Device and method for preparing cobaltosic oxide by using cobalt carbonate

Abstract

The invention discloses a device and method for preparing cobaltosic oxide from cobalt carbonate, and relates to the technical field of new energy, the device comprises a preheater, a suspension roaster, a cyclone separator, a fluidization reactor and a suspension cooler; a discharging port of the preheater is communicated with a feeding port of the suspension roaster, a material gas outlet of the suspension roaster is communicated with a material gas inlet of the cyclone separator, a gas outlet of the cyclone separator is communicated with a second gas inlet of the preheater, and a discharging port of the cyclone separator is communicated with a feeding port of the fluidization reactor. A material gas outlet in the middle of the fluidization reactor is communicated with a material gas inlet of the suspension cooler, a gas outlet in the top of the fluidization reactor is communicated with a gas inlet of the suspension roaster, and a gas inlet in the bottom of the fluidization reactor is communicated with a gas outlet of the suspension cooler. The cobaltosic oxide is prepared by combining the suspension roaster and the fluidized bed reactor, so that the production time is shortened, the production energy consumption is reduced, the production efficiency is improved, the product quality is improved, and the heat energy utilization rate is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and particularly to an apparatus and method for preparing cobalt tetroxide using cobalt carbonate. Background Art

[0002] Cobalt tetroxide (Co3O4) is of great strategic significance in promoting the upgrading of the new energy industry, resource sustainability and environmental protection benefits, enhancing the competitiveness of high-end industrial chains, and technological innovation and industrial collaboration. It is widely used in fields such as lithium-ion batteries, electrolytes and anode catalysts of fuel cells, energy storage technologies such as supercapacitors and energy storage batteries. In addition, it can also be used in industrial catalysis and functional materials, the blue or green tones of glass and ceramics, semiconductor manufacturing, temperature and gas sensors.

[0003] At present, there are various roasting apparatuses and methods in related fields that can be used to prepare cobalt tetroxide. For example, the invention patent with the patent name "A Cobalt Carbonate, Cobalt Tetroxide and Preparation Method, Cathode Material and Lithium Battery" and the application number "202211347174.6" mentions sintering cobalt carbonate to obtain cobalt tetroxide. The sintering temperature is 700 - 850 °C. When using a rotary kiln for sintering, the induced air velocity in the rotary kiln furnace tube is 0.5 - 5 m / s. Its disadvantages are: large investment, high energy consumption, large floor area, and difficult control of calcination temperature, etc. Another example is the invention patent with the patent name "A Dolomite Air Flotation Roaster Apparatus and Dolomite Air Flotation Roasting Method" and the application number "202410421091.X". The disclosed air flotation roaster apparatus can also be used to prepare cobalt tetroxide. This patent mentions that the calcined white material discharged from the high-temperature separator enters the retention tank. The calcined white is blown up by the fluidizing air blown in by the fluidizing air blower in the retention tank and is in a fluidized state, and further decomposes in the retention tank. The completely decomposed calcined white is discharged from the retention tank and enters the primary cyclone cooler. Its disadvantages are: the fluidizing air uses ambient air. After the material in the retention tank exchanges heat with the ambient air, the material temperature decreases, affecting the quality of the calcined white, and the waste heat of the high-temperature calcined white is not fully utilized, resulting in energy loss.

[0004] Therefore, there is an urgent need for a new solution to reduce energy consumption, improve productivity, and improve product quality. Summary of the Invention

[0005] The object of the present invention is to provide an apparatus and method for preparing cobalt tetroxide using cobalt carbonate to solve the problems existing in the above-mentioned prior art. The cobalt tetroxide is prepared by combining a suspension roaster and a fluidized bed reactor, shortening the production time, improving the thermal energy utilization rate, reducing the production energy consumption, improving the production efficiency, and at the same time improving the product quality.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] An apparatus for preparing cobalt tetroxide from cobalt carbonate includes a preheater, a suspension roasting furnace, a cyclone separator, a fluidized bed reactor and a suspension cooler; the preheater is provided with a feed inlet for cobalt carbonate to enter, a first air inlet for preheated gas to enter and an air outlet for communicating with an induced draft fan, the discharge outlet of the preheater is communicated with the feed inlet of the suspension roasting furnace, the material-gas outlet of the suspension roasting furnace is communicated with the material-gas inlet of the cyclone separator, the air outlet of the cyclone separator is communicated with the second air inlet of the preheater, the discharge outlet of the cyclone separator is communicated with the feed inlet of the fluidized bed reactor, the material-gas outlet in the middle of the fluidized bed reactor is communicated with the material-gas inlet of the suspension cooler, the air outlet at the top of the fluidized bed reactor is communicated with the air inlet of the suspension roasting furnace, the air inlet at the bottom of the fluidized bed reactor is communicated with the air outlet of the suspension cooler, the air inlet of the suspension cooler is communicated with the atmosphere, and cobalt tetroxide is produced at the discharge outlets of the fluidized bed reactor and the suspension cooler.

[0008] In an exemplary embodiment, the preheater includes a dryer and a suspension preheater, the dryer is provided with a feed inlet for cobalt carbonate to enter and an air inlet for preheated gas to enter, the material-gas outlet of the dryer is communicated with the material-gas inlet of the suspension preheater, the discharge outlet of the suspension preheater is communicated with the feed inlet of the suspension roasting furnace, the air outlet of the suspension preheater is communicated with the air inlet of the dryer, and the air outlet of the cyclone separator is communicated with the air inlet of the suspension preheater.

[0009] In an exemplary embodiment, the suspension preheater includes N-stage suspension preheaters connected in sequence, 1≤N≤4, and N is an integer.

[0010] In an exemplary embodiment, the suspension cooler includes N-stage suspension coolers connected in sequence, 2≤N≤4, and N is an integer.

[0011] In an exemplary embodiment, the air outlet of the suspension cooler is further communicated with the air inlet of the suspension roasting furnace, and a regulating valve is provided between the air outlet of the suspension cooler and the air inlet of the fluidized bed reactor, or between the air outlet of the suspension cooler and the air inlet of the suspension roasting furnace.

[0012] The present invention also provides a method for preparing high-purity cobalt tetroxide from cobalt carbonate, using the above apparatus for preparing cobalt tetroxide from cobalt carbonate, including the following steps:

[0013] Step 1: Start the induced draft fan communicated with the air outlet of the preheater, air enters the suspension roasting furnace through the suspension cooler and the fluidized bed reactor, and at the same time, fuel is introduced into the suspension roasting furnace to burn with the hot gas from the air outlet of the fluidized bed reactor, and the generated high-temperature gas enters the suspension roasting furnace.

[0014] Step 2: Ignite the fuel at the inlet of the dryer to generate preheated gas and introduce it into the dryer. Quantitatively feed cobalt carbonate into the dryer. The cobalt carbonate evaporates the attached water in the dryer and enters the suspension preheater.

[0015] Step 3: Part of the carbon dioxide is removed from the cobalt carbonate in the suspension preheater, and the material after removing part of the carbon dioxide enters the suspension calciner; the waste gas at the outlet of the suspension preheater enters the dryer to participate in the drying of cobalt carbonate, and then flows out from the outlet of the dryer for treatment and discharge.

[0016] Step 4: All the carbon dioxide is removed from the material after removing part of the carbon dioxide in the suspension calciner to generate cobalt oxide, and the cobalt oxide enters the cyclone separator with the gas.

[0017] Step 5: The cobalt oxide that enters the cyclone separator with the gas is subjected to gas-solid separation in the cyclone separator to obtain cobalt oxide and gas. The gas is introduced into the suspension preheater to heat the cobalt carbonate, and the cobalt oxide enters the fluidized bed reactor.

[0018] Step 6: The cobalt oxide in the fluidized bed reactor reacts with the oxygen in the hot air from the suspension cooler to generate cobalt tetroxide. Part of the cobalt tetroxide enters the suspension cooler with the gas for cooling, and the other part of the cobalt tetroxide is discharged from the discharge port of the fluidized bed reactor.

[0019] Step 7: The cobalt tetroxide that enters the suspension cooler exchanges heat with air for cooling. The hot air after heat exchange enters the fluidized bed reactor to fluidize the cobalt oxide, and the cooled cobalt tetroxide is discharged from the discharge port of the suspension cooler.

[0020] In an exemplary embodiment, the fuel in Step 1 and Step 2 is gaseous fuel or liquid fuel. The parameters of the cobalt carbonate fed into the dryer in Step 2 are: CoCO3 ≥ 99.5 wt%, dry-based attached water: 15 wt% - 20 wt%, fineness 2 - 20 μm.

[0021] In Step 3, the mass of the removed carbon dioxide accounts for 50% - 80% of the mass of the carbon dioxide in the cobalt carbonate.

[0022] In Step 4, the residence time of the material in the suspension calciner is 2 - 40 s; the temperature of the high-temperature gas at the inlet of the suspension calciner is 770 - 790 °C, and the volume of oxygen content is 17% - 18%.

[0023] In Step 6, the reaction formula of cobalt oxide and oxygen is:

[0024] 3CoO + 0.5O2 → Co3O4 - 816.4 kJ / kg·Co3O4

[0025] The reaction time is 90 - 120 mins.

[0026] In step 7, the temperature of the material entering the suspension cooler is 770 - 790 °C, the temperature of the discharged material is ≤65 °C, the Co3O4 content of the product by mass percentage is ≥99.5 wt%, and the ignition loss is ≤0.2 wt%.

[0027] The present invention also provides a method for preparing cobalt tetroxide from cobalt carbonate. Using the device for preparing cobalt tetroxide from cobalt carbonate as described above, it includes the following steps:

[0028] Step 1: Start the induced draft fan connected to the air outlet of the preheater, open the regulating valve. Part of the air enters the suspension roasting furnace through the suspension cooler, and another part of the air enters the suspension roasting furnace through the suspension cooler and the fluidized bed reactor. At the same time, fuel is introduced into the suspension roasting furnace and burns with the hot gas from the air outlets of the suspension cooler and the fluidized bed reactor, and the generated high-temperature gas enters the suspension roasting furnace.

[0029] Step 2: Ignite the fuel at the air inlet of the dryer, generate preheated gas and introduce it into the dryer. Quantitatively feed cobalt carbonate into the dryer. The cobalt carbonate evaporates the attached water in the dryer and enters the suspension preheater.

[0030] Step 3: The cobalt carbonate removes part of the carbon dioxide in the suspension preheater, and the material after removing part of the carbon dioxide enters the suspension roasting furnace. The waste gas at the air outlet of the suspension preheater enters the dryer to participate in the drying of cobalt carbonate, and then flows out from the air outlet of the dryer for treatment and discharge.

[0031] Step 4: The material after removing part of the carbon dioxide removes all the carbon dioxide in the suspension roasting furnace to generate cobalt oxide, and the cobalt oxide enters the cyclone separator with the gas.

[0032] Step 5: The cobalt oxide entering the cyclone separator with the gas undergoes gas-solid separation in the cyclone separator to obtain cobalt oxide and gas. The gas is introduced into the suspension preheater to heat the cobalt carbonate, and the cobalt oxide enters the fluidized bed reactor.

[0033] Step 6: The cobalt oxide reacts with the oxygen in the air from the suspension cooler in the fluidized bed reactor to generate cobalt tetroxide. Part of the cobalt tetroxide enters the suspension cooler with the gas for cooling, and another part of the cobalt tetroxide is discharged from the discharge port of the fluidized bed reactor.

[0034] Step 7: The cobalt tetroxide entering the suspension cooler exchanges heat with the air for cooling. The heated air after heat exchange is discharged from the air outlet of the suspension cooler. Part of the heated air is mixed with the fuel and enters the suspension roasting furnace from the air inlet of the suspension roasting furnace, and another part of the heated air enters the fluidized bed reactor to fluidize the cobalt oxide. The cooled cobalt tetroxide is discharged from the discharge port of the suspension cooler.

[0035] In an exemplary embodiment, control the opening degree of the regulating valve so that the air ratio entering the air inlet of the suspension roaster and the air inlet of the fluidized bed reactor is 30% - 70%: 70% - 30%.

[0036] In an exemplary embodiment, the fuel in the step 1 and step 2 is gaseous fuel or liquid fuel, and the parameters of the cobalt carbonate raw material fed in step 2 are: CoCO3: ≥99.5wt%, dry basis attached water: 15wt% - 20wt%, fineness 2 - 20μm;

[0037] In the step 3, the mass of the removed carbon dioxide accounts for 40% - 70% of the mass of carbon dioxide in the cobalt carbonate;

[0038] In the step 4, the residence time of the material in the suspension roaster is 2 - 40s, the temperature of the high-temperature gas at the air inlet of the suspension roaster is 590 - 620°C, and the oxygen content is 18% - 19% by volume ratio;

[0039] In the step 6, the reaction formula of cobalt oxide and oxygen is:

[0040] 3CoO + 0.5O2 → Co3O4 - 816.4kJ / kg·Co3O4

[0041] The reaction temperature is 700 - 750°C, and the reaction time is 45 - 60 mins;

[0042] In the step 7, the temperature of the material entering the suspension cooler is 700 - 750°C, the discharged material temperature ≤60°C, and the product has a Co3O4 content ≥75wt% by mass percentage and a loss on ignition ≤0.2wt%.

[0043] The present invention has achieved the following technical effects compared with the prior art:

[0044] 1. By adopting a preheater, a suspension roaster, a cyclone separator, a fluidized bed reactor and a suspension cooler, and connecting the gas outlet of the cyclone separator to the second air inlet of the preheater to recover the heat of the gas at the gas outlet of the cyclone separator; connecting the gas outlet at the top of the fluidized bed reactor to the air inlet of the suspension roaster, and connecting the material-gas outlet in the middle of the fluidized bed reactor to the material-gas inlet of the suspension cooler to recover the heat of the material and gas flowing out of the fluidized bed reactor; connecting the air inlet at the bottom of the fluidized bed reactor to the gas outlet of the suspension cooler to recover the heat of the gas at the gas outlet of the suspension cooler, thereby improving the thermal energy utilization rate.

[0045] 2. Most of the carbon dioxide is removed from the cobalt carbonate in the preheater, which requires less thermal energy compared to removing carbon dioxide in a rotary kiln.

[0046] 3. Generally, compared with a rotary kiln, more than 35% of thermal energy can be saved per ton of product.

[0047] 4. In the fluidized bed reactor, since the heat-exchanging fluidizing air is in direct contact with the calcined product - cobalt oxide particles, the rate of formation of high-purity cobalt tetroxide can be accelerated, the reaction time can be shortened, and the product quality can be improved.

[0048] 5. The capital investment is reduced, the production cost is lowered, and the economic efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0050] Figure 1 It is a schematic structural diagram of a device for preparing cobalt tetroxide from cobalt carbonate disclosed in a specific embodiment of the present invention;

[0051] Figure 2 It is a schematic structural diagram of a device for preparing cobalt tetroxide from cobalt carbonate disclosed in another specific embodiment of the present invention;

[0052] Among them, 1. Preheater; 2. Suspension calcination furnace; 3. Cyclone separator; 4. Fluidized bed reactor; 5. Suspension cooler; 6. High-temperature blower; 7. High-temperature valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0054] The purpose of the present invention is to provide a device and method for preparing cobalt tetroxide from cobalt carbonate to solve the problems existing in the prior art. The suspension calcination furnace and the fluidized bed reactor are combined to prepare cobalt tetroxide, shortening the production time, improving the thermal energy utilization rate, reducing the production energy consumption, improving the production efficiency, and at the same time improving the product quality.

[0055] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0056] Embodiment 1

[0057] Please refer to Figure 1 , this embodiment provides a device for preparing cobalt tetroxide using cobalt carbonate, which includes a preheater 1, a suspension roasting furnace 2, a cyclone separator 3, a fluidized bed reactor 4, and a suspension cooler 5; the preheater 1 is provided with a feed inlet for cobalt carbonate A to enter, a first air inlet for the preheated gas generated after the fuel D2 is ignited to enter, and an air outlet for communicating with a induced draft fan to discharge the waste gas C, and a conventional flue gas purification system is connected at the air outlet for purifying the waste gas C. The discharge outlet of the preheater 1 is communicated with the feed inlet of the suspension roasting furnace 2, the material-gas outlet of the suspension roasting furnace 2 is communicated with the material-gas inlet of the cyclone separator 3, the air outlet of the cyclone separator 3 is communicated with the second air inlet of the preheater 1, the discharge outlet of the cyclone separator 3 is communicated with the feed inlet of the fluidized bed reactor 4, the material-gas outlet in the middle of the fluidized bed reactor 4 is communicated with the material-gas inlet of the suspension cooler 5, the air outlet at the top of the fluidized bed reactor 4 is communicated with the air inlet of the suspension roasting furnace 2, the air inlet at the bottom of the fluidized bed reactor 4 is communicated with the air outlet of the suspension cooler 5, a high-temperature blower 6 is arranged at the air inlet at the bottom of the fluidized bed reactor 4, the air inlet of the suspension cooler 5 is communicated with the atmosphere E, and the discharge outlets of the fluidized bed reactor 4 and the suspension cooler 5 produce cobalt tetroxide B1 and B2.

[0058] The preheater 1 in this embodiment includes a dryer and a suspension preheater. The dryer is provided with a feed inlet for cobalt carbonate to enter and an air inlet for the preheated gas to enter. The air inlet of the dryer serves as the first air inlet of the preheater 1. The material-gas outlet of the dryer is communicated with the material-gas inlet of the suspension preheater. The discharge outlet of the suspension preheater is communicated with the feed inlet of the suspension roasting furnace 2. The air outlet of the suspension preheater is communicated with the air inlet of the dryer. The air outlet of the cyclone separator 3 is communicated with the air inlet of the suspension preheater. The air inlet of the suspension preheater serves as the second air inlet of the preheater 1.

[0059] The suspension preheater in this embodiment includes N-stage suspension preheaters connected in sequence, where 1 ≤ N ≤ 4 and N is an integer. Preferably, 2 stages are selected, namely a primary suspension preheater and a secondary suspension preheater.

[0060] The dryer in this embodiment is a Venturi dryer, a drying and dispersing machine, or a flash dryer. Preferably, a flash dryer is selected.

[0061] The suspension cooler 5 in this embodiment includes N-stage suspension coolers 5 connected in sequence, where 2 ≤ N ≤ 4 and N is an integer. Preferably, 3 stages are selected, namely a primary suspension cooler 5, a secondary suspension cooler 5, and a tertiary suspension cooler 5.

[0062] The fluidized bed reactor 4 in this embodiment is horizontal or vertical. Preferably, a vertical fluidized bed reactor 4 is selected. The fluidized bed in the fluidized bed reactor 4 has 1 to 3 layers, preferably 2 layers.

[0063] Please refer to Figure 2 , in this embodiment, the air outlet of the suspension cooler 5 is also communicated with the air inlet of the suspension roasting furnace 2. A regulating valve 7 is provided between the air outlet of the suspension cooler 5 and the air inlet of the fluidized bed reactor 4, or between the air outlet of the suspension cooler 5 and the air inlet of the suspension roasting furnace 2.

[0064] Embodiment 2

[0065] This embodiment provides a method for preparing high-purity cobalt tetroxide from cobalt carbonate. The device for preparing cobalt tetroxide from cobalt carbonate in Embodiment 1 is adopted. The oxygen demand for preparing high-purity cobalt tetroxide is high. In this embodiment, the scheme that the air outlet of the suspension cooler 5 is not communicated with the air inlet of the suspension roasting furnace 2 is adopted, that is, no branch is provided between the air outlet of the suspension cooler 5 and the air inlet of the suspension roasting furnace 2, or a branch is provided, but a regulating valve 7 is provided on this branch, and the regulating valve 7 is closed, so that all the air in the system enters the fluidized bed reactor 4 to ensure sufficient contact between oxygen and cobalt oxide in the fluidized bed reactor 4, and then high-purity cobalt tetroxide is produced by reaction. The air entering the fluidized bed reactor 4 all flows into the air inlet of the suspension roasting furnace 2, and the oxygen in the air can ensure the complete combustion of the fuel D1.

[0066] Specifically, it includes the following steps:

[0067] Step 1: Start the induced draft fan, flue gas purification system and high-temperature blower 6. Air enters the suspension roasting furnace 2 through the suspension cooler 5 and the fluidized bed reactor 4. At the same time, fuel D1 is introduced into the suspension roasting furnace 2 and burns with the hot gas from the air outlet of the fluidized bed reactor 4, and the generated high-temperature gas enters the suspension roasting furnace 2;

[0068] Step 2: Ignite the fuel D2 at the air inlet of the dryer, generate preheated gas and introduce it into the dryer. The cobalt carbonate A is quantitatively fed into the dryer. The preheated gas is mixed with the cobalt carbonate to disperse and dry the cobalt carbonate, and the attached water is evaporated. The material temperature at this time is 120-130 °C. The dried cobalt carbonate enters the material-gas inlet of the suspension preheater together with the preheated gas from the material-gas outlet of the dryer, and then enters the suspension preheater;

[0069] In this embodiment, the fuel in Step 1 and Step 2 is gaseous fuel or liquid fuel. The parameters of the cobalt carbonate fed into the dryer in Step 2 are: CoCO3: ≥99.5 wt%, dry-based attached water: 15 wt% - 20 wt%, fineness 2 - 20 μm;

[0070] Step 3: Cobalt carbonate exchanges heat with the high-temperature gas from the cyclone separator 3 in the suspension preheater at a temperature of 480 - 520°C to remove part of the carbon dioxide. The mixed material after removing part of the carbon dioxide enters the feed port of the suspension roasting furnace 2 from the discharge port of the suspension preheater and then enters the suspension roasting furnace 2. The waste gas from the outlet of the suspension preheater enters the inlet of the dryer from the outlet of the suspension preheater and then enters the dryer to participate in the drying of cobalt carbonate. After the heat in the waste gas is reused, it is discharged from the outlet of the dryer and enters the flue gas purification system for purification and then discharged.

[0071] In this embodiment, the mass of the removed carbon dioxide in Step 3 accounts for 50% - 80% of the mass of carbon dioxide in cobalt carbonate.

[0072] Step 4: The high-temperature gas generated in Step 1 enters the suspension roasting furnace 2 through the inlet at the bottom of the suspension roasting furnace 2 to heat the material after removing part of the carbon dioxide that enters the suspension roasting furnace 2 from the material-gas inlet. The material is suspended under the action of the gas flow, removes all the carbon dioxide in the suspension roasting furnace 2 to generate cobalt oxide, and then enters the cyclone separator 3 with the high-temperature gas.

[0073] In this embodiment, the residence time of the material in the suspension roasting furnace 2 in Step 4 is 2 - 40 s; the temperature of the high-temperature gas at the inlet of the suspension roasting furnace 2 is 770 - 790°C, and the volume ratio of oxygen content is 17% - 18%, preferably 17.3%.

[0074] Step 5: The cobalt oxide entering the cyclone separator 3 with the high-temperature gas undergoes gas-solid separation in the cyclone separator 3 to obtain cobalt oxide and high-temperature gas. The high-temperature gas is introduced into the suspension preheater to heat cobalt carbonate, and the cobalt oxide enters the fluidized bed reactor 4.

[0075] Step 6: The hot air from the suspension cooler 5 is introduced from the lower part of the fluidized bed reactor 4 to fluidize the cobalt oxide entering from the feed port at the top of the fluidized bed reactor 4. The cobalt oxide reacts with the oxygen in the hot air in the fluidized bed reactor 4 to generate high-purity cobalt tetroxide. The reaction temperature is 770 - 790°C. Part of the cobalt tetroxide enters the suspension cooler 5 with the gas for cooling, and the other part of the cobalt tetroxide is discharged from the outlet of the fluidized bed reactor 4 with the hot air.

[0076] In this embodiment, in Step 6, the reaction formula of cobalt oxide and oxygen is:

[0077] 3CoO + 0.5O2 → Co3O4 - 816.4 kJ / kg·Co3O4

[0078] The reaction time is 90 - 120 mins.

[0079] Step 7: The cobalt tetroxide entering the suspension cooler 5 exchanges heat and cools with the air in the N-stage suspension cooler 5 in sequence. The hot air after heat exchange enters the fluidized bed reactor 4 to fluidize the cobalt oxide. The cooled cobalt tetroxide is discharged from the discharge port of the suspension cooler 5.

[0080] In this embodiment, in step 7, the temperature of the material entering the suspension cooler 5 is 770 - 790 °C, the temperature of the discharged material is ≤ 65 °C, the Co3O4 content of the product by mass percentage is ≥ 99.5 wt%, and the ignition loss is ≤ 0.2 wt%.

[0081] Embodiment III

[0082] The present invention also provides a method for preparing cobalt tetroxide using cobalt carbonate. By adopting the device for preparing cobalt tetroxide using cobalt carbonate in Embodiment I, the oxygen demand for preparing cobalt tetroxide of general purity is relatively low. In this embodiment, the air outlet of the suspension cooler 5 is connected to the air inlet of the suspension roasting furnace 2, that is, a branch is provided between the air outlet of the suspension cooler 5 and the air inlet of the suspension roasting furnace 2. A regulating valve 7 is provided between the air outlet of the suspension cooler 5 and the air inlet of the fluidized bed reactor 4, or between the air outlet of the suspension cooler 5 and the air inlet of the suspension roasting furnace 2, so that part of the air in the system enters the fluidized bed reactor 4 and part of the air enters the suspension roasting furnace 2. By controlling the opening degree of the regulating valve 7, the ratio of the air entering the fluidized bed reactor 4 and the suspension roasting furnace 2 is controlled, so as to adjust the amount of oxygen entering the fluidized bed reactor 4 according to the product purity requirement, and then participate in the process of the reaction between cobalt oxide and oxygen to produce cobalt tetroxide.

[0083] Specifically, it includes the following steps:

[0084] Step 1: Control the opening degree of the regulating valve 7 so that the air ratio entering the air inlet of the suspension roasting furnace 2 and the air inlet of the fluidized bed reactor 4 is 30% - 70%: 70% - 30%; Start the induced draft fan, flue gas purification system, and high-temperature blower 6. Part of the air enters the suspension roasting furnace 2 through the suspension cooler 5, and the other part of the air enters the suspension roasting furnace 2 through the suspension cooler 5 and the fluidized bed reactor 4. At the same time, fuel D1 is introduced into the suspension roasting furnace 2 to burn with the hot gas from the fluidized bed reactor 4 and the air outlet of the suspension cooler 5, and the generated high-temperature gas enters the suspension roasting furnace 2;

[0085] Step 2: Ignite the fuel D2 at the air inlet of the dryer to generate preheated gas and introduce it into the dryer. Quantitatively feed cobalt carbonate A into the dryer. The preheated gas is mixed with the cobalt carbonate to disperse and dry the cobalt carbonate, evaporating the attached water. At this time, the temperature of the material is 120 - 130 °C. The dried cobalt carbonate enters the material-gas inlet of the suspension preheater together with the preheated gas from the material-gas outlet of the dryer, and then enters the suspension preheater;

[0086] In this embodiment, the fuel in Step 1 and Step 2 is gaseous fuel or liquid fuel. The parameters of cobalt carbonate fed into the dryer in Step 2 are as follows: CoCO3 ≥ 99.5 wt%, moisture content on dry basis 15 wt% - 20 wt%, fineness 2 - 20 μm.

[0087] Step 3: Cobalt carbonate exchanges heat with the high-temperature gas from the cyclone separator 3 in the suspension preheater at a temperature of 400 - 450 °C, and part of the carbon dioxide is removed. The mixed material after removing part of the carbon dioxide enters the feed port of the suspension roasting furnace 2 from the discharge port of the suspension preheater, and then enters the suspension roasting furnace 2. The waste gas at the outlet of the suspension preheater enters the inlet of the dryer from the outlet of the suspension preheater and then enters the dryer, participates in the drying of cobalt carbonate, and is discharged from the outlet of the dryer after the heat in the waste gas is reused, and then enters the flue gas purification system for purification and discharge.

[0088] In this embodiment, the mass of carbon dioxide removed in Step 3 accounts for 40% - 70% of the mass of carbon dioxide in cobalt carbonate.

[0089] Step 4: The high-temperature gas generated in Step 1 enters the suspension roasting furnace 2 through the inlet at the bottom of the suspension roasting furnace 2, heats the material after removing part of the carbon dioxide entering the suspension roasting furnace 2 from the gas-feed inlet. The material is suspended under the action of the gas flow, and all the carbon dioxide is removed in the suspension roasting furnace 2 to generate cobalt oxide, and then enters the cyclone separator 3 along with the high-temperature gas.

[0090] In this embodiment, the residence time of the material in the suspension roasting furnace 2 in Step 4 is 2 - 40 s; the temperature of the high-temperature gas at the inlet of the suspension roasting furnace 2 is 590 - 620 °C, and the volume ratio of oxygen content is 18% - 19%, preferably 18.5%.

[0091] Step 5: The cobalt oxide entering the cyclone separator 3 along with the high-temperature gas is subjected to gas-solid separation in the cyclone separator 3 to obtain cobalt oxide and high-temperature gas. The high-temperature gas is introduced into the suspension preheater to heat cobalt carbonate, and the cobalt oxide enters the fluidized bed reactor 4.

[0092] Step 6: The hot air from the suspension cooler 5 is introduced from the lower part of the fluidized bed reactor 4, fluidizes the cobalt oxide entering from the feed port at the top of the fluidized bed reactor 4. The cobalt oxide reacts with the oxygen in the hot air in the fluidized bed reactor 4 to generate high-purity cobalt tetroxide. The reaction temperature is 700 - 750 °C. Part of the cobalt tetroxide enters the suspension cooler 5 along with the gas for cooling, and the other part of the cobalt tetroxide is discharged from the outlet of the fluidized bed reactor 4 along with the hot air.

[0093] In this embodiment, in Step 6, the reaction formula of cobalt oxide and oxygen is as follows:

[0094] 3CoO + 0.5O2 → Co3O4 - 816.4 kJ / kg·Co3O4

[0095] The reaction time is 45 - 60 mins;

[0096] Step 7: The cobalt tetroxide entering the suspension cooler 5 exchanges heat and cools with the air in the N - stage suspension cooler 5 in sequence. The hot air after heat exchange enters the fluidized bed reactor 4 to fluidize the cobalt oxide, and the cooled cobalt tetroxide is discharged from the discharge port of the suspension cooler 5.

[0097] In this embodiment, in step 7, the temperature of the material entering the suspension cooler 5 is 700 - 750 °C, the temperature of the discharged material is ≤ 60 °C, the Co3O4 content of the product by mass percentage is ≥ wt75%, and the loss on ignition is ≤ 0.2wt%.

[0098] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, and are only used for facilitating the description of the present invention, rather than implying or requiring that the device or element referred to must have a specific orientation or construction method. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the described objects, and should not be construed as a limitation to the importance or order, and the features defined by such terms may explicitly or implicitly include one or more of such features. Unless otherwise specified, "a plurality" in the description of the present invention means two or more.

[0099] For the terms "installed", "connected", "connected to", unless otherwise clearly defined, should be understood in a broad sense, including but not limited to fixed connection, detachable connection or integral molding connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and the communication inside two elements. Those skilled in the art can understand its meaning according to the specific technical solution. In the present invention, the fixed connection involved, unless otherwise stated, includes both detachable fixed connections (such as bolt and screw connections) and non - detachable fixed connections (such as riveting and welding), and can also include the overall structure realized by integral molding process (except for those that are obviously impossible to adopt integral molding).

[0100] In any technical solution disclosed by the present invention, the terms used to represent the positional relationship or shape, unless otherwise stated, cover the states or shapes that are approximate, similar or close to it.

[0101] Any component provided by the present invention can either be assembled from a plurality of individual components or be a single component manufactured by integral molding process.

[0102] It should be noted that the structures, proportions, sizes, etc. depicted in the accompanying drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have any substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0103] In the embodiments of this application, the same reference numeral is used to represent the same component or the same part.

[0104] Adaptability changes made according to actual needs are all within the protection scope of the present invention.

[0105] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference numeral in the claims should not be regarded as limiting the claimed right.

[0106] Specific examples are used in the present invention to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, there will be changes in the specific implementation manners and application scopes according to the idea of the present invention. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An apparatus for preparing cobalt tetroxide using cobalt carbonate, characterized in that: It includes a preheater (1), a suspension roasting furnace (2), a cyclone separator (3), a fluidized bed reactor (4) and a suspension cooler (5); the preheater (1) is provided with a feed inlet for cobalt carbonate to enter, a first air inlet for preheated gas to enter, and an air outlet for communicating with a draft fan. The discharge outlet of the preheater (1) is communicated with the feed inlet of the suspension roasting furnace (2). The material-gas outlet of the suspension roasting furnace (2) is communicated with the material-gas inlet of the cyclone separator (3). The air outlet of the cyclone separator (3) is communicated with the second air inlet of the preheater (1). The discharge outlet of the cyclone separator (3) is communicated with the feed inlet of the fluidized bed reactor (4). The material-gas outlet in the middle of the fluidized bed reactor (4) is communicated with the material-gas inlet of the suspension cooler (5). The air outlet at the top of the fluidized bed reactor (4) is communicated with the air inlet of the suspension roasting furnace (2). The air inlet at the bottom of the fluidized bed reactor (4) is communicated with the air outlet of the suspension cooler (5). The air inlet of the suspension cooler (5) is communicated with the atmosphere. Cobalt tetroxide is produced at the discharge outlets of the fluidized bed reactor (4) and the suspension cooler (5).

2. The device for preparing cobalt tetroxide using cobalt carbonate according to claim 1, characterized in that: The preheater (1) includes a dryer and a suspension preheater. The dryer is provided with a feed inlet for cobalt carbonate to enter and an air inlet for preheated gas to enter. The material-gas outlet of the dryer is communicated with the material-gas inlet of the suspension preheater. The discharge outlet of the suspension preheater is communicated with the feed inlet of the suspension roasting furnace (2). The air outlet of the suspension preheater is communicated with the air inlet of the dryer. The air outlet of the cyclone separator (3) is communicated with the air inlet of the suspension preheater.

3. The device for preparing cobalt tetroxide using cobalt carbonate according to claim 2, characterized in that: The suspension preheater includes N-stage suspension preheaters connected in sequence, where 1≤N≤4 and N is an integer.

4. The device for preparing cobalt tetroxide using cobalt carbonate according to claim 1, characterized in that: The suspension cooler (5) includes N-stage suspension coolers connected in sequence, where 2≤N≤4 and N is an integer.

5. The device for preparing cobalt tetroxide from cobalt carbonate according to any one of claims 2-4, characterized in that: The air outlet of the suspension cooler (5) is also communicated with the air inlet of the suspension roasting furnace (2). A regulating valve (7) is provided between the air outlet of the suspension cooler (5) and the air inlet of the fluidized bed reactor (4), or between the air outlet of the suspension cooler (5) and the air inlet of the suspension roasting furnace (2).

6. A method for preparing high-purity cobalt tetroxide using cobalt carbonate, characterized in that, Using the device for preparing cobalt tetroxide from cobalt carbonate according to any one of claims 2-4, it includes the following steps: Step 1: Start the draft fan communicated with the air outlet of the preheater (1). Air enters the suspension roasting furnace (2) through the suspension cooler (5) and the fluidized bed reactor (4). At the same time, fuel is introduced into the suspension roasting furnace (2) and burns with the hot gas from the air outlet of the fluidized bed reactor (4), and the generated high-temperature gas enters the suspension roasting furnace (2). Step 2: Ignite the fuel at the air inlet of the dryer to generate preheated gas and introduce it into the dryer. Quantitatively feed cobalt carbonate into the dryer. The cobalt carbonate evaporates the attached water in the dryer and enters the suspension preheater. Step 3: Part of the carbon dioxide is removed from cobalt carbonate in the suspension preheater, and the material after removing part of the carbon dioxide enters the suspension roaster (2); the waste gas from the outlet of the suspension preheater enters the dryer to participate in the drying of cobalt carbonate, and then flows out from the outlet of the dryer and is discharged after treatment; Step 4: All the carbon dioxide is removed from the material after removing part of the carbon dioxide in the suspension roaster (2) to generate cobalt oxide, and the cobalt oxide enters the cyclone separator (3) along with the gas; Step 5: The cobalt oxide entering the cyclone separator (3) is subjected to gas-solid separation in the cyclone separator (3) to obtain cobalt oxide and gas. The gas is introduced into the suspension preheater to heat cobalt carbonate, and the cobalt oxide enters the fluidized bed reactor (4); Step 6: The cobalt oxide reacts with oxygen in the hot air from the suspension cooler (5) in the fluidized bed reactor (4) to generate cobalt spinel. Part of the cobalt spinel enters the suspension cooler (5) along with the gas for cooling, and the other part of the cobalt spinel is discharged from the outlet of the fluidized bed reactor (4); Step 7: The cobalt spinel entering the suspension cooler (5) exchanges heat with air for cooling. The hot air after heat exchange enters the fluidized bed reactor (4) to fluidize the cobalt oxide, and the cooled cobalt spinel is discharged from the outlet of the suspension cooler (5).

7. The method for preparing high-purity cobalt spinel from cobalt carbonate according to claim 6, wherein: The fuel in Steps 1 and 2 is gaseous fuel or liquid fuel. The parameters of cobalt carbonate fed into the dryer in Step 2 are: CoCO3: ≥99.5 wt%, dry-based attached water: 15 wt% - 20 wt%, fineness 2 - 20 μm; In Step 3, the mass of the removed carbon dioxide accounts for 50% - 80% of the mass of carbon dioxide in cobalt carbonate; In Step 4, the residence time of the material in the suspension roaster (2) is 2 - 40 s; the temperature of the high-temperature gas at the inlet of the suspension roaster (2) is 770 - 790 °C, and the volume ratio of oxygen content is 17 - 18%; In Step 6, the reaction formula of cobalt oxide and oxygen is: 3CoO + 0.5O2 → Co3O4 - 816.4 kJ / kg·Co3O4 The reaction time is 90 - 120 mins; In Step 7, the temperature of the material entering the suspension cooler (5) is 770 - 790 °C, the discharged material temperature ≤ 65 °C, and the product has a Co3O4 content ≥ 99.5 wt% by mass percentage and a loss on ignition ≤ 0.2 wt%.

8. A method for preparing cobalt tetroxide using cobalt carbonate, characterized in that, Using the device for preparing cobalt spinel from cobalt carbonate according to claim 5, the following steps are included: Step 1: Start the induced draft fan connected to the outlet of the preheater (1), open the regulating valve (7). Part of the air enters the suspension roaster (2) through the suspension cooler (5), and the other part of the air enters the suspension roaster (2) through the suspension cooler (5) and the fluidized bed reactor (4). At the same time, the fuel is introduced into the suspension roaster (2) and burns with the hot gas from the outlets of the suspension cooler (5) and the fluidized bed reactor (4), and the generated high-temperature gas enters the suspension roaster (2); Step 2: Ignite the fuel at the inlet of the dryer to generate preheated gas and introduce it into the dryer. Quantitatively feed cobalt carbonate into the dryer. The cobalt carbonate evaporates the attached water in the dryer and enters the suspension preheater. Step 3: The cobalt carbonate removes part of the carbon dioxide in the suspension preheater. The material after removing part of the carbon dioxide enters the suspension roasting furnace (2). The waste gas at the outlet of the suspension preheater enters the dryer to participate in the drying of cobalt carbonate, and then flows out from the outlet of the dryer for treatment and discharge. Step 4: The material after removing part of the carbon dioxide removes all the carbon dioxide in the suspension roasting furnace (2) to generate cobalt oxide. The cobalt oxide enters the cyclone separator (3) with the gas. Step 5: The cobalt oxide that enters the cyclone separator (3) with the gas is subjected to gas-solid separation in the cyclone separator (3) to obtain cobalt oxide and gas. The gas is introduced into the suspension preheater to heat the cobalt carbonate, and the cobalt oxide enters the fluidized bed reactor (4). Step 6: The cobalt oxide reacts with the oxygen in the air from the suspension cooler (5) in the fluidized bed reactor (4) to generate cobalt tetroxide. Part of the cobalt tetroxide enters the suspension cooler (5) with the gas for cooling, and the other part of the cobalt tetroxide is discharged from the discharge port of the fluidized bed reactor (4). Step 7: The cobalt tetroxide that enters the suspension cooler (5) exchanges heat with the air for cooling. The hot air after heat exchange is discharged from the outlet of the suspension cooler (5). Part of the hot air is mixed with the fuel and enters the suspension roasting furnace (2) from the inlet of the suspension roasting furnace (2), and the other part of the hot air enters the fluidized bed reactor (4) to fluidize the cobalt oxide. The cooled cobalt tetroxide is discharged from the discharge port of the suspension cooler (5).

9. The method for preparing cobalt tetroxide using cobalt carbonate according to claim 8, characterized in that: In the above Step 1, control the opening degree of the regulating valve (7) so that the air ratio entering the inlet of the suspension roasting furnace (2) and the inlet of the fluidized bed reactor (4) is 30% - 70%: 70% - 30%.

10. The method for preparing cobalt tetroxide from cobalt carbonate according to claim 9, characterized in that: The fuel in Step 1 and Step 2 is gaseous fuel or liquid fuel. The parameters of the cobalt carbonate raw material fed in Step 2 are: CoCO3: ≥99.5wt%, dry-based attached water: 15wt% - 20wt%, fineness 2 - 20μm. In the above Step 3, the mass of the removed carbon dioxide accounts for 40% - 70% of the carbon dioxide mass in the cobalt carbonate. In the above Step 4, the residence time of the material in the suspension roasting furnace (2) is 2 - 40s, the temperature of the high-temperature gas at the inlet of the suspension roasting furnace (2) is 590 - 620°C, and the volume ratio of oxygen content is 18% - 19%. In the above Step 6, the reaction formula of cobalt oxide and oxygen is: 3CoO + 0.5O2 → Co3O4 - 816.4kJ / kg·Co3O4 The reaction temperature is 700 - 750°C, and the reaction time is 45 - 60 mins. In the above Step 7, the temperature of the material entering the suspension cooler (5) is 700 - 750°C, the discharged material temperature ≤60°C, and the product has a Co3O4 content ≥75wt% by mass percentage and a loss on ignition ≤0.2wt%.

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