Method for producing low nickel matte from laterite nickel ore

Abstract

The present invention provides a method for producing low-nickel matte from laterite nickel ore. The method for producing low-nickel matte from laterite nickel ore comprises: subjecting laterite nickel ore, a first sulfiding agent, and a first carbon-based reducing agent to reduction-sulfidation roasting to obtain sulfided roasted sand, wherein the first sulfiding agent is gypsum slag, and the amount of the first sulfiding agent is 12-25% and the amount of the first carbon-based reducing agent is 2-18% based on the weight percentage of the laterite nickel ore; subjecting the sulfided roasted sand, the second carbon-based reducing agent, and the second sulfiding agent to supplementary sulfidation reaction to obtain supplementary sulfided roasted sand; subjecting the supplementary sulfided roasted sand to smelting to obtain low-nickel matte and slag. Compared with the existing RKEF resulfurization process for producing nickel iron, the method for producing low-nickel matte provided by the present application has the advantages of short process, low energy consumption, coordinated realization of gypsum slag solid waste resource utilization, significantly reduced process cost, and high recovery rate of valuable metals nickel and cobalt.

Description

Technical Field

[0001] The invention relates to laterite nickel ore smelting, and in particular to a method for producing low-nickel matte from laterite nickel ore. Background Art

[0002] At present, there are two types of pyrometallurgical processes for laterite nickel ore: reduction smelting to produce nickel iron matte and reduction sulfidation smelting to produce nickel matte. The more mature smelting methods include rotary kiln drying pre-reduction-electric furnace smelting method (RKEF), sintering-blast furnace sulfidation smelting method, and sintering-blast furnace reduction smelting method.

[0003] The nickel-iron sulfidation production process is: spraying molten sulfur into molten nickel-iron alloy for sulfidation, and then blowing to produce high-nickel matte. The production process of processing laterite nickel ore abroad to prepare nickel matte is: splashing molten sulfur liquid onto roasted sand with a certain temperature roasted in a rotary kiln, using the residual heat of the roasted sand for sulfidation, and converting the pre-reduced nickel and iron particles into sulfides; then transferring the roasted sand into an electric furnace for smelting to produce low-nickel matte, and then blowing in a converter to finally obtain a high-nickel matte product.

[0004] The biggest disadvantage of the rotary kiln pre-reduction-electric furnace smelting process is that it consumes a lot of electricity during electric furnace smelting, resulting in high total process energy consumption and production costs. The main reason is that the amount of slag is large during the smelting of laterite nickel ore, and the slag requires a high smelting temperature. In order to ensure the separation of molten iron and slag, the slag temperature generally needs to be maintained above 1550℃, or even more than 1600℃, which leads to huge power consumption of the electric furnace. Therefore, the use of RKEF to smelt nickel iron products has a relatively strict requirement for the power supply of the smelter's location, especially in areas with power shortages, where it is difficult to carry out production work using laterite nickel ore resources.

[0005] At present, the pyrometallurgical smelting technology of laterite nickel ore has developed rapidly, but it has also exposed problems such as large fluctuations in raw materials, poor process applicability, long production process, high energy consumption, serious environmental pollution, and high dependence on power facilities in areas rich in mineral resources. These problems have become hidden dangers restricting the development of the nickel metallurgical industry. It is urgent to develop a low-cost, high-efficiency, green smelting process to process the abundant reserves of laterite nickel ore resources to meet the demand for nickel products in various industries.

[0006] In view of the above problems, it is necessary to develop a production method of high nickel matte with short process, low energy consumption and cost and high recovery rate of valuable metals. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for producing low-nickel matte from laterite nickel ore to solve the problems of long process, high energy consumption and cost and low recovery rate of valuable metals in the existing low-nickel matte production process.

[0008] In order to achieve the above-mentioned object, the present invention provides a method for producing low-nickel matte from laterite nickel ore, comprising: subjecting the laterite nickel ore, a first sulfiding agent, and a first carbon-based reducing agent to reduction sulfidation roasting to obtain sulfided roasted sand, wherein the first sulfiding agent is gypsum slag, and the amount of the first sulfiding agent is 12-25% by weight percentage of the laterite nickel ore, and the amount of the first carbon-based reducing agent is 2-18%; subjecting the sulfided roasted sand, the second carbon-based reducing agent, and the second sulfiding agent to supplementary sulfidation reaction to obtain supplementary sulfided roasted sand; and subjecting the supplementary sulfided roasted sand to smelting to obtain low-nickel matte and slag.

[0009] Furthermore, the reduction-sulfurization roasting process is carried out in a rotary kiln or a drying kiln.

[0010] Furthermore, the temperature of the reduction-sulfurization calcination is 900-1250°C.

[0011] Furthermore, the amount of the second vulcanizing agent is 0-10%, and the amount of the second carbon-based reducing agent is 2-6% based on the weight percentage of the sulfided roasted sand; preferably, the second vulcanizing agent is sulfur.

[0012] Furthermore, the temperature of the supplementary vulcanization reaction is 400-850°C.

[0013] Further, the smelting process is carried out in an electric furnace or a side-blown furnace.

[0014] Furthermore, the temperature of the smelting process is 1350-1550°C.

[0015] Furthermore, before the reduction sulfidation roasting, the method for producing low-nickel matte from laterite nickel ore further comprises: drying the laterite nickel ore.

[0016] Furthermore, the temperature of the drying process is 100-120° C., and the water content of the laterite nickel ore after drying is 13-15wt%.

[0017] Furthermore, before the supplementary sulfidation reaction, the method for producing low-nickel matte from laterite nickel ore further comprises: pressing the second carbon-based reducing agent and the optional second sulfiding agent into pellets.

[0018] By applying the technical solution of the present invention, the first vulcanizing agent (gypsum slag) is combined with the carbon element in the carbon-based reducing agent to achieve the fixation of sulfur element, which is conducive to reducing the probability of sulfur element loss in the form of flue gas, thereby improving the utilization rate of sulfur element and reducing process costs. Sulfur in gypsum slag is used as a vulcanizing agent to vulcanize valuable metals nickel, cobalt, and iron; calcium sulfate in gypsum slag decomposes to form CaO as a slag component to adjust the slag type, reduce the temperature of the smelting process, improve the fluidity of the slag, and facilitate better separation of slag and matte, improve the recovery rate of valuable metals nickel and cobalt, and reduce smelting energy consumption. By limiting the amount of the first carbon-based reducing agent and the first vulcanizing agent, valuable metals nickel, cobalt, and an appropriate amount of iron can be converted into sulfide mineral phases, and iron oxides can be converted into ferrous oxide and a small amount of metallic iron, thereby avoiding iron reduction into low-nickel matte and achieving selective reduction sulfidation. By supplementing the sulfidation reaction, the sulfidation rate of valuable metals can be further improved, providing basic conditions for the production of low-nickel matte by electric furnace smelting slag-matte. Finally, the slag and nickel matte are melted and separated in an electric furnace to directly produce low-nickel matte. The transformation of the smelting product from high-melting-point nickel iron to low-melting-point nickel matte can effectively reduce or avoid the risk of furnace freezing; in addition, the use of gypsum slag as the first vulcanizing agent can achieve the purpose of solid waste resource utilization. On this basis, compared with the existing RKEF nickel iron resulfurization process for production, the method for producing low-nickel matte provided in this application has the advantages of short process steps, low energy consumption, and can collaboratively realize the solid waste resource utilization of gypsum slag, significantly reducing process costs and high recovery rates of valuable metals nickel and cobalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A process flow chart of a preferred method for producing low-nickel matte from laterite nickel ore provided in Example 1 of the present application. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0022] As described in the background technology, the existing production process of low-nickel matte has the problems of long process, high energy consumption and cost, and low recovery rate of valuable metals. In order to solve the above technical problems, the present application provides a method for producing low-nickel matte from laterite nickel ore, comprising: subjecting laterite nickel ore, a first sulfiding agent, and a first carbon-based reducing agent to reduction sulfidation roasting to obtain sulfided roasted sand, wherein the first sulfiding agent is gypsum slag, and the amount of the first sulfiding agent is 12-25% and the amount of the first carbon-based reducing agent is 2-18% based on the weight percentage of the laterite nickel ore; subjecting the sulfided roasted sand, the second carbon-based reducing agent, and the second sulfiding agent to supplementary sulfidation reaction to obtain supplementary sulfided roasted sand; subjecting the supplementary sulfided roasted sand to sequential smelting to obtain low-nickel matte and slag.

[0023] The main reactions of gypsum reduction sulfide in this process are as follows:

[0024] CaSO4·2H2O=CaSO4+2H2O(g); CaSO4+4C=CaS+4CO(g);

[0025] NiO+C=Ni+CO(g); 3Fe2O3+C=2Fe3O4+CO(g); Fe2O3+3C=2Fe+3CO(g);

[0026] 2CaS+3NiO+C=Ni3S2+2CaO+CO(g); 2CaS+Fe2O3+C=2FeS+2CaO+CO(g);

[0027] CaO+FeO+SiO2=(Fe,Ca)O·SiO2.

[0028] During the supplementary vulcanization process, the main reactions of sulfur vulcanization are as follows: 3Ni(s)+2S(g)=Ni3S2(s); Fe(s)+S(g)=FeS(s).

[0029] The first vulcanizing agent (gypsum slag) combines with the carbon element in the carbon-based reducing agent to fix the sulfur element, which is beneficial to reduce the probability of sulfur loss in the form of flue gas, thereby improving the utilization rate of sulfur element and reducing process costs. Sulfur in gypsum slag is used as a vulcanizing agent to vulcanize valuable metals nickel, cobalt, and iron; calcium sulfate in gypsum slag decomposes to form CaO as a slag component to adjust the slag type, reduce the temperature of the smelting process, improve the fluidity of the slag, and facilitate better separation of slag and matte, improve the recovery rate of valuable metals nickel and cobalt, and reduce smelting energy consumption. By limiting the amount of the first carbon-based reducing agent and the first vulcanizing agent, valuable metals nickel, cobalt, and an appropriate amount of iron can be converted into sulfide mineral phases, and iron oxides can be converted into ferrous oxide and a small amount of metallic iron, thereby avoiding iron reduction into low-nickel matte and achieving selective reduction sulfidation. By supplementing the sulfidation reaction, the sulfidation rate of valuable metals can be further improved, providing basic conditions for the production of low-nickel matte by electric furnace smelting slag-matte. Finally, the slag and nickel matte are melted and separated in an electric furnace to directly produce low-nickel matte. The transformation of the smelting product from high-melting-point nickel iron to low-melting-point nickel matte can effectively reduce or avoid the risk of furnace freezing; in addition, the use of gypsum slag as the first vulcanizing agent can achieve the purpose of solid waste resource utilization. On this basis, compared with the existing RKEF nickel iron production resulfurization process, the method for producing low-nickel matte provided in the present application has the advantages of short process steps, low energy consumption, and can synergistically realize the resource utilization of gypsum slag solid waste, significantly reducing the process cost and high recovery rate of valuable metals nickel and cobalt. The Ni grade of the low-nickel matte obtained by the process provided in the present application can be controlled to be: 12~28wt%, the sulfur content can be controlled to be 12~28wt%, and the iron content can be controlled to be 45~75wt%.

[0030] If higher grade nickel matte is needed, it can be obtained by blowing low nickel matte.

[0031] In a preferred embodiment, the reduction-sulfurization roasting process is carried out in a rotary kiln or a drying kiln. During the reduction-sulfurization roasting process, calcium sulfate is finally converted into CaO, which can promote the formation of pyroxene and reduce the formation of olivine, change the structure of nickel-containing silicate minerals in laterite nickel ore, improve the reactivity of laterite nickel ore, promote the reduction of nickel and improve the recovery rate of nickel. CaO promotes the reduction of iron and nickel and the growth of metal particles, and the growth of metal particles is beneficial to the separation of slag-matte in the subsequent electric furnace smelting process.

[0032] Through the reduction sulfidation roasting process, most or all of the nickel elements can be reduced, while all or most of the iron elements are not reduced, thereby achieving selective reduction, improving the slag-matte separation rate, and the recovery rate of the nickel element. Preferably, the temperature of the reduction sulfidation roasting is 900-1250°C. During the reduction calcination process in the low temperature section (<700°C), the nickel oxide in the laterite nickel ore can be reduced, but the gypsum cannot be decomposed into CaS. In the high temperature section (700-1250°C), under the conditions of the participation of the reducing medium, the gypsum calcium sulfate is decomposed into CaS, and then CaS reacts with valuable metals (Ni, Co, Fe) and gangue phase SiO2 to form nickel and iron sulfides. A small amount of the remaining iron oxides in the laterite nickel ore are reduced to magnetic iron and metallic elemental iron. During the high temperature calcination process, the metal matte phase\metal phase particles complete aggregation and growth. Therefore, the temperature of the reduction sulfidation roasting includes but is not limited to the above range, and limiting it within the above range is beneficial to further improve the reduction conversion rate of the nickel element, thereby further improving the grade of the final nickel matte.

[0033] Since there is a partial loss of carbon-based reducing agent and sulfiding agent during the reduction sulfidation roasting process, in order to make the sulfidation reaction more complete during the supplementary sulfidation reaction, a certain amount of carbon-based reducing agent and sulfiding agent can be added as needed for supplementation, which is conducive to further improving the sulfidation rate of valuable metals. In a preferred embodiment, the temperature of the supplementary sulfidation reaction is 400-850°C. Compared with other ranges, limiting the temperature of the supplementary sulfidation reaction to the above range is conducive to further improving the sulfidation rate of valuable metals, thereby further improving the slag-matte separation rate and the grade of nickel matte.

[0034] Preferably, the second sulfiding agent is used in an amount of 0-10% and the second carbon-based reducing agent is used in an amount of 2-6% by weight of the sulfided roasted sand. The second sulfiding agent used in the supplementary roasting process can be a sulfiding agent commonly used in the art, preferably sulfur.

[0035] The above-mentioned supplementary vulcanization reaction needs to be carried out in a heat-insulating and closed environment. Any device that can achieve the above-mentioned function can be used as a place for the supplementary vulcanization reaction. Preferably, the above-mentioned supplementary vulcanization reaction is carried out in a roasting pot.

[0036] The slag-matte separation can be achieved through the smelting process to obtain low-nickel matte. Preferably, the smelting process is carried out in an electric furnace or a side-blown furnace.

[0037] In a preferred embodiment, the temperature of the smelting process is 1350-1550° C. The temperature of the smelting process includes but is not limited to the above range, and limiting it to the above range is conducive to further improving the slag-matte separation rate.

[0038] In a preferred embodiment, before performing reduction sulfidation roasting, the method for producing low-nickel matte from laterite nickel ore further includes: drying the laterite nickel ore (for example, the water content is ≤15%). Drying the laterite nickel ore is beneficial to reducing the energy consumption of the reduction sulfidation roasting process, thereby further reducing the process cost. More preferably, the temperature of the drying process is 100-120°C, and the water content of the laterite nickel ore after drying is 13-15%. The temperature of the drying process and the water content of the laterite nickel ore include but are not limited to the above ranges, and limiting them within the above ranges can further improve the drying efficiency without increasing energy consumption, while ensuring that the composition and microstructure of the laterite nickel ore are not changed.

[0039] In a preferred embodiment, before the supplementary sulfidation reaction, the method for producing low-nickel matte from laterite nickel ore further comprises: pressing the second carbon-based reducing agent and the optional second sulfiding agent into balls. The above method can solidify sulfur and improve the utilization rate of sulfur element on the one hand, and reduce dust and improve the environmental friendliness of the process on the other hand.

[0040] The first carbon-based reducing agent and the second carbon-based reducing agent both function to reduce metal elements in the laterite nickel ore. In a preferred embodiment, the first carbon-based reducing agent and the second carbon-based reducing agent are independently selected from one or more of the group consisting of anthracite, lignite, coal powder and coke.

[0041] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0042] Example 1

[0043] The composition of nickel laterite ore (dry basis, wt%) is shown in Table 1.

[0044] Table 1

[0045] NiO <![CDATA[Fe2O3]]> CoO MnO MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> CaO 1.941 24.91 0.055 0.39 11.48 28.99 0.626 2.854 0.63

[0046] A method for producing low-nickel matte from the above laterite nickel ore, the process flow is shown in Figure 1 Specifically, the method comprises: drying the laterite ore in a drying kiln at 100-120°C, wherein the water content after drying is 13-15wt%, and the laterite ore is calcined in a rotary kiln at a high temperature of 1050°C for 2 hours to obtain sulfide roasted sand, wherein the weight of gypsum slag (wet basis, water content 15wt%) is 22% of the weight of the laterite ore (dry basis), and the weight of the carbonaceous reducing agent (anthracite) is 8% of the weight of the laterite nickel ore (dry basis).

[0047] The sulfide roasted sand produced by the rotary kiln roasting is supplemented with sulfide in a hot roasting tank to obtain supplemented sulfide roasted sand. The supplemented sulfide temperature is 900°C.

[0048] After the supplementary sulfidation is completed, the supplementary sulfidation roasted sand is transported to the electric furnace for smelting, and the material is fed by a vibrating automatic feeder, wherein the temperature of the electric furnace smelting is 1465±15°C, and the smelting output is low-nickel matte and slag. After the smelting is completed, the nickel recovery rate is 93.81wt%, the iron recovery rate is 36.88wt%, and the sulfiding agent utilization rate is 84.79wt%. The specific composition of the product is shown in Table 2.

[0049] Table 2

[0050] Components, wt% Ni Fe S MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> Roasted Sand 1.71 21.45 4.83 13.94 31.55 8.27 3.63 Low nickel matte 13.02 64.29 17.27 \ \ \ \ slag 0.07 17.12 2.77 17.98 40.28 10.66 4.68

[0051] Example 2

[0052] The composition of laterite nickel ore is the same as that of Example 1. The process flow of the method for producing low-nickel matte from laterite nickel ore is shown in Figure 1 , specifically including:

[0053] The laterite ore is dried in a drying kiln at 100-120° C., and contains 13-15wt% of water after drying. It is then calcined in a rotary kiln at a high temperature of 1150° C. for 2 hours. The weight of gypsum slag (wet basis, containing 15wt% of water) is 18% of the weight of the laterite ore (dry basis), and the weight of a carbonaceous reducing agent (anthracite) is 6% of the weight of the laterite nickel ore (dry basis).

[0054] The sulfide roasted sand produced by the rotary kiln roasting is supplemented with sulfide in a hot roasting tank to obtain supplemented sulfide roasted sand. The supplemented sulfide temperature is 650°C.

[0055] After the supplementary sulfidation is completed, the supplementary sulfidation roasted sand is transported to the electric furnace for smelting, and the material is fed by a vibrating automatic feeder. The temperature of the electric furnace smelting is 1445±15℃, and the smelting output is low-nickel matte and slag. After the smelting is completed, the nickel recovery rate is 85wt%, the iron recovery rate is 35.41wt%, and the sulfiding agent utilization rate is 78wt%. The specific composition of the product is shown in Table 3.

[0056] Table 3

[0057] Components, wt% Ni Fe S MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> Roasted Sand 1.63 15.56 3.37 19.34 40.20 7.06 3.36 Low nickel matte 18.30 57.63 22.68 \ \ \ \ slag 0.18 18.54 0.22 25.38 48.15 9.57 3.46

[0058] Example 3

[0059] The composition of the laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the weight of the first sulfiding agent (gypsum slag) added is 12% of the weight of the laterite ore (dry basis), and the weight of the carbonaceous reducing agent (anthracite) added is 18% of the weight of the laterite ore (dry basis). The specific composition of the product is shown in Table 4.

[0060] Table 4

[0061] Components, wt% Ni Fe S MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> Roasted Sand 1.68 15.98 2.57 18.62 39.12 4.79 3.16 Low nickel matte 8 79.23 12 \ \ \ \ slag 0.08 4.29 0.075 16.22 50.79 7.02 4.899

[0062] The nickel recovery rate was 85wt%, the iron recovery rate was 34.7wt%, and the sulfiding agent utilization rate was 68wt%.

[0063] Example 4

[0064] The composition of the laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the weight of the first sulfiding agent (gypsum slag) is 25% of the weight of the laterite ore (dry basis), and the weight of the carbonaceous reducing agent (anthracite) is 2% of the weight of the laterite ore (dry basis). The specific composition of the product is shown in Table 5.

[0065] Table 5

[0066] Components, wt% Ni Fe S MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> Roasted Sand 1.72 17.89 4.98 14.78 36.89 5.21 3.12 Low nickel matte 12 74.79 12 \ \ \ \ slag 0.28 11.32 0.12 13.83 42.27 11.41 3.59

[0067] The nickel recovery rate was 82wt%, the iron recovery rate was 44.7wt%, and the sulfiding agent utilization rate was 65wt%.

[0068] Example 5

[0069] The composition of laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the temperature of reduction sulfidation roasting is 900°C.

[0070] The nickel recovery rate is 92wt%, the iron recovery rate is 34wt%, and the sulfiding agent utilization rate is 85wt%.

[0071] Example 6

[0072] The composition of laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the temperature of reduction sulfidation roasting is 1250°C.

[0073] The nickel recovery rate is 96wt%, the iron recovery rate is 36wt%, and the sulfiding agent utilization rate is 87wt%.

[0074] Example 7

[0075] The composition of laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the temperature of reduction sulfidation roasting is 500°C.

[0076] The nickel recovery rate is 78wt%, the iron recovery rate is 26wt%, and the sulfiding agent utilization rate is 30wt%.

[0077] Example 8

[0078] The composition of laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the temperature of electric furnace smelting is 1350°C.

[0079] The nickel recovery rate is 90wt%, the iron recovery rate is 31wt%, and the sulfiding agent utilization rate is 82wt%.

[0080] Example 9

[0081] The composition of laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the temperature of electric furnace smelting is 1550°C.

[0082] The nickel recovery rate is 98wt%, the iron recovery rate is 35wt%, and the sulfiding agent utilization rate is 83wt%.

[0083] Example 10

[0084] The composition of laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the temperature of electric furnace smelting is 1300°C.

[0085] The nickel recovery rate is 87wt%, the iron recovery rate is 25wt%, and the sulfiding agent utilization rate is 75wt%.

[0086] Comparative Example 1

[0087] The composition of the laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that the weight of the first sulfiding agent (gypsum slag) is 8% of the weight of the laterite ore (dry basis), and the weight of the carbonaceous reducing agent (anthracite) is 20% of the weight of the laterite ore (dry basis). The specific composition of the product is shown in Table 6.

[0088] The nickel recovery rate is 75wt%, the iron recovery rate is 30wt%, and the sulfiding agent utilization rate is 36wt%.

[0089] Table 6

[0090] Components, wt% Ni Fe S MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> Roasted Sand 1.71 21.45 4.83 13.94 31.55 8.27 3.63 Low nickel matte 13.02 64.29 17.27 \ \ \ \ slag 0.07 17.12 1.7 17.98 40.28 10.66 4.68

[0091] Comparative Example 2

[0092] The composition of the laterite nickel ore is the same as that of Example 1. The difference between the method for producing low-nickel matte from laterite nickel ore and Example 1 is that no supplementary sulfidation reaction is performed. The specific composition of the product is shown in Table 7.

[0093] The nickel recovery rate is 78wt%, the iron recovery rate is 32wt%, and the sulfiding agent utilization rate is 75wt%.

[0094] Table 7

[0095] Components, wt% Ni Fe S MgO <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> Roasted Sand 1.71 21.45 4.83 13.94 31.55 8.27 3.63 Low nickel matte 9 75 8 \ \ \ \ slag 0.35 19.12 0.28 18.93 39.41 9.87 3.67

[0096] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: compared with the existing RKEF nickel-iron resulfurization process, the method for producing low-nickel matte provided by the present application has the advantages of short process, low energy consumption, coordinated realization of gypsum slag solid waste resource utilization, significantly reduced process costs and high recovery rate of valuable metals nickel and cobalt, etc. And by selecting the preferred amount of gypsum slag and carbonaceous reducing agent, the temperature of sulfurization roasting, and the temperature of electric furnace smelting.

[0097] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for producing low-nickel matte from laterite nickel ore, characterized in that: The method for producing low-nickel matte from laterite nickel ore comprises: The laterite nickel ore, the first sulfiding agent, and the first carbon-based reducing agent are subjected to reduction sulfidation roasting to obtain sulfided roasted sand, wherein the first sulfiding agent is gypsum slag, and the amount of the first sulfiding agent is 12-25% by weight of the laterite nickel ore, and the amount of the first carbon-based reducing agent is 2-18% by weight; The sulfided roasted sand, the second carbon-based reducing agent and the second sulfiding agent are subjected to a supplementary sulfidation reaction to obtain a supplementary sulfided roasted sand; Smelting the supplementary sulfide roasted sand to obtain low-nickel matte and slag; The temperature of the reduction sulfidation roasting is 900-1250°C The temperature of the supplementary vulcanization reaction is 400-850°C; Calculated by weight percentage of the sulfided roasted sand, the amount of the second sulfidizing agent is 0-10%, and the amount of the second carbon-based reducing agent is 2-6%.

2. The method for producing low-nickel matte from laterite nickel ore according to claim 1, characterized in that: The reduction-sulfurization calcination is carried out in a rotary kiln or a drying kiln.

3. The method for producing low-nickel matte from laterite nickel ore according to claim 1 or 2, characterized in that: The second vulcanizing agent is sulfur.

4. The method for producing low-nickel matte from laterite nickel ore according to claim 1, characterized in that: The smelting is carried out in an electric furnace or a side-blown furnace.

5. The method for producing low-nickel matte from laterite nickel ore according to claim 4, characterized in that: The smelting temperature is 1350-1550°C.

6. The method for producing low-nickel matte from laterite nickel ore according to claim 1, characterized in that: Before performing the reduction sulfidation roasting, the method for producing low-nickel matte from laterite nickel ore further comprises: drying the laterite nickel ore.

7. The method for producing low-nickel matte from laterite nickel ore according to claim 6, characterized in that: The drying temperature is 100-120° C., and the water content of the laterite nickel ore after drying is 13-15wt%.

8. The method for producing low-nickel matte from laterite nickel ore according to claim 1, characterized in that: Before performing the supplementary sulfiding reaction, the method for producing low-nickel matte from laterite nickel ore further comprises: pressing the second carbon-based reducing agent and the second sulfiding agent into balls.

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