Method for separating magnesium and manganese in laterite-nickel ore hydrometallurgy

Abstract

The invention relates to a method for separating magnesium and manganese in laterite-nickel ore hydrometallurgy, which comprises the following steps of: firstly, adding a neutralizing agent into laterite-nickel ore pickle liquor to react so as to remove iron and aluminum impurities contained in the laterite-nickel ore pickle liquor to obtain iron and aluminum removed liquor; then, adding a neutralizer into the iron and aluminum removed liquid to perform nickel-cobalt-manganese precipitation treatment so as to obtain nickel-cobalt-manganese hydroxide and nickel-cobalt-manganese precipitated liquid; and finally, introducing carbon dioxide into the nickel-cobalt-manganese settled solution to carry out air floatation-gravity settling treatment to obtain an upper emulsion and a lower emulsion, and then carrying out solid-liquid separation to respectively obtain magnesium carbonate and manganese carbonate. The separation method provided by the invention can effectively remove iron and aluminum slag, separate and recover manganese and magnesium elements in the nickel, cobalt and manganese precipitated liquid, and improve the utilization rate of resources.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. Background Art

[0002] Laterite nickel ore is formed by long-term weathering and metamorphism of ultramafic rocks containing iron-magnesium silicate minerals. The upper layer is limonite, which is mainly composed of iron oxides, the middle is a transition layer, and the lower layer is a silicon-magnesium-nickel ore layer. Laterite nickel ore resources are abundant, the mining cost is low, and the beneficiation and smelting process is becoming mature. It can produce a variety of intermediate products such as nickel oxide and nickel iron, and is the main source of nickel resources in the future.

[0003] At present, the wet acid leaching process is often used to extract nickel, cobalt, manganese and other elements from laterite nickel ore. Specifically, the raw laterite nickel ore is processed by wet processes such as "ore dressing pretreatment-high pressure acid leaching-pre-neutralization-CCD washing-iron and aluminum removal-precipitation of nickel, cobalt and manganese" to obtain nickel, cobalt and manganese hydroxide materials and use them to prepare ternary precursors.

[0004] In the wet process, the nickel-cobalt-manganese precipitation liquid obtained after the nickel-cobalt-manganese precipitation step also contains a large amount of manganese ions and magnesium ions, and the existing process usually does not effectively separate the manganese and magnesium elements in the nickel-cobalt-manganese precipitation liquid, resulting in the failure to effectively recycle these metal ions, resulting in a waste of resources. Therefore, it is necessary to propose a new treatment method to solve the above problems existing in the prior art. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. Compared with the prior art, the separation method provided by the present invention can effectively remove iron-aluminum slag while separating and recovering manganese and magnesium elements in the liquid after precipitation of nickel, cobalt and manganese, thereby improving the utilization rate of resources.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy, the separation method comprising the following steps:

[0008] S1, adding a neutralizing agent to the laterite nickel ore acid leaching solution to react, and after the reaction, performing iron and aluminum slag sedimentation treatment and solid-liquid separation to obtain a liquid after iron and aluminum removal;

[0009] S2, adding a neutralizing agent to the iron- and aluminum-removed liquid obtained in step S1 to perform nickel-cobalt-manganese precipitation treatment, and then performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and nickel-cobalt-manganese precipitation liquid;

[0010] S3, introducing carbon dioxide into the nickel-cobalt-manganese precipitated liquid obtained in step S2 for flotation-gravity sedimentation treatment to obtain an upper emulsion and a lower emulsion, and then performing solid-liquid separation on the upper emulsion and the lower emulsion to obtain magnesium carbonate and manganese carbonate respectively.

[0011] In the separation method provided by the present invention, firstly, a neutralizing agent is added to the laterite nickel ore acid leaching solution to precipitate the iron and aluminum ions therein and generate iron-aluminum slag, and then the iron-aluminum slag is removed by sedimentation treatment to obtain an iron-aluminum-removed liquid; then, a neutralizing agent is added to the iron-aluminum-removed liquid to precipitate the nickel, cobalt and manganese therein, to obtain nickel-cobalt-manganese hydroxide and nickel-cobalt-manganese-precipitated liquid. It is worth noting that in the existing process for the nickel-cobalt-manganese-precipitated liquid, the manganese and magnesium elements therein are usually not recovered, resulting in resource loss. In the present invention, the inventors have found that after an excess of carbon dioxide is introduced into the nickel-cobalt-manganese-precipitated liquid, under gas floating, the carbon dioxide and the magnesium and manganese ions in the nickel-cobalt-manganese-precipitated liquid fully react to obtain an emulsion, which is separated into upper and lower layers under the action of gravity to obtain an upper emulsion and a lower emulsion, and the upper emulsion and the lower emulsion are further subjected to solid-liquid separation to obtain magnesium carbonate and manganese carbonate, respectively. The above separation process can realize efficient separation of magnesium and manganese ions in the solution after nickel, cobalt and manganese precipitation, and the whole separation process is simple, green and environmentally friendly, and is convenient for large-scale promotion and application.

[0012] In the present invention, the solid-liquid separation is not particularly limited, and any method commonly used in the art for separating solids and liquids may be used, such as filtration, and further such as filter pressing.

[0013] Preferably, the laterite nickel ore acid leaching solution in step S1 comprises the following components: 2-5 g / L iron, 4-8 g / L aluminum, 5-7 g / L nickel, 0.4-0.8 g / L cobalt, 3-5 g / L manganese and 6-10 g / L magnesium.

[0014] In the laterite nickel ore acid leaching solution provided by the present invention, the iron content can be, for example, 2g / L, 2.5g / L, 3g / L, 3.5g / L, 4g / L, 4.5g / L or 5g / L, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable; the aluminum content can be, for example, 4g / L, 4.5g / L, 5g / L, 5.5g / L, 6g / L, 6.5g / L, 7g / L, 7.5g / L or 8g / L, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable; the nickel content can be, for example, 5g / L, 5.5g / L, 6g / L, 6.5g / L or 7g / L, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable. The listed values ​​are equally applicable; the cobalt content can be, for example, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L or 0.8 g / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable; the manganese content can be, for example, 3 g / L, 3.5 g / L, 4 g / L, 4.5 g / L or 5 g / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable; the magnesium content can be, for example, 6 g / L, 6.5 g / L, 7 g / L, 7.5 g / L, 8 g / L, 8.5 g / L, 9 g / L, 9.5 g / L or 10 g / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable.

[0015] Preferably, the neutralizing agent in step S1 includes any one of sodium hydroxide, sodium carbonate, magnesium oxide, potassium hydroxide or calcium carbonate, or a combination of at least two thereof.

[0016] In the present invention, the calcium carbonate is generally added in the form of limestone slurry to reduce the cost of raw materials.

[0017] Preferably, the reaction temperature in step S1 is 60-80°C, for example, it can be 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the pH value of the reaction is 2-6, for example, 2, 3, 4, 5 or 6, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] In the present invention, the pH value of the reaction is preferably controlled within a specific range, so that the iron and aluminum ions in the laterite nickel ore acid leaching solution are precipitated to achieve iron and aluminum removal.

[0020] Preferably, the reaction time is 4-8 h, for example, 4 h, 5 h, 6 h, 7 h or 8 h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the iron-aluminum slag sedimentation treatment in step S1 comprises: adding clay to the reaction solution obtained by the reaction.

[0022] Preferably, the clay comprises any one of montmorillonite, illite, kaolin, sepiolite or attapulgite, or a combination of at least two thereof, preferably a combination of montmorillonite and sepiolite.

[0023] Preferably, the mass ratio of montmorillonite to sepiolite in the clay is (3-10):(2-5), for example, 3:2, 4:3, 5:4, 6:5, 7:2, 8:3, 9:4 or 10:5, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0024] Preferably, the mass concentration of the added clay is 5-10%, which means the ratio of the mass of the added clay (g) / the volume of the reaction solution (L), that is, W / V, for example, it can be 5%, 6%, 7%, 8%, 9% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In the present invention, the iron and aluminum ions in the laterite nickel ore acid leaching solution are precipitated and settled by adding a neutralizing agent, so as to achieve the separation of nickel, cobalt, manganese and iron and aluminum impurities in the leachate. However, since the generated iron and aluminum slag, i.e., iron and aluminum hydroxide, mostly exists in the form of colloid, there are problems of difficulty and incompleteness in the subsequent solid-liquid separation process, resulting in low recovery purity of the nickel, cobalt, manganese hydroxide product. Based on this, the present invention adds clay to the iron and aluminum slag sedimentation treatment to adsorb and settle the iron and aluminum hydroxide colloid therein. It is worth noting that in the present invention, the adsorption and sedimentation effect can be synergistically improved by preferably using a clay combination of montmorillonite and sepiolite and controlling the mass ratio of the two. This is because montmorillonite has unique charge characteristics, has a large specific surface area and a high negative charge density, and can adsorb a large amount of positively charged colloids; and sepiolite has excellent structural characteristics, and the honeycomb pores of sepiolite provide a large specific surface area and porosity, thereby further improving the adsorption and sedimentation of colloids.

[0026] Preferably, the neutralizing agent in step S2 includes any one of sodium hydroxide, sodium carbonate, magnesium oxide or potassium hydroxide, or a combination of at least two thereof.

[0027] Preferably, the temperature of the nickel-cobalt-manganese precipitation treatment in step S2 is 70-90°C, for example, it can be 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C or 90°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the pH value of the nickel, cobalt and manganese precipitation treatment is 7-9, for example, it can be 7, 7.2, 7.4, 7.6, 7.8, 8, 8.2, 8.4, 8.6, 8.8 or 9, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In the present invention, the pH value of the nickel-cobalt-manganese precipitation treatment is controlled within a specific range to precipitate nickel-cobalt and part of manganese in the solution after iron and aluminum removal, and the obtained nickel-cobalt-manganese hydroxide is used to prepare a ternary precursor.

[0030] Preferably, the nickel-cobalt-manganese precipitation treatment time is 3-6 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] Preferably, the air flotation-gravity sedimentation treatment in step S3 comprises: compressing carbon dioxide and then feeding it into a bubble generator to obtain carbon dioxide bubbles, and passing the carbon dioxide bubbles into the nickel-cobalt-manganese precipitation liquid from the bottom.

[0032] Preferably, the flow rate of the carbon dioxide is 5-20 L / min, for example, it can be 5 L / min, 6 L / min, 8 L / min, 10 L / min, 12 L / min, 14 L / min, 16 L / min, 18 L / min or 20 L / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In the present invention, by preferably controlling the flow rate range of carbon dioxide, the separation effect of the upper emulsion and the lower emulsion can be further improved, and the flow rate of carbon dioxide is avoided to be too fast, and the rate of introducing bubbles is also accelerated, resulting in a stirring effect of the solution, which is not conducive to the formation of stratification and reduces the recovery rate of manganese and magnesium; at the same time, the flow rate of carbon dioxide is avoided to be too slow, resulting in the formation of larger particles of precipitation, which affects the separation of magnesium and manganese.

[0034] Preferably, the diameter of the carbon dioxide bubbles is 100nm-100μm, for example, it can be 100nm, 200nm, 400nm, 600nm, 800nm, 1μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm or 100μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In the present invention, by preferably controlling the diameter range of the carbon dioxide bubbles, the stratification of the upper emulsion and the lower emulsion can be further promoted, and the disturbance of the entire solution caused by the bubble diameter being too large or the bubble residence time being too short, which is not conducive to the separation of magnesium and manganese, can be avoided.

[0036] Preferably, the carbon dioxide bubbles are added in excess relative to the manganese and magnesium ions in the solution after nickel, cobalt and manganese precipitation.

[0037] Preferably, step S3 further comprises: calcining the magnesium carbonate to obtain magnesium oxide and carbon dioxide.

[0038] In the present invention, the separated magnesium carbonate is calcined, and the obtained magnesium oxide and carbon dioxide can be reused, further improving the utilization rate of the separated products. In the present invention, the filtrate obtained by solid-liquid separation in step S3 can also be mixed with a neutralizing agent and used for the reaction in step S1 and / or the nickel, cobalt and manganese precipitation treatment in step S2 to achieve comprehensive utilization of the filtrate.

[0039] Preferably, the carbon dioxide obtained by the calcination is reused in the flotation-gravity sedimentation treatment in step S3.

[0040] Preferably, the magnesium oxide obtained by calcination is used as a neutralizing agent in the reaction in step S1 and / or the nickel, cobalt and manganese precipitation treatment in step S2.

[0041] As a preferred technical solution of the present invention, the separation method comprises the following steps:

[0042] S1, adding a neutralizing agent to a laterite nickel ore acid leaching solution, reacting for 4-8 hours at a temperature of 60-80° C. and a pH value of 2-6, adding clay to the reaction solution obtained by the reaction to carry out iron and aluminum slag sedimentation treatment and solid-liquid separation to obtain a liquid after iron and aluminum removal, wherein the laterite nickel ore acid leaching solution comprises the following components: 2-5 g / L iron, 4-8 g / L aluminum, 5-7 g / L nickel, 0.4-0.8 g / L cobalt, 3-5 g / L manganese and 6-10 g / L magnesium, the mass ratio of montmorillonite to sepiolite in the clay is (3-10):(2-5), and the mass concentration of the clay added is 5-10%;

[0043] S2, adding a neutralizing agent to the iron-deoxidized aluminum solution obtained in step S1, performing nickel-cobalt-manganese precipitation treatment for 3-6 hours at a temperature of 70-90° C. and a pH value of 7-9, and then performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and nickel-cobalt-manganese precipitation solution;

[0044] S3, compressing the carbon dioxide, and then feeding it into a bubble generator at a flow rate of 5-20L / min to obtain carbon dioxide bubbles with a diameter of 100nm-100μm, and passing the carbon dioxide bubbles from the bottom into the liquid after the nickel, cobalt and manganese precipitation obtained in step S2 for flotation-gravity sedimentation treatment to obtain an upper emulsion and a lower emulsion, and then performing solid-liquid separation on the upper emulsion and the lower emulsion to obtain magnesium carbonate and manganese carbonate respectively; calcining the magnesium carbonate to obtain magnesium oxide and carbon dioxide, wherein the carbon dioxide obtained by calcination is reused in the flotation-gravity sedimentation treatment in step S3, and the magnesium oxide is reused as a neutralizer in the reaction in step S1 and / or the nickel, cobalt and manganese precipitation treatment in step S2.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The separation method provided by the present invention introduces excess carbon dioxide into the solution after nickel, cobalt and manganese precipitation. Under the floating of gas, the carbon dioxide and the magnesium and manganese ions in the solution after nickel, cobalt and manganese precipitation fully react to obtain an emulsion. Under the action of gravity, the emulsion is separated into upper and lower layers to obtain an upper emulsion and a lower emulsion. After further solid-liquid separation of the upper emulsion and the lower emulsion, magnesium carbonate and manganese carbonate are obtained respectively, thereby realizing efficient separation and recovery of magnesium and manganese ions in the solution after nickel, cobalt and manganese precipitation. The separation process is simple, green and environmentally friendly, and is convenient for large-scale promotion and application.

[0047] (2) In the separation method provided by the present invention, after magnesium carbonate is calcined, the product can be recycled, thereby improving the utilization rate of the separated product.

[0048] (3) In the separation method provided by the present invention, by designing a process for the sedimentation treatment of iron-aluminum slag and adding a specific clay combination, the adsorption and sedimentation effect of the iron-aluminum hydroxide colloid can be synergistically improved, the iron and aluminum content in the nickel-cobalt-manganese hydroxide can be reduced, and the purity of the product can be improved.

[0049] (4) The separation method provided by the present invention can achieve an iron and aluminum removal rate of more than 88.9%, a magnesium recovery rate of more than 69.5%, and a manganese recovery rate of more than 80.7%; under optimal conditions, the separation method provided by the present invention can achieve an iron and aluminum removal rate of more than 95.8%, a magnesium recovery rate of more than 79.8%, and a manganese recovery rate of more than 88.5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of the method for separating magnesium and manganese in laterite nickel ore hydrometallurgy provided in Example 1. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0052] The experimental methods in the following examples and comparative examples without specifying specific conditions are generally carried out according to conventional conditions and conditions described in the manual, or according to conditions recommended by the manufacturer. The general equipment, materials, reagents, etc. used are all commercially available unless otherwise specified.

[0053] Example 1

[0054] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy, such as Figure 1 As shown, the separation method comprises the following steps:

[0055] S1, adding limestone slurry (mainly calcium carbonate) to a laterite nickel ore acid leaching solution (including the following components: 3 g / L iron, 6 g / L aluminum, 6 g / L nickel, 0.6 g / L cobalt, 4 g / L manganese, and 8 g / L magnesium), reacting for 6 hours at a temperature of 70° C. and a pH value of 2, adding clay (the mass ratio of montmorillonite to sepiolite is 7:3) to the reaction solution obtained by the reaction at a mass concentration of 8%, performing iron-aluminum slag sedimentation treatment and filtering to obtain a liquid after iron and aluminum removal;

[0056] S2, adding sodium hydroxide to the iron and aluminum removal solution obtained in step S1, performing nickel, cobalt and manganese precipitation treatment at a temperature of 80° C. and a pH value of 9 for 5 hours, and then filtering to obtain nickel, cobalt and manganese hydroxide and nickel, cobalt and manganese precipitation solution;

[0057] S3, compressing the carbon dioxide, and then feeding it into a bubble generator at a flow rate of 20L / min to obtain carbon dioxide bubbles with a diameter of 100nm-100μm, and passing the carbon dioxide bubbles from the bottom into the nickel-cobalt-manganese precipitation liquid obtained in step S2 for flotation-gravity sedimentation treatment, the carbon dioxide bubbles are added in excess relative to the manganese and magnesium ions in the nickel-cobalt-manganese precipitation liquid to obtain an upper emulsion and a lower emulsion, and then the upper emulsion and the lower emulsion are respectively filtered to obtain magnesium carbonate and manganese carbonate respectively; the magnesium carbonate is calcined to obtain magnesium oxide and carbon dioxide, wherein the carbon dioxide obtained by calcination is reused in the flotation-gravity sedimentation treatment in step S3, and the magnesium oxide is reused as a neutralizer in the reaction in step S1 and / or the nickel-cobalt-manganese precipitation treatment in step S2.

[0058] Example 2

[0059] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy, and the separation method comprises the following steps:

[0060] S1, adding sodium carbonate to a laterite nickel ore acid leaching solution (including the following components: 2 g / L iron, 8 g / L aluminum, 5 g / L nickel, 0.8 g / L cobalt, 3 g / L manganese, and 10 g / L magnesium), reacting for 4 hours at a temperature of 60° C. and a pH value of 4, adding clay (the mass ratio of montmorillonite to sepiolite is 3:5) to the reaction solution obtained by the reaction at a mass concentration of 10%, performing iron and aluminum slag sedimentation treatment and filtering to obtain a liquid after iron and aluminum removal;

[0061] S2, adding sodium carbonate to the iron and aluminum removal solution obtained in step S1, performing nickel, cobalt and manganese precipitation treatment at a temperature of 90° C. and a pH value of 7.5 for 6 hours, and then filtering to obtain nickel, cobalt and manganese hydroxide and nickel, cobalt and manganese precipitation solution;

[0062] S3, compressing the carbon dioxide, and then feeding it into a bubble generator at a flow rate of 10L / min to obtain carbon dioxide bubbles with a diameter of 100nm-100μm, and passing the carbon dioxide bubbles from the bottom into the nickel-cobalt-manganese precipitation liquid obtained in step S2 for flotation-gravity sedimentation treatment, the carbon dioxide bubbles are added in excess relative to the manganese and magnesium ions in the nickel-cobalt-manganese precipitation liquid to obtain an upper emulsion and a lower emulsion, and then the upper emulsion and the lower emulsion are respectively filtered to obtain magnesium carbonate and manganese carbonate respectively; the magnesium carbonate is calcined to obtain magnesium oxide and carbon dioxide, wherein the carbon dioxide obtained by calcination is reused in the flotation-gravity sedimentation treatment in step S3, and the magnesium oxide is reused as a neutralizer in the reaction in step S1 and / or the nickel-cobalt-manganese precipitation treatment in step S2.

[0063] Example 3

[0064] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The separation method comprises the following steps:

[0065] S1, adding potassium hydroxide to a laterite nickel ore acid leaching solution (including the following components: 5 g / L iron, 4 g / L aluminum, 7 g / L nickel, 0.4 g / L cobalt, 5 g / L manganese, and 6 g / L magnesium), reacting for 8 hours at a temperature of 80° C. and a pH value of 6, adding clay (the mass ratio of montmorillonite to sepiolite is 10:2) at a mass concentration of 5% to the reaction solution, performing iron-aluminum slag sedimentation treatment and filtering to obtain a solution after iron and aluminum removal;

[0066] S2, adding sodium hydroxide to the iron and aluminum removal solution obtained in step S1, performing nickel, cobalt and manganese precipitation treatment at a temperature of 70° C. and a pH value of 8 for 3 hours, and then filtering to obtain nickel, cobalt and manganese hydroxide and nickel, cobalt and manganese precipitation solution;

[0067] S3, compressing the carbon dioxide, and then feeding it into a bubble generator at a flow rate of 5L / min to obtain carbon dioxide bubbles with a diameter of 100nm-100μm, and passing the carbon dioxide bubbles from the bottom into the nickel-cobalt-manganese precipitation liquid obtained in step S2 for flotation-gravity sedimentation treatment, the carbon dioxide bubbles are added in excess relative to the manganese and magnesium ions in the nickel-cobalt-manganese precipitation liquid to obtain an upper emulsion and a lower emulsion, and then the upper emulsion and the lower emulsion are respectively filtered to obtain magnesium carbonate and manganese carbonate respectively; the magnesium carbonate is calcined to obtain magnesium oxide and carbon dioxide, wherein the carbon dioxide obtained by calcination is reused in the flotation-gravity sedimentation treatment in step S3, and the magnesium oxide is reused as a neutralizer in the reaction in step S1 and / or the nickel-cobalt-manganese precipitation treatment in step S2.

[0068] Example 4

[0069] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The only difference between the separation method and that of Example 2 is that the flow rate of carbon dioxide is 3 L / min.

[0070] Example 5

[0071] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The only difference between the separation method and that of Example 2 is that the flow rate of carbon dioxide is 25 min / L.

[0072] Example 6

[0073] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The only difference between the separation method and the method in embodiment 2 is that the diameter of the carbon dioxide bubbles is 300-500 μm.

[0074] Example 7

[0075] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The only difference between the separation method and the method in Example 1 is that the mass ratio of montmorillonite to sepiolite in the clay is 1:5.

[0076] Example 8

[0077] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The difference between the separation method and the method in Example 1 is that the mass ratio of montmorillonite to sepiolite in the clay is 8:1.

[0078] Example 9

[0079] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The difference between the separation method and the method in Example 1 is that the total amount of the clay remains unchanged and the component is only montmorillonite.

[0080] Example 10

[0081] This embodiment provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The difference between the separation method and the method in embodiment 1 is that the total amount of the clay remains unchanged and the component is only sepiolite.

[0082] Comparative Example 1

[0083] This comparative example provides a method for separating magnesium and manganese in laterite nickel ore hydrometallurgy. The only difference between the separation method and Example 1 is that no flotation-gravity sedimentation treatment is performed, and instead: without passing through a bubble generator, carbon dioxide with the same flow rate and volume as in Example 1 is directly introduced into the solution after the nickel, cobalt and manganese precipitation, and two stratified emulsions cannot be formed. Manganese carbonate precipitate is obtained at the bottom of the solution, but magnesium carbonate cannot be directly recovered, and a subsequent additional process operation for recovering magnesium is required.

[0084] The removal rates of iron and aluminum in the nickel-cobalt-manganese hydroxides obtained in the above examples and comparative examples are shown in Table 1; the recovery rates of magnesium carbonate and manganese carbonate obtained relative to magnesium and manganese in the solution after nickel-cobalt-manganese precipitation are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] In Table 1, “ / ” indicates that magnesium cannot be recovered.

[0089] From the data in Table 1, we can see the following points:

[0090] (1) It can be seen from the data of Examples 1-10 that the separation method provided by the present invention can achieve an iron and aluminum removal rate of more than 88.9%, a magnesium recovery rate of more than 69.5%, and a manganese recovery rate of more than 80.7%; under optimal conditions, the separation method provided by the present invention can achieve an iron and aluminum removal rate of more than 95.8%, a magnesium recovery rate of more than 79.8%, and a manganese recovery rate of more than 88.5%.

[0091] (2) A comprehensive comparison of the data of Example 2 and Examples 4-6 shows that the magnesium and manganese recovery rate in Example 2 is significantly higher than that in Examples 4-6. This shows that the present invention can further improve the separation effect of magnesium and manganese by preferentially controlling the flow rate of carbon dioxide and the diameter of carbon dioxide bubbles.

[0092] (3) A comprehensive comparison of the data of Example 1 and Examples 7-10 shows that the iron and aluminum removal rate in Example 1 is significantly higher than that in Examples 7-10. This shows that the present invention can synergistically improve the adsorption and sedimentation effect by adopting a clay combination of montmorillonite and sepiolite and controlling the mass ratio of the two.

[0093] (4) A comprehensive comparison of the data of Example 1 and Comparative Example 1 shows that, compared with Comparative Example 1, Example 1 can effectively separate and recover the manganese and magnesium elements in the liquid after precipitation of nickel, cobalt and manganese by adopting air flotation-gravity sedimentation treatment, thereby improving the utilization rate of resources.

[0094] In summary, the separation method provided by the present invention can effectively remove the iron-aluminum slag while separating and recovering the manganese and magnesium elements in the liquid after precipitation of nickel, cobalt and manganese, thereby improving the utilization rate of resources.

[0095] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for separating magnesium and manganese in laterite nickel ore hydrometallurgy, characterized in that: The separation method comprises the following steps: S1, adding a neutralizing agent to the laterite nickel ore acid leaching solution to react, and after the reaction, performing iron and aluminum slag sedimentation treatment and solid-liquid separation to obtain a liquid after iron and aluminum removal; S2, adding a neutralizing agent to the iron- and aluminum-removed liquid obtained in step S1 to perform nickel-cobalt-manganese precipitation treatment, and then performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and nickel-cobalt-manganese precipitation liquid; S3, introducing carbon dioxide into the nickel-cobalt-manganese precipitated liquid obtained in step S2 for flotation-gravity sedimentation treatment to obtain an upper emulsion and a lower emulsion, and then performing solid-liquid separation on the upper emulsion and the lower emulsion to obtain magnesium carbonate and manganese carbonate respectively.

2. The separation method according to claim 1, characterized in that The laterite nickel ore acid leaching solution in step S1 comprises the following components: 2-5 g / L iron, 4-8 g / L aluminum, 5-7 g / L nickel, 0.4-0.8 g / L cobalt, 3-5 g / L manganese and 6-10 g / L magnesium.

3. The separation method according to claim 1 or 2, characterized in that The neutralizing agent in step S1 includes any one of sodium hydroxide, sodium carbonate, magnesium oxide, potassium hydroxide or calcium carbonate, or a combination of at least two thereof.

4. The separation method according to any one of claims 1 to 3, characterized in that The reaction temperature in step S1 is 60-80°C; Preferably, the pH value of the reaction is 2-6; Preferably, the reaction time is 4-8 hours.

5. The separation method according to any one of claims 1 to 4, characterized in that: The iron-aluminum slag sedimentation treatment in step S1 includes: adding clay to the reaction solution obtained by the reaction; Preferably, the clay comprises any one of montmorillonite, illite, kaolin, sepiolite or attapulgite, or a combination of at least two thereof, preferably a combination of montmorillonite and sepiolite; Preferably, the mass ratio of montmorillonite to sepiolite in the clay is (3-10):(2-5); Preferably, the clay is added at a mass concentration of 5-10%.

6. The separation method according to any one of claims 1 to 5, characterized in that The neutralizing agent in step S2 includes any one of sodium hydroxide, sodium carbonate, magnesium oxide or potassium hydroxide, or a combination of at least two thereof.

7. The separation method according to any one of claims 1 to 6, characterized in that: The temperature of the nickel-cobalt-manganese precipitation treatment in step S2 is 70-90°C; Preferably, the pH value of the nickel-cobalt-manganese precipitation treatment is 7-9; Preferably, the nickel-cobalt-manganese precipitation treatment time is 3-6 hours.

8. The separation method according to any one of claims 1 to 7, characterized in that: The air flotation-gravity sedimentation treatment in step S3 includes: compressing carbon dioxide and then feeding it into a bubble generator to obtain carbon dioxide bubbles, and passing the carbon dioxide bubbles into the nickel, cobalt and manganese precipitation liquid from the bottom; Preferably, the flow rate of the carbon dioxide is 5-20 L / min; Preferably, the diameter of the carbon dioxide bubbles is 100 nm-100 μm; Preferably, the carbon dioxide bubbles are added in excess relative to the manganese and magnesium ions in the solution after nickel, cobalt and manganese precipitation.

9. The separation method according to any one of claims 1 to 8, characterized in that Step S3 also includes: calcining the magnesium carbonate to obtain magnesium oxide and carbon dioxide; Preferably, the carbon dioxide obtained from the calcination is reused in the flotation-gravity sedimentation treatment in step S3; Preferably, the magnesium oxide obtained by calcination is used as a neutralizing agent in the reaction in step S1 and / or the nickel, cobalt and manganese precipitation treatment in step S2.

10. A separation method according to any one of claims 1 to 9, characterized in that: The separation method comprises the following steps: S1, adding a neutralizing agent to a laterite nickel ore acid leaching solution, reacting for 4-8 hours at a temperature of 60-80° C. and a pH value of 2-6, adding clay to the reaction solution obtained by the reaction to carry out iron and aluminum slag sedimentation treatment and solid-liquid separation to obtain a liquid after iron and aluminum removal, wherein the laterite nickel ore acid leaching solution comprises the following components: 2-5 g / L iron, 4-8 g / L aluminum, 5-7 g / L nickel, 0.4-0.8 g / L cobalt, 3-5 g / L manganese and 6-10 g / L magnesium, the mass ratio of montmorillonite to sepiolite in the clay is (3-10):(2-5), and the mass concentration of the clay added is 5-10%; S2, adding a neutralizing agent to the iron-deoxidized aluminum solution obtained in step S1, performing nickel-cobalt-manganese precipitation treatment for 3-6 hours at a temperature of 70-90° C. and a pH value of 7-9, and then performing solid-liquid separation to obtain nickel-cobalt-manganese hydroxide and nickel-cobalt-manganese precipitation solution; S3, compressing the carbon dioxide, and then feeding it into a bubble generator at a flow rate of 5-20L / min to obtain carbon dioxide bubbles with a diameter of 100nm-100μm, and passing the carbon dioxide bubbles from the bottom into the liquid after the nickel, cobalt and manganese precipitation obtained in step S2 for flotation-gravity sedimentation treatment to obtain an upper emulsion and a lower emulsion, and then performing solid-liquid separation on the upper emulsion and the lower emulsion to obtain magnesium carbonate and manganese carbonate respectively; calcining the magnesium carbonate to obtain magnesium oxide and carbon dioxide, wherein the carbon dioxide obtained by calcination is reused in the flotation-gravity sedimentation treatment in step S3, and the magnesium oxide is reused as a neutralizer in the reaction in step S1 and / or the nickel, cobalt and manganese precipitation treatment in step S2.

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