagents include: Activator: copper sulfate, dosage is 150-250g / t; Collector: BK606 dosage is 100-200g / t, BK608 dosage is 100-200g / t, and butyl xanthocyanate dosage is 40-60g / t; Foaming agent: 2# oil, dosage is 40-60g / t.

3. The ore dressing method for reducing zinc in zinc-containing iron concentrate and recovering sulfur concentrate according to claim 1, characterized in that: The grinding in step (2) adopts a laboratory Φ240×90 conical ball mill.

4. The method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur concentrate according to claim 1, characterized in that: The roughing agent in step (3) comprises: Activator: copper sulfate, the rough amount is 400-500g / t; Collector: MK-306, the rough usage amount is 200~400g / t.

5. The method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur concentrate according to claim 1, characterized in that: The reagent used in the selection 2 of step (3) is: MK306 in an amount of 20 to 40 g / t.

6. The method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur concentrate according to claim 1, characterized in that: The reagent used in the selection 3 in step (3) is: MK306 in an amount of 20 to 40 g / t.

7. The method for beneficiating zinc from zinc-containing iron concentrate and recovering sulfur concentrate according to claim 1, characterized in that: The reagent used for the scanning in step (3) is: MK306 in an amount of 80 to 120 g / t.

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