Method for drying cobalt hydroxide based on copper-cobalt sulfide ore oxygen pressure leaching waste heat

Abstract

The invention discloses a method for drying cobalt hydroxide based on oxygen pressure leaching waste heat of copper-cobalt sulfide ore, which comprises the following steps: S1, carrying out oxygen pressure leaching on the copper-cobalt sulfide ore, and feeding the generated ore pulp into a primary flash evaporation system; s2, steam produced by the first-stage flash evaporation system is discharged into a cleaning system, and ore pulp is discharged into a second-stage flash evaporation system; s3, steam produced by the primary flash evaporation system is subjected to washing, gas-liquid-solid separation, purification and pH value adjustment, and clean steam is obtained; s4, secondary flash evaporation treatment is conducted on the ore pulp through a secondary flash evaporation system; s5, carrying out gas-liquid separation and washing on steam discharged by the second-stage flash evaporation system; s6, the cobalt precipitation pre-solution is subjected to preheating treatment and neutralization cobalt precipitation; and S7, drying the cobalt hydroxide wet material by using the obtained primary clean steam to obtain a cobalt hydroxide product. By means of the method, the problems that in the existing copper-cobalt ore treatment process, low-temperature waste heat cannot be conveyed, waste heat utilization is low, carbon emission is high, and exhausted gas pollutes the environment can be solved.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, and more specifically, to a method for drying cobalt hydroxide based on the residual heat from oxygen pressure leaching of copper-cobalt sulfide ore. Background Technology

[0002] Copper is an indispensable metal in modern industry, widely used in power, electronics, construction, and other sectors. Cobalt, on the other hand, is an important strategic metal, primarily used in batteries (such as lithium batteries), aerospace, and chemicals. With global economic development, especially the widespread adoption of new energy vehicles and electronic devices, the demand for both copper and cobalt continues to grow.

[0003] Global copper and cobalt resources are unevenly distributed, and many ores are of low grade. Traditional smelting technologies struggle to effectively process low-grade ores, leading to resource waste. Oxygen pressure leaching (OPL) technology can efficiently extract copper and cobalt from low-grade ores, improving resource utilization. Copper-cobalt sulfide ores are an important resource, containing copper, cobalt, and other metallic elements with high economic value. Traditional pyrometallurgical processes cause environmental pollution and resource waste, while hydrometallurgical processes are more environmentally friendly and efficient. Oxygen pressure leaching, as a highly efficient hydrometallurgical process, offers advantages such as high leaching rates, good sulfate balance, no significant excess sulfuric acid production, and easy treatment of the leaching solution.

[0004] The final products of copper-cobalt ore smelting are copper cathode copper and cobalt hydroxide intermediate product. Cobalt hydroxide is obtained by chemical precipitation. After liquid-solid separation, the product still contains more than 50% water, resulting in large transportation volumes and high transportation costs. If the water content of the cobalt hydroxide product can be dried to below 10%, transportation costs can be significantly reduced.

[0005] Because multi-stage flash evaporation is used in the oxygen pressure leaching process of copper-cobalt ore, steam suitable for drying is generated. The steam after flash evaporation needs to be washed and purified before entering a specific steam drying equipment for product drying.

[0006] Most existing copper-cobalt mines use atmospheric pressure leaching, and the resulting cobalt hydroxide product is mainly dried using flash drying technology, which uses diesel as a heat source. The hot gas from the combustion process dries the product, resulting in high costs, high carbon emissions, and significant exhaust pollution.

[0007] In addition, in the existing oxygen pressure leaching process for sulfide ores, most of the waste heat steam is discharged directly after washing, without any recovery of waste heat.

[0008] To address the aforementioned issues, there is an urgent need for a method for drying cobalt hydroxide using waste heat from oxygen pressure leaching of copper-cobalt sulfide ores, which enables waste heat recovery, avoids environmental pollution, and achieves steam purification. Summary of the Invention

[0009] In view of the above problems, the purpose of this invention is to provide a method for drying cobalt hydroxide based on the residual heat of oxygen pressure leaching of copper-cobalt sulfide ore, so as to solve the problems of environmental pollution and inability to recover residual heat in existing oxygen pressure leaching methods.

[0010] This invention provides a method for drying cobalt hydroxide using residual heat from oxygen pressure leaching of copper-cobalt sulfide ore, comprising: S1: The slurry produced by oxygen pressure leaching of copper-cobalt sulfide ore is fed into the primary flash evaporation system; S2: Discharge the waste steam produced by the primary flash evaporation system into the cleaning system, and discharge the slurry into the secondary flash evaporation system; S3: The waste steam produced by the primary flash evaporation system is washed, separated into gas, liquid and solid, purified and pH adjusted by the cleaning system to obtain clean steam. S4: The slurry discharged from the primary flash system is subjected to secondary flash evaporation treatment through the secondary flash evaporation system; S5: Perform gas-liquid separation and washing on the secondary steam generated by the secondary flash evaporation system; S6: The cobalt precipitation pre-liquid is preheated with secondary steam that has undergone gas-liquid separation and washing, and then an alkaline reagent is added to the preheated cobalt precipitation pre-liquid to neutralize and precipitate cobalt to obtain cobalt hydroxide; and the secondary steam after preheating the cobalt precipitation pre-liquid is purified and discharged into the air. S7: The filtered cobalt hydroxide is dried using the clean steam through a drying device to obtain the cobalt hydroxide product.

[0011] Alternatively, in S1 and S2, the primary flash evaporation system and the secondary flash evaporation system are used to depressurize and cool the slurry discharged from the oxygen pressure leaching process, while simultaneously generating waste steam with residual heat. Each flash system includes flash valves, a flash tank, and flash exhaust facilities, among which... The flash valve is used to regulate the pressure of the slurry, so that the slurry pressure is adjusted to the set flash pressure; The flash tank is used to receive the de-cooled and de-pressurized slurry and to perform gas-liquid-solid separation on the gas-liquid-solid mixture generated after being regulated by the flash valve. The flash steam exhaust system is used to collect, transport, and treat the flash steam generated by the flash tank.

[0012] Alternatively, in S2, the waste steam discharged from the primary flash evaporation system is transported to the cleaning system under its own pressure, wherein the waste steam contains solid particles and acidic droplets.

[0013] Alternatively, in step S3, the waste steam produced by the primary flash evaporation system is washed with a detergent, separated by a multiphase medium, and its pH is adjusted using an alkaline reagent; wherein, The solid particles and acidic droplets in the waste steam are purified and washed. The washing method includes either tower washing or bed washing, and the detergent includes pure water, process solution, and alkaline reagent. The solid content of the steam after washing is not higher than 30 ppm. The multiphase media separation includes any one of centrifugal separation and Venturi separation; The alkaline reagent includes any one of sodium hydroxide, calcium hydroxide, and magnesium oxide, and the pH adjustment range is 6.5-7.5.

[0014] Alternatively, in S3, the waste steam generated by the primary flash evaporation system is saturated steam, and during the production of saturated steam, the steam pressure is 200 kPa(A)-1100 kPa(A) and the temperature is 120℃~184℃.

[0015] Alternatively, in S4, the secondary steam generated by the secondary flash evaporation system is saturated steam, which contains solid particles and acidic droplets.

[0016] Alternatively, in S5, the gas-liquid separation of the secondary steam may include either centrifugal separation or Venturi separation.

[0017] Alternatively, in step S6, the secondary steam after preheating the cobalt precipitation liquid is purified and discharged. The remaining secondary steam after preheating the cobalt precipitation liquid is washed with a detergent. Washing methods include either tower washing or bed washing; Detergents include any one of pure water, process solutions, and alkaline reagents.

[0018] Alternatively, in step S7, the clean steam is introduced into the drying equipment to dry the wet cobalt hydroxide material after filtration, producing the cobalt hydroxide product, and condensate is discharged.

[0019] Alternatively, the moisture content of the wet cobalt hydroxide material after filtration is 50% to 65%.

[0020] Alternatively, the drying equipment can use steam as a heat source and include a drying chamber, a steam conveying assembly, a condensate discharge assembly, a material inlet / outlet assembly, and a dust collection assembly. The steam conveying assembly delivers steam to the drying chamber, whereby the wet cobalt hydroxide material is dried under the action of the steam. The condensate generated after drying is discharged from the drying equipment through the condensate discharge component. The material inlet / outlet assembly is used to convey the wet cobalt hydroxide material and the dried cobalt hydroxide. The dust collection component is used to collect the dust generated during the drying process.

[0021] As can be seen from the above technical solution, the method for drying cobalt hydroxide based on waste heat from oxygen pressure leaching of copper-cobalt sulfide ore provided by this invention involves sending the ore slurry discharged from oxygen pressure leaching to the waste heat steam generated after flash evaporation. This waste heat steam is then washed, purified, and transported to the cobalt hydroxide drying process. The cleaned steam is then input into a steam-drying type drying equipment to dry the cobalt hydroxide. This maximizes the recycling of waste heat generated in the oxygen pressure leaching process of copper-cobalt sulfide ore, thereby reducing costs. This invention achieves waste heat recovery and utilization; avoids the use of diesel fuel, reducing carbon emissions and preventing environmental pollution; and achieves clean steam production. Therefore, it solves the problems of environmental pollution and inability to recover waste heat existing in existing oxygen pressure leaching methods.

[0022] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0023] 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 only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a method for drying cobalt hydroxide based on oxygen pressure leaching of copper-cobalt sulfide ore using residual heat, according to an embodiment of the present invention. Detailed Implementation

[0025] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] This invention can be modified and has various embodiments, with specific embodiments illustrated in the accompanying drawings. However, this invention is not limited to this particular implementation and all modifications, equivalents, and substitutions falling within the spirit and technical scope of this invention are to be understood as included.

[0028] Ordinal terms such as "first," "second," etc., may be used to describe various constituent elements, but the constituent elements are not limited to these terms. The terms are used only to distinguish one constituent element from another. For example, without departing from the scope of the claims of this invention, a second constituent element may be named a first constituent element, and similarly, a first constituent element may be named a second constituent element. Terms and / or include combinations of multiple associated items or one of multiple associated items.

[0029] It should be understood that when referring to a constituent element being "connected" or "in contact" with other constituent elements, this includes not only cases where it is directly connected or in contact with other constituent elements, but also cases where other constituent elements exist between them. Conversely, when referring to a constituent element being "directly connected" or "directly in contact" with other constituent elements, it should be understood that no other constituent elements exist between them.

[0030] In response to the environmental pollution and waste heat recovery problems of the existing oxygen pressure leaching methods mentioned above, this invention proposes a method for drying cobalt hydroxide based on waste heat from oxygen pressure leaching of copper-cobalt sulfide ore.

[0031] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0032] To illustrate the method for drying cobalt hydroxide based on residual heat from oxygen pressure leaching of copper-cobalt sulfide ore provided by this invention... Figure 1 A process flow diagram for drying cobalt hydroxide based on residual heat from oxygen pressure leaching of copper-cobalt sulfide ore, according to an embodiment of the present invention, is shown.

[0033] like Figure 1As shown, the present invention provides a method for drying cobalt hydroxide based on the residual heat of oxygen pressure leaching of copper-cobalt sulfide ore, comprising: S1: The slurry produced by oxygen pressure leaching of copper-cobalt sulfide ore is fed into the primary flash evaporation system; S2: Discharge the waste steam produced by the primary flash evaporation system into the cleaning system, and discharge the slurry into the secondary flash evaporation system; S3: The waste steam produced by the primary flash evaporation system is washed, separated into gas, liquid and solid, purified and pH adjusted by the cleaning system to obtain clean steam. S4: The slurry discharged from the primary flash system is subjected to secondary flash evaporation treatment through the secondary flash evaporation system; S5: Perform gas-liquid separation and washing on the secondary steam generated by the secondary flash evaporation system; S6: The cobalt precipitation liquid is preheated with secondary steam that has undergone gas-liquid separation and washing, and then an alkaline reagent is added to the preheated cobalt precipitation liquid to obtain cobalt hydroxide; and the secondary steam after preheating the cobalt precipitation liquid is purified and discharged. S7: The filtered cobalt hydroxide is dried using the clean steam through a drying device to obtain the cobalt hydroxide product.

[0034] In this invention, the copper-cobalt sulfide ore is mainly a copper- and cobalt-containing sulfide ore, or it can be a mixture of sulfide and oxide ores. The processing adopts a pressurized oxygen leaching process, which can rely on the heat released by the oxidation of sulfur to achieve self-heating, resulting in a large surplus of heat during the production process.

[0035] In S1 and S2, the primary flash evaporation system and the secondary flash evaporation system are used to depressurize and cool the slurry discharged from oxygen pressure leaching, while simultaneously generating waste steam with residual heat. Each flash evaporation system includes a flash valve, a flash tank, and a flash exhaust system. The flash valve is used to regulate the pressure of the slurry to a set flash pressure. The flash tank receives the depressurized slurry and performs gas-liquid-solid separation on the gas-liquid-solid mixture generated after regulation by the flash valve. The flash exhaust system collects, transports, and treats the flash steam generated by the flash tank. Specifically, the flash evaporation system is a process system that utilizes a sudden pressure drop to rapidly vaporize and separate supersaturated liquids. It mainly includes three core components: a flash valve, a flash tank, and a flash exhaust system, as well as a feeding or discharging system, a temperature measurement system, and a heat preservation system.

[0036] The flash valve is a pressure regulating device in the flash evaporation system, belonging to the throttling valve category. Common types include needle valves, angle throttling valves, and eccentric rotary valves. The valve body is made of temperature and pressure resistant materials (such as stainless steel and alloy steel), and the valve core has a structure that allows for precise adjustment of the opening. The function of the flash valve is to receive high-pressure supersaturated feed liquid, and through throttling by the valve core, rapidly reduce the liquid pressure to the set flash pressure, while ensuring that the liquid forms a turbulent flow after throttling, creating conditions for subsequent rapid vaporization. The opening can be adjusted by the automatic control system to precisely control the degree of flash evaporation.

[0037] The flash tank is the core of the flash evaporation system's vaporization and separation mechanism. It is a vertical / horizontal pressure vessel, and its interior can include baffles, demisters, and distributors as needed. The flash tank's functions are: to provide sufficient space and residence time for the throttled gas-liquid mixture, achieving thorough separation of the gas and liquid phases; and to maintain stable flash pressure and liquid level within the tank, preventing liquid carryover in the gas phase or pressure buildup in the liquid phase. The demister (wire mesh / baffle type) captures liquid droplets in the gas phase, ensuring the purity of the exhaust vapor; the distributor evenly distributes the throttled liquid within the tank, improving vaporization efficiency.

[0038] The flash steam venting system is a complete set of facilities for collecting, transporting, treating, or utilizing the flash steam phase. It is not a single component, and mainly includes a venting pipe, a gas-liquid separator (for secondary demisting), a condenser / heat exchanger, and a steam storage tank (for recycling). Its functions are: to collect the gas phase (flash steam) separated from the flash tank, and according to process requirements, to recover waste heat (e.g., for heat exchange to heat other materials), to condense and recover (e.g., for solvent recovery), to directly transport and utilize (e.g., as a low-pressure steam heat source), or to treat the contaminated gas phase to meet emission standards.

[0039] In addition, the feeding or discharging system mainly includes a feed pipe, a liquid phase discharge pipe and a gas phase discharge pipe. The feed pipe is used to transport high-pressure supersaturated liquid to the flash valve; the liquid phase discharge pipe is used to transport the concentrated liquid phase in the flash tank to the subsequent process; and the gas phase discharge pipe is connected to the flash exhaust system.

[0040] The measurement and control system mainly includes pressure transmitters (monitoring the pressure before and after the flash valve and inside the flash tank), level transmitters (controlling the liquid level in the flash tank), temperature sensors, flow meters, automatic control valves, and PLC control cabinets, etc., to realize the automatic adjustment of the pressure, liquid level, and flash volume of the flash system and ensure stable operation.

[0041] The insulation system uses rock wool or polyurethane to provide insulation for the flash valve, flash tank, and pipelines.

[0042] In embodiments of the present invention, the flash evaporation system utilizes the relationship between the saturated vapor pressure and the pressure of a liquid. By throttling and reducing the pressure, the phase equilibrium of the liquid is broken, causing the supersaturated liquid to undergo instantaneous and large-scale self-evaporation (flash evaporation), and gas-liquid separation is completed within the flash evaporation tank. The basic principle is that the saturated vapor pressure of a liquid increases with increasing temperature and decreases with decreasing pressure. When a liquid is in a supersaturated state under high pressure (i.e., the liquid temperature is higher than its saturation temperature at the current pressure), if the pressure drops suddenly, the saturation temperature of the liquid will decrease rapidly. The original liquid temperature will then be much higher than the saturation temperature at the new pressure, causing the liquid to lose phase equilibrium and undergo self-vaporization. The faster the pressure reduction rate, the more intense the vaporization; this process is called flash evaporation.

[0043] In embodiments of the present invention, the throttling and pressure reduction accuracy of the flash valve determines the degree of flashing. Excessive or insufficient opening will lead to over-flashing (liquid phase entrainment of gas phase) or insufficient flashing. The pressure and liquid level stability of the flash tank are the basis for gas-liquid separation and need to be adjusted in conjunction with the opening of the flash valve and the flow rate of the discharge pump to avoid pressure fluctuations in the tank affecting the throttling effect of the flash valve. The gas phase conveying capacity of the flash exhaust system needs to match the flashing volume. During positive pressure flashing, the pressure in the tank is controlled by the exhaust regulating valve. During negative pressure flashing, the vacuum in the tank is maintained by the pumping capacity of the vacuum pump to avoid gas phase pressure buildup leading to an increase in the pressure of the flash tank and disrupting the flashing balance.

[0044] In S2, the waste steam discharged from the primary flash evaporation system is transported to the cleaning system under its own pressure. The waste steam includes solid particles and acidic droplets. In other words, the waste steam discharged from the primary flash evaporation system is transported to the cleaning system under its own pressure without the need for additional power. During the generation of the waste steam, a large amount of solid particles and acidic droplets are entrained, requiring further treatment. The slurry after primary flash evaporation is discharged to the secondary flash evaporation system for further treatment.

[0045] In S3, the waste steam produced by the primary flash evaporation system is washed with a detergent, separated by a multiphase medium, and pH adjusted with an alkaline reagent; the solid particles and acidic droplets in the waste steam are purified by washing; the washing method includes either tower washing or bed washing; the detergent includes pure water, process solution, or alkaline reagent; the solid content of the washed steam is not higher than 30 ppm; the multiphase medium separation includes either centrifugal separation or Venturi separation; the alkaline reagent includes either sodium hydroxide, calcium hydroxide, or magnesium oxide; and the pH adjustment range is 6.5-7.5.

[0046] In S3, the steam generated by the primary flash evaporation system is saturated steam. During the production of saturated steam, the steam pressure is 200 kPa(A)-1100 kPa(A) and the temperature is 120℃~184℃.

[0047] In step S4, the secondary steam generated by the secondary flash evaporation system is saturated steam, which contains solid particles and acidic droplets. Since the steam generated by the secondary flash evaporation system is saturated steam and carries a large number of solid particles and acidic droplets, further processing is required.

[0048] In S5, the gas-liquid separation of the secondary steam includes any one or more of centrifugal separation and Venturi separation.

[0049] In S6, the secondary steam after preheating the pre-cobalt precipitation liquid is purified and discharged; wherein, the secondary steam after preheating the pre-cobalt precipitation liquid is washed with a detergent; the washing method includes either tower washing or bed washing; the detergent includes either pure water, process solution, or alkaline reagent. It should be noted that the pre-cobalt precipitation liquid refers to the cobalt-containing liquid in the cobalt extraction process of hydrometallurgy, which is leached, purified and removed from impurities, and is to undergo cobalt precipitation reaction to obtain cobalt products such as cobalt hydroxide. The process is generally as follows: (1) Leaching: Copper-cobalt ore, purification slag and other raw materials are leached with sulfuric acid to allow cobalt and impurities to enter the solution. (2) Iron removal: An oxidant (such as H2O2) is added to remove Fe 2+ Oxidized to Fe 3+ Adjust the pH to generate Fe(OH)3 precipitate. (3) Removal of copper and cadmium: Remove Cu by displacement method (adding zinc powder) or sulfide precipitation method (adding Na2S). 2+ Cd 2+ (4) Manganese removal: Add oxidizing agents such as ammonium persulfate to remove manganese. 2+ Oxidized to MnO2 precipitate. (5) Filtration: After removing the precipitate, the purified cobalt pre-precipitation liquid is obtained.

[0050] In step S7, the clean steam is introduced into the drying equipment to dry the wet cobalt hydroxide material after it has passed through the filtration equipment, thereby producing the cobalt hydroxide product and discharging the condensate.

[0051] The moisture content of the wet cobalt hydroxide material after filtration is 50%~65%. The drying equipment uses steam as a heat source and includes a drying chamber, a steam conveying assembly, a condensate discharge assembly, a material inlet / outlet assembly, and a dust collection assembly. The steam conveying assembly delivers steam to the drying chamber, where the wet cobalt hydroxide material is dried under the action of the steam. The condensate discharge assembly discharges the condensate generated after drying from the drying equipment. The material inlet / outlet assembly is used to convey the wet cobalt hydroxide material and the dried cobalt hydroxide. The dust collection assembly is used to collect the dust generated during the drying process.

[0052] To illustrate the effects of this invention in detail, specific embodiments are as follows.

[0053] Example 1 A copper-cobalt mine's atmospheric pressure leaching project produces 180,000 tons of copper (metal content) and 80,000 tons of cobalt (metal content) annually. It uses magnesium oxide to produce cobalt hydroxide precipitate. The wet cobalt hydroxide material has a moisture content of about 61%. The cobalt hydroxide product needs to be dried with diesel fuel, consuming about 12 million liters of diesel fuel annually, equivalent to about RMB 192 million.

[0054] Example 2 A copper-cobalt ore oxygen pressure leaching project has an annual production capacity of 80,000 tons of copper (metal content) and 40,000 tons of cobalt (metal content). Magnesium oxide is used to produce cobalt hydroxide precipitate. The wet cobalt hydroxide material has a moisture content of approximately 61%. If an atmospheric pressure leaching process is used, the cobalt hydroxide product needs to be dried with diesel fuel, which is estimated to consume approximately 11 million liters of diesel fuel annually, equivalent to approximately RMB 96 million. By adopting an oxygen pressure leaching process, the steam generated by the flash evaporation system, after washing and purification, can produce 35-40 t / h of clean steam at a pressure of 0.4 MPa(A) and a temperature of 143.5℃, which can fully meet the drying requirements of the wet cobalt hydroxide material, avoiding the use of diesel fuel. The waste heat steam can also be fully utilized, and the generated condensate is returned to the system for product washing.

[0055] Example 3 A copper-cobalt ore oxygen pressure leaching project has an annual production capacity of 120,000 tons of copper (metal content) and 55,000 tons of cobalt (metal content). Sodium hydroxide is used to produce cobalt hydroxide precipitate, and the wet cobalt hydroxide material has a moisture content of approximately 55%. The oxygen pressure leaching process utilizes steam generated by a flash evaporation system. After washing and purification, it can produce 50-60 t / h of clean steam at a pressure of 0.5 MPa(A) and a temperature of 152℃, which fully meets the drying requirements of the wet cobalt hydroxide material. The waste heat steam can be fully utilized, and the generated condensate is returned to the system for product washing.

[0056] The above are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. A method for drying cobalt hydroxide based on the waste heat of pressure oxidation of cobalt-copper sulfide ores, characterized in that, The method comprises the following steps: S1: the slurry generated by the pressure oxidation leaching of copper cobalt sulfide ore is sent to a first flash system; S2: the waste steam generated by the first flash system is discharged into a cleaning system, and the slurry is discharged into a second flash system; S3: the waste steam generated by the first flash system is washed, gas-liquid-solid separated, purified and pH adjusted by the cleaning system to obtain clean steam; S4: the slurry discharged from the first flash system is subjected to secondary flash treatment by the second flash system; S5: the secondary steam generated by the second flash system is subjected to gas-liquid separation and washing; S6: the secondary steam subjected to gas-liquid separation and washing is used to preheat the cobalt precipitation liquid, and then a basic reagent is added to the preheated cobalt precipitation liquid to neutralize and precipitate cobalt to obtain cobalt hydroxide; and the secondary steam after the preheating of the cobalt precipitation liquid is purified and discharged; S7: the clean steam is used to dry the filtered cobalt hydroxide by a drying device to obtain cobalt hydroxide product.

2. The method according to claim 1, wherein in S1 and S2, the first flash system and the second flash system are used to reduce the temperature and pressure of the slurry discharged from the pressure oxidation leaching, and generate waste steam with waste heat; Each flash system comprises a flash valve, a flash tank and a flash exhaust facility, wherein the flash valve is used to adjust the pressure of the slurry to a set flash pressure; the flash tank is used to receive the slurry after temperature and pressure reduction, and to separate gas-liquid-solid mixture generated after the adjustment by the flash valve; and the flash exhaust facility is used to collect, transport and discharge the flash steam generated by the flash tank. In S2, the waste steam discharged from the first flash system is transported to the cleaning system by its own pressure, wherein the waste steam contains solid particles and acidic droplets.

4. The method according to claim 3, wherein in S3, the waste steam generated by the first flash system is washed by a washing agent, separated by a multiphase medium, and adjusted in pH by a basic reagent; wherein the solid particles and acidic droplets in the waste steam are purified and washed; the washing method comprises any one of tower washing and bed washing; the washing agent comprises pure water, process solution and basic reagent; the solid content of the washed steam is not higher than 30 ppm; the multiphase medium separation comprises any one of centrifugal separation and Venturi separation; and the basic reagent comprises any one of sodium hydroxide, calcium hydroxide and magnesium oxide, and the pH adjustment range is 6.5-7.

5. In S3, the waste steam generated by the first flash system is saturated steam, and in the production of saturated steam, the steam pressure is 200 kPa(A)-1100 kPa(A), and the temperature is 120℃-184℃. ​ 3. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 1, characterized by, ​ ​ ​ ​ ​ ​ ​ 5. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 1, characterized by, ​ 6. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 1, characterized by, In S4, the secondary flash system generates secondary steam which is saturated steam, wherein the secondary steam contains solid particles and acidic droplets.

7. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 1, characterized by, In S5, the gas-liquid separation of the secondary steam includes any one of centrifugal separation and Venturi separation.

8. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 1, characterized by, In S6, the remaining secondary steam after the preheating treatment of the cobalt precipitation solution is purified and exhausted; wherein, The remaining secondary steam after the preheating treatment of the cobalt precipitation solution is washed by a washing agent. The washing method includes any one of tower washing and bed washing. The washing agent includes any one of pure water, process solution and alkaline reagent.

9. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 1, characterized by, In S7, the clean steam is introduced into the drying device to dry the wet cobalt hydroxide material after the filtering device, to produce the cobalt hydroxide product and to discharge condensed water.

10. The method of drying cobalt hydroxide based on the waste heat of copper-cobalt sulfide pressure oxidation leaching according to claim 9, characterized in that, The wet cobalt hydroxide material after the filtering device has a water content of 50% to 65%.

11. The method of drying cobalt hydroxide based on copper cobalt oxide pressure leaching waste heat according to claim 9, characterized by, The drying device uses steam as a heat source, and includes a drying cavity, a steam conveying assembly, a condensed water discharging assembly, a material feeding and discharging assembly and a dust collecting assembly, wherein, The steam conveying assembly conveys the steam to the drying cavity to dry the wet cobalt hydroxide material under the action of the steam. The condensed water discharging assembly discharges the condensed water generated after drying out of the drying device. The material feeding and discharging assembly is used to convey the wet cobalt hydroxide material and the dried cobalt hydroxide. The dust collecting assembly is used to collect dust generated in the drying process.

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