An active magnesium-based material, a preparation method and applications thereof

Abstract

The application discloses an active magnesium-based material, a preparation method and application thereof, and relates to the technical field of magnesium-based materials. The method comprises the following steps: grinding and crushing at least one of an interface modification additive, a chelating agent and a heterogeneous nucleating agent to prepare a modifier; taking active magnesium oxide and / or common magnesium oxide as raw materials, mixing and stirring the magnesium oxide raw materials with the modifier to modify the magnesium oxide raw materials, and obtaining an active magnesium-based material, wherein the addition amount of the modifier is 0.05-3% of the total mass of the magnesium oxide. The method can modify the magnesium oxide raw materials through the modifier to adjust the hydration activity of the active magnesium-based material, and can also improve the dispersion performance, chelating performance and / or precipitation speed of the active magnesium-based material, thereby improving the application performance of the active magnesium-based material in the field of hydrometallurgy. When the active magnesium-based material is used for precipitating nickel and cobalt, the active magnesium-based material has excellent precipitation efficiency, low unit consumption, and can also reduce the content of impurities in nickel hydroxide and cobalt hydroxide.

Description

Technical Field

[0001] This invention relates to the field of magnesium-based materials technology, and in particular to an active magnesium-based material, its preparation method, and its application. Background Technology

[0002] In the global industrial landscape, laterite nickel ore and copper-cobalt ore, as key nickel and cobalt resources, are increasingly prominent in strategic importance. With the booming development of industries such as new energy vehicles and stainless steel, the demand for nickel and cobalt has risen sharply, making the development and utilization of nickel and cobalt ores such as laterite nickel ore and copper-cobalt ore a focus of attention for all parties.

[0003] Traditional hydrometallurgical processes for nickel and cobalt precipitation often use strongly alkaline precipitants such as sodium hydroxide and calcium hydroxide to precipitate nickel and cobalt from the leachate. However, this process has significant drawbacks: firstly, the highly alkaline environment easily leads to localized over-alkaliness, causing impurities such as magnesium and manganese to precipitate along with nickel and cobalt, severely reducing product purity; secondly, the precipitated products have extremely poor filtration performance, and the filtration process is time-consuming, labor-intensive, and inefficient, significantly increasing production costs and energy consumption; furthermore, the sodium-containing precipitate cannot be recycled, not only wasting water resources but also posing a potential threat to the environment. These problems severely restrict the economic and environmental viability of traditional processes.

[0004] In recent years, magnesium oxide has come into focus in the field of hydrometallurgy as a precipitant. It can effectively avoid localized over-alkaliness, improve product purity, reduce the burden of impurity removal, lower costs, and improve production efficiency. However, when magnesium oxide is directly used in hydrometallurgy to precipitate nickel and cobalt, it often suffers from poor activity, poor precipitation performance, and high unit consumption, resulting in poor production efficiency and high costs. Furthermore, the precipitated nickel hydroxide and cobalt hydroxide contain excessive levels of impurities such as magnesium and manganese, leading to a significant increase in the cost of impurity removal in downstream processes.

[0005] Chinese patent document (CN202010286751.X) discloses a method for nickel precipitation without impurities in lateritic nickel ore leaching solution. This method uses magnesium oxide to precipitate the purified lateritic nickel ore leaching solution, obtaining nickel hydroxide with a nickel content of 35%-45% and a nickel precipitation rate of 99.98%. However, the leaching solution studied in this method is a purified solution; besides nickel and magnesium, the total amount of iron and other impurities in this solution is less than 0.0002 g / L. In actual industrial production, this leaching solution cannot undergo such a clean purification process. Furthermore, the conventional magnesium oxide used in this invention is not suitable for nickel precipitation solutions with more complex compositions.

[0006] Chinese patent document (CN202411084556.3) discloses a composite precipitant and a method for the wet refining of laterite nickel ore. The composite precipitant for wet refining laterite nickel ore is a mixture of magnesium oxide and sodium hydroxide. The nickel hydroxide (cobalt hydroxide) precipitate obtained using this method has a nickel content of over 40% and a magnesium content of ≤2%. Furthermore, the filter cake moisture content is reduced, accelerating the settling and filtration rates, and resulting in low unit consumption. While this composite precipitant combines the advantages of both sodium hydroxide and magnesium oxide, it also retains some of the disadvantages of sodium hydroxide, such as the tendency to produce localized over-alkaliness and excessively large flocs, increasing the processing capacity of the downstream thickening tank. Moreover, the sodium hydroxide in the composite precipitant readily absorbs water and releases heat, producing concentrated alkaline solution. In this system environment, the contact area between magnesium oxide particles and water increases, leading to moisture absorption and denaturation. The entire process is self-accelerated, causing the mixture to easily become damp, clump, and generate heat.

[0007] Currently, there is an urgent need for the development of suitable precipitation materials in the field of hydrometallurgical precipitation of nickel and cobalt ore from laterite and copper-cobalt ores. Summary of the Invention

[0008] This invention discloses an active magnesium-based material, its preparation method, and its application, in order to solve the technical problems in related technologies where magnesium oxide is used as a precipitant to extract nickel and cobalt from nickel and cobalt ores, resulting in poor activity, poor precipitation performance, high unit consumption, and excessively high levels of impurities such as magnesium and manganese in the precipitated nickel hydroxide and cobalt hydroxide.

[0009] To solve the above problems, the present invention adopts the following technical solution:

[0010] The first aspect of the present invention provides a method for preparing an active magnesium-based material.

[0011] The method for preparing the active magnesium-based material of the present invention includes the following steps:

[0012] The modifier is prepared by pulverizing and grinding at least one of the interface modifying agent, chelating agent, and heterogeneous nucleating agent.

[0013] Using active magnesium oxide and / or ordinary magnesium oxide as raw materials, the magnesium oxide raw materials are mixed and stirred with a modifier to obtain an active magnesium-based material, wherein the amount of the modifier added is 0.05~3% of the total mass of magnesium oxide.

[0014] According to an optional embodiment, the interface modifying agent is one or more of magnesium bicarbonate, magnesium carbonate, titanate coupling agent, magnesium acetate, polyethylene glycol, and stearic acid; the chelating agent is one or more of hydroxamic acid organic compounds, carboxylic acid organic compounds and their salts; and the heterogeneous nucleating agent is one or more of calcium dihydrogen phosphate, polyacrylate, aminobisphosphonate, and rare earth oxides.

[0015] According to an optional embodiment, the modifier includes an interface modifying agent, a chelating agent, and a heterogeneous nucleating agent, and the mass ratio of the interface modifying agent, the chelating agent, and the heterogeneous nucleating agent is 1~6∶1~3∶1~10.

[0016] According to an optional embodiment, the temperature during the mixing and grinding of the interface modifier, the chelating agent, and the heterogeneous nucleating agent is below 70°C, and the particle size after grinding is less than 100 mesh.

[0017] According to one optional embodiment, when the magnesium oxide and the modifier are stirred and mixed, the stirring speed is 2000~5000 rpm, the stirring time is 5~240 min, and the temperature is room temperature.

[0018] According to an optional embodiment, the raw material is active magnesium oxide, wherein the active magnesium oxide has a purity >93%, a D50 particle size <20μm, a D90 particle size <50μm, and a citric acid value <30s.

[0019] Alternatively, the raw material is ordinary magnesium oxide, wherein the purity of the ordinary magnesium oxide is >93%, the D50 particle size is <20μm, the D90 particle size is <50μm, and the citric acid value is <30s;

[0020] Alternatively, the raw materials may include active magnesium oxide and ordinary magnesium oxide, with a mass ratio of active magnesium oxide to ordinary magnesium oxide of 0.5~2:1~10, and the purity of the active magnesium oxide and / or the ordinary magnesium oxide is >93%, the D50 particle size is <20μm, the D90 particle size is <50μm, and the citric acid value is <30s.

[0021] According to one optional embodiment, the preparation of active magnesium oxide includes the following steps:

[0022] The first magnesium ore was calcined and dissociated into calcined white ore in a high-temperature furnace;

[0023] After calcined white liquor is leached with digested water, it is then filtered through microfiltration to remove residue and obtain digested liquid.

[0024] The digestion liquid is pumped into an enhanced gas-liquid reactor and an activator is added. Carbon dioxide is then introduced to carbonize the mixture, resulting in a carbonized liquid. The activator consists of oxalic acid, sodium phosphate, and magnesium polycarboxylate, with a mass ratio of oxalic acid, sodium phosphate, and magnesium polycarboxylate of 6-12:5:1. The amount of activator added is 0.05%-5.0% of the mass of magnesium oxide in the digestion liquid.

[0025] The carbonation solution was separated into calcium carbonate and an active low-calcium, magnesium-rich solution.

[0026] The active low-calcium-rich magnesium liquid is pumped into a pyrolysis tank and heated to obtain a solid-liquid mixture. Then, the solid and liquid are separated to obtain basic magnesium carbonate wet residue and pyrolysis liquid.

[0027] The wet residue of basic magnesium carbonate is conveyed to a flash dryer, where it is broken up, dried into powder, and then calcined at low temperature to obtain active magnesium oxide.

[0028] According to one optional embodiment, the preparation of ordinary magnesium oxide includes the following steps:

[0029] The second magnesium ore is crushed and ground to obtain mineral powder;

[0030] The mineral powder is purified using a combined reverse-direct flotation process to obtain flotation concentrate.

[0031] The flotation concentrate is dried and dehydrated to obtain dry concentrate powder;

[0032] The dry refined powder is calcined and decomposed into ordinary magnesium oxide.

[0033] A second aspect of the present invention provides an active magnesium-based material.

[0034] The active magnesium-based material of the present invention is prepared by the preparation method of active magnesium-based material according to any one of the technical solutions of the present invention. The active magnesium-based material includes at least one of active magnesium oxide and ordinary magnesium oxide. The active magnesium-based material further includes a modifier, wherein the modifier is at least one of an interface modifying agent, a chelating agent, and a heterogeneous nucleating agent, and the mass of the modifier is 0.05-3% of the total mass of magnesium oxide; the bulk density of the active magnesium-based material is greater than 0.5 g / cm³. 3 The hydration activity is 70%~95%.

[0035] A third aspect of the invention also provides an application of an active magnesium-based material.

[0036] The application of the active magnesium-based material according to any one of the technical solutions of this invention, wherein the active magnesium-based material is used to extract nickel and cobalt from nickel- and cobalt-containing ores, and the extraction of nickel and cobalt from nickel- and cobalt-containing ores includes the following steps:

[0037] Nickel and cobalt-containing ores are used as raw materials for leaching to obtain nickel and cobalt enriched solutions;

[0038] Dry powder or slurry of active magnesium-based material is added to the nickel and cobalt enrichment solution. After stirring, nickel and cobalt ions in the nickel and cobalt enrichment solution are precipitated. After solid-liquid separation, nickel and cobalt precipitates are obtained. The amount of active magnesium-based material added is 0.5 to 1.5 times the theoretically required mass of precipitant.

[0039] The nickel and cobalt precipitates were washed to remove impurities, yielding nickel hydroxide and cobalt hydroxide.

[0040] The technical solution adopted in this invention can achieve the following beneficial effects:

[0041] Firstly, the preparation method of the active magnesium-based material of the present invention uses active magnesium oxide and / or ordinary magnesium oxide as raw materials. The magnesium oxide raw materials are mixed and stirred with a modifier. The modifier can modify the magnesium oxide raw materials to adjust the hydration activity of the active magnesium-based material, and also improve the dispersion performance, chelation performance, and / or precipitation rate of the active magnesium-based material. This enhances the application performance of the active magnesium-based material in hydrometallurgy, especially in the extraction of nickel and cobalt from nickel- and cobalt-containing ores such as laterite nickel ore and copper-cobalt ore. The active magnesium-based material prepared by the method of the present invention has a hydration activity of 70% to 95%, which can improve reaction efficiency while preventing localized over-alkaliness, thus avoiding the potential for high impurity content and affecting product purity.

[0042] Secondly, in the preparation method of the active magnesium-based material of the present invention, during the mixing and stirring of magnesium oxide raw material and modifier, the interface modifier can penetrate into the magnesium oxide crystal layer and increase lattice defects to modify it; the interface modifier can also form a coating layer on the surface of magnesium oxide, which can not only improve the dispersibility of magnesium oxide, but also activate the surface and enhance the interaction with water. By controlling the process conditions, the hydration activity of the active magnesium-based material can be adjusted to the optimal range to improve the application performance of the active magnesium-based material in the field of hydrometallurgy.

[0043] Thirdly, the present invention provides an active magnesium-based material prepared by mixing and stirring magnesium oxide raw materials with a modifier. The added modifier also includes a chelating agent, which can chelate impurities such as manganese and lead, further reducing the impurity content in nickel hydroxide and cobalt hydroxide, thereby improving the nickel and cobalt grades of nickel hydroxide and cobalt hydroxide, and thus reducing the impurity removal cost in the downstream processes of nickel hydroxide and cobalt hydroxide.

[0044] Fourthly, the active magnesium-based material prepared by mixing and stirring magnesium oxide raw material with a modifier in this invention includes anisotropic nucleating agents. These anisotropic nucleating agents can form micro-nuclei with large specific surface area and high surface energy during the reaction. The precipitated nickel hydroxide and cobalt hydroxide can be directly generated on the surface of these pre-formed nuclei, changing the original homogeneous nucleation to heterogeneous nucleation. The energy barrier required for heterogeneous nucleation is much lower than that for homogeneous nucleation, thus significantly accelerating the formation rate of nickel hydroxide and cobalt hydroxide precipitates, promoting the formation of denser and larger particles, avoiding the formation of small, difficult-to-settle colloids, and improving the solid-liquid separation effect. Furthermore, the active magnesium-based material prepared by mixing and stirring magnesium oxide raw material with a modifier in this invention, when precipitating nickel and cobalt to form nickel hydroxide and cobalt hydroxide precipitates, changes from the original homogeneous nucleation to heterogeneous nucleation, effectively preventing the encapsulation of magnesium ions in the system during homogeneous nucleation, which would otherwise lead to a significant increase in the magnesium content of nickel hydroxide and cobalt hydroxide. Attached Figure Description

[0045] 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 of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a process flow diagram of the preparation of active magnesium-based materials according to embodiments of this application;

[0047] Figure 2 This is a SEM image of the active magnesium-based material in Example 1 of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0049] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0050] Figure 1 A process flow diagram for preparing the active magnesium-based material according to this application is shown. Figure 1 As shown, the preparation method of active magnesium-based materials includes the following steps:

[0051] The first step is to prepare the raw materials. The following instructions use activated magnesium oxide and ordinary magnesium oxide as raw materials.

[0052] For example, magnesium oxide produced according to the process of steps S111 to S116 is defined as active magnesium oxide; magnesium oxide not produced according to the process of steps S111 to S116 is defined as ordinary magnesium oxide. Ordinary magnesium oxide can be produced using the process of steps S121 to S124, or it can be produced using other processes (such as the high-purity magnesium oxide process).

[0053] S110: Active magnesium oxide is obtained by calcining and dissociating the first magnesium ore, followed by enhanced leaching, carbonization separation, high-efficiency pyrolysis, solid-liquid separation, and drying and calcining.

[0054] Specifically, the preparation of active magnesium oxide includes the following steps:

[0055] S111: The first magnesium ore is calcined and dissociated in a high-temperature furnace to form calcined white ore.

[0056] Preferably, the first magnesium ore is one of dolomite, magnesite, or by-product magnesium salts. The by-product magnesium salts are inorganic salt solids such as magnesium carbonate and magnesium hydroxide produced by industrial production enterprises, and other impurities are mainly calcium carbonate. For example, the magnesium ore size is less than 50 mm, the calcination dissociation temperature is 800~1200℃, and the calcination time is 0.1~240 min.

[0057] The dissociation reaction of magnesium ore during calcination is: MgCO3 + CaCO3 = MgO + CaO + 2CO2↑.

[0058] S112: After calcined white liquor is leached with digested water, it is then filtered through microfiltration to remove residue and obtain digested liquid.

[0059] Preferably, the solid-liquid ratio for enhanced leaching is 1g:15~50ml, the temperature is 30~90℃, and the time is 30~90min.

[0060] The leaching reaction for calcined white metal is: MgO + CaO + 2H2O = Mg(OH)2 + Ca(OH)2.

[0061] S113: The digestate is pumped into an enhanced gas-liquid reactor and an activator is added. Carbon dioxide is then introduced for carbonization to obtain a carbonized liquid. The activator is oxalic acid, sodium phosphate, and magnesium polycarboxylate, with a mass ratio of oxalic acid, sodium phosphate, and magnesium polycarboxylate of 6-12:5:1. The amount of activator added is 0.05%-5.0% of the mass of magnesium oxide in the digestate. For example, the activator is prepared as a 10% (w / w) solution and added to the digestate.

[0062] Preferably, the carbonization process is a single-stage carbonization process or a multi-stage carbonization process.

[0063] Preferably, the endpoint pH is 7.5 to 10.0.

[0064] Preferably, the carbonization process is carried out at a temperature of 15~40℃.

[0065] The reaction formula for the carbonization separation of digestive fluid is:

[0066] Mg(OH)2+Ca(OH)2+3CO2=Mg(HCO3)2+CaCO3↓+H2O.

[0067] S114: The carbonized liquid is separated into calcium carbonate and active low-calcium magnesium-rich liquid through solid-liquid separation.

[0068] Preferably, the solid-liquid separation method is centrifugal dehydration or plate and frame filtration dehydration. The active low-calcium and magnesium-rich solution is a magnesium bicarbonate solution, wherein the calcium ion concentration is less than 1 mmol / L and the magnesium ion concentration is greater than 0.15 mol / L.

[0069] S115: Pump the active low-calcium-rich magnesium liquid into the pyrolysis tank, heat it to obtain a solid-liquid mixture, and then separate the solid and liquid to obtain basic magnesium carbonate wet slag and pyrolysis liquid.

[0070] Preferably, during the heating process, the stirring rate is 30~200 rpm, the pressure is -40~-10 kPa, the heating temperature is 50~90℃, and the pyrolysis time is 30~180 min.

[0071] Furthermore, the pyrolysis liquid can be pumped back to the digester as digested water for reuse.

[0072] The pyrolysis reaction formula for active low-calcium, magnesium-rich liquid is as follows:

[0073] 5Mg(HCO3)2=4MgCO3·Mg(OH)2·4H2O+6CO2↑.

[0074] S116: Basic magnesium carbonate wet slag is conveyed to a flash dryer, where it is broken up, dried into powder, and then calcined at low temperature to obtain active magnesium oxide.

[0075] Preferably, the flash drying temperature is 120~250℃.

[0076] Preferably, the low-temperature calcination equipment is a rotary kiln, a suspension kiln, or a fluidized bed kiln, with a calcination temperature of 500~800℃ and a calcination time of 0.1~120min.

[0077] The reaction formula for the calcination of basic magnesium carbonate is as follows:

[0078] 4MgCO3·Mg(OH)2·4H2O=5MgO+5H2O+4CO2↑.

[0079] In the above preparation process, in step S111, the first magnesium ore is calcined and dissociated in a high-temperature furnace. The high-temperature furnace can be a roller kiln, suspension kiln, rotary kiln, fluidized bed kiln, or ring kiln. For example, the high-temperature furnace is indirectly heated by gas calcination. For example, the carbon dioxide flue gas generated from gas oxidation and material decomposition in step S111 is recycled to the carbonization process in S113 after being processed by a plate heat exchanger and purified and compressed. The waste heat generated from the carbon dioxide flue gas heat exchange is supplied to the pyrolysis system in step S115; the waste heat from calcination in step S116 is supplied to the flash drying system in step S116, thereby achieving full utilization of heat.

[0080] The active magnesium oxide prepared by the above method has a purity >93%, a D50 particle size <20μm, a D90 particle size <50μm, and a citric acid value <30s.

[0081] S120: Ordinary magnesium oxide is prepared by crushing, flotation, flash drying and calcination of the second magnesium ore.

[0082] Specifically, the preparation of ordinary magnesium oxide includes the following steps:

[0083] S121: The second magnesium ore is crushed and ground to obtain mineral powder.

[0084] Preferably, the second magnesium ore is one or more of magnesite, hydromagnesite, brucite, magnesium carbonate, and magnesium hydroxide. The second magnesium ore is crushed to a size of less than 50 mm.

[0085] Preferably, the second magnesium ore is crushed and ground to control the fineness of the ore to be 75%-80% of 200 mesh.

[0086] S122: The mineral powder is purified by a reverse-forward flotation combined process to obtain flotation concentrate.

[0087] Preferably, the mineral powder is first subjected to reverse flotation to remove silicate gangue minerals such as talc and quartz, and then forward flotation is used to suppress calcium- and iron-containing impurities such as dolomite and calcite to obtain flotation concentrate.

[0088] Specifically, during reverse flotation, the pulp concentration is adjusted to 35%, and a pH adjuster (such as sulfuric acid) is added to adjust the pulp pH to 5.5. Depressants (such as sodium silicate) and collectors (such as dodecylamine) are also added, and the pulp is passed through a flotation device to obtain a magnesium-containing underflow pulp. The underflow pulp from reverse flotation is then adjusted to 30% concentration by adding water, and a pH adjuster (such as sodium hydroxide) is added to adjust the pulp pH to 9.5. Depressants (such as sodium hexametaphosphate) and collectors (such as sodium oleate) are also added, and the pulp is passed through a flotation device to obtain a flotation concentrate.

[0089] Flotation concentrate specifications: MgO grade ≥46%, SiO2 content <1.0%, CaO content <0.8%.

[0090] S123: Dry and dehydrate the flotation concentrate to obtain dry concentrate powder.

[0091] Preferably, the flotation concentrate is dried and dehydrated to <1% to obtain dry concentrate powder.

[0092] S124: The dry refined powder is calcined and decomposed into ordinary magnesium oxide.

[0093] Preferably, the dry refined powder is calcined to decompose it into ordinary magnesium oxide. The calcination temperature is 500~800℃, and the calcination time is 0.1~120min.

[0094] The ordinary magnesium oxide prepared by the above method has a purity >93%, a D50 particle size <20μm, a D90 particle size <50μm, and a citric acid value <30s.

[0095] Not limited to this, the raw materials, active magnesium oxide and ordinary magnesium oxide, can also be prepared by other methods, or the raw materials, active magnesium oxide and ordinary magnesium oxide, can be purchased as commercial products.

[0096] The second step is to prepare the modifier. The following explanation uses a composite modifier prepared by combining an interface modifier, a chelating agent, and a heterogeneous nucleating agent as an example.

[0097] Specifically, the preparation of the composite modifier includes the following steps:

[0098] After mixing the interface modifier, chelating agent, and heterogeneous nucleating agent in a certain proportion, the mixture is pulverized and ground under low temperature conditions to form a composite modifier.

[0099] Preferably, the interface modifying agent is one or more of magnesium bicarbonate, magnesium carbonate, titanate coupling agent, magnesium acetate, polyethylene glycol, and stearic acid.

[0100] Preferably, the chelating agent is one or more of hydroxamic acid organic compounds, carboxylic acid organic compounds, and their salts.

[0101] Preferably, the heterogeneous nucleating agent is one or more of calcium dihydrogen phosphate, polyacrylate, amino bisphosphonate, and rare earth oxides.

[0102] Preferably, the mass ratio of the interface modifier, chelating agent, and heterogeneous nucleating agent is 1~6:1~3:1~10.

[0103] Preferably, the temperature during the mixing and grinding of the interface modifier, chelating agent, and heterogeneous nucleating agent is below 70°C. More preferably, the temperature during the mixing and grinding of the interface modifier, chelating agent, and heterogeneous nucleating agent is 20~40°C.

[0104] Preferably, the particle size after grinding is less than 200 mesh.

[0105] The third step involves using active magnesium oxide and ordinary magnesium oxide as raw materials, mixing and stirring the magnesium oxide raw materials with a modifier to obtain active magnesium-based materials.

[0106] Preferably, the amount of modifier added is 0.05~3% of the total mass of magnesium oxide.

[0107] Preferably, when mixing magnesium oxide and the composite modifier, the stirring speed is 2000~5000 rpm.

[0108] Preferably, the stirring time is 5~240 min and the temperature is room temperature.

[0109] Preferably, the mass ratio of activated magnesium oxide to ordinary magnesium oxide is 0.5~2:1~10, the purity of activated magnesium oxide and / or ordinary magnesium oxide is >93%, the D50 particle size is <20μm, the D90 particle size is <50μm, and the citric acid value is <30s. Using activated magnesium oxide and ordinary magnesium oxide in this proportion as raw materials helps reduce the production cost of activated magnesium-based materials. Furthermore, when activated magnesium oxide and / or ordinary magnesium oxide modified with the above-mentioned parameters are used to extract nickel and cobalt from nickel- and cobalt-containing ores, not only can precipitation efficiency be ensured, but the excessively high magnesium impurity content in the formed nickel hydroxide and cobalt hydroxide can also be avoided, preventing the complex and difficult downstream impurity removal processes for nickel hydroxide and cobalt hydroxide.

[0110] Not limited to this, activated magnesium oxide can also be used as the raw material. The activated magnesium oxide is mixed and stirred with a modifier to obtain activated magnesium-based materials. In this case, the purity of activated magnesium oxide is >93%, the D50 particle size is <20μm, the D90 particle size is <50μm, and the citric acid value is <30s.

[0111] Not limited to this, ordinary magnesium oxide can also be used as a raw material. The ordinary magnesium oxide is mixed and stirred with a modifier to obtain an active magnesium-based material. The purity of ordinary magnesium oxide is >93%, D50 particle size is <20μm, D90 particle size is <50μm, and citric acid value is <30s.

[0112] Not limited to this, when the purity of ordinary magnesium oxide is high enough to reach the purity of high-purity magnesium oxide, it can also be used as a magnesium oxide raw material.

[0113] The active magnesium-based material prepared by the above-described method comprises at least one of active magnesium oxide and ordinary magnesium oxide. The active magnesium-based material further comprises a modifier, wherein the modifier is at least one of an interface modifying agent, a chelating agent, and a heterogeneous nucleating agent, and the mass of the modifier is 0.05-3% of the total mass of magnesium oxide; the bulk density of the active magnesium-based material is greater than 0.5 g / cm³. 3 The hydration activity is 70%~95%.

[0114] The active magnesium-based material of this application is used to extract nickel and cobalt from nickel- and cobalt-containing ores, and the extraction of nickel and cobalt from nickel- and cobalt-containing ores includes the following steps:

[0115] Nickel and cobalt-containing ores are used as raw materials for leaching to obtain nickel and cobalt enriched solutions;

[0116] Dry powder or slurry of active magnesium-based material is added to the nickel and cobalt enrichment solution. After stirring, nickel and cobalt ions in the nickel and cobalt enrichment solution are precipitated. After solid-liquid separation, nickel and cobalt precipitates are obtained. The amount of active magnesium-based material added is 0.5 to 1.5 times the theoretically required mass of precipitant.

[0117] The nickel and cobalt precipitates are washed to remove impurities, yielding nickel hydroxide and cobalt hydroxide. Preferably, purified water or a solution that selectively leaches impurities can be used to wash the nickel and cobalt precipitates.

[0118] The active magnesium-based materials, preparation methods, and applications of this application are described in detail below with reference to specific embodiments.

[0119] Example 1

[0120] The preparation method of the active magnesium-based material in this embodiment includes the following steps:

[0121] S100: Prepares active magnesium oxide and ordinary magnesium oxide.

[0122] S110: Preparation of active magnesium oxide.

[0123] S111: Calcined white dolomite is obtained by calcining dolomite with a particle size of 10~30mm and a magnesium content (calculated as magnesium oxide) of 20.15% in a flame-retardant roller kiln at 1100℃ for 2.5h.

[0124] S112: Calcined white powder is conveyed to the digestion tank via belt. Digestion water is added at 50°C at a solid-liquid ratio of 1g:35ml. After leaching for 60 minutes, a mixed solution is obtained. The mixed solution is then screened through a drum microfilter to remove large, indigestible impurities, resulting in a digestion liquid.

[0125] S113: After the digestion liquid is cooled by a water-cooled jacket, it is pumped into an enhanced gas-liquid reactor. Carbon dioxide is introduced to carry out carbonation reaction until the final pH is 7.6. A diaphragm filter press is used to separate the solid and liquid of the carbonized liquid to obtain calcium carbonate and active low-calcium magnesium-rich liquid.

[0126] The active low-calcium, high-magnesium liquid is pumped into the next stage enhanced gas-liquid reactor, where an activator is added and carbon dioxide is introduced to carbonize the solution to pH 8.2, resulting in a carbonized liquid.

[0127] S114: A diaphragm filter press is used to separate the carbonized liquid into magnesium-rich slag and active low-calcium magnesium-rich liquor. The magnesium-rich slag is returned to the digestion section, while the active low-calcium magnesium-rich liquor enters the buffer mixing tank.

[0128] In this embodiment, the activator added to the enhanced gas-liquid reactor is 0.1% of the total magnesium oxide mass in the digestion liquid. The activator is a 10% solution prepared by mixing oxalic acid, sodium phosphate, and magnesium polycarboxylate in a mass ratio of 10:5:1.

[0129] S115: The active low-calcium-rich magnesium solution is pumped into the pyrolysis tank and pyrolyzed for 60 minutes at a stirring speed of 120 rpm, a pressure of -40 kPa, and a heating temperature of 60℃. The pyrolyzed mixture is then transported to a centrifugal dehydrator via a hot water pump for solid-liquid separation to obtain a basic magnesium carbonate wet slag with a water content of 63% and a pyrolysis liquid.

[0130] S116: Basic magnesium carbonate wet slag is conveyed to a flash dryer at 180℃ via a screw feeder. After drying, basic magnesium carbonate dry powder with a moisture content of 1.4% is obtained. The basic magnesium carbonate dry powder is conveyed to a rotary kiln under negative pressure. After calcination, cooling and screw discharge, active magnesium oxide with a D50 particle size of 12µm, a D90 particle size of 35µm, a citric acid value of 10.5s and a purity of 95.8% is obtained.

[0131] S120: Preparation of ordinary magnesium oxide.

[0132] S121: Magnesite with a magnesium content (calculated as magnesium oxide) of 46.26% is used as raw material. The raw ore is crushed to less than 50 mm by a jaw crusher for coarse crushing, and further crushed to 15 mm by a cone crusher for medium crushing. Closed-circuit screening ensures that the ore particle size meets the standard.

[0133] S122: Adjust the ore powder concentration to 35%, add sulfuric acid to adjust the pH to 5.5, add sodium silicate at 300 g / ton of raw ore and dodecylamine at 300 g / ton of raw ore, and remove talc, quartz and other silicate gangue minerals through flotation equipment to obtain magnesium-containing underflow slurry. Adjust the concentration of the underflow slurry after reverse flotation to 30% by adding water, add sodium hydroxide to adjust the slurry pH to 9.5, add sodium hexametaphosphate at 100 g / ton of raw ore and sodium oleate at 1500 g / ton of raw ore, and suppress calcium and iron impurities such as dolomite and calcite through flotation equipment to obtain flotation concentrate.

[0134] S123 introduces the waste heat negative pressure of the calcining furnace into the drying host, and the wet concentrate powder is continuously conveyed into the drying host. The material and hot air undergo high-speed mass and heat transfer, causing the moisture to vaporize and evaporate instantly, drying and dehydrating to <1%, and obtaining dry concentrate powder.

[0135] S124 dry powder is preheated in multiple stages and then enters a flash vortex dynamic calcination furnace. In the upward rotating airflow of the flash vortex dynamic calcination furnace, it undergoes a full thermal decomposition reaction at 780℃ to obtain ordinary magnesium oxide with a silicon content of 0.4%, a calcium content of 1.1%, an iron content of 0.3%, and a purity of 96.18%.

[0136] S200: Preparation of modifier.

[0137] Magnesium bicarbonate, polyethylene glycol, calcium dihydrogen phosphate, cerium oxide, and sodium ethylenediaminetetraacetate were mixed in a mass ratio of 1:1:1:1:1, then fed into a pulverizer and ground to 300 mesh at 35°C to obtain a composite modifier.

[0138] S300: Modified magnesium oxide.

[0139] One component of active magnesium oxide and nine components of ordinary magnesium oxide were added to a hybrid modified mixer. A composite modifier was added at 0.5% of the total mass of the active and ordinary magnesium oxides. The mechanical stirring time was 150 min. The stirring speed was 4000 rpm. After physicochemical modification, an active magnesium-based material was obtained.

[0140] The average particle size D50 of the active magnesium-based material obtained in this embodiment is 12µm, the average particle size D90 is 35µm, the citric acid value is 10.5s, the purity is 95.7%, and the loose bulk density is 0.58g / cm³. 3 The hydration level is 80.8%. Figure 2 The SEM image of the active magnesium-based material prepared in this embodiment is shown.

[0141] Example 2

[0142] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 200, magnesium bicarbonate, polyethylene glycol, calcium dihydrogen phosphate, cerium oxide, and sodium ethylenediaminetetraacetate are mixed in a mass ratio of 1:1:2:2:2. The remaining steps are the same as in Example 1 and will not be repeated here.

[0143] Example 3

[0144] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 200, magnesium bicarbonate, polyethylene glycol, calcium dihydrogen phosphate, cerium oxide, and sodium ethylenediaminetetraacetate are mixed in a mass ratio of 1:1:2:1:3. The remaining steps are the same as in Example 1 and will not be repeated here.

[0145] Example 4

[0146] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 200, magnesium carbonate, stearic acid, N,N-bis(methylenephosphonic acid)-3-pyridinemethylamine, cerium oxide, and sodium ethylenediaminetetraacetate are mixed in a mass ratio of 1:1:1:1:1. The remaining steps are the same as in Example 1 and will not be repeated here.

[0147] Example 5

[0148] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 300, a composite modifier is added at 3% of the total mass of active magnesium oxide and ordinary magnesium oxide. The remaining steps are the same as in Example 1 and will not be repeated here.

[0149] Example 6

[0150] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 300, a composite modifier is added at 0.05% of the total mass of active magnesium oxide and ordinary magnesium oxide. The remaining steps are the same as in Example 1 and will not be repeated here.

[0151] Example 7

[0152] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 300, 10 components of active magnesium oxide (prepared by the method in Example 1) are added to a hybrid modified stirrer, and a composite modifier is added at 0.5% of the mass of the active magnesium oxide. The remaining steps are the same as in Example 1 and will not be repeated here.

[0153] Example 8

[0154] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 300, 10 components of ordinary magnesium oxide (prepared by the method in Example 1) are added to a hybrid modified stirrer, and a composite modifier is added at 0.5% of the mass of the active magnesium oxide. The remaining steps are the same as in Example 1 and will not be repeated here.

[0155] Example 9

[0156] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that the stirring speed in step 300 is 3000 rpm. The remaining steps are the same as in Example 1 and will not be repeated here.

[0157] Example 10

[0158] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 200, magnesium carbonate and stearic acid are mixed in a 1:1 mass ratio. The remaining steps are the same as in Example 1 and will not be repeated here.

[0159] Example 11

[0160] The preparation method of the active magnesium-based material in this embodiment differs from that in Example 1 in that, in step 200, sodium polyacrylate, lanthanum oxide, and ethylenediaminetetraacetic acid are mixed in a mass ratio of 1:1:1. The remaining steps are the same as in Example 1 and will not be repeated here.

[0161] Comparative Example 1

[0162] The preparation method of the comparative example of active magnesium-based material differs from that of Example 1 in that no activator is added in step S114 during the preparation of active magnesium oxide. The remaining steps are the same as in Example 1 and will not be repeated here.

[0163] Comparative Example 2

[0164] The preparation method of the comparative active magnesium-based material differs from that of Example 1 in that: no composite modifier is prepared; in step 300, one component of active magnesium oxide and nine components of ordinary magnesium oxide are added to a hybrid modified stirrer, and the mechanical stirring time is 150 min and the stirring speed is 4000 rpm.

[0165] The preparation steps for activated magnesium oxide and ordinary magnesium oxide are the same as in Example 1, and will not be repeated here.

[0166] Comparative Example 3

[0167] The preparation method of this comparative example of active magnesium-based material differs from that of Example 1 in that the stirring speed in step 300 is 1500 rpm. The remaining steps are the same as in Example 1 and will not be repeated here.

[0168] The active magnesium-based materials prepared in Examples 1-11 and Comparative Examples 1-3 were tested, and the test results are shown in Table 1 below.

[0169] Purity was determined according to HG / T 3928-2012, the method for determining industrial active light magnesium oxide.

[0170] Bulk density was determined according to GB / T 23771-2009, "Determination of Bulk Density in Inorganic Chemical Products".

[0171] The citric acid value was determined according to HG / T 3928-2012, the method for determining industrial active light magnesium oxide.

[0172] Hydration was determined using the method for determining the chemical activity of ordinary magnesium oxide, as specified in YB / T 4019-2006.

[0173] The average particle size is based on HG / T 3821-2006 industrial magnesium hydroxide.

[0174] Table 1. Test results of products obtained in Examples 1-11 and Comparative Examples 1-3

[0175]

[0176] As shown in Table 1 above, adding a suitable modifier helps to improve the hydration of the product; compared with Example 1 and Comparative Example 1, the activator has a significant effect on the citric acid value and particle size of the product.

[0177] Application Example 1

[0178] Cobalt was extracted using a cobalt-containing liquid from a copper-cobalt ore mine owned by a certain enterprise. The cobalt-containing liquid contained 10.5 g / L of Co, 2.5 g / L of Mn, 5.3 g / L of Mg, and 0.43 g / L of Ca.

[0179] The cobalt extraction process using the active magnesium-based material obtained in Example 1 involves the following steps:

[0180] (1) Turn on the constant temperature water bath and set the temperature to 30℃.

[0181] (2) Pour 800 mL of cobalt-containing solution into a beaker, place it in a constant temperature water bath, connect a digital display electric stirrer, and set the speed to 500 rpm.

[0182] (3) Prepare a 10% slurry of active magnesium-based material and stir and mature for 60 minutes. Take the theoretical amount of slurry and slowly add it to the cobalt-containing solution in step (2). Start timing after completion. The reaction lasts for a total of 5 hours. The theoretical amount of 10% active magnesium-based material slurry is 57.12g.

[0183] (4) After the reaction is completed, the reaction solution is filtered, the volume of the filtrate is recorded, and then the cobalt content of the liquid after cobalt precipitation is detected.

[0184] (5) Transfer the cobalt hydroxide slag to a reaction beaker, add water to rinse, and after rinsing, send it to a forced-air drying oven to dry to constant weight, and test the content of magnesium, cobalt and manganese in cobalt hydroxide.

[0185] (6) After the experiment, calculate the cobalt deposition rate and unit consumption: Cobalt deposition rate = 1 - Co metal content in the liquid after cobalt deposition / Co metal content in the liquid before cobalt deposition; Unit consumption = Amount of active magnesium-based material used / Amount of cobalt hydroxide Co metal.

[0186] The cobalt-precipitated liquid and cobalt slag were tested according to the method in "Crude Nickel-Cobalt Hydroxide" (YS / T 1460-2021). In this application example 1, the volume of the cobalt-precipitated liquid was 832 mL and the cobalt concentration was 185 mg / L; the cobalt grade in the cobalt hydroxide slag was 47.7%, the magnesium content was 2.54%, and the manganese content was 2.03%.

[0187] The cobalt deposition rate of the active magnesium-based material = 1 - (0.832L * 0.185g / L) / (0.8L * 10.5g / L) = 98.17%.

[0188] The consumption of active magnesium-based material is 57.12g * 0.1 / (0.8L * 10.5g / L - 0.832L * 0.185g / L) = 693kg / tCo.

[0189] Application Example 2

[0190] The difference between this application example and application example 1 is that the precipitant used to precipitate the cobalt-containing solution is the active magnesium-based material obtained by modifying ordinary magnesium oxide in example 8. The remaining steps are the same as in application example 1, and will not be repeated here.

[0191] In this application example, the volume of the liquid after cobalt precipitation is 817 mL, and the cobalt concentration is 224 mg / L; the cobalt grade in the cobalt hydroxide slag is 47.2%, the magnesium content is 2.66%, the manganese content is 2.11%, the cobalt precipitation rate of the active magnesium-based material is 97.82%, and the consumption is 695 kg / tCo.

[0192] Application Example 3

[0193] Nickel and cobalt were extracted from nickel-bearing liquid in a laterite nickel ore mine by a certain enterprise. The nickel-bearing liquid contained 3.63 g / L Ni, 0.33 g / L Co, 2.51 g / L Mn, 8.2 g / L Mg, and 0.41 g / L Ca.

[0194] The process of extracting nickel and cobalt from the above-mentioned nickel-containing liquid using the active magnesium-based material obtained in Example 1 includes the following steps:

[0195] (1) Turn on the constant temperature water bath and set the temperature to 60℃.

[0196] (2) Pour 800 mL of nickel-containing liquid into a beaker, place it in a constant temperature water bath, connect a digital display electric stirrer, and set the speed to 500 rpm.

[0197] (3) Prepare a 10% slurry of active magnesium-based material and stir and mature for 60 minutes. Take the theoretical amount of slurry and slowly add it to the nickel-containing solution in step (2). Start timing after completion. The reaction lasts for a total of 3 hours. The theoretical amount of 10% active magnesium-based material slurry is 21.54g.

[0198] (4) After the reaction is completed, the reaction solution is filtered, the volume of the filtrate is recorded, and then the nickel and cobalt content of the precipitated liquid is detected.

[0199] (5) Transfer the nickel hydroxide and cobalt hydroxide slag to a reaction beaker, add water to rinse, and after rinsing, send it to a forced-air drying oven to dry to constant weight, and test the content of nickel, magnesium, cobalt and manganese in nickel hydroxide and cobalt hydroxide.

[0200] (6) After the experiment, calculate the nickel deposition rate, cobalt deposition rate and unit consumption: Unit consumption = amount of active magnesium-based material used / amount of nickel hydroxide, cobalt hydroxide Ni and Co metals; Cobalt deposition rate = 1 - amount of Ni and Co metals in the liquid after nickel deposition / amount of Ni and Co metals in the liquid before nickel deposition.

[0201] The liquid and nickel slag after nickel precipitation were tested according to the method in "Crude Nickel-Cobalt Hydroxide" (YS / T 1460-2021). In this application example 2, the volume of the liquid after nickel precipitation was 801 mL, the nickel concentration was 144 mg / L, and the cobalt concentration was 12.4 mg / L. The nickel grade in nickel hydroxide and cobalt hydroxide was 43.21%, the cobalt grade was 3.92%, the magnesium content was 0.32%, and the manganese content was 4.16%.

[0202] Nickel deposition rate of active magnesium-based materials = 1 - (0.801L * 0.144g / L) / (0.8L * 3.63g / L) = 96.03%.

[0203] The cobalt deposition rate of the active magnesium-based material = 1 - (0.801L * 0.0124g / L) / (0.8L * 0.33g / L) = 96.24%.

[0204] The unit consumption of active magnesium-based material = 21.54g * 0.1 / ((0.8L * 3.63g / L + 0.8L * 0.33g / L) - (0.801L * 0.144g / L + 0.801L * 0.0124g / L)) = 708kg / t (Ni, Co).

[0205] Application Comparative Example 1

[0206] The difference between this comparative example and application example 1 is that the precipitant used to precipitate the cobalt-containing solution is the product obtained in comparative example 2. The remaining steps are the same as in application example 1, and will not be repeated here.

[0207] In this application example, the volume of the liquid after cobalt precipitation is 820 mL, and the cobalt concentration is 1140 mg / L; the cobalt grade in the cobalt hydroxide slag is 42.5%, the magnesium content is 4.58%, the manganese content is 3.05%, the cobalt precipitation rate of the active magnesium-based material is 88.87%, and the consumption is 765 kg / t Co.

[0208] Application Comparative Example 2

[0209] The difference between this comparative example and application example 3 is that the precipitant used to precipitate the nickel-containing solution is the product obtained in comparative example 1. The remaining steps are the same as in application example 2, and will not be repeated here.

[0210] In this comparative application, the volume of the liquid after nickel immersion was 805 mL, the nickel concentration was 221 mg / L, and the cobalt concentration was 21 mg / L. The nickel content in nickel hydroxide and cobalt hydroxide was 40.11%, the cobalt content was 3.64%, the magnesium content was 0.69%, and the manganese content was 4.68%. The nickel immersion rate of the active magnesium-based material was 93.87%, the cobalt immersion rate was 93.60%, and the consumption per unit was 724 kg / t (Ni, Co).

[0211] Application Comparative Example 3

[0212] The difference between this comparative example and application example 3 is that the precipitant used to precipitate the nickel-containing solution is the product obtained in comparative example 2. The remaining steps are the same as in application example 2, and will not be repeated here.

[0213] In this comparative application, the volume of the liquid after nickel immersion was 802 mL, the nickel concentration was 356 mg / L, and the cobalt concentration was 32 mg / L. The nickel grade in nickel hydroxide and cobalt hydroxide was 38.98%, the cobalt grade was 3.51%, the magnesium content was 1.23%, and the manganese content was 4.77%. The nickel immersion rate of the active magnesium-based material was 90.17%, the cobalt immersion rate was 90.28%, and the consumption per unit was 754 kg / t (Ni, Co).

[0214] Application Comparative Example 4

[0215] The difference between this comparative example and application example 3 is that the precipitant used to precipitate the nickel-containing solution is the product obtained in comparative example 3. The remaining steps are the same as in application example 2, and will not be repeated here.

[0216] In this comparative application, the volume of the liquid after nickel immersion was 805 mL, the nickel concentration was 173 mg / L, and the cobalt concentration was 13.5 mg / L. The nickel content in nickel hydroxide and cobalt hydroxide was 42.87%, the cobalt content was 3.93%, the magnesium content was 0.47%, and the manganese content was 4.34%. The nickel immersion rate of the active magnesium-based material was 95.20%, the cobalt immersion rate was 95.88%, and the consumption per unit was 714 kg / t (Ni, Co).

[0217] As can be seen from the application examples and comparative examples, the active magnesium-based material prepared by the present invention has significant advantages in the precipitation of nickel and cobalt in the hydrometallurgical process of laterite nickel ore and copper-cobalt ore. Specifically, compared with the comparative examples, the active magnesium-based material prepared by the present invention has improved nickel precipitation rate and cobalt precipitation rate, and reduced unit consumption, indicating that the active magnesium-based material prepared by the present invention has the advantage of high activity. In addition, the active magnesium-based material prepared by the present invention also has the advantages of low magnesium residue and low content of impurities such as manganese when precipitating nickel and cobalt.

[0218] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing an active magnesium-based material, characterized in that, Includes the following steps: The interface modifier, chelating agent, and heterogeneous nucleating agent are pulverized and ground to form the modifier. The mass ratio of the interface modifier, the chelating agent, and the heterogeneous nucleating agent is 1~6:1~3:1~10. The interface modifier is one or more of magnesium bicarbonate, magnesium carbonate, titanate coupling agent, magnesium acetate, polyethylene glycol, and stearic acid. The chelating agent is one or more of hydroxamic acid organic compounds, carboxylic acid organic compounds, and their salts. The heterogeneous nucleating agent is one or more of calcium dihydrogen phosphate, polyacrylate, aminobisphosphonate, and rare earth oxides. Using active magnesium oxide and / or ordinary magnesium oxide as raw materials, the magnesium oxide raw materials are mixed and stirred with a modifier to obtain an active magnesium-based material. When the magnesium oxide and the modifier are mixed, the stirring speed is 2000~5000 rpm, and the amount of the modifier added is 0.05~3% of the total mass of magnesium oxide.

2. The method for preparing the active magnesium-based material according to claim 1, characterized in that, The temperature during the mixing and grinding of the interface modifier, the chelating agent, and the heterogeneous nucleating agent is below 70°C, and the particle size after grinding is less than 100 mesh.

3. The method for preparing the active magnesium-based material according to claim 1 or 2, characterized in that, When the magnesium oxide and the modifier are mixed, the stirring time is 5~240 minutes and the temperature is room temperature.

4. The method for preparing the active magnesium-based material according to claim 1 or 2, characterized in that, The raw material is active magnesium oxide, with a purity >93%, D50 particle size <20μm, D90 particle size <50μm, and citric acid value <30s. Alternatively, the raw material is ordinary magnesium oxide, wherein the purity of the ordinary magnesium oxide is >93%, the D50 particle size is <20μm, the D90 particle size is <50μm, and the citric acid value is <30s; Alternatively, the raw materials may include active magnesium oxide and ordinary magnesium oxide, with a mass ratio of active magnesium oxide to ordinary magnesium oxide of 0.5~2:1~10, and the purity of the active magnesium oxide and / or the ordinary magnesium oxide is >93%, the D50 particle size is <20μm, the D90 particle size is <50μm, and the citric acid value is <30s.

5. The method for preparing the active magnesium-based material according to claim 4, characterized in that, The preparation of active magnesium oxide includes the following steps: The first magnesium ore was calcined and dissociated into calcined white ore in a high-temperature furnace; After calcined white liquor is leached with digested water, it is then filtered through microfiltration to remove residue and obtain digested liquid. The digestion liquid is pumped into an enhanced gas-liquid reactor and an activator is added. Carbon dioxide is then introduced to carbonize the mixture, resulting in a carbonized liquid. The activator consists of oxalic acid, sodium phosphate, and magnesium polycarboxylate, with a mass ratio of oxalic acid, sodium phosphate, and magnesium polycarboxylate of 6-12:5:

1. The amount of activator added is 0.05%-5.0% of the mass of magnesium oxide in the digestion liquid. The carbonation solution was separated into calcium carbonate and an active low-calcium, magnesium-rich solution. The active low-calcium-rich magnesium liquid is pumped into a pyrolysis tank and heated to obtain a solid-liquid mixture. Then, the solid and liquid are separated to obtain basic magnesium carbonate wet residue and pyrolysis liquid. The wet residue of basic magnesium carbonate is conveyed to a flash dryer, where it is broken up, dried into powder, and then calcined at low temperature to obtain active magnesium oxide.

6. The method for preparing the active magnesium-based material according to claim 4, characterized in that, The preparation of ordinary magnesium oxide includes the following steps: The second magnesium ore is crushed and ground to obtain mineral powder; The mineral powder is purified using a combined reverse-direct flotation process to obtain flotation concentrate. The flotation concentrate is dried and dehydrated to obtain dry concentrate powder; The dry refined powder is calcined and decomposed into ordinary magnesium oxide.

7. An active magnesium-based material prepared by the method according to any one of claims 1 to 6, characterized in that, The active magnesium-based material includes at least one of active magnesium oxide and ordinary magnesium oxide, and the active magnesium-based material further includes a modifier. The modifier is an interface modifier, a chelating agent, and a heterogeneous nucleating agent. The mass ratio of the interface modifier, the chelating agent, and the heterogeneous nucleating agent is 1~6:1~3:1~10. The interface modifier is one or more of magnesium bicarbonate, magnesium carbonate, titanate coupling agent, magnesium acetate, polyethylene glycol, and stearic acid. The chelating agent is one or more of hydroxamic acid organic compounds, carboxylic acid organic compounds, and their salts. The heterogeneous nucleating agent is one or more of calcium dihydrogen phosphate, polyacrylate, aminobisphosphonate, and rare earth oxides. The mass of the modifier is 0.05~3% of the total mass of magnesium oxide. The active magnesium-based material has a bulk density greater than 0.5 g / cm³. 3 The hydration activity is 70%~95%.

8. The application of the active magnesium-based material according to claim 7, characterized in that, The active magnesium-based material is used to extract nickel and cobalt from nickel- and cobalt-containing ores, and the extraction of nickel and cobalt from nickel- and cobalt-containing ores includes the following steps: Nickel and cobalt-containing ores are used as raw materials for leaching to obtain nickel and cobalt enriched solutions; Dry powder or slurry of active magnesium-based material is added to the nickel and cobalt enrichment solution. After stirring, nickel and cobalt ions in the nickel and cobalt enrichment solution are precipitated. After solid-liquid separation, nickel and cobalt precipitates are obtained. The amount of active magnesium-based material added is 0.5 to 1.5 times the theoretically required mass of precipitant. The nickel and cobalt precipitates were washed to remove impurities, yielding nickel hydroxide and cobalt hydroxide.

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