A multi-component comprehensive recycling method of high-ice nickel oxide pressure leaching residue by combining fire method with wet method

Abstract

The application discloses a kind of high ice nickel oxygen pressure leaching residue fire method wet method combined multi-group element comprehensive recycling method, comprising the following steps: (1) high ice nickel oxygen pressure leaching residue is mixed with sulphidizing agent, carbonaceous reducing agent, and is carried out reduction sulphidation roasting treatment, and after cooling, get calcine and rich germanium dust;(2) the calcine is added in dilute sulfuric acid, and constant flow rate SO2 is imported, and reduction acid leaching reaction is carried out, and after filtration, get ferrous solution and nickel sulphide residue;(3) the ferrous solution is frozen crystallization and gets ferrous sulfate heptahydrate;(4) the nickel sulphide residue is carried out and adds acid oxygen pressure leaching, and after filtration, get nickel sulfate solution, and cooling crystallization is carried out and gets again six water nickel sulfate.The application adopts fire method wet method combined processing technology and comprehensively recycles iron, nickel, germanium and other valuable metal elements, and selective reduction sulphidation roasting is used to preferentially process beneficial to the efficient separation among nickel, iron and germanium, and the recovery rate and separation rate of nickel and iron elements are improved.

Description

Technical Field

[0001] This invention belongs to the field of resource recycling, and in particular relates to a method for treating high-nickel matte oxygen pressure leaching residue. Background Technology

[0002] In recent years, with the continuous decline in the production of sulfide nickel ore, laterite nickel ore has gradually become an important resource in the nickel production field. Sulfide smelting is one of the main methods for processing limonite-type laterite nickel ore. After removing gangue and producing nickel-iron matte through sulfide smelting, low-grade nickel matte is produced. After blowing and de-ironizing, high-grade nickel matte with a nickel content of about 70% is obtained. At present, one of the main hydrometallurgical processes for high-grade nickel matte is the selective oxygen pressure leaching process, which is used to produce nickel sulfate solution and produce high-grade nickel matte oxygen pressure leaching residue, which is mainly composed of hematite and contains a variety of valuable metal elements. The comprehensive utilization of high-grade nickel matte oxygen pressure leaching residue not only helps to clean up the overall process production line of laterite nickel ore, but also helps to maximize the utilization of resources.

[0003] Patent CN115558797A discloses a comprehensive resource utilization process for high-grade nickel matte oxygen pressure leaching residue. It uses sulfuric acid as the leaching agent and sulfur dioxide as the reducing agent to comprehensively leach nickel, iron, and copper elements. Then, ferrous sulfide precipitation is used to separate copper and nickel, yielding a mixed copper-nickel-iron sulfide and a ferrous sulfate solution, which is then used to prepare ferrous sulfate heptahydrate. This method comprehensively utilizes nickel, iron, and copper, but nickel sulfide in the raw material cannot be leached, resulting in some nickel loss. Furthermore, iron inevitably mixes in during the sulfide precipitation process, making complete separation difficult. High-grade nickel matte oxygen pressure leaching residue from limonite-type laterite nickel ore is characterized by high iron, low nickel, low copper, and the presence of certain precious metal elements such as germanium. How to achieve efficient separation and recovery of these elements is an urgent problem to be solved. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings and defects mentioned in the background art above, and to provide a multi-component comprehensive recycling method for high-precision nickel matte leaching residue using a combination of pyrometallurgical and hydrometallurgical processes, which has high separation efficiency and high recovery rate. To solve the above technical problem, the technical solution proposed by this invention is as follows:

[0005] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0006] (1) The high nickel matte oxygen pressure leaching residue is mixed with sulfiding agent and carbonaceous reducing agent, and then subjected to reduction sulfidation roasting treatment. After cooling, roasted sand and germanium-rich flue dust are obtained.

[0007] (2) The calcined sand is added to dilute sulfuric acid and SO2 is introduced at a constant flow rate to carry out a reducing acid leaching reaction. After filtration, ferrous solution and nickel sulfide slag are obtained.

[0008] (3) The ferrous solution is subjected to freeze crystallization to obtain ferrous sulfate heptahydrate;

[0009] (4) The nickel sulfide slag is subjected to acid oxygen pressure leaching, filtered to obtain nickel sulfate solution, and then cooled and crystallized to obtain nickel sulfate hexahydrate.

[0010] In the aforementioned multi-element comprehensive recycling method, preferably, the high-grade nickel matte oxygen pressure leaching residue contains 50-60% iron, 4-6% nickel, and 0.2-0.5% germanium by mass. Iron is primarily present as hematite, with the presence of ferric sulfate; nickel is primarily present as nickel sulfate and nickel ferrite, with the presence of nickel sulfide. The content of other elements is less than 0.1%. Furthermore, the aforementioned high-grade nickel matte oxygen pressure leaching residue is dried, crushed, and sieved through a 100-mesh screen.

[0011] In the above-mentioned multi-component integrated recycling method, preferably, the carbonaceous reducing agent is lignite, and the sulfiding agent is sulfur; the amount of carbonaceous reducing agent added is 4-10% of the mass of high-grade nickel matte leaching residue, and the amount of sulfiding agent added is 5-12% of the mass of high-grade nickel matte leaching residue.

[0012] In the above-mentioned multi-component comprehensive recycling method, preferably, the heating rate is controlled at 10-15℃ / min during the reduction sulfidation roasting treatment, and the temperature is maintained at 1050-1100℃ for 1-1.5h.

[0013] In this invention, the dosage of carbonaceous reducing agent and sulfiding agent, as well as the roasting temperature and time, have a significant impact on the reaction results and need to be properly controlled. If the amount of carbonaceous reducing agent added is too small, the iron in the raw material cannot be completely reduced to magnetite, leading to iron sulfidation. Simultaneously, the reduction reaction of germanium dioxide is incomplete, resulting in a decrease in germanium recovery. If the amount of carbonaceous reducing agent added is too large, nickel is reduced to metallic nickel, consuming more sulfiding agent and hindering the sulfidation reaction. If the amount of sulfiding agent added is too small, the nickel sulfidation reaction in the raw material is incomplete, and nickel oxide is leached out during the reducing acid leaching process, reducing the purity of the ferrous solution and decreasing the nickel recovery rate. If the amount of sulfiding agent added is too large, it results in raw material waste and increases the possibility of iron being sulfided.

[0014] If the roasting temperature is too low, other reactions such as the reduction of germanium oxide and the sulfidation of nickel cannot proceed or are incomplete during roasting, reducing the recovery rate of each element. If the roasting temperature is too high, exceeding 1150℃, magnetite will react with sulfur dioxide, causing iron sulfidation, which will then enter the leaching residue along with nickel sulfide, resulting in resource loss and reducing the separation efficiency of each element. If the holding time is too short, the reactions will not proceed completely during roasting, reducing the sulfidation rate of nickel, the reduction rate of iron, and the volatilization rate of germanium, resulting in resource waste. If the holding time is too long, the reactions are already basically completed, and extending the time will not significantly improve the efficiency of each reaction, while wasting energy.

[0015] In the aforementioned multi-component integrated recycling method, the preferred approach involves first mixing high-grade nickel matte leaching residue with a carbonaceous reducing agent for pre-roasting, followed by the addition of a sulfiding agent and subsequent re-roasting. During pre-roasting, the heating rate is controlled at 10-15℃ / min, and the temperature is held at 500-600℃ for 20-30 minutes. During re-roasting, based on the pre-roasting process, the heating rate is controlled at 10-15℃ / min, and the temperature is held at 1050-1100℃ for 1-1.5 hours. This pre-roasting + re-roasting process first reduces iron, followed by sulfidation, which facilitates selective reduction sulfidation, causing nickel in the raw material to sulfide while iron exists as magnetite (Fe3O4). The pre-roasting temperature is controlled at 500-600℃, and the holding time is 20-30 minutes to ensure complete reduction of hematite and prevent the sulfidation of any unreduced iron. If the temperature is too low, the ferric sulfate will not decompose, and the reduction reaction will not proceed completely; if the temperature is too high, energy will be wasted. If the holding time is too short, the reduction reaction will not proceed completely; if the holding time is too long, energy will be wasted.

[0016] In the aforementioned multi-component integrated recycling method, preferably, after the reduction sulfidation roasting treatment, flowing nitrogen gas is introduced during cooling for natural cooling, with a nitrogen flow rate of 1.5-2 sL / min. The purpose of introducing nitrogen gas is to prevent the generated Fe3O4 and FeO from being oxidized during the cooling process. If the nitrogen flow rate is too low, insufficient nitrogen flow will result in the presence of oxygen in the furnace, which may cause oxidation of ferrous iron, hindering subsequent recovery processes. If the flow rate is too high, it will lead to resource waste.

[0017] In the above-mentioned multi-component integrated recycling method, preferably, during the reducing acid leaching reaction, the concentration of the dilute sulfuric acid is 80-90 g / L, the mass ratio of the high-grade nickel matte oxygen pressure leaching residue to the volume of added dilute sulfuric acid is 1 g: 5-7 mL, and the flow rate of SO2 is 200-250 mL / min. If the sulfuric acid concentration is too low, the iron dissolution reaction will be incomplete and the reaction rate will be greatly reduced; if the concentration is too high, a small amount of nickel sulfide may dissolve, affecting the separation efficiency of nickel-iron. If the liquid-to-solid ratio is too low, there will be less leaching agent in the solution, resulting in incomplete reaction; if the liquid-to-solid ratio is too high, the effect on improving the leaching rate is not significant, and it will reduce the iron concentration in the leachate, wasting reagents. If the SO2 flow rate is too slow, there will be insufficient reducing agent, resulting in incomplete reaction; if the flow rate is too fast, the gas-solid reaction contact area will be small, and a large portion of SO2 will be lost, causing resource waste.

[0018] In the above-mentioned multi-component integrated recycling method, preferably, the reduction acid leaching reaction is carried out at a water bath temperature of 60-70℃ and a stirring speed of 400-500 rpm, with a reaction time of 20-30 minutes. If the water bath temperature is too low, molecular motion slows down, the mass transfer rate is greatly reduced, and the reaction rate decreases, thus reducing the element leaching rate within the same time period. If the water bath temperature is too high, a small amount of nickel may dissolve, affecting the nickel-iron separation efficiency. If the stirring speed is too slow, the reaction mass transfer rate slows down, reducing the element leaching rate within the same time period. If the stirring speed is too fast, the improvement in the iron leaching rate is not significant. If the reaction time is too short, the reaction is incomplete; if the reaction time is too long, the improvement in the leaching rate is not significant, and energy consumption is wasted.

[0019] This invention utilizes reduction sulfidation roasting and two-step acid leaching to recover nickel and iron. By controlling the process conditions of reduction sulfidation roasting and two-step acid leaching, and through the synergistic effect of each step and process condition, efficient separation and recovery of nickel and iron can be achieved. During reduction sulfidation roasting, process conditions should be controlled to maximize nickel sulfidation while minimizing iron sulfidation. In the reduction acid leaching process, by using lower concentration sulfuric acid, lower water bath temperature, and shorter reaction time, almost all iron can be leached out, while nickel remains largely unleached (if iron sulfidates, it is difficult to completely leach it under these acid leaching conditions, reducing nickel-iron separation efficiency; if acid concentration and temperature are increased to ensure complete leaching of sulfidated iron, nickel sulfide may be leached out, again reducing nickel-iron separation efficiency). This reduction acid leaching achieves efficient separation of nickel and iron, and nickel can be completely leached through subsequent oxygen pressure acid leaching, resulting in a high overall metal recovery rate.

[0020] In the above-mentioned comprehensive recycling method for multiple components, preferably, pure sulfuric acid is added to the ferrous sulfate solution before cooling and crystallizing until the concentration of sulfuric acid in the ferrous sulfate solution is 200-300 g / L; the freeze crystallization is carried out at -20 to -15°C for 20-30 minutes. Adding sulfuric acid increases the acidity of the solution system and prevents the hydrolysis of ferrous iron. If the freeze crystallization temperature is too low or too high, the crystal form will differ from that of ferrous sulfate heptahydrate or the crystallization effect will be poor; if the holding time is too short, crystallization will be incomplete; if the time is too long, crystallization will be essentially complete, and extending the time will waste energy.

[0021] In the above-mentioned multi-component comprehensive recycling method, preferably, during acid-oxygen pressure leaching, the acid added is sulfuric acid with a concentration of 1-1.5 mol / L, and the mass ratio of the nickel sulfide slag to the volume of sulfuric acid is 1 g: 5-6 mL; during acid-oxygen pressure leaching, the oxygen pressure is 1.4-1.5 MPa, the reaction temperature is 180-190℃, and the reaction time is 2-3 h. If the sulfuric acid concentration is too low, the reaction will be incomplete and the reaction rate will be greatly reduced; if the concentration is too high, the effect on improving the leaching rate will be insignificant. If the liquid-to-solid ratio is too low, there will be insufficient leaching agent in the solution, resulting in incomplete reaction. If the liquid-to-solid ratio is too high, the effect on improving the leaching rate will be insignificant, and reagents will be wasted. In acid-oxygen pressure leaching, oxygen pressure leaching requires high temperature conditions. If the leaching temperature is too low, the nickel sulfide leaching reaction will be difficult to occur, and molecular motion will slow down, mass transfer rate will be greatly reduced, and reaction rate will be slowed down, reducing the element leaching rate in the same time. If the temperature is too high, the effect on improving the leaching rate will be insignificant, and energy consumption will be wasted. If the leaching time is too short, the reaction will be incomplete. If the time is too long, the effect on improving the leaching rate will be insignificant, and energy consumption will be wasted. If the oxygen pressure is too low, the oxygen supply will be insufficient, the reaction will be incomplete, the nickel leaching rate will be low, and if it is too high, resources will be wasted.

[0022] In the above-mentioned comprehensive recycling method for multiple components, the preferred method is to cool the reaction system to 33-35℃ and maintain the temperature for 8-9 hours during cooling crystallization. If the crystallization temperature is too low, the resulting product is nickel sulfate heptahydrate, which easily loses its water of crystallization in humid air. If the crystallization temperature is too high, the supersaturation of the solution decreases, affecting the crystallization rate. If the crystallization time is too short, the crystallization is incomplete. If the crystallization time is too long, the product particle size gradually increases, the number of fine particles decreases, the particle size distribution becomes uneven, and the dissolution rate slows down.

[0023] The multi-component integrated recycling method for high-nickel matte oxygen pressure leaching residue, combining pyrometallurgical and hydrometallurgical processes, may involve the following reactions during selective reduction sulfidation roasting:

[0024] 0.5S²⁺ + O₂ → SO₂;

[0025] C + O2 → CO2;

[0026] Fe2(SO4)3→Fe2O3+3SO3;

[0027] 3Fe₂O₃ + C → 2Fe₃O₄ + CO;

[0028] 3Fe₂O₃ + CO → 2Fe₃O₄ + CO₂;

[0029] NiSO4→NiO+SO3;

[0030] NiO + CO → Ni + CO2;

[0031] 2NiO + 2SO₂ → 2NiS + 3O₂;

[0032] 2NiO + 1.5S2 → 2NiS + SO2;

[0033] Ni + 0.5S²⁻ → NiS;

[0034] Ni+SO2→NiS+O2;

[0035] 1.5NiFe2O4+1.25S2→1.5NiS+Fe3O4+SO2;

[0036] 3GeO2·Fe2O3+4CO→3GeO+2Fe3O4+4CO2;

[0037] GeO2+C→GeO+CO.

[0038] Nickel preferentially undergoes sulfidation compared to iron. The sulfidation of hematite is suppressed upon the addition of a carbonaceous reducing agent. Based on the Gibbs free energy curves of metal oxides with CO and SO2, the reduction reaction between hematite and the carbonaceous reducing agent will occur preferentially, producing magnetite. The sulfidation reaction temperature of magnetite reaches 1150℃. Controlling the reaction temperature below this level can prevent the sulfidation of magnetite, thus achieving selective reduction sulfidation. This results in the sulfidation of nickel in the raw material, while iron exists as magnetite (Fe3O4). Germanium in the raw material exists as an oxide in the hematite lattice. It reacts with the carbonaceous reducing agent at high temperature to produce germanium monoxide. Due to its low boiling point, germanium monoxide easily sublimates into dust, thus achieving separation.

[0039] This invention targets high-grade nickel matte leaching residue and employs a combined pyrometallurgical and hydrometallurgical process to comprehensively recover valuable metal elements such as iron, nickel, and germanium. Through exploratory research and repeated experimental verification, the inventors of this invention have found that selective reduction sulfidation roasting is beneficial for the efficient separation of nickel, iron, and germanium, and improves the recovery and separation rates of nickel and iron.

[0040] Compared with the prior art, the advantages of the present invention are as follows:

[0041] 1. The multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-grade nickel matte leaching residue of this invention achieves comprehensive and efficient recycling of multiple components. By employing a pre-selective reduction sulfidation roasting method, the problem of difficult leaching of some nickel and germanium elements in the raw material as ferrates is addressed. Selective roasting allows germanium to be enriched in the flue dust, nickel to form nickel sulfide, and iron to form magnetite (Fe3O4). Subsequent leaching yields ferrous sulfate heptahydrate and nickel sulfate hexahydrate products. Compared to existing methods for treating high-grade nickel matte leaching residue, this invention, targeting the characteristics of raw materials rich in iron and nickel elements and with low impurity content, prepares ferrous sulfate heptahydrate and nickel sulfate hexahydrate products while simultaneously obtaining germanium-rich flue dust, maximizing resource utilization.

[0042] 2. The multi-component integrated recovery and utilization method of high-grade nickel matte oxy-pressure leaching residue combining pyrometallurgical and hydrometallurgical processes achieves efficient separation of nickel, iron, and germanium. Compared with the multi-component complete reduction acid leaching method, this invention prioritizes the separation and enrichment of germanium during roasting while selectively sulfiding nickel, ensuring that iron exists in the form of magnetite (Fe3O4) and avoiding sulfidation. Subsequent reduction leaching can then be performed with a shorter time to recover iron, significantly shortening the reduction leaching time. Nickel sulfide is then recovered through oxy-pressure acid leaching. The stepwise acid leaching of nickel sulfide and magnetite (Fe3O4) enables the stepwise leaching and recovery of iron and nickel, resulting in high nickel-iron separation efficiency. This method avoids the problem in traditional processes where some nickel exists in the form of nickel sulfide, which cannot be directly recovered through reduction leaching, thus reducing the recovery rate and improving the recovery rate of each element.

[0043] In summary, this invention employs a combination of pyrometallurgical and hydrometallurgical processes to achieve efficient separation and recovery of valuable elements, as well as comprehensive high-value utilization. The process is short, energy-efficient, and highly effective. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a process flow diagram of the multi-component integrated recycling method for high-nickel matte leaching residue using a combination of pyrometallurgical and hydrometallurgical processes, as described in this invention. Detailed Implementation

[0046] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0047] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0048] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0049] The main components of the high-grade nickel matte oxygen pressure leaching residue to be treated in the following examples and comparative examples are Fe: 52.50%, Ni: 4.9%, Ge: 0.33%, and the contents of other elements are all less than 0.1%. Among them, iron mainly exists in the form of hematite, with some ferric sulfate, and nickel mainly exists in the form of nickel sulfate and nickel ferrite, with a small amount of nickel sulfide.

[0050] Example 1:

[0051] like Figure 1 As shown, a multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0052] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0053] (2) Take 10g of the sieved material, mix it with 5% lignite and 6% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 1050℃ for 1h. Then, introduce nitrogen gas at a flow rate of 1.5sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 99%, the iron element mainly exists in the form of iron(III) oxide, the sulfidation rate of iron element reaches 7%, and the germanium element recovery rate reaches 96%.

[0054] (3) Add calcined sand to a 90 g / L dilute sulfuric acid solution at a ratio of 1 g: 5 mL, and pass SO2 gas at a flow rate of 200 mL / min. After reacting for 20 min at a water bath temperature of 60 °C and a stirring speed of 400 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 92% and the iron concentration in the solution is 94 g / L.

[0055] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 97%.

[0056] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 93%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 94%.

[0057] Example 2:

[0058] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0059] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0060] (2) Take 10g of the sieved material, mix it with 8% lignite and 10% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 1100℃ for 1.5h. Then, introduce nitrogen gas at a flow rate of 2sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 99%, the iron element mainly exists in the form of iron(III) oxide, the sulfidation rate of iron element reaches 6%, and the germanium element recovery rate reaches 97%.

[0061] (3) Add calcined sand to 80 g / L dilute sulfuric acid solution at a ratio of 1 g: 6 mL, and pass SO2 gas at a flow rate of 250 mL / min. After reacting for 30 min at a water bath temperature of 70℃ and a stirring speed of 500 rpm, filter to obtain a high concentration of ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 94% and the iron concentration in the solution is 81 g / L.

[0062] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 300 g / L, then keep it at -20℃ for 20 min and filter to obtain FeSO4·7H2O product with a purity of 98%.

[0063] (5) Add 1 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 6 mL, and leach for 3 h at an oxygen pressure of 1.5 MPa and a temperature of 190 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 95%. Place it in a water bath and slowly cool it to 35 °C and keep it at that temperature for 9 h. After filtration, obtain NiSO4·6H2O product with a purity of 95%.

[0064] Example 3:

[0065] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0066] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150 μm.

[0067] (2) Take 10g of the sieved material and mix it with 5% lignite, then put it into a tube furnace. Adjust the heating rate to 10℃ / min, heat to 500℃ and hold for 30min. Then add 6% sulfur and heat to 1050℃ at the same heating rate and hold for 1h. Then pass nitrogen gas at a flow rate of 1.5sL / min and cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 99%, and no iron element sulfidation is detected. Iron element mainly exists in the form of iron(III) oxide. The germanium element recovery rate reaches 96%.

[0068] (3) Add calcined sand to a 90 g / L dilute sulfuric acid solution at a ratio of 1 g: 5 mL, and pass SO2 gas at a flow rate of 200 mL / min. After reacting for 20 min at a water bath temperature of 60 °C and a stirring speed of 400 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 98% and the iron concentration in the solution is 100 g / L.

[0069] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 98%.

[0070] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 95%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 96%.

[0071] Comparative Example 1:

[0072] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0073] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0074] (2) Take 10g of the sieved material, mix it with 2% lignite and 6% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 1050℃ for 1h. Then, introduce nitrogen gas at a flow rate of 1.5sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 99%, the sulfidation rate of iron element reaches 34%, the iron element mainly exists in the form of iron(III) oxide, and the germanium element recovery rate reaches 79%.

[0075] (3) Add calcined sand to a 90 g / L dilute sulfuric acid solution at a ratio of 1 g: 5 mL, and pass SO2 gas at a flow rate of 200 mL / min. After reacting for 20 min at a water bath temperature of 60℃ and a stirring speed of 400 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 43% and the iron concentration in the solution is 42 g / L.

[0076] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 95%.

[0077] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 93%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 72%.

[0078] Comparative Example 2:

[0079] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0080] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0081] (2) Take 10g of the sieved material, mix it with 5% lignite and 2% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 1050℃ for 1h. Then, introduce nitrogen gas at a flow rate of 1.5sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 41%, iron element mainly exists in the form of iron(III) oxide, and germanium element recovery rate reaches 96%.

[0082] (3) Add calcined sand to a 90 g / L dilute sulfuric acid solution at a ratio of 1 g: 5 mL, and pass SO2 gas at a flow rate of 200 mL / min. After reacting for 20 min at a water bath temperature of 60℃ and a stirring speed of 400 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 95% and the iron concentration in the solution is 98 g / L.

[0083] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 89%.

[0084] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 90%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 91%.

[0085] Comparative Example 3:

[0086] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0087] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0088] (2) Take 10g of the sieved material, mix it with 5% lignite and 6% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 800℃ for 1h. Then, introduce nitrogen gas at a flow rate of 1.5sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 56%, iron element mainly exists in the form of iron(III) oxide, the sulfidation rate of iron element reaches 7%, and the germanium element recovery rate reaches 7%.

[0089] (3) Add calcined sand to a 90 g / L dilute sulfuric acid solution at a ratio of 1 g: 5 mL, and pass SO2 gas at a flow rate of 200 mL / min. After reacting for 20 min at a water bath temperature of 60℃ and a stirring speed of 400 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 91% and the iron concentration in the solution is 93 g / L.

[0090] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 89%.

[0091] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 92%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 92%.

[0092] Comparative Example 4:

[0093] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0094] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0095] (2) Take 10g of the sieved material, mix it with 5% lignite and 6% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 1200℃ for 1h. Then, introduce nitrogen gas at a flow rate of 1.5sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 99%, the sulfidation rate of iron element is 27%, the iron element mainly exists in the form of iron(III) oxide, and the germanium element recovery rate reaches 97%.

[0096] (3) Add calcined sand to a 90 g / L dilute sulfuric acid solution at a ratio of 1 g: 5 mL, and pass SO2 gas at a flow rate of 200 mL / min. After reacting for 20 min at a water bath temperature of 60℃ and a stirring speed of 400 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 69% and the iron concentration in the solution is 70 g / L.

[0097] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 96%.

[0098] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 93%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 79%.

[0099] Comparative Example 5:

[0100] A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte leaching residue includes the following steps:

[0101] (1) After drying and crushing the high nickel matte oxygen pressure leaching residue, it is screened with a 100-mesh standard sieve to ensure that the particle size is below 150μm.

[0102] (2) Take 10g of the sieved material, mix it with 5% lignite and 6% sulfur, and put it into a tube furnace. Adjust the heating rate to 10℃ / min and keep it at 1050℃ for 1h. Then, introduce nitrogen gas at a flow rate of 1.5sL / min and let it cool naturally to obtain roasted sand and collect germanium-rich dust. The sulfidation rate of nickel element reaches 99%, the iron element mainly exists in the form of iron(III) oxide, the sulfidation rate of iron element reaches 7%, and the germanium element recovery rate reaches 96%.

[0103] (3) Add calcined sand to a 50 g / L dilute sulfuric acid solution at a ratio of 1 g: 3 mL, and pass SO2 gas at a flow rate of 100 mL / min. After reacting for 20 min at a water bath temperature of 30℃ and a stirring speed of 200 rpm, filter to obtain a high-concentration ferrous solution and nickel sulfide slag, in which the iron leaching rate reaches 32% and the iron concentration in the solution is 53 g / L.

[0104] (4) Add pure sulfuric acid to the high-concentration ferrous solution until the sulfuric acid concentration in the solution is 200 g / L, then keep it at -15℃ for 30 min and filter to obtain FeSO4·7H2O product with a purity of 95%.

[0105] (5) Add 1.5 mol / L sulfuric acid solution to nickel sulfide slag at a ratio of 1 g: 5 mL, and leach for 2 h at an oxygen pressure of 1.4 MPa and a temperature of 180 °C. After filtration, obtain nickel sulfate solution with a nickel leaching rate of 91%. Place it in a water bath and slowly cool it to 33 °C and keep it at that temperature for 8 h. After filtration, obtain NiSO4·6H2O product with a purity of 73%.

Claims

1. A multi-component integrated recycling method combining pyrometallurgical and hydrometallurgical processes for high-nickel matte oxygen pressure leaching residue, characterized in that... Includes the following steps: (1) The high nickel matte oxygen pressure leaching residue is mixed with sulfiding agent and carbonaceous reducing agent, and then subjected to reduction sulfidation roasting treatment. After cooling, roasted sand and germanium-rich flue dust are obtained. (2) The calcined sand is added to dilute sulfuric acid and SO2 is introduced to carry out a reducing acid leaching reaction. After filtration, ferrous solution and nickel sulfide slag are obtained. (3) The ferrous solution is subjected to freeze crystallization to obtain ferrous sulfate heptahydrate; (4) The nickel sulfide slag is subjected to acid oxygen pressure leaching, filtered to obtain nickel sulfate solution, and then cooled and crystallized to obtain nickel sulfate hexahydrate; The carbonaceous reducing agent is lignite, and the sulfiding agent is sulfur; the amount of carbonaceous reducing agent added is 4-10% of the mass of the high-grade nickel matte oxygen pressure leaching residue, and the amount of sulfiding agent added is 5-12% of the mass of the high-grade nickel matte oxygen pressure leaching residue; During the reduction sulfidation roasting treatment, the heating rate is controlled at 10-15℃ / min, and the temperature is held at 1050-1100℃ for 1-1.5h. During the reducing acid leaching reaction, the concentration of the dilute sulfuric acid is 80-90 g / L, the mass ratio of the high-grade nickel matte oxygen pressure leaching residue to the volume of dilute sulfuric acid added is 1 g: 5-7 mL, and the flow rate of SO2 is 200-250 mL / min. The reduction acid leaching reaction was carried out in a water bath at a temperature of 60-70℃ and a stirring speed of 400-500 rpm for 20-30 minutes.

2. The multi-component integrated recycling method according to claim 1, characterized in that, The high-grade nickel matte oxygen pressure leaching residue contains 50-60% iron, 4-6% nickel, and 0.2-0.5% germanium by mass. Iron mainly exists in the form of hematite and contains ferric sulfate, while nickel mainly exists in the form of nickel sulfate and nickel ferrite and contains nickel sulfide.

3. The multi-component integrated recycling method according to claim 1, characterized in that, First, the high-grade nickel matte oxygen pressure leaching residue is mixed with a carbonaceous reducing agent and pre-roasted. Then, a sulfiding agent is added and roasted again. During the pre-roasting treatment, the heating rate is controlled at 10-15℃ / min and held at 500-600℃ for 20-30min. During the second roasting treatment, based on the pre-roasting treatment, the heating rate is controlled at 10-15℃ / min and held at 1050-1100℃ for 1-1.5h.

4. The multi-component integrated recycling method according to claim 1, characterized in that, After reduction sulfidation roasting, the gas is cooled by passing flowing nitrogen gas at a flow rate of 1.5-2 sL / min.

5. The multi-component integrated recycling method according to any one of claims 1-4, characterized in that, Before freezing crystallization, pure sulfuric acid is added to the ferrous solution until the concentration of sulfuric acid in the ferrous solution is 200-300 g / L; freezing crystallization is carried out at -20~-15℃ for 20-30 min.

6. The multi-component integrated recycling method according to any one of claims 1-4, characterized in that, During acid-oxygen pressure leaching, the acid added is sulfuric acid with a concentration of 1-1.5 mol / L, and the mass ratio of the nickel sulfide slag to the volume of sulfuric acid is 1 g: 5-6 mL. During acid-oxygen pressure leaching, the oxygen pressure is 1.4-1.5 MPa, the reaction temperature is 180-190℃, and the reaction time is 2-3 h. Cooling crystallization involves cooling the reaction system to 33-35℃ and holding it at that temperature for 8-9 h.

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