A system for a chemical precipitation method using magnesium oxide

Abstract

The application discloses a system for using a chemical precipitation method of magnesium oxide, comprising a slurry preparation module and a reaction module. The slurry preparation module comprises pulp preparation units; the number of the pulp preparation units is 1-4, and the pulp preparation units comprise dispersion activation devices; the input end of the most upstream pulp preparation unit is provided with a first flow control device and a second flow control device, and magnesium oxide powder and pulp preparation liquid are continuously input into the most upstream pulp preparation unit through the first flow control device and the second flow control device at a controlled flow rate and are mixed; and the output end of the slurry preparation module continuously outputs magnesium oxide slurry. The reaction module is arranged downstream of the slurry preparation module; after the magnesium oxide slurry is output from the slurry preparation module, the magnesium oxide slurry is continuously input into the reaction module to implement a precipitation reaction. The pulp preparation liquid comprises process water and / or a pre-reaction liquid capable of being used for the precipitation reaction. The application can be used to realize that a metal precipitation reaction is efficiently and stably performed.

Description

Technical Field

[0001] This invention belongs to the fields of hydrometallurgical technology and metal removal technology, and particularly relates to a system for a chemical precipitation method using magnesium oxide. Background Technology

[0002] Chemical precipitation is an important technical means for the separation, enrichment, and purification of metals. It is widely used in hydrometallurgy to extract metals such as cobalt, nickel, copper, and rare earth metals from chemical solutions. It is also used in the chemical treatment of industrial wastewater to separate and remove metals such as arsenic, copper, chromium, cadmium, nickel, zinc, lead, mercury, and manganese. The chemical precipitation process requires a precipitant to carry out a precipitation reaction, converting soluble compounds into precipitates for extraction or removal. These precipitates are primarily in the form of hydroxides. The selection of the precipitant has a significant impact on the efficiency and economy of the chemical precipitation process.

[0003] In recent years, magnesium oxide (especially ore-processed magnesium oxide) has begun to be used as a precipitant in hydrometallurgical processes due to its wide availability, low cost, environmental friendliness, and excellent precipitation selectivity. It is used to separate and extract metal ions by generating target metal hydroxide precipitates. This trend of precipitant application is particularly prominent in processes such as nickel-cobalt precipitation and cobalt precipitation in hydrometallurgical processes of laterite nickel ore and copper-cobalt ore.

[0004] In current industrial applications of metal precipitation reactions using magnesium oxide as a precipitant, the process typically involves first mixing activated magnesium oxide powder with water in a specific ratio to prepare a magnesium oxide slurry. This slurry is then continuously fed into the reaction system, or passed through a buffer tank before being introduced into the system for precipitation. However, magnesium oxide slurries prepared using these methods often suffer from problems such as significant activity degradation, poor and unstable precipitation performance, and high magnesium oxide consumption. This results in low precipitation rates of the target metal, substandard product quality, and unstable production, failing to meet the demands of large-scale, high-quality industrial production.

[0005] Recently, although some people in the industry have tried to improve the application performance of magnesium oxide powder in precipitation reactions by adding modifiers, finely pulverizing magnesium oxide, and controlling particle morphology and structure, they still cannot fundamentally solve the problem and achieve the expected results due to various reasons. Summary of the Invention

[0006] To address the aforementioned problems, this invention proposes a system for a chemical precipitation method using magnesium oxide, enabling the magnesium oxide slurry to be used immediately after preparation. This solves the problem of severe activity decay in the magnesium oxide slurry, improves the precipitation efficiency of the target metal precipitation reaction and the target metal content in the product, reduces magnesium oxide consumption and magnesium impurity content in the product, and achieves efficient and stable target metal precipitation reaction.

[0007] The system provided by this invention can be used in processes for extracting metals from chemical solutions containing tungsten, molybdenum, tantalum, niobium, cobalt, nickel, rare earth elements, uranium, thorium, bismuth, tin, copper, lead, zinc, titanium, manganese, vanadium, gold, silver, platinum, palladium, indium, ruthenium, osmium, iridium, germanium, gallium, and other metallic minerals. In typical applications, the system can be used for the precipitation and recovery of nickel and cobalt from cobalt- and nickel-containing minerals, particularly in the hydrometallurgical process of laterite nickel ore, and for the precipitation and recovery of cobalt from copper-cobalt ore.

[0008] In addition, the chemical precipitation method of the present invention can also be used in chemical treatment processes to separate and remove metals such as arsenic, copper, chromium, cadmium, nickel, zinc, lead, mercury, and manganese from industrial wastewater.

[0009] This invention provides a system for a chemical precipitation method using magnesium oxide. The system comprises: The slurry preparation module includes a slurry preparation unit for preparing magnesium oxide powder and slurry liquid. The number of slurry preparation units is 1-4, including a dispersion and activation device. The input end of the upstream slurry preparation unit is equipped with a first flow control device and a second flow control device. Magnesium oxide powder and slurry liquid are continuously input into the upstream slurry preparation unit at controlled flow rates through the first flow control device and the second flow control device, respectively, and are mixed. The output end of the slurry preparation module continuously outputs magnesium oxide slurry. The reaction module is located downstream of the slurry preparation module; after being output from the slurry preparation module, the magnesium oxide slurry is continuously fed into the reaction module to carry out the precipitation reaction. The slurry includes process water and / or a pre-reaction liquid that can be used for precipitation reactions.

[0010] In one possible implementation, the number of reaction modules is one or more; when there are multiple reaction modules, the reaction modules are connected in series and / or in parallel.

[0011] The dispersion and activation device is used to disperse and activate a mixture of magnesium oxide powder and slurry, or to directly mix the input magnesium oxide powder and slurry into a mixture and then disperse and activate it.

[0012] In one possible implementation, the dispersion activation device includes one or more selected from high-shear dispersion devices, grinding dispersion devices, ultrasonic dispersion activation devices, mechanical stirring dispersion activation devices, jet dispersion activation devices, and pipeline in-line dispersion activation devices.

[0013] For example, the dispersion and activation device includes, but is not limited to, one or more of the following: high-speed disperser, high-shear disperser / emulsifier, inline high-shear dispersion pump / emulsifier, sand mill, stirred mill, ball mill, ultrasonic tank, ultrasonic rod, ultrasonic reactor, reactor, slurry tank, dispersion tank, jet injector, venturi ejector, homogenizer, and inline mixer.

[0014] In one possible implementation, at least one pulping unit includes a high-shear dispersion device for high-shear dispersion activation treatment of the mixture of magnesium oxide powder and pulping liquid. This high-shear dispersion activation treatment helps to form a highly active, non-agglomerated pulp.

[0015] In one possible implementation, the high-shear dispersion device is located inside the pulping unit and / or on the piping within the pulp preparation module. For example, the high-shear dispersion device includes one or more of a high-shear disperser and an inline high-shear dispersion pump.

[0016] When mixed with slurry, magnesium oxide powder is prone to agglomeration and clumping, which seriously affects the sedimentation reaction performance of the slurry. Due to the poor dispersibility of magnesium oxide powder, even when using conventional methods such as stirring to disperse and activate the mixture, it is difficult to achieve the ideal dispersion and activation effect due to the low stirring speed and short stirring time, and the particle agglomeration phenomenon is obvious.

[0017] This application employs a high-shear dispersion device to perform high-shear dispersion activation treatment on a mixture of magnesium oxide powder and slurry. This dispersion activation treatment is intense, with concentrated energy and a wide and uniform shear energy distribution. On one hand, it ensures uniform dispersion of magnesium oxide powder in the slurry, forming a highly active, non-agglomerated slurry, resulting in consistent high activity across all parts of the slurry. On the other hand, while achieving the same dispersion activation effect, it significantly shortens the dispersion activation treatment time, reducing the time the mixture spends within the preparation system, thereby shortening the interval time Δt. In this application, the combination of shortened interval time Δt and high-shear activation dispersion treatment ensures that the slurry entering the reaction module has the freshest activity and optimal dispersion state.

[0018] In one possible implementation, the pulping unit further includes a mixing and conditioning device for mixing and conditioning the magnesium oxide powder input to the pulp preparation module with the pulping liquid.

[0019] In one possible implementation, the mixing and conditioning device includes one or more selected from mechanical stirring devices, jet conditioning devices, circulating conditioning devices, pipeline mixing and conditioning devices, and high-speed mixing and conditioning devices.

[0020] For example, mixing and slurry preparation devices include, but are not limited to, one or more of the following: paddle mixers / anchor mixers / propeller mixers / frame mixers, high-speed dispersion discs, jet mixers, venturi jetters, slurry preparation tanks + centrifugal pumps / diaphragm pumps circulating slurry preparation devices, pipeline static mixers, high-speed mixers, and kneaders.

[0021] The pulping unit is used to carry out pulping processes.

[0022] In one possible implementation, the slurry preparation module includes 1-3 slurry preparation units connected in series.

[0023] In one possible implementation, when there are multiple pulping units, the pulping units are connected in series and / or in parallel.

[0024] In one possible implementation, the process of feeding magnesium oxide powder into the slurry preparation module and then into a highly active magnesium oxide slurry that is fed into the reaction module is completed rapidly with an interval Δt of less than 40 minutes.

[0025] In one possible implementation, the interval Δt is less than 20 minutes.

[0026] In one possible implementation, the interval Δt is less than 10 minutes.

[0027] In one possible implementation, the interval Δt is less than 5 minutes.

[0028] In one possible implementation, the magnesium oxide slurry, after being continuously output from the slurry preparation module, can be directly and continuously input into the reaction module, or it can flow through a buffer device before being input into the reaction module. During the flow through the buffer device, the magnesium oxide slurry remains in a dynamic flow state.

[0029] In one possible implementation, the mixture of magnesium oxide powder and slurry and the magnesium oxide slurry during the slurry preparation module, as well as the magnesium oxide slurry during the period from output from the slurry preparation module to entry into the reaction module, are all in a dynamic flow state, with a flow ratio q of over 95% and a flow ratio q of V. flow / V total , where V flow V is the volume of fluid in a dynamic flow state. total This represents the total volume of the fluid.

[0030] In one possible implementation, temperature measuring devices are installed at both the output end of the slurry preparation module and the input end of the upstream slurry preparation unit to monitor the temperature rise ΔT of the magnesium oxide slurry relative to the temperature when the slurry liquid is input into the slurry preparation module, so that ΔT is within a preset value T1.

[0031] In one possible implementation, the value of T1 is no greater than 10℃.

[0032] In one possible implementation, the value of T1 is no greater than 5℃.

[0033] In one possible implementation, when ΔT is greater than T1, the input flow rate of the slurry can be increased, and the temperature of the magnesium oxide slurry can be adjusted by reducing the slurry concentration, so that ΔT is within T1.

[0034] In one possible implementation, the temperature T2 of the magnesium oxide slurry input to the reaction module is below 40°C; more preferably, the temperature T2 is below 35°C.

[0035] In the system of this application, ΔT and T2 are monitored and controlled to prevent the temperatures ΔT and T2 from being too high. This can reduce the activity decay of the slurry before it is input into the reaction module and ensure that the slurry input into the reaction module has high activity.

[0036] In one possible implementation, control of ΔT and / or T2 is achieved by controlling the initial temperature of the slurry in the input slurry preparation module and / or by installing a cooling device in the slurry preparation module.

[0037] In another possible implementation, control of ΔT and / or T2 is achieved by setting a cooling device along the path from the slurry preparation module to the reaction module.

[0038] In one possible implementation, the temperature rise ΔT and / or T2 is controlled by controlling the interval time Δt.

[0039] In this application, by reducing the time the mixture of magnesium oxide powder and slurry spends within the slurry preparation module, the temperature rise caused by the work done on the mixture by the dispersion and activation device within the slurry preparation module can be reduced. Furthermore, the temperature rise caused by the exothermic slow hydration reaction of the mixture over time can also be reduced. By reducing the time the magnesium oxide slurry spends on its path from the slurry preparation module to the reaction module, the temperature rise of the slurry caused by the exothermic slow hydration reaction over time can also be reduced, thereby lowering T2. Combining these two factors, the temperature rise ΔT can be reduced by shortening the interval time Δt, thus lowering T2. Simultaneously, reducing the temperature rise ΔT also achieves a reduction in T2.

[0040] In this invention, by shortening the interval time Δt, the slurry can be "used immediately after preparation" and "quick in and quick out", thereby reducing the decay of slurry activity.

[0041] In one possible implementation, at any point during the stable operation of the reaction module, when the input flow rates of both magnesium oxide powder and slurry are non-zero, M1 + M2 = (1 ± k)M3 is satisfied, where M1 is the mass flow rate of magnesium oxide powder input to the slurry preparation module, M2 is the mass flow rate of slurry input to the slurry preparation module, M3 is the mass flow rate of magnesium oxide slurry input to the reaction module, and k is a deviation coefficient; k takes a value in the range of 0 to 0.2.

[0042] In one possible implementation, the first flow control device and the second flow control device can adopt at least one of controlling volumetric flow rate or controlling mass flow rate. When controlling volumetric flow rate, the volumetric flow rate value can be converted into a mass flow rate value, satisfying M1 + M2 = (1 ± k)M3.

[0043] In one possible implementation, the working volume of each pulping unit in the slurry preparation module is designed to match the processing capacity per unit time of the reaction module, so that the sum of the flow rates of magnesium oxide powder and slurry input to the slurry preparation module, the flow rate of the slurry output from the slurry preparation module, and the input flow rate of the slurry consumed by the reaction module to meet the processing capacity are synchronized, which is reflected as M1+M2=(1±k)M3.

[0044] In this application, the slurry preparation cycle of the slurry preparation module is synchronized with the slurry usage cycle of the reaction module, achieving "ready-to-use" slurry. This ensures that the interval time Δt, including the time spent by magnesium oxide material in the slurry preparation module, is significantly shorter than the time required for significant slurry activity decay, avoiding activity loss due to slurry retention. If the slurry preparation cycle and the slurry usage cycle are not synchronized, for example, when M1+M2 is greater than M3 by a significant margin, the slurry will be retained before entering the reaction module, resulting in activity loss; when M1+M2 is less than M3 by a significant margin, the slurry flow rate entering the reaction module will not meet the processing capacity requirements of the reaction module, causing instability in the target metal precipitation reaction process.

[0045] To shorten the interval time Δt, the working volume of each pulping unit can be reduced, or the number of pulping units connected in series can be decreased, when designing the pulp preparation module. To further shorten Δt, the working volume of the pulping unit can be reduced while decreasing the number of pulping units connected in series.

[0046] In this application, the temperature rise ΔT and / or T2 can also reflect the length of the interval Δt experienced by the magnesium oxide material before it enters the reaction module, the amount of work done by the dispersion and activation device, and the degree of slow hydration reaction that occurs over time. Therefore, in this application, by monitoring ΔT and T2, it is also possible to determine whether parameters such as the interval Δt, the working volume of the pulping unit, and the intensity of the activation and dispersion treatment are appropriate, whether adjustments are needed, and whether the system is operating healthily, thereby ensuring that the magnesium oxide slurry entering the reaction module has the freshest and most active form.

[0047] The magnesium oxide materials mentioned in this specification include mixtures of magnesium oxide powder and slurry.

[0048] In one possible implementation, a third flow control device is provided between the slurry preparation module and the reaction module to monitor the flow rate of magnesium oxide slurry output from the slurry preparation module.

[0049] In one possible implementation, a storage device is also provided upstream of the pulping unit to store magnesium oxide powder.

[0050] In one possible implementation, a status monitoring device is provided in the reaction module to monitor the status value within the reaction module and adjust the flow control values ​​of the first and second flow control devices according to the status value, so that the status value is within the range of m ± f, where m is a preset status control value and f is an allowable threshold. The status value includes one or more of the following: the content of the target metal and the pH value.

[0051] In one possible implementation, the status value monitoring device is connected to a controller, which automatically adjusts the flow control values ​​of the first flow control device and / or the second flow control device through feedback control based on the status value monitored by the status value monitoring device.

[0052] In one possible implementation, the input flow rates of magnesium oxide powder and slurry are adjusted to match, so that the two conditions are simultaneously met: the temperature rise ΔT is within the preset value T1 and the state value within the reaction module is within the range of m±f.

[0053] In one possible implementation, magnesium oxide powder is obtained by pulverizing and grinding lightly calcined magnesium oxide. The particle size distribution parameter D of the magnesium oxide powder... 50 ≤15µm, D 97 ≤50µm.

[0054] In existing metal precipitation reactions using magnesium oxide as a precipitant, magnesium oxide slurry is mostly prepared intermittently and then gradually added to the reaction system. The applicant has conducted in-depth research into the problems of poor activity, poor precipitation performance, and instability of the slurry in this type of technology. The root cause lies in the mismatch between the intermittent slurry preparation and the continuous precipitation process of the target metal. This means that several cubic meters or even tens of cubic meters of magnesium oxide slurry prepared in a single batch often need several hours to be fully incorporated into the continuous precipitation reaction. On the one hand, this causes the activity of the prepared slurry that is not added to the reaction in time to continuously decrease during the long waiting period, rendering its initial activity useless and affecting the performance indicators of the precipitation reaction. On the other hand, even if the initial activity of the batch of slurry is relatively consistent, because it needs to be added to the reaction sequentially over a long period, the activity of the slurry added later decreases during the transfer and storage process, resulting in inconsistent activity of the same batch of slurry when added to the reaction. This causes significant fluctuations in the precipitation reaction performance indicators in the reaction module, seriously affecting the stability of the precipitation reaction production. Although industry researchers have tried various methods to improve the application performance of magnesium oxide powder in precipitation reactions by enhancing its activity and dispersibility, they have failed to address the root cause of the problem and achieve the desired results. Furthermore, even existing technologies employing continuous magnesium oxide pulping often suffer from problems such as excessively large pulping unit volumes, leading to prolonged residence time of the magnesium oxide material and hindering rapid inflow and outflow, thus deteriorating precipitation reaction performance.

[0055] It is worth noting that the mismatch in rhythm between the pulping and precipitation reaction processes in existing technologies cannot be completely resolved by simply improving the continuous pulping process. The applicant has found that simple continuous pulping processes cannot achieve a satisfactory synchronization between the pulp preparation cycle and the pulp usage cycle in the reaction module, resulting in varying degrees of compromise in the "ready-to-use" effect of the pulp. However, if the synchronization between the pulp preparation and usage cycles exceeds the acceptable range, it will significantly impact the overall chemical precipitation process. For example, if the sum of the input magnesium oxide powder and the pulping liquid flow rates exceeds the pulp input flow rate into the reaction slightly beyond the acceptable range, the pulp will experience varying degrees of stagnation within the pulp preparation module or along the path from the pulp preparation module to the reaction module, reducing the dynamic flow state of the pulp. The slight retention of the slurry within the slurry preparation module allows it to undergo more dispersion and activation treatment, absorbing more energy from the process. This extended time and increased energy provide conditions for the deepening hydration reaction between magnesium oxide and the slurry. This deepening hydration reaction releases more heat, and the accumulated heat further promotes the hydration reaction, affecting the slurry's activity. This creates an avalanche effect, gradually accelerating the decline in slurry activity, manifested as uncontrolled temperature rise. On the other hand, if the uncontrolled temperature rise of the slurry extends its journey from the preparation module to the reaction, both the temperature rise and the extended time will intensify the hydration reaction, again creating an avalanche effect and further accelerating the decline in slurry activity. These two factors combined mean that even a simple continuous slurry preparation process cannot achieve the significant technical effects of the proposed solution.

[0056] Other common technical solutions that are separate from the overall technical solution of this application cannot achieve the significant technical effects of this application for similar reasons, which will not be elaborated here.

[0057] The preparation and input of magnesium oxide slurry into the reaction module in this application is continuous and controllable. To achieve "ready-to-use" slurry preparation, this application employs various design and control methods to ensure that the slurry preparation cycle is highly synchronized with the slurry usage cycle in the reaction module. First, by shortening the interval time Δt, the "fast in and fast out" of the slurry is achieved while continuously preparing the slurry. On this basis, combined with keeping the temperature rise ΔT within the preset control range, and / or designing the working volume and series number of the slurry preparation unit to match the unit time processing capacity of the reaction module, controlling the flow rates of magnesium oxide powder and slurry into the slurry preparation module and the flow rate of slurry into the reaction module to satisfy M1+M2=(1±k)M3, and keeping the state values ​​within the reaction module within the preset control range, the continuous slurry preparation cycle is highly synchronized with its continuous use cycle in the reaction module. This synchronization is continuously monitored, and if the synchronization exceeds the deviation range, one or more of the parameters such as the interval time Δt, temperature rise ΔT, reaction module state values, and flow rates of M1, M2, and M3 are immediately adjusted through various control methods to ensure that the synchronization meets the requirements. In addition, to ensure that the slurry is "ready to use immediately after preparation", the interval time Δt needs to be shortened as much as possible. This will keep the mixture of magnesium oxide powder and slurry and the magnesium oxide slurry in a highly dynamic flow state. While ensuring that the interval time Δt is as short as a few minutes, the high shear activation and dispersion treatment can make the magnesium oxide powder uniformly dispersed in the slurry in a very short time, forming a highly active and non-agglomerated slurry. Thus, the high shear activation and dispersion treatment is combined with other parts of the overall technical solution to make the slurry preparation cycle highly synchronized with the slurry usage cycle in the reaction module. In summary, this application demonstrates that the slurry is continuously prepared, continuously used, and ready for immediate use. Multiple methods ensure that slurry preparation and usage are highly synchronized and synchronized. This involves shortening the interval time Δt, reducing the temperature rise ΔT, lowering the slurry temperature T2 when mixed with the target metal pre-reaction liquid, and ensuring M1+M2=(1±k)M3. These technical features are closely integrated to form the overall technical solution of this application. This ensures that every drop of magnesium oxide slurry entering the reaction module has the freshest and most active properties, not only improving the efficiency of the precipitation reaction and reducing magnesium oxide consumption, but also maintaining consistent activity of the slurry during continuous reaction. This keeps the precipitation reaction performance indicators in the reaction module stable, thereby achieving efficient and stable precipitation of the target metal.

[0058] The beneficial effects of this invention are: 1. This application effectively solves the dual problems of poor dispersibility and slurry activity decay when mixing magnesium oxide powder and slurry through the synergistic effect of "continuous process" and "high shear dispersion", forming a highly active magnesium oxide slurry and ensuring consistent activity in all parts of the slurry. At the same time, by strictly controlling the interval time Δt, temperature rise ΔT and slurry mixing temperature T2, the slurry can be "used immediately after preparation" and "quick in and quick out", avoiding the activity decay caused by slurry retention, greatly improving the effectiveness of the slurry in the precipitation reaction, increasing the precipitation rate of the target metal and the content of the target metal in the product, reducing the consumption of magnesium oxide, and solving the core problems of poor slurry activity and unstable precipitation performance in the prior art.

[0059] 2. This application optimizes the working volume and series number of the pulping unit, and regulates the input and output flow rates of magnesium oxide powder, pulping liquid, and slurry, so that the slurry preparation cycle is highly synchronized with the slurry usage cycle of the reaction module. At the same time, it also dynamically monitors and adjusts the target metal content, pH value, and other status values ​​in the reaction module in real time, avoiding the problems of slurry stagnation or insufficient supply, eliminating the reaction performance fluctuations caused by slurry activity decay, ensuring the continuous and stable operation of the target metal precipitation reaction production process, and solving the technical bottlenecks of the mismatch between the rhythm of intermittent pulping and continuous reaction, and the insufficient synchronization of simple continuous pulping.

[0060] 3. This application achieves precise process control through a dual regulation mechanism. On the one hand, it regulates the temperature rise ΔT and slurry mixing temperature T2 during slurry preparation to ensure stable slurry activity. On the other hand, it also monitors the state values ​​of the pre-liquid, post-liquid, and precipitated products in the reaction module, and adjusts the input flow rate of magnesium oxide powder in real time to control the reaction environment state values ​​within the preset range, effectively improving the purity of the precipitated products, reducing impurity content, and reducing parameter fluctuations during the reaction process, thereby improving the controllability and operability of the entire hydrometallurgical process.

[0061] 4. This application reduces energy consumption in dispersion activation treatment and material waste caused by slurry retention by shortening the slurry interval time Δt and optimizing the design of the pulping unit; by using high-shear dispersion activation treatment, the dispersion time is shortened while ensuring the dispersion effect, further reducing energy consumption; at the same time, the pulping unit can be connected in series, parallel or mixed to adapt to the processing capacity requirements of different reaction modules, and the process parameters can be flexibly adjusted according to actual production without complicated equipment modification, making it easy to promote and apply in industrial applications. Compared with the existing technology, it greatly improves the economy and practicality of the process.

[0062] 5. This application breaks away from the limitations of existing technologies that only improve the activity and dispersibility of magnesium oxide powder. It recognizes that the mismatch between pulping and reaction rhythm is the core root cause of pulp activity decay and reaction instability. Through an integrated technical solution of "continuous pulping + fast in and fast out + high synchronization", it fundamentally solves the technical problems that existing technologies cannot overcome, realizes the technical upgrade of chemical precipitation process, and has significant technical innovation and progress.

[0063] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of one embodiment of the system for a chemical precipitation method using magnesium oxide in this invention.

[0065] Figure 2 This is a schematic diagram of another embodiment of the system for the chemical precipitation method using magnesium oxide in this invention.

[0066] Figure 3 This is a schematic diagram of another embodiment of the system for the chemical precipitation method using magnesium oxide in this invention.

[0067] Figure label: 1. Slurry preparation module; 101, First pulping unit; 102, Second pulping unit; 103, Third pulping unit; 104, Fourth pulping unit; 105, Paddle mixer; 106, High shear disperser; 20, First flow control device; 30, Second flow control device; 40. Metering and conveying device; 50, Flow control valve; 60, First Flow Meter; 70, Variable frequency pump; 80, Second Flow Meter; 90, Inline high-shear dispersion pump; 2. Reaction module; 3. Storage device. Detailed Implementation

[0068] To better illustrate the content of this invention, specific embodiments are further described below. These embodiments or examples are merely for the purpose of more directly describing this invention and are only a part of this invention, and should not be construed as limiting the invention in any way.

[0069] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein.

[0070] In addition, the terms “setup,” “connection,” and “association” should be interpreted broadly. For example, “connection” and “association” can refer to fixed connections, detachable connections, or integral structures; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two devices, components, or components.

[0071] This application provides a system for a chemical precipitation method using magnesium oxide. In such... Figure 1 In the illustrated embodiment, the system includes a slurry preparation module 1 and a reaction module 2. The slurry preparation module 1 includes: a first slurry preparation unit 101, a second slurry preparation unit 102, a first flow control device 20, and a second flow control device 30.

[0072] The first pulping unit 101 and the second pulping unit 102 are connected in series to perform pulping treatment on magnesium oxide powder and pulping liquid. The pulping treatment includes at least one of mixing and conditioning treatment and dispersion and activation treatment.

[0073] The mixing and slurry preparation process is used to mix the input magnesium oxide powder with the slurry to form a mixture; the dispersion and activation process is used to disperse and activate the mixture of magnesium oxide powder and slurry, or to directly mix the input magnesium oxide powder with the slurry to form a mixture and then disperse and activate it.

[0074] The first flow control device 20 and the second flow control device 30 are disposed at the input end of the first pulping unit 101, and are used to continuously input magnesium oxide powder and pulping liquid into the first pulping unit 101 at controlled flow rates and mix them. The output end of the slurry preparation module 1 continuously outputs magnesium oxide slurry.

[0075] The reaction module 2 is located downstream of the slurry preparation module 1. Magnesium oxide slurry is continuously fed into the reaction module 2 after being output from the slurry preparation module 1 to carry out the precipitation reaction.

[0076] The pulping solution includes process water and / or a pre-reaction liquid that can be used for precipitation reactions. The pulping unit includes a dispersion and activation device.

[0077] It is understood that the reaction module in the embodiments of this application includes a system, apparatus or container, site, etc., capable of carrying out the precipitation reaction in the embodiments of this application.

[0078] In one possible implementation, the number of reaction modules is one or more; when there are multiple reaction modules, the reaction modules are connected in series and / or in parallel.

[0079] The dispersion and activation device is used to disperse and activate a mixture of magnesium oxide powder and slurry, or to directly mix the input magnesium oxide powder and slurry into a mixture and then disperse and activate it.

[0080] In one possible implementation, the dispersion activation device includes one or more selected from high-shear dispersion devices, grinding dispersion devices, ultrasonic dispersion activation devices, mechanical stirring dispersion activation devices, jet dispersion activation devices, and in-line dispersion activation devices. For example, the dispersion activation device specifically includes, but is not limited to, high-shear dispersers / emulsifiers, in-line high-shear dispersion pumps / emulsifying pumps, sand mills, stirred mills, ball mills, ultrasonic tanks, ultrasonic rods, ultrasonic reactors, reactors, slurry tanks, dispersion tanks, jet injectors, venturi ejectors, homogenizers, and in-line mixers.

[0081] In one possible implementation, the pulping unit further includes a mixing and conditioning device for mixing and conditioning the magnesium oxide powder input to the pulp preparation module with the pulping liquid.

[0082] In one possible implementation, the mixing and conditioning device includes one or more selected from mechanical agitators, jet conditioning devices, circulating conditioning devices, pipeline mixing and conditioning devices, and high-speed mixing and conditioning devices. For example, the mixing and conditioning device specifically includes, but is not limited to, one or more of the following: paddle mixers / anchor / propeller / frame mixers, high-speed dispersion discs, jet injectors, venturi ejectors, circulating conditioning devices with a conditioning tank and centrifugal / diaphragm pump, pipeline static mixers, high-speed mixers, and kneaders.

[0083] In one implementation, at least one pulping unit includes a high-shear dispersion device for performing high-shear dispersion activation treatment on the mixture of magnesium oxide powder and pulping liquid.

[0084] For example, the high-shear dispersion device is located inside the pulping unit and / or on the piping within the pulp preparation module.

[0085] For example, a high-shear dispersion device includes one or more of a high-shear disperser and a line-type high-shear dispersion pump.

[0086] The number of pulping units is 1 to 4. In one implementation, when there are multiple pulping units, the pulping units are connected in series and / or in parallel.

[0087] As an example, multiple pulping units are connected in series to form a preparation system with multi-stage pulping units, progressively increasing the dispersion and activation degree of the magnesium oxide powder and pulping liquid mixture, thereby ultimately obtaining a magnesium oxide slurry that meets the requirements. For example, in... Figure 1 In the embodiment shown, there are two pulping units, with the first pulping unit 101 and the second pulping unit 102 connected in series.

[0088] As another example, when the precipitation reaction in the reaction module requires a large amount of magnesium oxide slurry per unit time, multiple slurry preparation units are connected in parallel. This allows the magnesium oxide slurry preparation module to supply magnesium oxide slurry to meet the needs of the reaction module, even when the processing capacity of a single slurry preparation unit is limited.

[0089] Therefore, in order to take into account both of the above aspects, multiple pulping units in the pulp preparation module can be connected in a series and parallel mixed manner.

[0090] In one possible implementation, the pulp preparation module includes 1-3 pulping units connected in series. For example, the pulp preparation module includes 2 or 3 pulping units connected in series.

[0091] For example, the working volume of the pulping unit is in the range of 0.5-5 cubic meters.

[0092] In one implementation, a storage device is also provided upstream of the pulping unit to store magnesium oxide powder.

[0093] In one possible implementation, the process of feeding magnesium oxide powder into the slurry preparation module and then into a highly active magnesium oxide slurry that is fed into the reaction module is completed rapidly with an interval Δt of less than 40 minutes.

[0094] In one possible implementation, the interval Δt is less than 20 minutes.

[0095] In one possible implementation, the interval Δt is less than 10 minutes.

[0096] In one possible implementation, the interval Δt is less than 5 minutes.

[0097] In one possible implementation, the magnesium oxide slurry, after being continuously output from the slurry preparation module, can be directly and continuously input into the reaction module, or it can flow through a buffer device before being input into the reaction module. During the flow through the buffer device, the magnesium oxide slurry remains in a dynamic flow state.

[0098] In one possible implementation, the mixture of magnesium oxide powder and slurry and the magnesium oxide slurry during the slurry preparation module, as well as the magnesium oxide slurry during the period from output from the slurry preparation module to entry into the reaction module, are all in a dynamic flow state, with a flow ratio q of over 95% and a flow ratio q of V. flow / V total , where V flow V is the volume of fluid in a dynamic flow state. total This represents the total volume of the fluid.

[0099] In one implementation, temperature measuring devices are installed at both the output end of the slurry preparation module and the input end of the upstream slurry preparation unit to monitor the temperature rise ΔT of the magnesium oxide slurry relative to the temperature of the slurry liquid when it is input into the slurry preparation module, so that ΔT is within a preset value T1, wherein the value of T1 is not greater than 10℃; furthermore, the value of T1 is not greater than 5℃.

[0100] In one possible implementation, when ΔT is greater than T1, the input flow rate of the slurry can be increased, and the temperature of the magnesium oxide slurry can be adjusted by reducing the slurry concentration, so that ΔT is within T1.

[0101] In one possible implementation, the temperature T2 of the magnesium oxide slurry input to the reaction module is below 40°C; more preferably, the temperature T2 is below 35°C.

[0102] In one possible implementation, control of ΔT and / or T2 is achieved by controlling the initial temperature of the slurry in the input slurry preparation module and / or by installing a cooling device in the slurry preparation module.

[0103] In another possible implementation, control of ΔT and / or T2 is achieved by setting a cooling device along the path from the slurry preparation module to the reaction module.

[0104] In one possible implementation, the temperature rise ΔT and / or T2 is controlled by controlling the interval time Δt.

[0105] In one possible implementation, at any point during the stable operation of the reaction module, when the input flow rates of both magnesium oxide powder and slurry are non-zero, M1 + M2 = (1 ± k)M3 is satisfied, where M1 is the mass flow rate of magnesium oxide powder input to the slurry preparation module, M2 is the mass flow rate of slurry input to the slurry preparation module, M3 is the mass flow rate of magnesium oxide slurry input to the reaction module, and k is a deviation coefficient, which takes a value in the range of 0 to 0.2.

[0106] Understandably, the stable operation period of the reaction module refers to the period during which magnesium oxide slurry is continuously fed into the reaction module, and the amount of slurry input is sufficient to maintain the precipitation reaction process within the reaction module in a normal and stable manner. This period does not include the initial stage when the slurry input gradually increases from zero at the beginning of the reaction module's operation, nor the final stage when the slurry input gradually decreases to zero at the end of the operation.

[0107] In one possible implementation, the first flow control device and the second flow control device can adopt at least one of controlling volumetric flow rate or controlling mass flow rate. When controlling volumetric flow rate, the volumetric flow rate value can be converted into a mass flow rate value, and through monitoring, M1 + M2 = (1 ± k)M3.

[0108] For example, the first flow control device and / or the second flow control device include a flow control valve.

[0109] For example, the first flow control device and / or the second flow control device include a metering conveying device.

[0110] For example, the first flow control device and / or the second flow control device include pumps with flow control functions such as metering pumps, gear pumps, frequency converters, and peristaltic pumps.

[0111] In one implementation, a third flow control device is provided between the slurry preparation module and the reaction module to monitor the flow rate of magnesium oxide slurry output from the slurry preparation module.

[0112] In such Figure 2 In the illustrated embodiment, the slurry preparation module includes a third slurry preparation unit 103 with a paddle agitator 105 connected in series and two fourth slurry preparation units 104 with high-shear dispersers 106. A metering and conveying device 40 and a flow control device mainly composed of a flow control valve 50 and a first flow meter 60 are provided at the input end of the third slurry preparation unit 103 for continuously feeding magnesium oxide powder and slurry liquid at controlled flow rates. A storage device 3 is also provided upstream of the third slurry preparation unit 103 for storing magnesium oxide powder and supplying it to the metering and conveying device 40. A reaction module 2 is connected downstream of the slurry preparation module to carry out a precipitation reaction. A flow control device mainly composed of a variable frequency pump 70 and a second flow meter 80 is provided between the slurry preparation module and the reaction module 2 to monitor the flow rate of the magnesium oxide slurry input to the reaction module.

[0113] In such Figure 3 In the embodiment shown, the slurry preparation module includes a fourth slurry preparation unit 104 equipped with a high-shear disperser 106 and a fifth slurry preparation unit mainly composed of a pipeline high-shear dispersion pump 90, with the remaining configurations similar to those in the previous embodiment. Figure 2The implementation methods shown are basically the same.

[0114] In some embodiments, a state value monitoring device is provided in the reaction module to monitor the state value within the reaction module and adjust the flow control values ​​of the first flow control device and the second flow control device according to the state value, so that the state value is within the range of m±f, so as to control the activity and input amount of magnesium oxide slurry, wherein m is a preset state control value and f is an allowable threshold; the state value includes one or more of the target metal content and pH value.

[0115] In one implementation, the status value monitoring device is connected to a controller, which automatically adjusts the flow control values ​​of the first flow control device and / or the second flow control device through feedback control based on the status value monitored by the status value monitoring device.

[0116] In one possible implementation, magnesium oxide powder is obtained by pulverizing and grinding lightly calcined magnesium oxide. The particle size distribution parameter D of the magnesium oxide powder... 50 ≤15µm, D 97 ≤50µm.

[0117] The above description is a systematic account of a chemical precipitation method using magnesium oxide, as described in embodiments of this application. This system enables the implementation of a chemical precipitation method using magnesium oxide. The chemical precipitation method includes: S1, magnesium oxide powder and slurry are continuously fed into the slurry preparation module at controlled flow rates through their respective flow control devices; the slurry preparation module performs slurry processing on the magnesium oxide powder and slurry, and continuously outputs the obtained magnesium oxide slurry; S2, after being output from the slurry preparation module, the magnesium oxide slurry is continuously input into the reaction module to carry out the precipitation reaction and generate a precipitated slurry containing hydroxides of the target metal.

[0118] The slurry includes process water and / or a pre-reaction liquid that can be used for precipitation reactions.

[0119] In one possible implementation, at any point during the stable operation of the reaction module, when the input flow rates of both magnesium oxide powder and slurry are non-zero, M1 + M2 = (1 ± k)M3 is satisfied; where M1 is the mass flow rate of magnesium oxide powder input to the slurry preparation module, M2 is the mass flow rate of slurry input to the slurry preparation module, M3 is the mass flow rate of magnesium oxide slurry input to the reaction module, and k is a deviation coefficient; k takes a value in the range of 0 to 0.2.

[0120] For example, the deviation coefficient k takes values ​​in the range of 0 to 0.1.

[0121] For example, the deviation coefficient k takes values ​​in the range of 0 to 0.05.

[0122] This system also enables another chemical precipitation method using magnesium oxide, in which a slurry is obtained using a pre-reaction liquid. This chemical precipitation method includes: S01, obtain a pre-reaction liquid that can be used for precipitation reaction; obtain a slurry; the slurry contains ions of the target metal from the pre-reaction liquid; S02, magnesium oxide powder and slurry are continuously fed into the slurry preparation module at controlled flow rates through their respective flow control devices; the slurry preparation module performs slurry processing on the magnesium oxide powder and slurry, and continuously outputs the obtained magnesium oxide slurry; S03, magnesium oxide slurry, after being output from the slurry preparation module, is continuously input into the reaction module to carry out a precipitation reaction and generate a precipitated slurry containing hydroxides of the target metal.

[0123] In one possible implementation, the chemical precipitation method further includes post-treatment of the precipitate slurry to obtain a metal hydroxide product; the post-treatment includes at least one of filtration, washing, and drying.

[0124] In one possible implementation, step S01 includes using the entire amount of the obtained pre-reaction liquid to obtain a slurry, wherein the amount of the pre-reaction liquid in the slurry is 1-100%, thereby making the slurry contain ions of the target metal.

[0125] In another possible implementation, step S01 includes dividing the obtained pre-reaction liquid into at least a first part and a second part, using the first part of the pre-reaction liquid to obtain a slurry, wherein the slurry contains 1-100% of the first part of the pre-reaction liquid, so that the slurry contains ions of the target metal. In step S03, magnesium oxide slurry is added to the reaction module and mixed with the second part of the pre-reaction liquid to carry out a precipitation reaction.

[0126] In some embodiments, prior to steps S1 and S01, magnesium oxide powder is obtained. Magnesium oxide powder is obtained by pulverizing and grinding lightly calcined magnesium oxide using one or more means selected from, but not limited to, air jet milling, solid grinding media milling, and mechanical lamination milling. The pulverization and grinding of lightly calcined magnesium oxide powder can be carried out by one or more means and apparatuses selected from, but not limited to, air jet mills, ring roller mills, stirred mills, sand mills, ball mills, vibratory mills, high-pressure roller mills, colloid mills, and impact mills. The particle size distribution parameter D of the magnesium oxide powder... 50 ≤15µm, D 97 ≤50µm. Preferably, the particle size distribution parameter D of the magnesium oxide powder is... 50 ≤8µm, D 97 ≤30µm.

[0127] The present invention will be further described below with reference to specific embodiments. In the following embodiments and comparative examples... First, the advantages of this invention will be further illustrated by examining its application in the hydrometallurgical process of laterite nickel ore, specifically in the case of nickel-cobalt immersion. In these examples and comparative examples, the magnesium oxide powder used was obtained by air jet milling of lightly calcined magnesium oxide powder, and its particle size distribution parameter is: D 50 =6.73μm, D 97 =23.38μm. The MgO content in this magnesium oxide powder is approximately 96.2%. The pre-nickel precipitation solution used was obtained by sulfuric acid leaching, with the main components being: Ni 3.72g / L, Co 0.364g / L, Mn 2.64g / L, and pH 5.0. Specific details are as follows.

[0128] Comparative Example 1 Magnesium oxide powder and slurry are fed into an intermittent slurry preparation module to produce magnesium oxide slurry. The slurry preparation module includes a mixing tank and a stirring tank. Dispersion and activation are carried out in the stirring tank using a paddle at a speed of 200 rpm for 30 minutes. The prepared magnesium oxide slurry undergoes a 60-minute residence period before being fed into a nickel-cobalt immersion reaction module for nickel-cobalt immersion.

[0129] Tests showed that the nickel precipitation rate was 70.69%, the cobalt precipitation rate was 85.64%, and the magnesium oxide consumption was approximately 957 kg / ton Ni. Example 1

[0130] Magnesium oxide powder and slurry are continuously fed into the slurry preparation module of this invention to prepare magnesium oxide slurry. This slurry preparation module includes a mixing tank and a stirring tank. Dispersion and activation are also carried out in the stirring tank using a paddle, with a stirring speed of 200 r / min and a slurry preparation time of 45 min. The magnesium oxide slurry continuously output from the slurry preparation module is continuously fed into a reaction module with the same nickel-cobalt precipitation conditions as Comparative Example 1 without any dwell time for nickel-cobalt precipitation.

[0131] Tests showed that the nickel precipitation rate was 80.56%, the cobalt precipitation rate was 89.29%, and the magnesium oxide consumption was approximately 839 kg / ton Ni. Example 2

[0132] The only difference between this embodiment and Embodiment 1 is that the pulping time is 30 minutes.

[0133] Tests showed that the nickel precipitation rate was 84.33%, the cobalt precipitation rate was 92.80%, and the magnesium oxide consumption was approximately 802 kg / ton Ni. Example 3

[0134] The only difference between this embodiment and Embodiment 1 is that the pulping time is 25 minutes.

[0135] Tests showed that the nickel precipitation rate was 84.52%, the cobalt precipitation rate was 93.60%, and the magnesium oxide consumption was approximately 800 kg / ton Ni. Example 4

[0136] The only difference between this embodiment and Embodiment 1 is that the pulping time is 20 minutes.

[0137] Tests showed that the nickel precipitation rate was 85.86%, the cobalt precipitation rate was 92.75%, and the magnesium oxide consumption was approximately 788 kg / ton Ni. Example 5

[0138] The only difference between this embodiment and Embodiment 1 is that the pulping time is 15 minutes.

[0139] Tests showed that the nickel precipitation rate was 86.48%, the cobalt precipitation rate was 94.53%, and the magnesium oxide consumption was approximately 782 kg / ton Ni. Example 6

[0140] The only difference between this embodiment and Embodiment 1 is that the pulping time is 10 minutes.

[0141] Tests showed that the nickel precipitation rate was 87.66%, the cobalt precipitation rate was 93.68%, and the magnesium oxide consumption was approximately 771 kg / ton Ni. Example 7

[0142] The only difference between this embodiment and Embodiment 1 is that the pulping time is 5 minutes.

[0143] Tests showed that the nickel precipitation rate was 87.69%, the cobalt precipitation rate was 93.96%, and the magnesium oxide consumption was approximately 771 kg / ton Ni. Example 8

[0144] The only difference between this embodiment and embodiment 6 is that a high-shear disperser is used in the mixing tank for high-shear dispersion and activation treatment.

[0145] Tests showed that the nickel precipitation rate was 89.78%, the cobalt precipitation rate was 94.24%, and the magnesium oxide consumption was approximately 753 kg / ton Ni. Example 9

[0146] The only difference between this embodiment and embodiment 7 is that a high-shear disperser is used in the mixing tank for high-shear dispersion and activation treatment.

[0147] Tests showed that the nickel precipitation rate was 90.34%, the cobalt precipitation rate was 95.46%, and the magnesium oxide consumption was approximately 748 kg / ton Ni.

[0148] A comparison of Comparative Example 1 and Example 1 shows that the continuous preparation of magnesium oxide slurry using the slurry preparation module and continuous slurry preparation method of the present invention, followed by continuous input into the reaction module for nickel-cobalt immersion, significantly improves the precipitation rate of nickel and cobalt and the magnesium oxide consumption compared to existing intermittent slurry preparation technologies. A comparison of Example 1 with Examples 2 to 7 shows that by controlling the interval time Δt to within 40 minutes, the magnesium oxide slurry is "ready to use immediately after preparation" and "quick in, quick out," effectively reducing slurry activity decay. This results in a more significant improvement in the precipitation rate of nickel and cobalt and the magnesium oxide consumption compared to Example 1. Furthermore, as the interval time Δt gradually shortens, the performance indicators of the immersion nickel-cobalt become increasingly superior; that is, the precipitation rate of nickel and cobalt gradually increases, and the magnesium oxide consumption gradually decreases. A comparison of Examples 6 to 9 shows that after combining high-shear dispersion activation treatment, the performance indicators of the immersion nickel-cobalt are significantly improved again. With an interval time Δt of 5 minutes and the use of high-shear dispersion activation treatment, the precipitation rate of nickel and cobalt reaches its highest level, and the magnesium oxide consumption reaches its lowest level. Observations showed that in Examples 8 and 9, the magnesium oxide slurry obtained by high shear dispersion activation treatment had good and uniform dispersion and no obvious agglomeration.

[0149] During the implementation of Examples 6 and 7, the mass flow rates M1 and M2 of the input magnesium oxide powder and slurry, as well as the mass flow rate M3 of the magnesium oxide slurry input to the reaction module, were measured at different times. The flow rate fluctuations measured in both examples were relatively stable. The average value of (M1+M2) / M3 in Example 6 was approximately 1.016, and the average value of (M1+M2) / M3 in Example 7 was approximately 1.011. The preparation cycle and usage cycle of the magnesium oxide slurry were well synchronized, achieving "ready to use after preparation" of the slurry.

[0150] Next, the implementation of the present application's technology in the precipitation reaction of manganese and copper metals will be used to further clarify the implementation of obtaining the slurry using the pre-reaction liquid in the embodiments of this application. In the examples and comparative examples, the magnesium oxide powder used was obtained by air jet milling of lightly calcined magnesium oxide powder, with an MgO content of approximately 96% and a particle size distribution parameter of: D 50 =7.17μm, D 97 =24.75μm; the copper and manganese precipitation solution obtained by sulfuric acid leaching before the reaction, with main components of Mn 3.2g / L, Cu 3.51g / L, and pH value 2.0. Specific details are as follows.

[0151] Comparative Example 2 Magnesium oxide powder and process water were intermittently mixed and pulped to produce a magnesium oxide slurry. Dispersion and activation were carried out using a stirring paddle at a speed of 200 rpm for 20 minutes. The prepared magnesium oxide slurry was then allowed to remain in the reaction module for a 60-minute hold before being fed into the reaction module for copper and manganese precipitation.

[0152] The test results showed that the manganese precipitation rate was 86.45%, the copper precipitation rate was 87.16%, and the magnesium oxide consumption was approximately 831 kg / ton·Mn and 752 kg / ton·Cu.

[0153] Example 10 The magnesium oxide powder and process water were continuously fed into the mixture for mixing and pulping. The resulting magnesium oxide slurry was then continuously output and fed into a reaction module under the same conditions as Comparative Example 2 for copper and manganese precipitation. Dispersion and activation were performed using a stirring paddle at a speed of 200 r / min for a pulping time of 20 min.

[0154] The test results showed that the manganese precipitation rate was 89.82%, the copper precipitation rate was 88.98%, and the magnesium oxide consumption was approximately 800 kg / ton·Mn and 736 kg / ton·Cu.

[0155] Example 11 The only difference between this embodiment and Embodiment 10 is that the pre-reaction liquid containing copper and manganese precipitates is used instead of process water as the pulping liquid for pulping.

[0156] The test results showed that the manganese precipitation rate was 94.45%, the copper precipitation rate was 93.27%, and the magnesium oxide consumption was approximately 761 kg / ton·Mn and 703 kg / ton·Cu.

[0157] Example 12 The only difference between this embodiment and Embodiment 11 is that a high-shear dispersion activation treatment is used in the pulping process.

[0158] The test results showed that the manganese precipitation rate was 96.23%, the copper precipitation rate was 95.34%, and the magnesium oxide consumption was approximately 747 kg / ton·Mn and 687 kg / ton·Cu.

[0159] A comparison of Comparative Example 2 and Example 10 shows that the continuous pulping method for preparing magnesium oxide slurry and continuously feeding it into the reaction module for copper and manganese precipitation allows the magnesium oxide slurry to be used immediately after preparation and to be processed quickly, which helps reduce the activity decay of the magnesium oxide slurry. The precipitation rates of copper and manganese and the magnesium oxide consumption per unit volume are significantly improved compared to existing intermittent pulping technologies. After using pre-reaction liquid instead of process water as the pulping liquid, the precipitation rates of copper and manganese and the magnesium oxide consumption per unit volume in Example 11 are further significantly improved. A comparison of Example 11 and Example 12 shows that the copper and manganese precipitation performance indicators are again significantly improved after combining high-shear dispersion activation treatment.

[0160] Example 13 The only difference between this embodiment and Embodiment 12 is that the pulping time is 40 minutes.

[0161] The test results showed that the manganese precipitation rate was 92.85%, the copper precipitation rate was 91.26%, and the magnesium oxide consumption was approximately 774 kg / ton·Mn and 703 kg / ton·Cu.

[0162] Example 14 The only difference between this embodiment and Embodiment 12 is that the pulping time is 7 minutes.

[0163] The test results showed that the manganese precipitation rate was 98.58%, the copper precipitation rate was 97.71%, and the magnesium oxide consumption was approximately 729 kg / ton·Mn and 671 kg / ton·Cu.

[0164] A comparison of Examples 12 to 14 shows that, under the same conditions of using pre-reaction liquid instead of process water as the slurry and employing high-shear dispersion activation treatment in the slurry preparation process, by controlling the interval time Δt to within 40 minutes, and with the gradual shortening of the interval time Δt, the precipitation performance of copper and manganese becomes increasingly superior; that is, the precipitation rate of copper and manganese gradually increases, while the magnesium oxide consumption gradually decreases. In Example 14, the precipitation rate of copper and manganese reached its highest level and the magnesium oxide consumption reached its lowest level when the interval time Δt was 7 minutes. Observation shows that in Examples 12 to 14, the magnesium oxide slurry obtained by high-shear dispersion activation treatment exhibits good and uniform dispersibility, with no obvious agglomeration.

[0165] The embodiments of the present invention are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The listed embodiments should not be construed as limiting the scope of protection claimed in this application.

Claims

1. A system for a chemical precipitation method using magnesium oxide, characterized in that, include: The slurry preparation module includes a slurry preparation unit for slurry preparation of magnesium oxide powder and slurry liquid; The number of pulping units is 1-4, including a dispersion and activation device; the input end of the upstream pulping unit is equipped with a first flow control device and a second flow control device. Magnesium oxide powder and pulping liquid are continuously input into the upstream pulping unit at controlled flow rates through the first flow control device and the second flow control device, respectively, and are mixed; the output end of the slurry preparation module continuously outputs magnesium oxide slurry. The reaction module is located downstream of the slurry preparation module; after being output from the slurry preparation module, the magnesium oxide slurry is continuously fed into the reaction module to carry out the precipitation reaction. The slurry includes process water and / or a pre-reaction liquid that can be used for precipitation reactions.

2. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, The number of reaction modules is one or more; when there are multiple reaction modules, the reaction modules are connected in series and / or in parallel.

3. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, The dispersion and activation device includes one or more selected from high-shear dispersion devices, grinding dispersion devices, ultrasonic dispersion and activation devices, mechanical stirring dispersion and activation devices, jet dispersion and activation devices, and pipeline online dispersion and activation devices.

4. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, At least one pulping unit includes a high-shear dispersion device for high-shear dispersion activation treatment of the mixture of magnesium oxide powder and pulping liquid.

5. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, When there are multiple pulping units, the pulping units are connected in series and / or in parallel.

6. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, Temperature measuring devices are installed at the output end of the slurry preparation module and the input end of the upstream slurry preparation unit to monitor the temperature rise ΔT of the magnesium oxide slurry relative to the temperature when the slurry liquid is input into the slurry preparation module.

7. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, A third flow control device is installed between the slurry preparation module and the reaction module to monitor the flow rate of magnesium oxide slurry output from the slurry preparation module.

8. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, An upstream storage device is also provided for storing magnesium oxide powder.

9. The system for a chemical precipitation method using magnesium oxide according to claim 1, characterized in that, The reaction module is equipped with a status value monitoring device to monitor the status value within the reaction module and adjust the flow control values ​​of the first flow control device and the second flow control device according to the status value, so that the status value is within the range of m±f, where m is the preset status control value and f is the allowable threshold.

10. The system for a chemical precipitation method using magnesium oxide according to claim 9, characterized in that, The status value monitoring device is connected to a controller, which automatically adjusts the flow control values ​​of the first flow control device and / or the second flow control device through feedback control based on the status value monitored by the status value monitoring device.

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