Treatment method for laterite-nickel ore acid leaching residues, and active material

Abstract

A treatment method for laterite-nickel ore acid leaching residues, and an active material. The method comprises the following steps: step S1, mixing laterite-nickel ore acid leaching residues, an adjusting material, a fluxing material and a reducing agent, and pressing the mixture, so as to obtain a prefabricate; step S2, roasting the prefabricate to obtain roasting slag and hot flue gas, wherein the hot flue gas is used for preparing an acid; step S3, subjecting the roasting slag to magnetic separation, so as to obtain a refined iron material and tailings; and step S4, mixing the tailings, an active feed and an excitation material, and grinding the mixture, so as to obtain an active material. The treatment method has the characteristics of a large solid waste consumption, multiple types of generated products, a high product output value, a low comprehensive production cost, a high resource utilization rate, etc., and provides a more effective solution way for full recovery of valuable components and full-component recycling of laterite-nickel ore acid leaching residues.

Description

Treatment method of laterite nickel ore acid leaching residue, active materials Technical Field

[0001] The present invention relates to the technical field of hydrometallurgy, and in particular to a treatment method for laterite nickel ore acid leaching residue and an active material. Background Art

[0002] Currently, nickel ores worldwide are primarily divided into two categories: nickel sulfide and laterite. Proven reserves of the two types of nickel ores are approximately 1:3 between nickel sulfide and laterite. In the past, nickel sulfide was the primary ore used worldwide, but as its reserves have gradually decreased, laterite is now the primary ore used, with its proportion gradually exceeding that of nickel sulfide.

[0003] Currently, the largest use of laterite nickel ore is primarily in the production of nickel-iron alloy, the raw material for stainless steel, using the RKEF pyrometallurgical smelting process. This produces primarily ferronickel slag, with most of the Ni and Fe in the laterite nickel ore reduced to the ferronickel. The solid slag primarily consists of MgO and SiO₂. However, this smelting process suffers from high power consumption and production costs. Because components such as MgO and SiO₂ in laterite nickel ore readily form high-melting-point phases during the smelting process, high furnace temperatures are often required to ensure slag and iron separation, resulting in large slag volumes and low resource utilization. With the development of new energy battery materials, market demand for a wide variety of nickel products is increasing. Furthermore, as the nickel grade in laterite nickel ore decreases, the use of wet acid leaching to treat laterite nickel ore is becoming increasingly popular. This process generates a variety of waste slags, including iron-containing acid leaching slag, ferroaluminum slag, gypsum slag, and other process wastes. As the hydrometallurgical process of laterite nickel ore is still in its initial development stage in China, most of the acid leaching slag of laterite nickel ore is still mainly stockpiled, and a small part is processed into ironmaking raw materials or iron red pigment products. The usage is small and the economic efficiency is low. It also fails to achieve the comprehensive utilization of waste slag in the entire process, and still lacks the characteristics of resource conservation, product diversification, and waste-free output.

[0004] As a result, the extensive use of laterite nickel ore inevitably generates a significant amount of laterite nickel acid leaching residue. The storage of large amounts of laterite nickel acid leaching residue not only pollutes the environment, but also causes the loss of residual metallic elements such as Fe and Ni in the residue, resulting in a waste of resources. my country is a typical country with insufficient nickel and iron resources, requiring the import of large quantities of nickel and iron ore from abroad annually. Laterite nickel ore is almost entirely imported. If the Fe, Ni, and other metallic elements in this acid leaching laterite nickel ore residue could be recovered and the remaining tailings could be made into building materials, the efficiency of laterite nickel ore resource utilization could be greatly improved.

[0005] Therefore, the present invention proposes a method for treating laterite nickel ore acid leaching residue to solve the problems that the resource utilization rate of existing laterite nickel ore acid leaching residue is low, most of the laterite nickel ore acid leaching residue can only be stored, and the economic value of the laterite nickel ore acid leaching residue cannot be fully utilized, resulting in resource waste and environmental pollution. Summary of the Invention

[0006] The main purpose of the present invention is to provide a method for treating laterite nickel ore acid leaching residue and an active material to solve the problem that the existing technology cannot effectively utilize laterite nickel ore acid leaching residue.

[0007] To achieve the above-mentioned object, according to one aspect of the present invention, there is provided a method for treating laterite nickel ore acid leaching residue, comprising the following steps: step S1, mixing the laterite nickel ore acid leaching residue, a regulating material, a fluxing material and a reducing agent and pressing the mixture to obtain a preform; step S2, roasting the preform to obtain hot slag and hot flue gas, and the hot flue gas is used to produce acid; step S3, magnetically separating the hot slag to obtain refined iron material and tailings; step S4, mixing the tailings, active material and stimulating material and grinding the mixture to obtain active material; wherein the regulating material is iron-containing waste slag; the fluxing material is an alkaline substance containing one or more of CaO, MgO and Na2O; the active material is selected from one or more of nickel iron slag, fly ash, blast furnace slag, bottom ash or coal slag; and the stimulating material is selected from one or more of desulfurized gypsum, steel slag tailings, carbide slag, quicklime, limestone, slaked lime or cement clinker.

[0008] Furthermore, the hot slag includes the following components: 38-52 wt% of Fe, 4-13 wt% of FeO, 8-22 wt% of SiO2, 5-23 wt% of CaO, 1-6 wt% of Al2O3 and 1-4 wt% of MgO.

[0009] Furthermore, the laterite nickel ore acid leaching residue includes the following components: 48-68wt% Fe2O3, 8-17wt% SO3, 1-5wt% CaO, 6-25wt% SiO2, 1-4wt% MgO and 3-8wt% Al2O3.

[0010] Furthermore, the hot flue gas includes SO2, and the volume concentration of SO2 is 4-10%.

[0011] Furthermore, in step S1, based on the weight of dry ore, the laterite nickel ore acid leaching residue is 100 parts, the adjustment material is 3 to 28 parts, the fluxing material is 0.5 to 22 parts, and the reducing agent is 5 to 20 parts.

[0012] Furthermore, in step S4, based on the weight of dry ore, the tailings are 20 to 40 parts, the active material is 50 to 70 parts, and the stimulating material is 3 to 10 parts.

[0013] Furthermore, in step S2, the calcination temperature is 900-1250°C, and the calcination time is 1-2 hours.

[0014] Furthermore, the volume concentration of O2 in the combustion-supporting gas used in the roasting process is 40-60%.

[0015] Furthermore, the fuel used in the roasting process is selected from natural gas and / or pulverized coal.

[0016] Furthermore, the volume concentration of O2 in the hot flue gas is ≤5%, and the temperature of the hot flue gas is ≥300°C.

[0017] Furthermore, the iron-containing waste slag is selected from one or more of steel slag, wet iron-aluminum slag or nickel smelting slag.

[0018] Furthermore, the alkaline substance is selected from one or more of limestone, dolomite, quicklime, gypsum slag, carbide slag or magnesium slag.

[0019] Furthermore, the reducing agent is selected from a solid reducing agent having a carbon content of 40 to 90% and a calorific value of ≥3000 kcal / kg.

[0020] Furthermore, the reducing agent is selected from one or more of anthracite, lignite, coke, waste graphite electrodes, and biomass waste.

[0021] Furthermore, in step S1, before pressing, the processing method further includes subjecting the laterite nickel ore acid leaching residue, the adjustment material, and the flux material to a first crushing process to control the particle size of the material to be ≤10 mm.

[0022] Furthermore, in step S3, before magnetic separation, the processing method further includes the step of air cooling the hot slag to obtain slag.

[0023] Furthermore, in step S3, the cinder is subjected to a second crushing process and a grinding process in sequence, and the particle size of the cinder after the grinding process meets the following requirement: more than 35% by mass of the cinder after the grinding process has a particle size of ≤0.074 mm.

[0024] Furthermore, in step S3, the magnetic separation includes two magnetic separation processes performed sequentially, and the magnetic field strength of the two magnetic separation processes is independently 80-250 kA / m.

[0025] Furthermore, the magnetic field intensity of the first magnetic separation process is higher than that of the second magnetic separation process, the first magnetic separation intensity is 150-250 kA / m, and the second magnetic separation intensity is 80-150 kA / m.

[0026] In order to achieve the above object, according to one aspect of the present invention, there is provided an active material obtained by the above-mentioned method for treating the acid leaching residue of laterite nickel ore, wherein the specific surface area of ​​the active material is ≥350m2 / kg.

[0027] By applying the technical solution of the present invention, the present application can further effectively recover the Fe element in the laterite nickel ore acid leaching residue by adjusting the material, the fluxing material and the reducing agent. The processing method of the laterite nickel ore acid leaching residue of the present invention realizes the comprehensive resource utilization of the laterite nickel ore acid leaching residue, has a high recovery rate of residual valuable Fe metal, realizes the full utilization of valuable metals (such as Fe, Ni), sulfur and other components, not only realizes the recycling of valuable metals, but also realizes the recycling of sulfur resources, and reduces the procurement cost of sulfuric acid. At the same time, the processing method of the laterite nickel ore acid leaching residue of the present invention can realize the purpose of synergistic treatment and utilization of various iron-containing waste slags produced in the surrounding supporting industrial production such as other nickel metallurgy (including hydrometallurgy and pyrometallurgy), steel metallurgy, thermal power, etc. The processing method of the present invention has the characteristics of large solid waste consumption, many types of products generated, high product output value, low comprehensive production cost, high resource utilization rate, etc., and provides a more effective solution for the full recovery of valuable components and full component resource utilization of laterite nickel ore acid leaching residue. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0029] FIG1 shows a flow chart of a method for treating laterite nickel ore acid leaching residue in one embodiment of the present invention. DETAILED DESCRIPTION

[0030] 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 with reference to the embodiments.

[0031] As described in the background technology section of this application, the existing technology cannot effectively utilize the laterite nickel ore acid leaching residue. In order to solve this problem, this application provides a method for treating laterite nickel ore acid leaching residue, as shown in Figure 1, which includes the following steps: step S1, mixing the laterite nickel ore acid leaching residue, a regulating material, a fluxing material and a reducing agent and pressing them to obtain a preform; step S2, roasting the preform to obtain hot slag and hot flue gas, and the hot flue gas is used to produce acid; step S3, magnetically separating the hot slag to obtain refined iron material and tailings; step S4, mixing the tailings, active material and stimulating material and grinding them to obtain active material; wherein the regulating material is iron-containing waste slag; the fluxing material is an alkaline substance containing one or more of CaO, MgO and Na2O; the active material is selected from one or more of nickel iron slag, fly ash, blast furnace slag, bottom ash or coal slag; and the stimulating material is selected from one or more of desulfurized gypsum, steel slag tailings, carbide slag, quicklime, limestone, slaked lime or cement clinker.

[0032] The present invention first mixes and compresses laterite nickel ore acid leaching residue, adjustment material, fluxing material and reducing agent to obtain a preform, and then roasts the preform to obtain hot slag and hot flue gas (this hot flue gas is sent to the acid production system to produce concentrated sulfuric acid, etc.), and then magnetically separates the hot slag to obtain refined iron material and tailings. Among them, the refined iron material can be directly used as an iron raw material. Through the above-mentioned operating steps, the residual Fe and Ni elements in the laterite nickel ore acid leaching residue are recycled; the tailings can be mixed with active materials and exciting materials for grinding to obtain active materials, which are used in the field of building materials, thereby effectively realizing the recycling of calcium elements in the laterite nickel ore acid leaching residue.

[0033] Among them, the adjustment material is mainly used to adjust the ratio between the various chemical components (alkaline components MgO, CaO and acidic components SiO2, Al2O3) in the laterite nickel ore acid leaching residue, which can make some weakly magnetic iron-containing materials in the material form magnetic iron-containing minerals, which can be subsequently recovered by simple magnetic separation to obtain Fe materials, thereby improving the recovery rate of Fe metal. At the same time, the adjustment material is selected from iron-containing waste slag, which can also effectively utilize such iron-containing solid waste and avoid resource waste. The flux is an alkaline substance containing one or more of CaO, MgO, and Na2O. It can react with acidic oxides such as SiO2 in the laterite nickel ore acid leaching residue and release Fe2O3 originally bound to SiO2, thereby improving the reduction reaction activity of iron oxides and increasing the yield of metallic iron.

[0034] In summary, the present application can further effectively recover the Fe element in the laterite nickel ore acid leaching residue by coordinating with each other between the adjustment material, the flux and the reducing agent. The processing method of the laterite nickel ore acid leaching residue of the present invention realizes the comprehensive resource utilization of the laterite nickel ore acid leaching residue, has a high recovery rate of residual valuable Fe metal, realizes the full utilization of valuable metals (such as Fe, Ni), sulfur and other components, not only realizes the recycling of valuable metals, but also realizes the recycling of sulfur resources, and reduces the procurement cost of sulfuric acid. At the same time, the processing method of the laterite nickel ore acid leaching residue of the present invention can realize the coordinated treatment and utilization purpose of a variety of iron-containing waste slags produced in the surrounding supporting industrial production such as other nickel metallurgy (including hydrometallurgy and pyrometallurgy), steel metallurgy, thermal power, etc. The processing method of the present invention has the characteristics of large solid waste consumption, many types of products generated, high product output value, low comprehensive production cost, high resource utilization rate, and provides a more effective solution for the full recovery of valuable components and full component resource utilization of the laterite nickel ore acid leaching residue.

[0035] The laterite nickel ore acid leaching residue of the present invention refers to waste residue produced after laterite nickel ore is treated by a wet acid leaching process, and comprises the following components: 38-52 wt% Fe, 4-13 wt% FeO, 8-22 wt% SiO2, 5-23 wt% CaO, 1-6 wt% Al2O3, and 1-4 wt% MgO. The hot slag comprises the following components: 48-68 wt% Fe2O3, 8-17 wt% SO3, 1-5 wt% CaO, 6-25 wt% SiO2, 1-4 wt% MgO, and 3-8 wt% Al2O3. The hot flue gas comprises SO2, and the volume concentration of SO2 is 4-10%.

[0036] In a preferred embodiment, based on the weight of the dry ore, the laterite nickel ore acid leaching residue is 100 parts, the adjusting material is 3-28 parts, the flux is 0.5-22 parts, and the reducing agent is 5-20 parts. Based on this, the synergistic effect of the laterite nickel ore acid leaching residue with the adjusting material, the flux, and the reducing agent is more significant, thereby promoting the full reduction of the Fe element in the laterite nickel ore acid leaching residue, and further allowing more laterite nickel ore acid leaching residue to be effectively processed, so that the iron content of the subsequently obtained refined iron material is higher and the performance of the tailings active material is better. At the same time, the laterite nickel ore acid leaching residue, the adjusting material, the flux, and the reducing agent within the above ratio range can improve the reduction efficiency of the roasted metal and reduce energy consumption and cost.

[0037] In order to further obtain active materials with better activity performance, preferably, based on the weight of dry ore, the tailings are 20 to 40 parts, the active material is 50 to 70 parts, and the stimulating material is 3 to 10 parts.

[0038] To further improve the resource utilization of laterite nickel ore acid leaching residue and fully recycle the iron, in step S2, the roasting temperature is 900-1250°C and the roasting time is 1-2 hours. If the roasting temperature is too high, the liquid phase content will increase and over-sintering will occur, which is not conducive to the stable operation of the roasting furnace and also increases energy consumption. If the roasting temperature is too low, the iron element will not be fully reduced.

[0039] To further improve roasting efficiency, the mixture of laterite nickel ore acid leaching residue, conditioning material, fluxing material, and reducing agent is preferably pressed into blocks or pellets for roasting. Preferably, the fuel used during roasting is selected from natural gas and / or pulverized coal. Preferably, the preform roasting and reduction process can be performed in a rotary kiln, rotary hearth furnace, sintering car, belt roaster, or tunnel kiln. In a preferred embodiment, the volume concentration of O2 in the combustion-supporting gas used during roasting is 40-60%. By controlling the volume concentration of O2 in the combustion-supporting gas within this range, the present invention achieves oxygen-enriched combustion and further reduces energy consumption.

[0040] In a preferred embodiment, the volume concentration of O2 in the hot flue gas is ≤5%, and the temperature of the hot flue gas is ≥300°C. The hot flue gas of the present invention can be recycled as a raw material for acid production, thereby recycling the sulfur resource in the laterite nickel ore acid leaching residue and reducing the sulfuric acid procurement cost in the laterite nickel ore wet acid leaching process. By controlling the volume concentration and temperature of the hot flue gas discharged from the furnace, the present invention can fully ensure the reducing atmosphere required for the reduction of metal oxides in the slag while simultaneously reducing the increase in production energy consumption caused by excessive CO generation and excessive flue gas temperature. Preferably, the volume concentration of O2 in the hot flue gas is 2-4%, and the temperature of the hot flue gas is 300-350°C.

[0041] In some optional embodiments, the iron-containing waste slag is selected from one or more of steel slag, wet iron-aluminum slag, or nickel smelting slag. The alkaline substance can be raw materials processed from natural ore resources, such as limestone, dolomite, quicklime, etc. From the perspective of turning waste into resources, metallurgical and chemical waste slag, such as gypsum slag, carbide slag, magnesium slag, etc., can also be used.

[0042] In a preferred embodiment, the reducing agent is selected from a solid reducing agent with a carbon content of 40-90% and a calorific value of ≥3000 kcal / kg. This solid reducing agent not only promotes the reduction of iron in laterite nickel ore acid leaching residue, but also serves as a fuel, improving roasting efficiency and further increasing the recovery rate of iron in laterite nickel ore acid leaching residue. Preferably, the reducing agent can be selected from mineral fuels such as anthracite, lignite, and coke, as well as from waste graphite electrodes and biomass waste (e.g., straw and carbonized rice husks). Preferably, the reducing agent has a particle size of ≤10 mm.

[0043] In a preferred embodiment, in step S1, prior to pressing, the processing method further includes subjecting the laterite nickel ore acid leaching residue, the conditioning material, and the fluxing material to a first crushing process to control the particle size of the materials to ≤10 mm. The present invention crushes the above materials to control the particle size of the materials to ≤10 mm to ensure sufficient mixing and contact between the materials, thereby improving reaction efficiency. Preferably, the particle size of the materials is 3 to 7 mm.

[0044] In a preferred embodiment, in step S3, prior to magnetic separation, the treatment method further includes air cooling the hot slag to obtain the slag. Through the above-mentioned treatment steps, the present invention not only recovers the waste heat of the hot slag to form cooling hot air, which can continue to be used as combustion-supporting air, but also promotes the formation of a glass phase in the slag tailings, thereby increasing the potential hydration and gelation activity of the tailings. When the hot slag is cooled with air, the waste heat of the hot slag converts the cold air into hot air. The present invention then returns the hot air to the preform roasting process as part of the combustion-supporting gas, fully utilizing the waste heat of the flue gas and saving energy.

[0045] In order to facilitate subsequent magnetic separation and improve the separation of tailings and fine iron, preferably, in step S3, the slag is subjected to a second crushing process and a grinding process in sequence, and more than 35% by mass of the ground slag has a particle size of ≤0.074 mm.

[0046] In order to further improve the separation degree of tailings and fine iron materials and enhance the performance of the product. In step S3, the magnetic separation includes two magnetic separation processes performed sequentially, and the magnetic field strength of the two magnetic separation processes is independently 80-250kA / m. Preferably, the magnetic field strength of the first magnetic separation process is higher than the magnetic field strength of the second magnetic separation process, and the magnetic separation strength of the first magnetic separation process is 150-250kA / m and the magnetic separation strength of the second magnetic separation process is 80-150kA / m.

[0047] The present invention also provides an active material, which is obtained by the above-mentioned method for treating the acid leaching residue of laterite nickel ore, and the specific surface area of ​​the active material is ≥350m 2 / kg.

[0048] Based on the aforementioned reasons, the active material obtained through the above-described treatment method of the present invention possesses potential hydration activity, and its activity is relatively good. This excellent hydration activity allows the material to be used as an active admixture and directly sold as an active admixture to manufacturers of concrete and cement products.

[0049] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0050] Example 1

[0051] The composition of the laterite nickel ore acid leaching residue is as follows: Fe2O3 is 57wt%, SiO2 is 15wt%, CaO is 4wt%, Al2O3 is 3.7wt%, MgO is 1.7wt%, SO3 is 11wt% and other impurities.

[0052] The laterite nickel ore acid leaching residue, the adjusting material (steel slag) and the fluxing material (quicklime) are crushed to a particle size of less than 10 mm, and then mixed with the reducing agent (anthracite) and pressed into balls to obtain a preform; wherein, based on the weight of the dry ore, the laterite nickel ore acid leaching residue is 100 parts, the adjusting material is 15 parts, the fluxing material is 2 parts, and the reducing agent is 15 parts.

[0053] The preformed product is fed into a rotary kiln for roasting at a temperature of 1100-1150°C for 2 hours. Natural gas is used as fuel, and oxygen-enriched combustion air with a volume concentration of 50% oxygen (wherein the volume concentrations of the gases are: 50% O2, 49% N2, and 1% H2O) is introduced. This produces hot slag (Fe: 43 wt%, FeO: 6 wt%, CaO: 8.1 wt%, SiO2: 12.3 wt%, Al2O3: 2.3 wt%, and MgO: 1.4 wt%) and hot flue gas. The hot flue gas is the flue gas discharged from the roasting furnace, has an SO2 content of 7%, a flue gas temperature of 340°C, and an O2 concentration of 5%. The recovered hot flue gas is cooled and dust-removed, and then used as a raw material for producing concentrated sulfuric acid.

[0054] The hot slag after being discharged from the furnace is air-cooled to 300°C to obtain slag, which is then crushed and ground to a particle size distribution of 25% after passing through a 0.074 mm sieve. The ground slag is then subjected to two magnetic separations, with the primary magnetic separation having a magnetic field strength of 240 kA / m to obtain middlings and tailings. The middlings are then subjected to a secondary magnetic separation with a magnetic field strength of 100 kA / m to obtain fine iron (TFe content of 78% and Fe recovery of 92%) and tailings.

[0055] According to the weight of dry ore, 30 parts of tailings, 65 parts of active material (fly ash) and 5 parts of exciting material (desulfurization gypsum) are mixed and ground until the specific surface area reaches 400-450m 2 / kg, the active material is obtained.

[0056] Example 2

[0057] The difference from Example 1 is that the laterite nickel ore acid leaching residue is 100 parts, the adjustment material is 28 parts, the fluxing material is 22 parts, and the reducing agent is 20 parts.

[0058] Example 3

[0059] The difference from Example 1 is that the laterite nickel ore acid leaching residue is 100 parts, the adjustment material is 3 parts, the fluxing material is 0.5 parts, and the reducing agent is 5 parts.

[0060] Example 4

[0061] The difference from Example 1 is that the laterite nickel ore acid leaching residue is 100 parts, the adjustment material is 15 parts, the fluxing material is 2 parts, and the reducing agent is 2 parts.

[0062] Example 5

[0063] The difference from Example 1 is that the calcination temperature is 780-800° C. and the calcination time is 2 h.

[0064] Example 6

[0065] The difference from Example 1 is that the calcination temperature is 1380-1400° C. and the calcination time is 2 h.

[0066] Example 7

[0067] The difference from Example 1 is that the volume concentration of O2 in the combustion-supporting gas is 20%.

[0068] Example 8

[0069] The difference from Example 1 is that, based on the weight of dry ore, 20 parts of tailings, 70 parts of active materials and 10 parts of exciting materials are mixed and ground.

[0070] Example 9

[0071] The difference from Example 1 is that, based on the weight of dry ore, 37 parts of tailings, 50 parts of active materials and 3 parts of exciting materials are mixed and ground.

[0072] Example 10

[0073] The difference from Example 1 is that, based on the weight of dry ore, 50 parts of tailings, 30 parts of active materials and 20 parts of exciting materials are mixed and ground.

[0074] Performance Characterization

[0075] TFe test: Fe recovery rate = weight of iron ore concentrate × Fe content of iron ore concentrate / (∑ amount of each input material × Fe content of each input material) × 100%.

[0076] Activity index test: The test was conducted with reference to GB / T 18046-2017. The test results of the above embodiment are shown in Table 1.

[0077] Table 1

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for treating laterite nickel ore acid leaching residue, characterized in that: The following steps are involved: Step S1, mixing the laterite nickel ore acid leaching residue, the adjusting material, the fluxing material and the reducing agent and pressing them to obtain a preform; Step S2, roasting the preform to obtain hot slag and hot flue gas, wherein the hot flue gas is used to produce acid; Step S3, magnetically separating the hot slag to obtain refined iron material and tailings; Step S4, mixing and grinding the tailings, active material and exciting material to obtain active material; Among them, the adjusting material is iron-containing waste slag; the fluxing material is an alkaline substance containing one or more of CaO, MgO, and Na2O; the active material is selected from one or more of nickel-iron slag, fly ash, blast furnace slag, bottom slag or coal slag; the exciting material is selected from one or more of desulfurized gypsum, steel slag tailings, carbide slag, quicklime, limestone, slaked lime or cement clinker.

2. The method for treating laterite nickel ore acid leaching residue according to claim 1, characterized in that: The hot slag comprises the following components: 38-52wt% Fe, 4-13wt% FeO, 8-22wt% SiO2, 5-23wt% CaO, 1-6wt% Al2O3 and 1-4wt% MgO; The laterite nickel ore acid leaching residue comprises the following components: 48-68wt% of Fe2O3, 8-17wt% of SO3, 1-5wt% of CaO, 6-25wt% of SiO2, 1-4wt% of MgO and 3-8wt% of Al2O3; The hot flue gas includes SO2, and the volume concentration of the SO2 is 4-10%.

3. The method for treating laterite nickel ore acid leaching residue according to claim 1, characterized in that: In the step S1, based on the weight of dry ore, the laterite nickel ore acid leaching residue is 100 parts, the adjusting material is 3 to 28 parts, the fluxing material is 0.5 to 22 parts, and the reducing agent is 5 to 20 parts.

4. The method for treating laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: In the step S4, based on the weight of dry ore, the tailings are 20 to 40 parts, the active material is 50 to 70 parts, and the stimulating material is 3 to 10 parts.

5. The method for treating laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: In the step S2, the calcination temperature is 900-1250°C and the calcination time is 1-2h; The volume concentration of O2 in the combustion-supporting gas used in the roasting process is 40-60%; The fuel used in the roasting process is selected from natural gas and / or coal powder.

6. The method for treating laterite nickel ore acid leaching residue according to claim 5, characterized in that: The volume concentration of O2 in the hot flue gas is ≤5%, and the temperature of the hot flue gas is ≥300°C.

7. The method for treating laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: The iron-containing waste slag is selected from one or more of steel slag, wet iron-aluminum slag or nickel smelting slag; The alkaline substance is selected from one or more of limestone, dolomite, quicklime, gypsum slag, carbide slag or magnesium slag; The reducing agent is selected from a solid reducing agent with a carbon content of 40-90% and a calorific value of ≥3000kcal / kg.

8. The method for treating laterite nickel ore acid leaching residue according to any one of claims 1 to 3, characterized in that: In the step S1, before the pressing, the processing method further comprises subjecting the laterite nickel ore acid leaching residue, the adjustment material, and the flux material to a first crushing process to control the particle size of the material to be ≤10 mm; In the step S3, before the magnetic separation, the processing method further includes the step of air cooling the hot slag to obtain slag.

9. The method for treating laterite nickel ore acid leaching residue according to claim 8, characterized in that: In the step S3, the slag is subjected to a second crushing process and a grinding process in sequence, and the particle size of the slag after the grinding process meets the following requirements: more than 35% by mass of the slag after the grinding process has a particle size of ≤0.074 mm; In step S3, the magnetic separation includes two magnetic separation processes performed sequentially, and the magnetic field strength of the two magnetic separation processes is independently 80-250 kA / m.

10. An active material, characterized in that The active material is obtained by the treatment method of laterite nickel ore acid leaching residue according to any one of claims 1 to 9, and the specific surface area of ​​the active material is ≥350m 2 / kg.

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