Synthesis method of nickel carbonyl

Abstract

The invention relates to a nickel carbonyl synthesis method, which comprises: carrying out a carbonylation reaction on a nickel-containing raw material and a CO gas in a reactor, introducing a hydrogen sulfide-containing mixed gas as a catalyst, controlling the reaction temperature to be 165-195 DEG C, the pressure to be 3.5-6.5 MPa and the reaction time to be 6-10 h, carrying out real-time monitoring through a pressure sensor, and dynamically adjusting the pressure fluctuation to be + / -0.5 MPa, the temperature control precision is + / -2 DEG C. According to the method, the molar ratio of the raw materials is optimized, the reaction efficiency and the product quality are improved, the catalyst is introduced to accelerate the reaction process, and the proportion of nickel, sulfur and other elements is adjusted, so that higher nickel extraction rate and lower reaction time are realized.

Description

Technical Field

[0001] The invention belongs to the field of powder metallurgy, and in particular relates to a method for synthesizing nickel carbonyl. Background Art

[0002] As an important metal organic compound, nickel carbonyl is widely used in many fields such as chemical industry, electronics, and metallurgy. In the field of nickel carbonyl synthesis technology, the existing technology has some limitations.

[0003] Chinese patent CN100357188C relates to a method for synthesizing carbonyl nickel. The raw material used in the method is a sulfur-containing copper-nickel alloy, and its chemical composition (weight %) is: Ni 76.9-80%, Cu 10.23-18%, Fe 3-5%, Co 0.5~2%, S1.5~3.5%, wherein Cu∶S>4∶1; the method comprises the following specific steps: (1) preparing active carbonyl synthesis raw material: first heating the above alloy components to a molten state of 1600℃~1650℃, then condensing the melt by 0.3~0.5Mpa high pressure atomization, controlling the water temperature at 10~15℃, and the atomization speed at 4~5kg / min, the obtained alloy particles have a particle size range of 0.5~5mm, wherein the particles with a particle size of 0.5~2mm are ≥85%; the particles with a particle size of 2~5mm are ≤15%; (2) carbonyl nickel synthesis: placing the alloy particles prepared above in an autoclave with a volume of 10 liters, the carbonyl synthesis conditions are: the CO content in the autoclave is ≥92%; the CO gas circulation rate in the carbonyl synthesis system is 8~12 times / hour, the pressure is 5~12MPa; temperature: 100~150℃; synthesis time: 24~32 hours.

[0004] Cu-Ni alloys with a certain sulfur content can be used as raw materials for carbonyl synthesis after water atomization and granulation. However, this synthesis method has many problems. The carbonyl synthesis reaction rate is slow, generally requiring more than 30 hours. Such a long reaction time seriously affects production efficiency, increases production costs, and reduces the economic benefits of the enterprise. Looking at the carbonyl synthesis rate, it is generally less than 95%. Especially when Cu:S is less than 4:1, a large amount of sulfur will lead to an increase in Ni3S2 compounds in the alloy. Since Ni3S2 cannot react with CO, the nickel in the sulfide cannot be carbonylated, which directly leads to a decrease in the synthesis rate. The lower synthesis rate means that the utilization rate of raw materials is not high, a large amount of resources is wasted, and production costs are further increased.

[0005] Therefore, we urgently need to improve the existing synthesis method to increase the nickel extraction rate and reduce the reaction time, thereby improving production efficiency, reducing costs, and enhancing the competitiveness of carbonyl nickel synthesis technology in industrial production. Summary of the Invention

[0006] The object of the present invention is to provide a method for synthesizing nickel carbonyl with simple process, low cost and high carbonyl synthesis rate.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for synthesizing nickel carbonyl comprises the following steps: subjecting a nickel-containing raw material to a carbonylation reaction with CO gas in a reactor, introducing a mixed gas containing hydrogen sulfide as a catalyst, controlling the reaction temperature to 165-195° C., the pressure to 3.5-6.5 MPa, and the reaction time to 6-10 hours.

[0009] Preferably, the composition and percentage of the nickel-containing raw material are Ni: 45-65wt%, Co: 2-5wt%, Cu: 12-20wt%, Fe: 6-9wt%, S: 0.1-0.3wt%, and C: 0.05-0.2wt%; the particle size of the nickel-containing raw material is controlled at 20-60 mesh to increase the reaction surface area and improve the reaction efficiency; the molar ratio of Cu to Ni is 1:(2.5-4).

[0010] Preferably, the volume concentration of the catalyst hydrogen sulfide gas in the reaction gas is 0.005% to 0.7%, and a staged introduction process is adopted: the volume concentration is 0.4% in the initial stage of the reaction for 0 to 2 hours, the volume concentration is reduced to 0.2% in the middle stage of the reaction for 2 to 8 hours, and the volume concentration is 0.06% in the final stage of the reaction until the reaction is completed; and before the mixed gas containing trace amounts of hydrogen sulfide is introduced, the air in the reactor is removed to ensure the catalytic effect and not introduce too many impurities; and before the mixed gas containing trace amounts of hydrogen sulfide is introduced, the air in the reactor is removed to avoid the influence of oxygen on the reaction.

[0011] Preferably, after the reaction is completed, the generated nickel carbonyl is discharged through a slag discharge port, and the airtightness of the reactor system is maintained during the collection process.

[0012] Preferably, the circulation rate of CO gas is controlled at 6 to 10 times per hour during the reaction process; the nickel-containing raw material is loaded into a corrosion-resistant reactor, and the reactor is one of a fixed bed reactor, a tubular reactor or a reactor.

[0013] Preferably, the method further includes, during the reaction process, monitoring the pressure changes in real time by a pressure sensor installed in the reactor, feeding back to the control system, and the control system adjusting the pressure according to preset parameters; and monitoring the temperature changes by a temperature monitoring device, and when the temperature deviates from the set range, adjusting it by a heating or cooling device, and monitoring and dynamically adjusting the pressure fluctuation of ±0.5MPa in real time by the pressure sensor, with a temperature control accuracy of ±2°C.

[0014] Preferably, the collected nickel carbonyl is further purified and processed, which may include filtration, distillation and crystallization operations.

[0015] The nickel-containing raw materials are carbonylated with CO gas in a reactor, and a catalyst is introduced to accelerate the reaction process. By adjusting the ratio of nickel, sulfur and other elements, the sulfur content is reduced and the nickel component in the solid solution is increased. Low-temperature and high-pressure water atomization technology is used to evenly distribute sulfur in the alloy solid solution, thereby improving the activity of the Cu-Ni alloy. Orthogonal experiments have shown that when the S content in the raw materials is controlled at 0.1-0.3wt% and the Cu:Ni ratio is 1:(2.5-4), the nickel sulfide active site density is the highest, the reaction time can be shortened to 6-10 hours, and the nickel extraction rate can reach more than 98.5%, which is 3-5% higher than the traditional process; the reaction energy consumption is reduced by 20%, the hydrogen sulfide catalyst consumption is reduced by 30%, and the by-product copper sulfide can be directly recycled. The key parameters are controlled as follows:

[0016] (1) Control of reaction temperature

[0017] Low-temperature water atomization technology: Low-temperature water atomization technology is used to evenly distribute sulfur in the alloy solid solution, thereby improving the activity of the Cu-Ni alloy and achieving a higher synthesis reaction rate and a synthesis rate greater than 98.5% under lower pressure. Low-temperature water atomization technology is the preferred technical solution, but is not included in the claims.

[0018] Specific temperature range: The reaction temperature is strictly controlled between 165 and 195°C. This temperature range meets the thermodynamic and kinetic requirements of the nickel carbonyl synthesis reaction, provides suitable energy conditions for the reaction, promotes effective collisions between reactant molecules and promotes the reaction, and avoids damage to equipment caused by excessive temperatures, such as deformation of equipment materials and increased corrosion, thereby extending equipment service life and reducing maintenance costs.

[0019] (2) Control of reaction pressure

[0020] Medium Pressure Range: The reaction pressure is controlled between 3.5 and 6.5 MPa. This range, determined through extensive experimental and theoretical research, ensures sufficient reaction progress while avoiding the safety hazards associated with excessive pressure. Within this pressure range, the reactant molecules have an appropriate collision frequency and energy, which promotes the forward progress of the nickel carbonyl synthesis reaction and improves reaction conversion and selectivity.

[0021] Dynamic regulation: Pressure is adjusted in real time during the reaction process based on actual conditions. Pressure sensors installed in the reaction system monitor pressure changes and provide feedback to the control system, which then adjusts pressure based on pre-set algorithms and strategies to ensure optimal reaction conditions, effectively controlling the reaction rate and preventing instability caused by pressure fluctuations. For example, if a reaction rate is too fast, which could lead to localized overheating or reduced product quality, lowering the pressure can slow the reaction; if the reaction rate is too slow, increasing the pressure can accelerate the reaction.

[0022] (3) Use of catalyst

[0023] Hydrogen sulfide concentration: Hydrogen sulfide is selected as the catalyst, and its volume concentration in the reaction gas is controlled between 0.0005% and 0.7% (staged introduction: initial 0.4% → mid-stage 0.2% → final stage 0.06%). This concentration range has been optimized through repeated experiments. The appropriate amount of hydrogen sulfide can accelerate the nickel conversion process without affecting product quality.

[0024] The role of the catalyst: Hydrogen sulfide plays an important role in the reaction. It not only acts as a catalyst to destroy the oxide film on the nickel surface, but also forms a Cu-S active intermediate with copper, synergistically promoting the carbonylation reaction of nickel. In situ infrared spectroscopy has confirmed that this intermediate can reduce the activation energy of the reaction by 15kJ / mol.

[0025] (4) Control of CO gas circulation rate

[0026] Circulation rate range: The CO gas circulation rate is controlled between 6 and 10 times per hour. This range is determined by the study of reaction kinetics and mass transfer processes.

[0027] Principle of Action: An appropriate CO gas circulation rate ensures effective desorption of reaction products and avoids the formation of a "vapor-phase nickel carbonyl saturation zone." If the CO gas circulation rate is too slow, the reaction products cannot be desorbed in time, forming a "vapor-phase nickel carbonyl saturation zone" that hinders the reaction and reduces the reaction rate. If the rate is too fast, the reactant molecules spend too little time in the reaction zone, preventing them from fully reacting, affecting conversion and selectivity. Controlling the CO gas circulation rate within the appropriate range can accelerate the reaction process.

[0028] Beneficial effects of the present invention:

[0029] The invention has a simple process, low cost and high carbonyl synthesis rate. The invention improves the nickel extraction rate and shortens the reaction time by adjusting the ratio of elements such as nickel, copper and sulfur in the raw materials, the concentration of catalyst (hydrogen sulfide), the reaction temperature (165-195°C), the reaction pressure (3.5-6.5MPa), the raw material particle size (20-60 mesh) and the CO gas circulation rate (6-10 times / hour) and other reaction conditions, and uses a pressure sensor to monitor and dynamically adjust the pressure fluctuation of ±0.5MPa in real time and the temperature control accuracy is ±2°C. The different conditions include but are not limited to the raw material component ratio, catalyst concentration, reaction temperature, reaction pressure, raw material particle size and CO gas circulation rate.

[0030] Temperature control of the present invention: The reaction temperature is controlled between 165 and 195° C., which effectively promotes the carbonylation reaction and avoids side reactions or equipment damage caused by excessively high temperature.

[0031] Pressure control of the present invention: The reaction pressure is controlled between 3.5 and 6.5 MPa, which is sufficient to drive the reaction toward the product while taking into account equipment safety and cost-effectiveness.

[0032] Reaction time of the present invention: Depending on the specific composition and particle size of the raw materials, the reaction time is usually set at 6 to 10 hours, which is sufficient to complete the reaction and maintain production efficiency.

[0033] Product collection of the present invention: After the reaction is completed, the generated nickel carbonyl is discharged through the slag discharge port. During the collection process, the system is kept airtight to prevent leakage of harmful gases.

[0034] Post-processing of the present invention: The collected nickel carbonyl may need to be further purified and processed to meet specific application requirements. DETAILED DESCRIPTION

[0035] 1. Raw Materials Preparation

[0036] The nickel-containing raw material composition includes 45-65 wt% Ni, 2-5 wt% Co, 12-20 wt% Cu, 6-9 wt% Fe, 0.1-0.3 wt% S, and 0.05-0.2 wt% C. The total percentages are less than 100%, as they contain trace impurities and unavoidable carrier components. The raw material particle size is controlled between 20 and 60 mesh, and the molar ratio of Cu to Ni is 1:(2.5-4) to increase the reaction surface area and improve reaction efficiency.

[0037] 2. Mixed gas configuration and introduction

[0038] Gas composition: a mixture of carbon monoxide (CO) gas and hydrogen sulfide (H2S), with the volume concentration of hydrogen sulfide in the reaction gas being 0.0005% to 0.7%. A staged introduction process is adopted: 0.4% in the initial stage (0 to 2h), 0.2% in the middle stage (2 to 8h), and 0.06% in the final stage (8h to the end), to ensure the catalytic effect without introducing too many impurities.

[0039] Gas pre-treatment: Before introducing the mixed gas, the air in the reactor must be removed to prevent oxygen from affecting the reaction. The reactor is an internal circulation fluidized bed reactor or tubular reactor, with a double-layer tungsten carbide coating on the inner wall for corrosion resistance and a built-in spiral gas distributor to ensure uniform contact between the CO gas and the raw material particles.

[0040] 3. Temperature increase and reaction condition control

[0041] Temperature control: The reaction temperature is controlled between 165 and 195°C to effectively promote the carbonylation reaction and avoid side reactions or equipment damage caused by excessive temperature.

[0042] Pressure control: The reaction pressure is controlled between 3.5 and 6.5 MPa, which is sufficient to drive the reaction toward the product while taking into account equipment safety and cost-effectiveness.

[0043] Reaction time: Depending on the specific composition and particle size of the raw materials, the reaction time is usually set at 6 to 10 hours, which is sufficient to complete the reaction and maintain production efficiency.

[0044] Product collection: After the reaction is completed, the generated nickel carbonyl is discharged through the slag discharge port. During the collection process, the system should be kept airtight to prevent the leakage of harmful gases.

[0045] During the reaction process, the pressure changes are monitored in real time by the pressure sensor installed in the reactor and fed back to the control system. The control system adjusts the pressure according to the preset parameters; and the temperature changes are monitored by the temperature monitoring device. When the temperature deviates from the set range, adjustments are made through the heating or cooling device.

[0046] Post-processing: The collected nickel carbonyl may require further purification and treatment to meet specific application requirements, including filtration, distillation and crystallization operations.

[0047] Example 1

[0048] 30 grams of a raw material containing 65% Ni was charged into an internal circulation fluidized bed reactor. The raw material composition was 65% Ni, 2% Co, 18% Cu, 6% Fe, 0.15% S by weight, and 0.08% C by weight (the remainder being trace impurities and unavoidable carrier components, so the total percentage is less than 100%, the same applies below). The particle size was 25-40 mesh. Hydrogen sulfide-containing CO gas was introduced (staged concentration: 0.5% at the beginning of the 0-2 hour period, 0.2% during the middle of the 2-8 hour period, and 0.06% at the end of the 8-10 hour period). The CO cycle rate was 8 times / hour, the temperature was 170°C, and the pressure was 4.0 MPa. The reaction was carried out for 10 hours. The final nickel conversion rate was 99.24%.

[0049] Example 2

[0050] 30 grams of a 65% Ni-containing feedstock (Ni 65%, Co 2%, Cu 18%, Fe 6%, S 0.15wt%, C 0.08wt%), with a particle size of 45-60 mesh) was charged into a tubular reactor. Hydrogen sulfide-containing CO gas (0.5% initial concentration over 0-2 hours, 0.2% over 2-6 hours, and 0.06% over 6-8 hours) was introduced at a CO circulation rate of 9 times / hour, a temperature of 185°C, and a pressure of 5.5 MPa for 8 hours. The final nickel conversion rate was 99.55%.

[0051] Example 3

[0052] 30 grams of a 50% nickel-containing feedstock (50% Ni, 16% Cu, 8% Fe, 5% Co, 0.25% S, 0.15% C, 30-50 mesh particle size) was charged into a tubular reactor. Hydrogen sulfide-containing CO gas (0.5% initial concentration over 0-2 hours, 0.2% over 2-6 hours, and 0.05% over 6-8 hours) was introduced at a CO circulation rate of 9 times / hour, a temperature of 185°C, and a pressure of 5.5 MPa for 8 hours. The final nickel conversion rate was 99.65%.

[0053] Example 4

[0054] 30 grams of a raw material containing 55% nickel (Ni: 60% Ni, Cu: 16% Cu, Fe: 7% Fe, Co: 3% Co, S: 0.22% S, C: 0.10% C) with a particle size of 25-50 mesh was charged into an internal circulation fluidized bed reactor. Hydrogen sulfide-containing CO gas (0.5% initial concentration over 0-2 hours, 0.2% over 2-6 hours, and 0.06% over 6-8 hours) was introduced at a CO circulation rate of 9 times / hour, a temperature of 185°C, and a pressure of 5.0 MPa for 8.5 hours. The final nickel conversion rate was 99.32%.

[0055] Example 5

[0056] 30 grams of a raw material containing 55% nickel (Ni: 55%, Cu: 16%, Fe: 6%, Co: 5%, S: 0.18wt%, C: 0.13wt%), with a particle size of 35-55 mesh, was charged into a tubular reactor. Hydrogen sulfide-containing CO gas (0.5% initial concentration over 0-2 hours, 0.2% over 2-6 hours, and 0.06% over 6-8 hours) was introduced at a CO circulation rate of 8 times / hour, a temperature of 170°C, and a pressure of 6.2 MPa for 9.5 hours. The final nickel conversion rate was 99.25%.

[0057] Example 6

[0058] 30 grams of a raw material containing 45% nickel (Ni: 45%), 19% Cu, 9% Fe, 4% Co, 0.25% S, and 0.16% C, with a particle size of 40-60 mesh, was charged into a fixed-bed reactor. Hydrogen sulfide-containing CO gas (0.5% initial concentration over 0-2 hours, 0.2% over 2-6 hours, and 0.06% over 6-8 hours) was introduced at a CO circulation rate of 10 times / hour, a temperature of 195°C, and a pressure of 4.5 MPa for 8 hours. The final nickel conversion rate was 99.08%.

[0059] These examples show that using different ratios of raw materials and catalysts under different conditions can significantly improve the nickel extraction rate and shorten the reaction time.

[0060] Comparative Example 1

[0061] 30 grams of a raw material containing 65% nickel (Ni) was loaded into a corrosion-resistant tubular reactor. The raw material composition was 65% Ni, 2% Co, 10% Cu (below the optimized lower limit), 6% Fe, 0.15% S by weight, and 0.08% C by weight. The raw material had a particle size of 25-40 mesh. Hydrogen sulfide-containing CO gas was introduced (0.5% initially in the 0-2 hour period, 0.2% in the middle of the 2-6 hour period, and 0.06% in the final 6-8 hour period). The CO was circulated at a rate of 8 times / hour, the temperature was 170°C, and the pressure was 4.0 MPa. The reaction was allowed to proceed for 10 hours. The final nickel extraction yield was 95.2%.

[0062] Comparative Example 2

[0063] 30 grams of a 65% nickel-containing raw material (Ni 65%, Co 6% (exceeding the optimized upper limit), Cu 18%, Fe 6%, S 0.15wt%, C 0.08wt%), with a particle size of 25-40 mesh, was charged into a corrosion-resistant tubular reactor. Hydrogen sulfide-containing CO gas (0.5% initial concentration over 0-2 hours, 0.2% over 2-6 hours, and 0.06% over 6-8 hours) was introduced at a CO circulation rate of 8 times / hour, a temperature of 170°C, and a pressure of 4.0 MPa for 10 hours. The final nickel conversion rate was 92.8%, and excessive sulfur impurities (CoS > 3.5wt%) were detected in the product.

[0064] Comparative Example 3

[0065] 30 grams of raw materials containing 65% Ni are packed into an internal circulation fluidized-bed reactor. The raw material composition is Ni 65%, Co 2%, Cu 18%, Fe 6%, S 0.15wt%, C 0.08wt%, and the particle size of the raw material is 25-40 mesh. Feed hydrogen sulfide-containing CO gas (0.5% in the initial stage of 0-2h, 0.2% in the mid-term of 2-6h, and 0.06% in the final stage of 6-8h), CO circulation rate 4 times / hour (6 times / hour lower limit of the present invention), temperature 170 ℃, pressure 4.0MPa, reaction for 10 hours. Final nickel conversion is 85.1%, and unreacted NiO particles (XRD detection shows 12% content) remain in the reaction product.

[0066] Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is intended to include these modifications and variations.

Claims

1. A method for synthesizing nickel carbonyl, characterized in that: The following steps are involved: The nickel-containing raw material and CO gas are subjected to carbonylation reaction in a reactor, and a mixed gas containing hydrogen sulfide is introduced as a catalyst. The reaction temperature is controlled at 165-195°C, the pressure is 3.5-6.5 MPa, and the reaction time is 6-10 hours.

2. A method for synthesizing nickel carbonyl according to claim 1, characterized in that: The composition and percentage of the nickel-containing raw material are Ni: 45-65wt%, Co: 2-5wt%, Cu: 12-20wt%, Fe: 6-9wt%, S: 0.1-0.3wt%, C: 0.05-0.2wt%; The particle size of the nickel-containing raw material is controlled at 20-60 meshes, and the molar ratio of Cu to Ni is 1:2.5-4.

3. The method for synthesizing nickel carbonyl according to claim 1, wherein: The volume concentration of hydrogen sulfide gas in the catalyst in the reaction gas is 0.005% to 0.7%, and a staged introduction process is adopted: the volume concentration is 0.4% in the initial stage of the reaction for 0 to 2 hours, the volume concentration is reduced to 0.2% in the middle stage of the reaction for 2 to 8 hours, and the volume concentration is 0.06% in the final stage of the reaction until the reaction is completed; and before the mixed gas containing hydrogen sulfide is introduced, the air in the reactor is removed.

4. The method for synthesizing nickel carbonyl according to claim 1, wherein: After the reaction is completed, the generated nickel carbonyl is discharged through the slag discharge port, and the airtightness of the reactor system is maintained during the collection process.

5. The method for synthesizing nickel carbonyl according to claim 1, wherein: During the reaction process, the circulation speed of CO gas is controlled to be 6 to 10 times per hour; the nickel-containing raw material is loaded into a corrosion-resistant reactor which is one of a fixed bed reactor, a tubular reactor or an internal circulation fluidized bed reactor.

6. The method for synthesizing nickel carbonyl according to claim 1, wherein: The method also includes, during the reaction process, monitoring pressure changes in real time through a pressure sensor installed in the reactor, feeding back to a control system, and adjusting the pressure according to preset parameters; monitoring temperature changes through a temperature monitoring device, and adjusting the temperature through a heating or cooling device when the temperature deviates from a set range; and using a pressure sensor to monitor and dynamically adjust pressure fluctuations in real time to ±0.5 MPa, with a temperature control accuracy of ±2°C.

7. The method for synthesizing nickel carbonyl according to claim 1, wherein: The collected nickel carbonyl is further purified and processed, which includes filtration, distillation and crystallization operations.