Chromite fluxed sintered ore and preparation method thereof

Abstract

The invention discloses chromite fluxed sintered ore and a preparation method thereof. The preparation method comprises the steps that chromite powder, chromium-containing slag, a calcium flux, a magnesium flux, a siliceous flux and fuel serve as raw materials to be subjected to burdening, even mixing and granulation, and a sintered mixture is obtained; and distributing, igniting, sintering, crushing, cooling and screening the sintered mixture to obtain the chromite fluxed sinter. According to the method, the fluxing agent adopted in the sintering process is based on the fluxing agent used for electric furnace smelting slagging, the calcium fluxing agent is added, the binary alkalinity is improved, the sintering mineralization consolidation process of chromite powder can be completed at the low sintering temperature by adjusting the composition and addition amount of the fluxing agent, developing a low-melting-point phase and reducing the sintering liquid phase generation temperature, and the high-purity chromite powder can be obtained. And meanwhile, the produced chromite fluxed sintered ore has the advantages of being high in strength, high in yield and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chromite smelting, and particularly relates to a chromite fluxed sinter and a preparation method thereof. BACKGROUND

[0002] High-carbon ferrochrome is a main alloy additive for producing stainless steel, and is mainly produced by an electric furnace method. Currently, the main charge structure for smelting high-carbon ferrochrome by an electric furnace is "chromite + flux + reducing agent". The charge can determine the smelting effect and is a main component of smelting cost. The production process of high-carbon ferrochrome has high requirements for the permeability, melting speed and reducibility of the charge. In the current production, the slag-making flux is directly charged into the furnace for smelting. Since the raw flux can participate in slag-making only after decomposition in the furnace, on the one hand, and is not conducive to uniform distribution of the flux in the furnace, on the other hand, the direct charging of the raw flux into the furnace for smelting affects the uniformity of slag-making and also lowers the utilization efficiency of the flux, which is one of the main reasons for unstable operation, high power consumption and other problems in the process of smelting high-carbon ferrochrome by an electric furnace.

[0003] It is one of the important measures for efficient and energy-saving production of high-carbon ferrochrome by an electric furnace method to use low-cost chromite powder to prepare high-quality high-carbon ferrochrome smelting charge by sintering or pelletizing. Sinter is a man-made lump ore obtained through a series of complex physical and chemical reactions at high temperature, and has good strength and metallurgical properties. The high porosity of the sinter increases the specific surface area and electrical resistivity of the sinter, which is beneficial to improving the reduction reaction rate. The use of chromite sinter instead of lump ore for smelting high-carbon ferrochrome can increase the yield of ferrochrome by 10-17%, reduce the power consumption for smelting by 250-300 kWh / t, and reduce the consumption of coke by 30-40 kg / t. However, since the melting point of chromite spinel is high, the amount of liquid phase produced is only about 20% of the solid phase, which is significantly lower than the 30%-40% of ordinary sinter. Small-scale tests have shown that when the temperature reaches 1400°C or above, the chromite sinter begins to bond into blocks. In large-scale production, the maximum sintering temperature is 1450-1500°C, and the high-temperature holding time is about 5 min, which requires a large amount of coke powder to provide heat, and the consumption of coke is about 100 kg / t. To solve the problem of chromite sintering, a Chinese patent document with publication number CN101705356B proposes a chromite powder sintering process, which is to grind the ore powder to more than 65% of -0.074 mm, add bentonite binder, fuel and water, mix uniformly, make pellets, wrap a layer of fuel on the surface of the pellets, load into a sintering machine, the layer height of the charge is 550-700 mm, after drying and preheating, ignite and sinter, and after cooling, crushing and screening, the finished sinter is obtained. This method grinds the chromite powder to prepare pellets and then sinter, which is mainly to improve the permeability of the sintering layer and the distribution state of the fuel, and has a certain effect on increasing the yield, but does not change the sintering system, and increases the chromite grinding and pelletizing processes, which increases the production flow, and the quality of the sinter and the fuel consumption do not change fundamentally.

[0004] In general, due to the high melting point of chromite, it is difficult to generate low melting point liquid phase, the chromite powder has poor granulation performance, the finished product rate is low and the energy consumption is high, the finished product rate of chromite sinter is about 68%, the drum index is about 57%, the utilization coefficient is about 1.1t / (m 2 In addition, in the process of producing high-carbon ferrochrome by electric furnace smelting of chromite, due to the separate addition of sintered ore, chromite pellets, flux and reducing agent, the distribution in the furnace is uneven, which affects the uniformity of slag making, the utilization efficiency of flux is low, the furnace condition fluctuates greatly, the operation of electric furnace smelting is difficult, and the power consumption is high. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art, especially to solve the technical problems of high melting point of chromite in chromite, difficulty in generating low melting point liquid phase, poor granulation performance of chromite powder, high sintering temperature, large production fluctuation, difficult production operation, high energy consumption and low finished product rate, and to provide a chromite flux sinter and a preparation method thereof, which can promote the increase of liquid phase in the sintering process of chromite, improve the quality of chromite sinter and save energy.

[0006] To solve the above technical problems, the following technical solutions are adopted.

[0007] A preparation method of a chromite flux sinter, comprising the following steps:

[0008] (1) The raw materials of chromite powder, chromium-containing slag, calcium flux, magnesium flux, silicon flux and fuel are proportioned, mixed and granulated to obtain sintered mixture; wherein the addition amount of the chromium-containing slag accounts for 2% to 10% of the total mass of the raw materials, the addition amount of the calcium flux is added according to the mass ratio of CaO to SiO2 in the composition of the chromite flux sinter is 0.4 to 1.5:1, the addition amount of the magnesium flux is added according to the mass ratio of MgO to Al2O3 in the composition of the chromite flux sinter is 0.8 to 2.4:1, the addition amount of the silicon flux is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) in the composition of the chromite flux sinter is 0.3 to 0.6:1, and the mass of the fuel accounts for 5.5% to 7.0% of the total mass of the raw materials;

[0009] (2) The sintered mixture is distributed, ignited, sintered, crushed, cooled and screened to obtain the chromite flux sinter.

[0010] The preparation method of the above-mentioned chromite flux sinter, preferably, in step (1), the raw materials also add return ore, the addition amount of the return ore accounts for 20% to 25% of the total mass of the raw materials, and the return ore is the sintered ore below-5mm screen after step (2).

[0011] The preparation method of the chromite fluxed sinter, preferably, in step (1), the mass fraction of Cr2O3 in the chromite powder is 30% to 60%.

[0012] The preparation method of the chromite fluxed sinter, preferably, in step (1), the mass fraction of Cr in the chromium-containing slag is 3% to 15%, and the particle size of the chromium-containing slag is controlled to be greater than or equal to 90% of -3 mm.

[0013] The preparation method of the chromite fluxed sinter, preferably, in step (1),

[0014] The calcareous flux includes one or more of limestone, dolomite, slaked lime, quicklime and high-calcium slag, the mass fraction of CaO in the high-calcium slag is greater than or equal to 40%, and the particle size of the calcareous flux is controlled to be greater than or equal to 90% of -3 mm.

[0015] The magnesian flux includes one or more of dolomite, magnesite, magnesium silicate, serpentine and magnesian slag, the mass fraction of MgO in the magnesian slag is greater than or equal to 30%, and the particle size of the magnesian flux is controlled to be greater than or equal to 90% of -3 mm.

[0016] The siliceous flux includes one or more of silica, diatomite, serpentine, quartz sand and siliceous slag, the mass fraction of SiO2 in the siliceous slag is greater than or equal to 40%, and the particle size of the siliceous flux is controlled to be greater than or equal to 90% of -3 mm.

[0017] When the magnesian flux and the calcareous flux are both dolomite, the maximum addition amount of the dolomite is constrained according to the maximum CaO / SiO2 mass ratio or the maximum MgO / Al2O3 mass ratio.

[0018] The preparation method of the chromite fluxed sinter, preferably, in step (1), the fuel includes coke powder and / or coal powder, the particle size of the fuel is greater than 0 and less than or equal to 5 mm, and the particle size is greater than or equal to 70% of -3 mm.

[0019] The preparation method of the chromite fluxed sinter, preferably, in step (1), water is added in the mixing process to adjust the moisture content of the material to be 6wt% to 12wt%, and the particle size of the sintering mixture is 0.5 mm to 8 mm.

[0020] The preparation method of the chromite fluxed sinter, preferably, in step (1), water is added in the mixing process to adjust the moisture content of the material to be 6wt% to 12wt%, and the particle size of the sintering mixture is 0.5 mm to 8 mm.

[0021] Preferably, in step (2), the process parameters of the ignition are as follows: the ignition temperature is 1050-1150 DEG C, the ignition time is 1.5-2 min, the holding time is 1.0-2.0 min, and the ignition negative pressure is 5-6 kPa; the sintering negative pressure is 8-10 kPa, the cooling negative pressure is 4-8 kPa, and the cooling time is 2-5 min.

[0022] As a general technical concept, the application further provides the chromite flux sinter prepared by the preparation method of the chromite flux sinter.

[0023] Compared with the prior art, the application has the following advantages:

[0024] In the prior art, because the chromite spinel has a high melting point, the amount of the generated liquid phase accounts for only about 20% of the solidified phase, which is significantly lower than the required 30%-40% for sintering. The chromite sintering small-scale test proves that the liquid phase can be obviously observed only when the sintering temperature is higher than 1350 DEG C, and the chromite sinter begins to be bonded into blocks when the temperature is higher than 1400 DEG C. This causes the problems of difficulty in generating a low-melting-point liquid phase in the sintering process, poor granulation of the chromite powder, high sintering temperature, high required fuel ratio, large production fluctuation, high energy consumption, and low product yield. In the application, the flux used in the sintering process is based on the flux used for electric furnace smelting and slagging, and the calcium flux is added to increase the binary basicity (CaO / SiO2). By adjusting the composition and addition amount of the flux, the flux can mineralize with the chromite in the sintering process to develop low-melting-point phases such as pyroxene and calcium-magnesium olivine, thereby promoting the increase of the amount of the liquid phase in the sintering process of the chromite, improving the quality of the chromite sinter, reducing the sintering liquid phase generation temperature, and reducing the solid fuel consumption. The added chromium-containing slag is not only beneficial to the development of the sintering liquid phase, but also can recover the chromium element in the slag, which is beneficial to the increase of the chromium recovery rate. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 FIG. 1 is a process flow diagram of the preparation method of the chromite flux sinter in Example 1 of the application. DETAILED DESCRIPTION

[0026] The application will be further described below in combination with the drawings and specific preferred examples, but the protection scope of the application is not limited by the following examples. The materials and instruments used in the following examples are commercially available.

[0027] Example 1

[0028] A preparation method of the chromite flux sinter of the application, as shown in FIG. 1, comprises the following steps: Figure 1 ​

[0029] (1) with Cr2O3 as 44.28% of chromite powder as raw material, add return ore, chromium-containing slag, flux and coke powder, with limestone, dolomite, silica as flux, the particle size of the three is controlled at -3mm≥90%, the addition amount of limestone is added according to the mass ratio of CaO to SiO2 of 0.4:1 in the composition of chromite flux sinter, the addition amount of dolomite is added according to the mass ratio of MgO to Al2O3 of 1.2:1 in the composition of chromite flux sinter, the addition amount of silica is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) of 0.3:1 in the composition of chromite flux sinter, taking the total mass of all raw materials as the basis, the mass of return ore accounts for 20% of the total mass of raw materials, the return ore is -5mm undersize sinter that cannot be added to the electric furnace smelting, the chromium content in the chromium-containing slag is 5.62%, the addition amount of chromium-containing slag accounts for 5% of the total mass of raw materials, the particle size of chromium-containing slag is controlled at -3mm≥90%, the mass of coke powder accounts for 7.0% of the total mass of raw materials, the particle size of coke powder is controlled at 0< coke powder particle size≤5mm, wherein -3mm is not more than 70%. The raw materials are mixed and granulated into 0.5mm-8mm sintering mixture, water is added during the mixing process to adjust the moisture content of the material to 10.3%.

[0030] (2) the sintering mixture is distributed, ignited and sintered, the layer thickness is 500mm, the ignition temperature is 1100±20℃, the ignition time is 2min, the holding time is 1min, the ignition negative pressure is 5kPa, the sintering exhaust negative pressure is 8kPa, after the sintering is completed, the cooling negative pressure is adjusted to 5kPa, the cooling time is 3min, after being sieved with a 5mm sieve, the iron ore flux sinter is obtained, the sinter product yield is 82.23%, the drum strength is 65.45%, and the utilization coefficient is 1.225t / (h·m 2 ).

[0031] Example 2

[0032] A preparation method of the chromite flux sinter of the present application comprises the following steps:

[0033] (1) with Cr2O3 as 41.34% of the chromite powder as raw material, and then add the return ore, coke powder, flux and chromium-containing slag, with quicklime, magnesite, silica as flux, the particle size of the three is controlled at-3mm≥90%, the addition amount of quicklime is added according to the mass ratio of CaO to SiO2 of 0.4:1 in the composition of chromite flux sinter, the addition amount of magnesite is added according to the mass ratio of MgO to Al2O3 of 1.0:1 in the composition of chromite flux sinter, the addition amount of silica is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) of 0.35:1 in the composition of chromite flux sinter, the particle size of the flux is controlled at-3mm≥90%, the mass ratio of coke powder is 6.5% based on the total mass of all raw materials, the particle size of coke powder is controlled at 0<particle size of fuel≤5mm, wherein-3mm is not more than 70%, the mass ratio of return ore is 20%, the return ore is-5mm sinter, the chromium content in the chromium-containing slag is 7.59%, the chromium-containing slag is 10%, and the particle size of the chromium-containing slag is controlled at-3mm≥90%. The raw materials are mixed and granulated into 0.5-8mm sintering mixture, and water is added to adjust the moisture content of the materials to 9.6% during the mixing process.

[0034] (2) the sintering mixture is distributed, ignited and sintered, the layer thickness is 500mm, the ignition temperature is 1100±20℃, the ignition time is 2min, the holding time is 1min, the ignition negative pressure is 5kPa, the sintering exhaust negative pressure is 9kPa, the cooling negative pressure is adjusted to 5kPa after sintering is completed, the cooling time is 3min, and the chromium-containing sinter is obtained after being sieved by a 5mm sieve, the sinter yield is 81.56%, the drum strength is 63.14%, and the utilization coefficient is 1.242t / (h·m 2 )。

[0035] Example 3

[0036] A preparation method of the chromite flux sinter of the present application comprises the following steps:

[0037] (1) taking chromite powder with Cr2O3 of 40.11% as raw material, additionally adding return fines, coal powder, flux and chromium-containing slag, taking limestone, serpentine and quartz sand as flux, the particle sizes of the three are all controlled to be -3mm≥90%, the limestone is added according to the mass ratio of CaO to SiO2 of 0.5:1 in the sinter composition, the serpentine is added according to the mass ratio of MgO to Al2O3 of 0.9:1 in the sinter composition, the quartz sand is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) of 0.4:1 in the sinter composition, the particle sizes of the fluxes are all controlled to be -3mm≥90%, the mass ratio of the coal powder is 7.0% based on the total mass of all raw materials, the particle size of the coal powder is controlled to be 0< fuel particle size≤5mm, wherein -3mm is not more than 70%, the mass ratio of the return fines is 20%, the return fines are -5mm sinter, the mass fraction of chromium in the chromium-containing slag is 10.89%, the chromium-containing slag is added in a ratio of 8%, and the particle size of the chromium-containing slag is controlled to be -3mm≥90%. The raw materials are mixed and granulated into 0.5-8mm sintering mixtures, and water is added in the mixing process to adjust the moisture content of the materials to 10.5%.

[0038] (2) the sintering mixtures are distributed, ignited and sintered, the layer thickness is 500mm, the ignition temperature is 1100±20℃, the ignition time is 2min, the holding time is 2min, the ignition negative pressure is 5kPa, the sintering exhaust negative pressure is 8kPa, the cooling negative pressure is adjusted to 5kPa after the sintering is completed, the cooling time is 3min, and the chromium-containing chromite flux sinter is obtained after being sieved by a 5mm sieve, the sinter yield is 80.24%, the drum strength is 62.65%, and the utilization coefficient is 1.211t / (h·m 2 ).

[0039] Example 4

[0040] A preparation method of the chromium-containing chromite flux sinter of the present application, comprising the following steps:

[0041] (1) with Cr2O3 as 44.36% of chromite powder as raw material, and then add return ore, coke powder, flux and chromium-containing slag, with slaked lime, dolomite, quartz sand as flux, the particle size of the three is controlled at-3mm≥90%, the addition amount of slaked lime is added according to the mass ratio of CaO and SiO2 in sinter composition is 0.6:1, the addition amount of dolomite is added according to the mass ratio of MgO and Al2O3 in sinter composition is 2.2:1, the addition amount of quartz sand is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) in sinter composition is 0.45:1, the particle size of the flux is controlled at-3mm≥90%, the mass ratio of coke powder is 6.0% based on the total mass of all raw materials, the particle size of coke powder is controlled at 0<particle size of fuel≤5mm, wherein-3mm is not more than 70%, the mass ratio of return ore is 20%, the return ore is-5mm sinter under the sieve, the chromium content in chromium-containing slag is 8.65%, the ratio of chromium-containing slag is 6%, and the particle size of chromium-containing slag is controlled at-3mm≥90%. The raw materials are mixed and granulated into 0.5-8mm sintering mixture, and water is added to adjust the moisture content of the mixture to 9.6% during the mixing process.

[0042] (2) the sintering mixture is distributed, ignited and sintered, the layer thickness is 500mm, the ignition time is 2min, the holding time is 1min, the ignition temperature is 1100±20℃, the ignition negative pressure is 6kPa, the sintering exhaust negative pressure is 10kPa, the cooling negative pressure is adjusted to 5kPa after sintering is completed, the cooling time is 3min, and the chromium-containing chromite flux sinter is obtained after being sieved by a 5mm sieve, the sinter yield is 80.55%, the drum strength is 63.96%, and the utilization coefficient is 1.245t / (h·m 2 )。

[0043] Example 5

[0044] A preparation method of the chromium-containing chromite flux sinter of the present application, comprising the following steps:

[0045] (1) with Cr2O3 as 43.12% of the chromite powder as raw material, and then add the return ore, coke powder, flux and chromium-containing slag, with quicklime, magnesite, silica as flux, the particle size of the three is controlled at-3mm≥90%, the addition amount of quicklime is added according to the mass ratio of CaO to SiO2 of 0.8:1 in the composition of chromite flux sinter, the addition amount of magnesite is added according to the mass ratio of MgO to Al2O3 of 2.0:1 in the composition of chromite flux sinter, and the addition amount of silica is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) of 0.5:1 in the composition of chromite flux sinter, the particle size of the flux is controlled at-3mm≥90%, the mass ratio of the coke powder is 5.5% based on the total mass of all raw materials, the particle size of the coke powder is controlled at 0< fuel particle size≤5mm, wherein-3mm is not more than 70%, the mass ratio of the return ore is 25%, the return ore is-5mm sinter, the chromium content in the chromium-containing slag is 12.54%, the chromium-containing slag is 2%, and the particle size of the chromium-containing slag is controlled at-3mm≥90%. The raw materials are mixed and granulated into 0.5-8mm sintering mixture, and water is added to adjust the moisture content of the materials to 10.6% during the mixing process.

[0046] (2) the sintering mixture is distributed, ignited and sintered, the layer thickness is 500mm, the ignition temperature is 1100±20℃, the ignition time is 2min, the holding time is 1min, the ignition negative pressure is 5kPa, the sintering exhaust negative pressure is 9kPa, the cooling negative pressure is adjusted to 5kPa after sintering is completed, the cooling time is 3min, and the chromium-containing sinter is obtained after screening with a 5mm sieve, the sinter yield is 78.21%, the drum strength is 61.65%, and the utilization coefficient is 1.164t / (h·m 2 )。

[0047] Example 6

[0048] A preparation method of the chromite flux sinter of the present application, comprising the following steps:

[0049] (1) The chromite powder with Cr2O3 of 43.12% is used as raw material, and the returned ore, coal powder, flux and chromium-containing slag are additionally added. The fluxes are lime, dolomite and silica, and the particle sizes of the three are all controlled to be greater than or equal to 90% of -3 mm. The addition amount of lime is added according to the mass ratio of CaO to SiO2 in the sintered ore composition of 1.0:1, the addition amount of dolomite is added according to the mass ratio of MgO to Al2O3 in the sintered ore composition of 2.4:1, and the addition amount of silica is added according to the mass ratio of SiO2 / (CaO+SiO2+MgO+Al2O3) in the sintered ore composition of 0.6:1. The particle sizes of the fluxes are all controlled to be greater than or equal to 90% of -3 mm. The mass ratio of the coal powder to the total mass of all raw materials is 6.0%, and the particle size of the coal powder is controlled to be 0 < fuel particle size ≤ 5 mm, wherein the particle size of -3 mm is not greater than 70%. The mass ratio of the returned ore is 25%, and the returned ore is -5 mm sintered ore. The chromium content in the chromium-containing slag is 14.96%, and the chromium-containing slag is added in a ratio of 4%. The particle size of the chromium-containing slag is controlled to be greater than or equal to 90% of -3 mm. The raw materials are mixed and granulated into 0.5-8 mm sintered mixture, and water is added during the mixing process to adjust the moisture content of the materials to 10.4%.

[0050] (2) The sintered mixture is distributed, ignited and sintered, the layer thickness is 500 mm, the ignition temperature is 1100±20℃, the ignition time is 1.5 min, the holding time is 2 min, the ignition negative pressure is 5 kPa, the sintering exhaust negative pressure is 9 kPa, and the cooling negative pressure is adjusted to 5 kPa after sintering is completed, and the cooling time is 3 min. After being sieved by a 5 mm sieve, the chromite flux sintered ore is obtained, the sintered ore yield is 79.14%, the drum strength is 62.34%, and the utilization coefficient is 1.195 t / (h·m 2 )·m

[0051] Comparative Example 1

[0052] A preparation method of chromite sintered ore is basically the same as that of Example 1, and the difference is only that no flux is added. The sintered ore yield is 65.35%, the drum strength is 50.11%, and the utilization coefficient is 1.002 t / (h·m 2 )·m

[0053] Comparative Example 2

[0054] A preparation method of chromite sintered ore is basically the same as that of Example 1, and the difference is only that no slag is added. The sintered ore yield is 73.59%, the drum strength is 56.68%, and the utilization coefficient is 1.124 t / (h·m 2 )·m

[0055] Comparative Example 3

[0056] A preparation method of chromite sintered ore is basically same as that of example 1, the only difference is that the slag accounts for 1% of the total mass of raw materials, the yield of the obtained sintered ore is 75.23%, the drum strength is 58.18%, and the utilization coefficient is 1.138 t / (h·m 2 )。

[0057] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any skilled person in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with equivalent changes, without departing from the spirit and technical solutions of the present application, by using the disclosed methods and technical contents. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solutions of the present application, still falls within the scope of protection of the technical solutions of the present application.

Claims

1. A method for producing a chromite fluxed sinter, characterized by, The method comprises the following steps: (1) preparing a sintering mixture by mixing and granulating raw materials including chromite powder, chromium-containing slag, calcareous flux, magnesian flux, siliceous flux and fuel; wherein the chromium-containing slag is added in an amount of 2-10% of the total mass of the raw materials, the calcareous flux is added in an amount such that the mass ratio of CaO to SiO2 in the composition of the chromite flux sinter is 0.4-1.5:1, the magnesian flux is added in an amount such that the mass ratio of MgO to Al2O3 in the composition of the chromite flux sinter is 0.8-2.4:1, the siliceous flux is added in an amount such that the mass ratio of SiO2 to (CaO+SiO2+MgO+Al2O3) in the composition of the chromite flux sinter is 0.3-0.6:1, and the fuel accounts for 5.5-7.0% of the total mass of the raw materials; (2) preparing a chromite flux sinter by distributing, igniting, sintering, crushing, cooling and screening the sintering mixture.

2. The method of producing chromite fluxed sinter according to claim 1, characterized in that, In step (1), the raw materials further include returned ore, which is added in an amount of 20-25% of the total mass of the raw materials and is the sinter under-5mm screen after screening in step (2).

3. The method of producing chromite fluxed sinter according to claim 1, characterized in that, In step (1), the chromite powder contains 30-60% of Cr2O3.

4. The method of producing chromite fluxed sinter according to claim 1, characterized by, In step (1), the chromium-containing slag contains 3-15% of chromium, and the particle size of the chromium-containing slag is controlled to be greater than or equal to 90% of-3mm.

5. The method of producing chromite fluxed sinter according to claim 1, characterized by, In step (1), the calcareous flux includes one or more of limestone, dolomite, slaked lime, quicklime and high-calcium slag, the mass fraction of CaO in the high-calcium slag is greater than or equal to 40%, and the particle size of the calcareous flux is controlled to be greater than or equal to 90% of-3mm; the magnesian flux includes one or more of dolomite, magnesite, magnesium silicate, serpentine and magnesian slag, the mass fraction of MgO in the magnesian slag is greater than or equal to 30%, and the particle size of the magnesian flux is controlled to be greater than or equal to 90% of-3mm; the siliceous flux includes one or more of silica, diatomite, serpentine, quartz sand and siliceous slag, the mass fraction of SiO2 in the siliceous slag is greater than or equal to 40%, and the particle size of the siliceous flux is controlled to be greater than or equal to 90% of-3mm. In step (1), the fuel includes coke powder and / or coal powder, the particle size of the fuel is greater than 0 and less than or equal to 5mm, and the particle size is greater than or equal to 70% of-3mm.

6. The method of producing chromite fluxed sinter according to any one of claims 1 to 5, characterized in that, In step (1), water is added to adjust the moisture content of the material to 6-12wt% during the mixing process, and the particle size of the sintering mixture is 0.5-8mm.

7. The method of producing chromite fluxed sinter according to any one of claims 1 to 5, characterized in that, In step (2), the ignition process parameters are as follows: the ignition temperature is 1050-1150℃, the ignition time is 1.5-2min, the holding time is 1.0-2.0min, and the negative pressure during ignition is 5-6kPa; the negative pressure during sintering is 8-10kPa, the negative pressure during cooling is 4-8kPa, and the cooling time is 2-5min.

8. The method of producing chromite fluxed sinter according to any one of claims 1 to 5, characterized in that, 9. A chromite flux sinter prepared by the method according to any one of claims 1-8. ​

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