Beneficiation method for recycling high-sulfur magnetite ore

Abstract

The invention discloses a beneficiation method for recycling high-sulfur magnetite ore, which comprises the following steps: feeding the high-sulfur magnetite ore into first-section ore grinding-flotation operation to obtain sulfur concentrate with ES grade greater than or equal to 41%, feeding flotation tailings into low-intensity magnetic roughing-second-section ore grinding-low-intensity magnetic concentration operation to obtain low-intensity magnetic concentrate, and feeding the low-intensity magnetic concentrate into open-circuit flotation desulfurization operation to obtain low-intensity magnetic concentrate; obtaining a TFe grade gt; the TS content is 68.0%, and the TS content is lt; and 0.35% of qualified iron ore concentrate products are sold as dense medium products separated by a dense medium hydrocyclone of a coal preparation plant after flotation middlings are combined. In the first-section ore grinding-flotation operation, one-roughing, two-concentration and one-scavenging concentration tailings are concentrated and returned to roughing, so that the influence of scavenged concentrate on the effective sulfur content of sulfur concentrate is avoided, and meanwhile, the influence of refractory iron minerals in the scavenged concentrate on the subsequent iron separation process is avoided; the obtained high-grade iron ore concentrate, the obtained high-grade sulfur concentrate and the obtained dense medium for high-density coal dressing all have good market sales, and economic benefits are remarkable.

Description

Technical Field

[0001] The present invention belongs to the technical field of iron ore dressing, and specifically relates to a dressing method for recycling high-sulfur magnetite ore. The main products are sulfur concentrate and magnetite concentrate. The present invention is particularly suitable for separating and enriching sulfur and iron in high-sulfur magnetite ore with a TFe grade of 30% to 40%, a TS content of 10% to 15%, and an ES content of 8% to 9%. Background Art

[0002] Sulfur is a harmful element in the steel production process. Excessive sulfur content in steel will cause hot brittleness of steel. In addition, sulfur will generate gaseous sulfides during blast furnace smelting, which not only pollutes the atmospheric environment, but also accelerates the corrosion of metal parts such as gas pipelines and engine rotor blades. Therefore, the sulfur content of iron ore entering the furnace should be controlled. According to the national standard GB / T 36704-2018, the impurity sulfur content in qualified magnetite concentrate should be ≤0.5%. In addition, as a by-product in the production process of high-sulfur magnetite ore, the effective sulfur content of qualified sulfur concentrate cannot be less than 35% according to the national standard YS-T 337-2021, and the effective sulfur content of grade 3 and above must be greater than 41%.

[0003] The beneficiation of high-sulfur magnetite usually adopts the combined process of stage grinding, flotation and magnetization or stage grinding, magnetization and flotation. The combined process of stage grinding, magnetization and flotation is to grind the raw ore to a suitable grinding particle size, discard the tailings with weak magnetic separation, obtain the magnetite concentrate with qualified iron grade, and then grind and flotate the magnetite concentrate for desulfurization. This process is not ideal when processing magnetite ore with TS content of 10%-15%, and the sulfur grade of flotation desulfurization foam is not high, which cannot be used as a qualified sulfur concentrate product, resulting in a waste of resources; the combined process of stage grinding, flotation and magnetization is to grind the raw ore, float it, select the sulfur of the raw ore as sulfur concentrate, and then grind and magnetically separate the flotation tailings to obtain iron concentrate. This process is very effective when the sulfur in the iron concentrate is mainly pyrite and the TS content is less than 10%, but it is not effective for high-sulfur magnetite with TS content higher than 10%. Summary of the invention

[0004] The purpose of the present invention is to provide a beneficiation method for recycling high-sulfur magnetite ore to address the problems of poor sulfur and iron separation and enrichment effects of high-sulfur magnetite ore, high sulfur content in iron concentrate and low effective sulfur content in sulfur concentrate.

[0005] To achieve the above-mentioned object of the present invention, a beneficiation method for recycling high-sulfur magnetite ore is provided, which is used to separate and enrich sulfur and iron in high-sulfur magnetite ore with a TFe grade of 30% to 40%, a TS content of 10% to 15%, and an ES content of 8% to 9%, and is specifically implemented by the following processes and steps:

[0006] S1 High Sulfur Magnetite Ore Primary Grinding-Flotation

[0007] The high-sulfur magnetite ore is fed into a first-stage grinding-flotation operation to obtain a sulfur concentrate with an ES grade of ≥41%, and the flotation tailings are discharged; the flotation operation adopts 1 roughing selection, 1 scavenging selection, 2 to 3 cleaning selections, and MK306 is used as a collector; the particle size of the first-stage grinding product is controlled at -0.076mm particle size, accounting for 46% to 60% by mass; the mass concentration of the first-stage grinding is controlled between 70% and 85%, with 75% to 80% being more appropriate.

[0008] S2 weak magnetic roughing-second stage grinding-weak magnetic concentrating

[0009] The flotation tailings discharged from step S1 are fed into weak magnetic roughing - two-stage grinding - weak magnetic concentration operation, the weak magnetic concentration is performed twice, and a weak magnetic concentrate with a TS grade of 0.5%-1% and a TFe grade>68% is obtained, and the weak magnetic roughing tailings, the first weak magnetic concentration tailings, and the second weak magnetic concentration tailings are discarded respectively, and the weak magnetic roughing tailings, the first weak magnetic concentration tailings, and the second weak magnetic concentration tailings are combined into magnetic separation tailings; the particle size of the second-stage grinding product is controlled at -0.076mm particle size accounting for 70% to 82% by mass, and the magnetic field strength of the weak magnetic roughing operation, the first weak magnetic concentration operation, and the second weak magnetic concentration operation is controlled in the range of 178 to 210kA / m, 110 to 135kA / m, and 85 to 105kA / m, respectively; the mass concentration of the second-stage grinding is controlled between 70% and 80%, and 73% to 76% is more appropriate.

[0010] S3 weak magnetic concentrate flotation desulfurization

[0011] The weak magnetic concentrate obtained in step S2 is fed into an open-circuit flotation desulfurization operation with one roughing and two scavenging to obtain a qualified iron concentrate product with a TFe grade of >68.0% and a TS content of <0.35%, and a floating sulfur roughing concentrate - middling ore 3 with TS <6.5% and a TFe grade of >65%, a floating sulfur scavenging 1 concentrate - middling ore 2 with TS <2.0% and a TFe grade of >66.5%, and a floating sulfur scavenging 2 concentrate - middling ore 3 with TS <1.9% and a TFe grade of >66.6% are obtained respectively; the flotation desulfurization operation adopts citric acid as a complexing agent, sulfuric acid as an activator, a compound mixture of butyl xanthate and butyl ammonium black medicine as a collector, and 2# oil as a frother.

[0012] Preferably, in step S1, the flotation operation adopts one roughing selection, one scavenging selection and two cleaning selections, the tailings of the first cleaning selection and the second cleaning selection are concentrated and returned to the roughing selection, the scavenging concentrate is used as the middling ore and does not return to the closed-loop process, the second cleaning concentrate is the sulfur concentrate, and the scavenging tailings are used as the feed for subsequent magnetic separation, and the TS content is less than 6%; according to the dry ore amount of the flotation feed, the dosage of the reagent is: 80-110g / t of MK306 for roughing selection, preferably 80-100g / t; 35-45g / t of MK306 for scavenging selection, preferably 35-40g / t; no reagent is added for cleaning; the particle size of the first-stage grinding product is controlled at 50%-55% of the mass of the -0.076mm particle size.

[0013] Preferably, in step S2, the particle size of the second-stage grinding product is controlled at -0.076 mm, accounting for 75% to 80% of the mass; the magnetic field strength of the weak magnetic roughing operation, the first weak magnetic concentrating operation, and the second weak magnetic concentrating operation is preferably controlled in the range of 183 to 199 kA / m, 119 to 127 kA / m, and 88 to 96 kA / m, respectively.

[0014] Preferably, in step S2, in the compound mixture of butyl xanthate and butyl ammonium black medicine, the mass ratio of butyl xanthate to butyl ammonium black medicine is preferably (0.85-1.2):1, and preferably 1:1.

[0015] Preferably, in step S3, based on the amount of dry ore fed to the flotation, the dosage of the roughing agent is: 1500-2500 g / t of citric acid, 800-1200 g / t of sulfuric acid, 1400-1600 g / t of butyl xanthate + butyl ammonium black medicine, and 40-50 g / t of frother 2 oil; the dosage of the first scavenging agent is the same as that of the roughing agent, and the dosage of the second scavenging agent is half of that of the roughing agent.

[0016] Preferably, in step S3, after the combination of middlings 1, 2 and 3, the iron content is as high as about 66.0% and it is magnetic iron, so it can be sold and used as a high-density high-quality heavy medium product for heavy medium hydrocyclone separation in coal preparation plants. The sulfur in the heavy medium is contained in pyrrhotite. The coal preparation plant recovers the heavy medium through magnetic separation, and the sulfur in the heavy medium will not enter the clean coal. Middlings 1 and 2 can also be combined and used as a raw material for ironmaking in steel plants, and middlings 3 can be sold as a heavy medium product for heavy medium hydrocyclone separation in coal preparation plants.

[0017] The MK-306 used in the method of the present invention is a brown-yellow transparent liquid, a highly efficient collector for nonferrous metal sulfide ores, and has self-foaming properties. It is mostly used for the flotation of sulfide copper ores, lead-zinc ores, gold-silver ores, and pyrites, and has excellent selectivity. It has the characteristics of being easy to use, having little odor, having strong collecting power, and having good flotation indexes, and is produced by China Steel Ma'anshan Mining Research Institute Co., Ltd.

[0018] The specific values ​​of the above parameters such as grinding particle size, magnetic field strength, flotation times, reagent dosage, etc. can be determined based on the properties of the ore and the results of laboratory test studies.

[0019] Compared with the prior art, the ore dressing method for recycling high-sulfur magnetite ore of the present invention has the following advantages:

[0020] (1) The first-stage grinding-flotation operation of high-sulfur magnetite ore adopts the process of "one roughing, two cleaning, and one scavenging (no return from scavenging)". The scavenging concentrate is mostly pyrite, pyrrhotite and gangue minerals that are difficult to separate. By not returning from scavenging, the impact of scavenging concentrate on the overall process is greatly reduced; and the sulfuric acid slag after acid production from the sulfur concentrate obtained from the secondary cleaning can be used as low-grade iron concentrate.

[0021] (2) For the weak magnetic separation concentrate obtained in step S2, if magnetic separation is used to reduce the sulfur content of the concentrate, the grinding fineness can only be further increased, which will inevitably increase the grinding energy consumption. However, the method of the present invention adopts flotation desulfurization of weak magnetic separation concentrate in step S3, which can effectively reduce the second-stage grinding fineness and greatly reduce the beneficiation cost.

[0022] (3) In the S1 step, the present invention adopts MK-306 high-efficiency collector, which has its own foaming performance and excellent selectivity. Through one roughing selection, one scavenging selection and two concentrating selections, a sulfur concentrate with an ES grade of ≥41% can be obtained. In the S3 step, citric acid is used as a complexing agent, sulfuric acid is used as an activator, a compound mixture of butyl xanthate and butyl ammonium black medicine is used as a collector, and 2# oil is used as a foaming agent. The combined synergistic effect of several agents is effectively exerted to obtain a qualified iron concentrate product with a TFe grade of >68.0% and a TS content of <0.35%.

[0023] (4) The entire mineral processing process is relatively simple and the energy consumption is relatively low. The three products obtained, namely high-grade iron concentrate, high-grade sulfur concentrate and high-density heavy medium for coal dressing, all have good market sales and significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a principle process flow chart of a mineral processing method for recycling high-sulfur magnetite ore.

[0025] Figure 2 The present invention is a full-process numerical and quality flow chart of an embodiment of a mineral processing method for recycling high-sulfur magnetite ore according to the present invention. DETAILED DESCRIPTION

[0026] To further describe the present invention, a beneficiation method for recycling high-sulfur magnetite ore of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that any modification, equivalent replacement, improvement, etc. made within the technical ideas and principles of the present invention should be included in the protection scope of the present invention.

[0027] The high-sulfur magnetite ore used in this embodiment is taken from an iron mine in Anhui Province. The chemical multi-element analysis results of the high-sulfur magnetite ore are shown in Table 1, the iron phase analysis results are shown in Table 2, and the sulfur phase analysis results are shown in Table 3.

[0028] Table 1 Chemical multi-element analysis results of high-sulfur magnetite ore

[0029] Test items TFe mxD S ES P Cu content(%) 36.61 20.93 12.36 8.67 0.468 0.078 <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> MnO 14.02 3.20 9.53 1.59 0.679 0.402 0.221 ZnO <![CDATA[V2O5]]> <![CDATA[TiO2]]> <![CDATA[Cr2O3]]> NiO 0.040 0.169 0.471 <0.005 <0.005

[0030] Table 2 Analysis results of iron phase in high sulfur magnetite ore

[0031] Iron Phase Iron content Occupancy Magnetite Iron 21.43 58.54 Siderite Iron 1.52 4.15 Iron from hematite 5.74 15.68 Pyrite Iron 6.6 18.03 Ferrosilicate Iron 0.4 1.09 Pyrrhotite 0.92 2.51 total 36.61 100.00

[0032] Table 3 High sulfur magnetite ore sulfur phase analysis results (%)

[0033]

[0034]

[0035] From the analysis of the properties of high-sulfur magnetite ore, it can be seen that the TS content in the ore is as high as 12.36%, of which 65.94% exists in the form of pyrite and pyrrhotite, and the remaining 34.06% exists in the form of sulfate minerals. Pyrrhotite is a strong magnetic mineral and enters the weak magnetic concentrate together with magnetite during the weak magnetic separation process. Therefore, it is difficult to remove pyrrhotite by single weak magnetic separation, so flotation removal is required.

[0036] Depend on Figure 1 The process flow chart of the principle of a high-sulfur magnetite ore recovery method of the present invention is shown, Figure 2 As shown in the full process flow chart of the embodiment of the high-sulfur magnetite ore recovery and utilization beneficiation method of the present invention, in the embodiment, the high-sulfur magnetite ore recovery and utilization beneficiation method of the present invention is implemented by the following process steps:

[0037] S1 High Sulfur Magnetite Ore Primary Grinding-Flotation

[0038] The high-sulfur magnetite ore is fed into a first-stage grinding-flotation operation to obtain a sulfur concentrate with an ES grade of 41.61%, and the flotation tailings are discharged; the flotation operation adopts one roughing selection, one scavenging selection, and two concentrating selections, and the first concentrating tailings and the second concentrating tailings are returned to the roughing selection, and the scavenging concentrate is not returned; the particle size of the first-stage grinding product is controlled at -0.076mm, and the mass proportion of the particle size is 50%; according to the dry ore amount of the flotation feed, the dosage of the reagent is: 100g / t of MK306 for roughing selection, 40g / t of MK306 for scavenging selection, and no reagent is added for concentrating.

[0039] S2 weak magnetic roughing-second stage grinding-weak magnetic concentrating

[0040] The flotation tailings discharged from step S1 are fed into weak magnetic roughing-secondary grinding-weak magnetic concentration operation, wherein the weak magnetic concentration is performed twice to obtain weak magnetic concentration concentrate, and the weak magnetic roughing tailings, the first weak magnetic concentration tailings, and the second weak magnetic concentration tailings are discarded respectively, and the weak magnetic roughing tailings, the first weak magnetic concentration tailings, and the second weak magnetic concentration tailings are combined into magnetic separation tailings; the particle size of the second-stage grinding product is controlled at -0.076mm particle size accounting for 75% by mass, and the magnetic field strength of the weak magnetic roughing operation, the first weak magnetic concentration operation, and the second weak magnetic concentration operation are controlled in the range of 183.03kA / m, 127.32kA / m, and 87.56kA / m, respectively;

[0041] S3 weak magnetic concentrate flotation desulfurization

[0042] The weak magnetic concentrate obtained in step S2 is fed into an open-circuit flotation desulfurization operation with one roughing and two scavenging operations to obtain a qualified iron concentrate product with a TFe grade of 68.46% and a TS content of 0.34%, and a floating sulfur roughing concentrate - middling ore 3 with TS 6.05% and a TFe grade of 65.11%, a floating sulfur scavenging 1 concentrate - middling ore 2 with TS1.99% and a TFe grade of 66.84%, and a floating sulfur scavenging 2 concentrate - middling ore 3 with TS1.85% and a TFe grade of 66.95% are respectively obtained; the flotation desulfurization operation adopts citric acid as a complexing agent, sulfuric acid as an activator, a mixed drug prepared by compounding butyl xanthate and butyl ammonium black drug in a mass ratio of 1:1 as a collector, and 2# oil as a frother. According to the amount of dry ore fed to flotation, the dosage of roughing reagents is: 2000g / t of citric acid, 1000g / t of sulfuric acid, 1500g / t of butyl xanthate + butyl ammonium black medicine, and 48g / t of frother 2# oil; the dosage of primary scavenging reagents is the same as that of roughing, and the dosage of secondary scavenging reagents is half of that of roughing.

[0043] After the merger of Zhongkuang 1, Zhongkuang 2 and Zhongkuang 3, they will be sold as heavy medium products for heavy medium hydrocyclones in coal preparation plants; or, after the merger of Zhongkuang 1 and Zhongkuang 2, they will be used as blending raw materials for ironmaking in steel plants, and Zhongkuang 3 will be sold as heavy medium products for heavy medium hydrocyclones in coal preparation plants.

Claims

1. A beneficiation method for recycling high-sulfur magnetite ore, which is used to separate and enrich sulfur and iron in high-sulfur magnetite ore with a TFe grade of 30% to 40%, a TS content of 10% to 15%, and an ES content of 8% to 9%, characterized in that Use the following steps: S1 High Sulfur Magnetite Ore Primary Grinding-Flotation The high-sulfur magnetite ore is fed into a first-stage grinding-flotation operation to obtain a sulfur concentrate with an ES grade of ≥41%, and the flotation tailings are discharged; the flotation operation adopts 1 roughing, 1 scavenging, 2-3 cleaning, and MK306 is used as the collector; the particle size of the first-stage grinding product is controlled at -0.076mm, and the mass proportion of the particle size is 46% to 60%; S2 weak magnetic roughing-second stage grinding-weak magnetic concentrating The flotation tailings discharged from step S1 are fed into weak magnetic roughing-secondary grinding-weak magnetic concentration operation, wherein the weak magnetic concentration is performed twice to obtain weak magnetic concentration concentrate, and the weak magnetic roughing tailings, the first weak magnetic concentration tailings, and the second weak magnetic concentration tailings are discarded respectively, and the weak magnetic roughing tailings, the first weak magnetic concentration tailings, and the second weak magnetic concentration tailings are combined into magnetic separation tailings; the particle size of the second-stage grinding product is controlled at -0.076mm particle size accounting for 70% to 82% by mass, and the magnetic field strength of the weak magnetic roughing operation, the first weak magnetic concentration operation, and the second weak magnetic concentration operation is controlled in the range of 178 to 210 kA / m, 110 to 135 kA / m, and 85 to 105 kA / m, respectively; S3 weak magnetic concentrate flotation desulfurization The weak magnetic concentrate obtained in step S2 is fed into an open-circuit flotation desulfurization operation with one roughing and two scavenging to obtain a qualified iron concentrate product with a TFe grade of >68.0% and a TS content of <0.35%, and a floating sulfur roughing concentrate - middling ore 3 with TS <6.5% and a TFe grade of >65%, a floating sulfur scavenging 1 concentrate - middling ore 2 with TS <2.0% and a TFe grade of >66.5%, and a floating sulfur scavenging 2 concentrate - middling ore 3 with TS <1.9% and a TFe grade of >66.6% are obtained respectively; the flotation desulfurization operation adopts citric acid as a complexing agent, sulfuric acid as an activator, a compound mixture of butyl xanthate and butyl ammonium black medicine as a collector, and 2# oil as a frother.

2. The ore dressing method for recycling high-sulfur magnetite ore according to claim 1, characterized in that: In step S1, the flotation operation adopts one roughing, one scavenging and two cleaning processes. The tailings of the first cleaning and the second cleaning are returned to the roughing, and the scavenging concentrate is not returned. According to the amount of dry ore fed to the flotation, the dosage of reagents is: 80-110g / t of MK306 for roughing, 35-45g / t of MK306 for scavenging, and no reagent is added for cleaning.

3. The ore dressing method for recycling high-sulfur magnetite ore according to claim 1, characterized in that: In step S1, the particle size of the first-stage grinding product is controlled at -0.076 mm, with the mass fraction accounting for 50% to 55%.

4. The ore dressing method for recycling high-sulfur magnetite ore according to claim 1, characterized in that: In step S2, the particle size of the secondary grinding product is controlled at -0.076 mm, with the mass fraction accounting for 75% to 80%.

5. The ore dressing method for recycling high-sulfur magnetite ore according to claim 1, characterized in that: In step S2, the magnetic field strengths of the weak magnetic roughing operation, the first weak magnetic concentrating operation, and the second weak magnetic concentrating operation are controlled in the ranges of 183-199 kA / m, 119-127 kA / m, and 88-96 kA / m, respectively.

6. A beneficiation method for recycling high-sulfur magnetite ore according to claim 1, characterized in that: In step S2, in the composite mixture of butyl xanthate and butyl ammonium black medicine, the mass ratio of butyl xanthate to butyl ammonium black medicine is (0.85-1.2):

1.

7. A beneficiation method for recycling high-sulfur magnetite ore according to claim 6, characterized in that: In step S2, in the composite mixture of butyl xanthate and butyl ammonium black medicine, the mass ratio of butyl xanthate to butyl ammonium black medicine is 1:

1.

8. A beneficiation method for recycling high-sulfur magnetite ore according to claim 1, 2, 3, 4, 5, 6 or 7, characterized in that: In step S3, according to the amount of dry ore fed to the flotation, the dosage of roughing reagents is: 1500-2500 g / t of citric acid, 800-1200 g / t of sulfuric acid, 1400-1600 g / t of butyl xanthate + butyl ammonium black medicine, and 40-50 g / t of frother 2 oil; the dosage of primary scavenging reagents is the same as that of roughing, and the dosage of secondary scavenging reagents is half of that of roughing.

9. A beneficiation method for recycling high-sulfur magnetite ore according to claim 8, characterized in that: In step S3, after the merger of Zhongkuang 1, Zhongkuang 2 and Zhongkuang 3, they are sold as heavy medium products for the heavy medium hydrocyclone selection of the coal preparation plant.

10. A beneficiation method for recycling high-sulfur magnetite ore according to claim 8, characterized in that: In step S3, medium ore 1 and medium ore 2 are combined and used as raw materials for ironmaking in steel plants; medium ore 3 is sold as a heavy medium product for heavy medium hydrocyclone separation in coal preparation plants.

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