A desulfurizer and a method for solid-state desulfurization treatment of high-sulfur pyrite

Abstract

The application relates to the field of solid pollutant treatment, in particular to a desulfurizer and a method for solid-state desulfurization treatment of high-sulfur pyrite; the desulfurizer comprises desulfurization ash and coal, and the mass ratio of the desulfurization ash and the coal is 1.5-2.5:1; the method comprises the following steps: roasting high-sulfur pyrite and the desulfurizer in the first aspect to simultaneously perform desulfurization and iron reduction of the high-sulfur pyrite, so as to obtain an iron-containing mixture; performing magnetic separation on the iron-containing mixture to obtain metallic iron; by means of the combination of the desulfurization ash and the coal, CaSO4 in the desulfurization ash serves as an oxygen carrier to oxidize and desulfurize S in the low-valence state in the high-sulfur pyrite, meanwhile, the coal can perform a reduction reaction with the iron ore after desulfurization, and the ratio of the desulfurization ash and the coal is controlled, so that sufficient coal participates in the reduction reaction under the premise of sufficient desulfurization, thereby realizing the synchronous performance of the desulfurization and reduction of the high-sulfur pyrite only by means of the desulfurizer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solid pollutant treatment, in particular to a desulfurizer and a method for solid-state desulfurization treatment of high-sulfur pyrite. BACKGROUND

[0002] Most of the conventional treatments for S elements in high-sulfur pyrite phases adopt high-temperature oxidation roasting processes, the main principle of which is to introduce oxygen elements in air under high-temperature conditions to oxidize low-valence S in high-sulfur pyrite phases to form SO2 gas, thereby achieving good desulfurization effect. Although the desulfurization process of high-temperature oxidation roasting has a simple process flow and obvious effect in the existing process technology, toxic gas SO2 will be formed in the high-temperature oxidation roasting process, and the emission of SO2 harmful gas is strictly limited by national environmental protection, thus posing a strong threat to the environment.

[0003] To solve the above problems, the conventional oxidation roasting process must be equipped with a related flue gas desulfurization treatment process, however, this treatment method will bring a large economic burden to the treatment of high-sulfur pyrite process. Therefore, most of the conventional desulfurizers for high-sulfur pyrite adopt low-cost lime, limestone and alkaline solutions prepared by lime-based reagents, and oxygen needs to be introduced to oxidize the separated sulfur elements to SO2 gas during the desulfurization process, and then the tail gas is treated, which can reduce the economic cost to a certain extent, but the low-cost desulfurizer such as lime or limestone can only remove the sulfur elements in high-sulfur pyrite, and cannot reduce the iron ore after removal, therefore, how to provide a desulfurizer that can desulfurize high-sulfur pyrite while reducing iron, is a technical problem that needs to be solved at present. SUMMARY

[0004] The present application provides a desulfurizer and a preparation method and application thereof, to solve the technical problem that the desulfurizer for high-sulfur pyrite in the prior art cannot simultaneously perform desulfurization and iron reduction processes.

[0005] In a first aspect, the present application provides a desulfurizer for high-sulfur pyrite, the desulfurizer comprising desulfurization ash and coal, and the mass ratio of the desulfurization ash to the coal being 1.5-2.5:1.

[0006] Optionally, the CaSO4 content in the desulfurization ash is ≥20%.

[0007] Optionally, the coal comprises at least one of anthracite, fat coal, lean coal and coking coal.

[0008] In a second aspect, the present application provides a method for solid-state desulfurization treatment of high-sulfur pyrite, the method comprising:

[0009] mixing the high-sulfur pyrite and the desulfurizer of the first aspect, and then roasting to simultaneously desulfurize and reduce the high-sulfur pyrite, to obtain an iron-containing mixture;

[0010] magnetic separation of the iron-containing mixture to obtain metallic iron.

[0011] Optionally, the chemical compositions of the desulfurization ash of the desulfurizer and the high-sulfur pyrite satisfy:

[0012] [FeS] / [CaSO4]=0.25-1.25,

[0013] wherein [FeS] is the molar content of FeS in the high-sulfur pyrite, and [CaSO4] is the molar content of CaSO4 in the desulfurization ash.

[0014] Optionally, the mass ratio of the desulfurizer to the high-sulfur pyrite is 1-1.5:1.

[0015] Optionally, the average particle sizes of the desulfurizer and the high-sulfur pyrite are both <90 μm.

[0016] Optionally, the magnetic separation of the iron-containing mixture to obtain metallic iron specifically includes:

[0017] first magnetic separation of the iron-containing mixture to obtain first magnetic separation products and first metallic iron;

[0018] second magnetic separation of the first magnetic separation products to obtain second metallic iron;

[0019] mixing the first metallic iron and the second metallic iron, and then drying and crushing to obtain metallic iron powder;

[0020] wherein the magnetic field strength of the first magnetic separation is greater than that of the second magnetic separation.

[0021] Optionally, the magnetic field strength of the first magnetic separation is 0.8-1 T, and the magnetic field strength of the second magnetic separation is 0.1-0.15 T.

[0022] The above technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0023] The desulfurizer provided by the embodiments of the present application uses desulfurization ash and coal in a collocation manner, and the CaSO4 in the desulfurization ash acts as an oxygen carrier to oxidize and desulfurize the low-valence S in the high-sulfur pyrite, while the coal can perform a reduction reaction with the iron ore after desulfurization. By controlling the ratio of the desulfurization ash and the coal, sufficient coal can participate in the reduction reaction under the premise of sufficient desulfurization, so that the desulfurization and reduction of the high-sulfur pyrite can be simultaneously completed by only using the desulfurizer. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and serve to explain the principles of the application.

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings required by the embodiments or prior art description will be briefly introduced as follows. Obviously, those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0026] Figure 1 A flowchart of the method provided by the embodiments of the present application is shown in the figure.

[0027] Figure 2 A detailed flowchart of the method provided by the embodiments of the present application is shown in the figure.

[0028] Figure 3 A principle diagram of the method provided by the embodiments of the present application is shown in the figure.

[0029] Figure 4 A comparison diagram of the mineral phase composition of the sample after solid-state desulfurization provided by the embodiments of the present application is shown in the figure.

[0030] Figure 5 A comparison diagram of the phase composition of the sample after two times of magnetic separation provided by the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0031] The advantages and various effects of the present application will be more clearly presented by the following specific embodiments and examples. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present application, rather than limit the present application.

[0032] Throughout the specification, unless otherwise specifically indicated, the terms used herein are understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as generally understood by those skilled in the art to which the present application belongs. If there is a conflict, the present specification takes precedence.

[0033] Unless otherwise specifically indicated, the various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0034] The creative thinking of the present application is:

[0035] To explore a new desulfurization process or desulfurizer to realize efficient desulfurization process while "reduction of iron", the existing ideas are to use sulfur-oxidizing acidithiobacillus for wet desulfurization of high-sulfur iron ore at low temperature, but this method has good desulfurization effect, but the desulfurization period is long, and the desulfurization temperature in the wet process is low, which cannot realize good "iron extraction" process.

[0036] The oxidation roasting process of high-sulfur iron ore is carried out in a rotary kiln, although this process has good reduction kinetics and desulfurization efficiency in the rotary kiln, but still produces a lot of SO2 gas, damages the equipment, and makes the equipment maintenance and operation cost high.

[0037] Because the desulfurization ash produced by the flue gas desulfurization process is rich in CaSO4, in the actual desulfurization process, the low-valence S in the high-sulfur iron ore is oxidized and desulfurized by using CaSO4 in the desulfurization ash, and then combined with a certain coal, so that the iron ore phase after desulfurization can be reduced, and the oxidation desulfurization process and the reduction process can be simultaneously reacted at high temperature, therefore, the desulfurization ash and the coal are matched into a desulfurizer, which can realize desulfurization and iron reduction process at high temperature, and the specific principle is as shown in Figure 3

[0038] The technical scheme provided by the embodiment of the present application is to solve the above technical problems, and the general idea is as follows:

[0039] In an embodiment of the present application, a desulfurizer for high-sulfur iron ore is provided, the desulfurizer comprises desulfurization ash and coal, and the mass ratio of the desulfurization ash to the coal is 1.5-2.5:1.

[0040] In the embodiment of the present application, the mass ratio of the desulfurization ash to the coal is 1.5-2.5:1, and the positive effect is that the iron ore phase after desulfurization of high-sulfur iron ore by the desulfurization ash can be further reduced by the coal to obtain sufficient metallic iron product.

[0041] In some optional embodiments, the CaSO4 content in the desulfurization ash is ≥20%.

[0042] In the embodiment of the present application, the positive effect of controlling the CaSO4 content in the desulfurization ash is 20%.

[0043] In some optional embodiments, the coal comprises at least one of anthracite, fat coal, lean coal and coking coal.

[0044] In the embodiment of the present application, the positive effect of controlling the specific type of coal is that the coal is a conventional coal, and the coal can also provide a certain amount of heat in the high-temperature oxidation roasting stage, saving cost, and the coal can be converted from C to CO in the reduction stage, so it has high reduction performance. ​

[0045] In one embodiment of the present application, as shown in Figure 1 and Figure 3 A method for high-sulfur pyrite solid-state desulfurization treatment is provided, and the method comprises:

[0046] S1. mixing high-sulfur pyrite and the desulfurizer, and then roasting to simultaneously desulfurize and reduce iron in the high-sulfur pyrite, to obtain an iron-containing mixture;

[0047] S2. magnetically separating the iron-containing mixture to obtain metallic iron;

[0048] The magnetic field strength of the first magnetic separation is greater than the magnetic field strength of the second magnetic separation, and the desulfurizer is the desulfurizer described in any of the preceding embodiments. For specific components, proportions, and contents of the desulfurizer, refer to the preceding description. Other implementation details can refer to related technologies. For the sake of brevity of the description, they will not be described here.

[0049] In the embodiments of the present application, the magnetic field strengths of the first magnetic separation and the second magnetic separation are controlled. Different magnetic field strengths are used to screen out large-particle iron-containing phases through a stronger magnetic field, but some non-magnetic substances may still be adsorbed on the surface of the iron phase due to the interaction force between the small particles. Then, the small-particle metallic iron product is screened out through a weaker magnetic field, to realize the recovery of metallic iron of different specifications.

[0050] In some optional embodiments, the chemical compositions of the desulfurization ash of the desulfurizer and the high-sulfur pyrite satisfy:

[0051] [FeS] / [CaSO4] = 0.25-1.25,

[0052] In the formula, [FeS] is the molar content of FeS in the high-sulfur pyrite, and [CaSO4] is the molar content of CaSO4 in the desulfurization ash.

[0053] In the latter embodiments of the present application, the positive effect of controlling [FeS] / [CaSO4] = 0.25-1.25 is that within this molar ratio range, the CaSO4 in the desulfurization ash and the FeS in the high-sulfur pyrite can fully react, so that the desulfurization of the high-sulfur pyrite is completely performed, which facilitates the subsequent reduction of the desulfurized iron ore phase, ensures the purity of the metallic iron, and simultaneously realizes the process of desulfurization and iron reduction in the high-temperature roasting stage.

[0054] In some optional embodiments, the mass ratio of the desulfurizer to the high-sulfur pyrite is 1-1.5:1.

[0055] In the embodiments of the present application, the positive effect of controlling the mass ratio of the desulfurizer and the high-sulfur iron ore to be 1-1.5:1 is that, within the range of the mass ratio, the desulfurizer and the high-sulfur iron ore can fully react, which not only enables the high-sulfur iron ore to be completely desulfurized, but also enables the reducing agent to fully react in the subsequent iron reduction process, thereby improving the metal conversion rate.

[0056] In some optional embodiments, the average particle size of the desulfurizer and the high-sulfur iron ore is less than 90 μm, respectively.

[0057] In the embodiments of the present application, the positive effect of controlling the average particle size of the desulfurizer and the high-sulfur iron ore to be less than 90 μm is that, within the particle size range, the desulfurizer and the high-sulfur iron ore can be fully mixed, and because the desulfurized ash with small particle size can be fully mixed with the high-sulfur iron ore, the desulfurization speed can be accelerated in the desulfurization reaction stage, and the desulfurized ash can fully react with the high-sulfur iron ore, thereby improving the desulfurization effect and the final iron metallization rate.

[0058] In some optional embodiments, the temperature of the roasting is 1100-1200°C, and the temperature rising rate of the roasting is 5-10°C / min, wherein the temperature of the roasting can be 1100°C, 1150°C or 1200°C; and the temperature rising rate of the roasting can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min.

[0059] In the embodiments of the present application, the positive effect of the temperature of the roasting being 1100-1200°C is that, within the temperature range, the high-sulfur iron ore and the desulfurizer can be fully roasted, the CaSO4 in the desulfurized ash in the desulfurizer is used to oxidize and desulfurize the low-valence S in the high-sulfur iron ore, and the coal in the desulfurizer is used to reduce the iron ore, thereby realizing the desulfurization of the high-sulfur iron ore and the reduction of the iron ore at the same time, and realizing the simultaneous desulfurization and reduction.

[0060] The positive effect of the temperature rising rate of the roasting being 5-10°C / min is that, within the temperature rising rate range, the stable reaction of the high-sulfur iron ore and the desulfurizer can be promoted, and the stable reduction reaction between the desulfurizer and the high-sulfur iron ore can be ensured.

[0061] In some optional embodiments, as shown in FIG. 1, the method for preparing high-sulfur iron ore comprises the following steps: Figure 2 As shown in FIG. 1, the method for preparing high-sulfur iron ore comprises the following steps:

[0062] S21. The iron-containing mixture is subjected to first magnetic separation to obtain first magnetic separation products and first metallic iron, respectively;

[0063] S22. performing second magnetic separation on the first magnetic separation product to obtain second metallic iron;

[0064] S23. mixing the first metallic iron and the second metallic iron, and then performing drying treatment and crushing to obtain metallic iron powder.

[0065] In the embodiment, the iron-containing mixture is subjected to two times of magnetic separation, so that metallic iron of different specifications is separated, thereby effectively separating the metallic iron.

[0066] In some optional embodiments, the magnetic field strength of the first magnetic separation is 0.8T-1T, and the magnetic field strength of the second magnetic separation is 0.1T-0.15T.

[0067] In the embodiment, the magnetic field strength of the first magnetic separation is 0.8T-1T, and the magnetic field strength of the second magnetic separation is 0.1T-0.15T.

[0068] The positive effect of the magnetic field strength of the second magnetic separation being 0.1T-0.15T is that, in the range of the magnetic field strength, small-particle iron-containing phases can be screened out, thereby being able to cooperate with the first magnetic separation to recover metallic iron of different specifications.

[0069] Example 1

[0070] The Peru mine is a typical high-sulfur pyrite resource, and a desulfurizer for high-sulfur pyrite is provided, which includes desulfurization ash and coal, and the mass ratio of the desulfurization ash and the coal is 2:1. The content of CaSO4 in the desulfurization ash is ≥20%.

[0071] The specific parameters of the desulfurization ash are shown in Table 1.

[0072] Table 1: Parameters of the desulfurization ash

[0073] Composition CaO SO3 MgO F Fe2O3 SiO2 Na2O K2O Al2O3 Content (%) 74.13 12.29 5.09 3.19 0.304 0.464 0.769 0.267 0.339

[0074] The coal is anthracite.

[0075] A method for solid-state desulfurization treatment of high-sulfur pyrite includes:

[0076] Mixing the Peru mine and the desulfurizer, and then performing roasting, so that the desulfurization and iron reduction of the Peru mine are simultaneously performed to obtain an iron-containing mixture;

[0077] Performing first magnetic separation on the iron-containing mixture to obtain first magnetic separation product and first metallic iron, respectively;

[0078] The product from the first magnetic separation is subjected to a second magnetic separation to obtain a second metallic iron.

[0079] The first and second metallic iron are mixed, dried, and then pulverized to obtain metallic iron powder.

[0080] Among them, the magnetic field strength of the first magnetic separation is greater than that of the second magnetic separation.

[0081] The calcination temperature is 1100℃, and the calcination heating rate is 8℃ / min.

[0082] like Figure 3 As shown, according to the principle of the method of this application, the oxidative roasting stage is divided into an S separation process, a calcium ferrite reduction process, and a magnetic separation process. The S separation process mainly uses Peruvian ore as the reaction matrix and introduces CaSO4 from the desulfurization ash as an oxygen carrier to react with FeS in the Peruvian ore, thereby separating S from FeS. The desulfurization ash and Peruvian ore generate 2CaO·Fe2O3, CaO·Fe2O3, CaO, and CaS under low temperature conditions and release high concentrations of SO2 gas.

[0083] Since the S separation process will form calcium ferrite, a reduction process will occur. In this process, the 2CaO·Fe2O3 and CaO·Fe2O3 in the reaction system are reduced one step or gradually by C and CO in the anthracite to form elemental iron. The reduction process of CaO·Fe2O3 in this process conforms to the unreacted core model, and the reduction process proceeds step by step from the core to the surface.

[0084] The final magnetic separation process uses an external magnetic field to separate the reduced metallic iron from the sulfur-containing impurity phase, achieving secondary removal of sulfur.

[0085] Example 2

[0086] Comparing Example 2 with Example 1, the difference between Example 2 and Example 1 is as follows:

[0087] To determine the effect of different coal blending ratios on the metallization rate of the reduced product, the effect of different coal blending amounts on the metallization rate was investigated, and the results are shown in Table 1.

[0088] Table 2

[0089] Coal blending amount TFe MFe Metalization rate (%) 0.20 48.44 42.34 87 0.25 48.16 45.60 95 0.30 46.21 45.97 99 0.35 47.14 46.67 99 0.40 41.12 40.71 99

[0090] As shown in Table 1, the metallization rate of the reduced product gradually increases with the continuous increase of coal blending amount, but the change in the metallization rate of the product is small in the later stage as the carbon content increases.

[0091] Specifically, when the amount of coal is less than 35%, the CF formed after desulfurization of the Peru ore cannot be completely reduced to form metallic iron; when the amount of coal is more than 35%, the excessive amount of coal brings a small increase in the metallization rate, resulting in waste of raw material resources.

[0092] Therefore, in order to ensure the effectiveness of reduction and save resources, the amount of coal is controlled to be 35% based on the weight of the Peru ore.

[0093] Example 3

[0094] Comparing Example 3 with Example 2, the difference between Example 3 and Example 2 is that:

[0095] In the case of 35% of the amount of coal, based on the S content of 3.5% in the Peru ore and the S content of 5% in the desulfurization ash, the effect of the molar ratio of FeS in the Peru ore to CaSO4 in the desulfurization ash on the metallization rate of the sample was investigated, and the results are shown in Table 2.

[0096] Table 3

[0097]

[0098]

[0099] As shown in Table 2, the most preferred value of the molar ratio of [FeS] / [CaSO4] is 0.25, at which the FeS in the Peru ore will be completely removed and form CaO·Fe2O3 with CaO. Therefore, when the molar ratio of FeS / CaSO4 is less than 0.25, the S in the Peru ore cannot be completely released, and a large amount of FeS still exists, which cannot form elemental iron under the reduction condition, resulting in a decrease in the metallization rate; when the molar ratio of FeS / CaSO4 is more than 1.25, it will cause a certain degree of waste of raw material resources and increase the production cost.

[0100] Example 4

[0101] Comparing Example 4 with Example 1, the difference between Example 4 and Example 1 is that:

[0102] According to the parameters of Example 2 and Example 3, the molar ratio of [FeS] / [CaSO4] is controlled to be 0.25, and the mass ratio of the Peru ore, the desulfurization ash and the anthracite is controlled to be 20:14:7.

[0103] In order to ensure the desulfurization effect and the metallization rate, the Peru ore, the desulfurization ash and the anthracite need to be crushed first, then sieved through a 160-mesh screen, and then dried at a temperature of 105°C for 3h-5h.

[0104] Related experiments:

[0105] During the process of the method in Embodiment 4, the mineral phase structure of the sample after desulfurization is completed is determined at the time of completion of desulfurization, and the results are shown in Table 1. Figure 4 At the same time, the phase composition of the sample after two times of magnetic separation is determined, and the results are shown in Table 2. Figure 5 Test methods of related experiments:

[0106] Test method of the mineral phase structure of the sample after desulfurization is completed:

[0107] Test method of the phase composition of the sample:

[0108] As shown in Table 1, the initial Peru ore is mainly composed of iron oxide and iron sulfide. Under the high-temperature desulfurization of desulfurization ash, S in the iron sulfide is released to form CaS. After removing S, the iron oxide combines with CaO to form CaO·Fe2O3, and the reduction process is carried out under the action of coal.

[0109] Figure 4 As shown in Table 2, after the solid-state reduction desulfurization sample is subjected to the first magnetic separation, the iron-containing phase is selected due to the large external magnetic field strength (0.8T-1T), but part of the non-magnetic material is still adsorbed on the surface of the iron phase due to the interaction force between the small particles. Therefore, the second washing separation is used to carry out the second magnetic separation in the weak magnetic field (0.1T-0.15T), so that the elemental iron can be further obtained.

[0110] Figure 5 The one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0111] (1) The desulfurizer provided by the embodiments of the present application uses desulfurization ash and coal in combination. CaSO4 in the desulfurization ash acts as an oxygen carrier to oxidize and desulfurize S in the low-valence state in the high-sulfur iron ore. At the same time, coal can be used for reduction reaction with the iron ore after desulfurization. By controlling the ratio of desulfurization ash and coal, sufficient coal can be used for reduction reaction under the premise of sufficient desulfurization, so that the desulfurization and reduction of high-sulfur iron ore can be simultaneously completed by using only the desulfurizer.

[0112] (2) The desulfurizer provided by the embodiments of the present application uses desulfurization ash, a solid waste produced by the flue gas desulfurization process. SO2 gas produced during the high-temperature roasting stage can be recovered and used to prepare sulfuric acid. Therefore, by using desulfurization ash as raw material, not only the utilization of desulfurization ash, an industrial difficult-to-treat waste resource, can be solved, but also the SO2 secondary waste gas produced during the process stage can be utilized.

[0113] (2) The desulfurizer provided by the embodiments of the present application uses desulfurization ash, a solid waste produced by the flue gas desulfurization process. SO2 gas produced during the high-temperature roasting stage can be recovered and used to prepare sulfuric acid. Therefore, by using desulfurization ash as raw material, not only the utilization of desulfurization ash, an industrial difficult-to-treat waste resource, can be solved, but also the SO2 secondary waste gas produced during the process stage can be utilized.

[0114] ​​(3) The method provided by the embodiment of the present application can completely convert S elements in high-sulfur pyrite into CaS products, and the metallization rate of Fe can reach more than 95%.

[0115] (4) The method provided by the embodiment of the present application can not only collect metal Fe of different specifications, but also separate metal Fe and CaS, so that Fe is collected.

[0116] (5) The method provided by the present application can realize the processes of desulfurization and iron reduction at the same high temperature, greatly saving energy and resources, and the obtained metal Fe has high metallization rate and low S content.

[0117] It should be noted that, in this document, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0118] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are approximate values and include values approximately the same as the stated values. For ranges, the endpoints are included in the ranges, and the ranges are inclusive of the endpoints. For numerical values, the value includes approximately the same value. Numerical values are not limited to the precise values stated. The numerical values are approximate values and include values approximately the same as the stated values. The endpoints of the ranges and any values are approximations.

[0119] The above description is merely one specific implementation of the application, and thus the technical personnel in the art can understand or implement the application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for solid state desulphurization treatment of high sulphur pyrite characterized in that, The method comprises: mixing high-sulfur pyrite and desulfurizer, and then roasting to simultaneously desulfurize and reduce iron of the high-sulfur pyrite to obtain an iron-containing mixture; the desulfurizer comprises desulfurization ash and coal, and the mass ratio of the desulfurization ash to the coal is 1.5-2.5:1; the CaSO4 content in the desulfurization ash is ≥20%; magnetic separation of the iron-containing mixture to obtain metallic iron; the chemical compositions of the desulfurization ash of the desulfurizer and the high-sulfur pyrite satisfy: [FeS] / [CaSO4]=0.25-1.25, wherein [FeS] is the molar content of FeS in the high-sulfur pyrite, and [CaSO4] is the molar content of CaSO4 in the desulfurization ash; the mass ratio of the desulfurizer to the high-sulfur pyrite is 1-1.5:1; the average particle sizes of the desulfurizer and the high-sulfur pyrite are both <90 μm; the roasting temperature is 1100-1200 °C, and the heating rate of the roasting is 5-10 °C / min.

2. The method of claim 1, wherein, The magnetic separation of the iron-containing mixture to obtain metallic iron specifically comprises: first magnetic separation of the iron-containing mixture to obtain first magnetic separation products and first metallic iron; second magnetic separation of the first magnetic separation products to obtain second metallic iron; mixing the first metallic iron and the second metallic iron, and then drying, and then crushing to obtain metallic iron powder; wherein the magnetic field strength of the first magnetic separation is higher than that of the second magnetic separation.

3. The method of claim 2, wherein, The magnetic field strength of the first magnetic separation is 0.8-1 T, and the magnetic field strength of the second magnetic separation is 0.1-0.15 T.

4. The method of claim 1, wherein, The coal comprises at least one of anthracite, fat coal, lean coal and coking coal.

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