Method for separating and recovering aluminum from aluminum-containing lithium ore acid leaching solution

Abstract

The invention provides a method for separating and recovering aluminum from an aluminum-containing lithium ore acid leaching solution, and relates to the field of hydrometallurgy. The method comprises the following steps: removing iron from an aluminum-containing lithium ore acid leaching solution to obtain an iron-removed solution; mixing the iron-removed liquid with an additive to obtain a mixed liquid, and then mixing the mixed liquid with a precipitator to obtain a mixed slurry; mixing the mixed slurry with an aluminum hydroxide seed crystal, then carrying out aging, and carrying out solid-liquid separation to obtain a solid substance and a liquid substance; mixing the liquid with a causticizing agent, and performing causticizing evaporation to obtain mixed gas and causticizing evaporation slurry; and carrying out second solid-liquid separation on the causticized evaporation slurry to obtain a solid and a liquid. According to the method, aluminum in the lithium ore pickle liquor is comprehensively recycled, impurity ions are not introduced, the loss rate of solution lithium is low, waste utilization of aluminum in the solution can be achieved, waste residue emission is reduced, the aluminum precipitant can be regenerated and recycled, the precipitant consumption is low, the process is simple, operation is stable, and the method is suitable for industrial large-scale production.

Description

Technical Field

[0001] The present application relates to the field of hydrometallurgy, and in particular to a method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore. Background Art

[0002] At present, lithium extraction from lithium ore resources mainly adopts sulfuric acid method and sulfate method. Especially sulfuric acid method has high adaptability and maturity, suitable for the treatment of most lithium ore resources, and high lithium leaching rate. However, during the treatment of lithium ore by sulfuric acid method, a large amount of impurities such as Fe and Al are leached into the solution, with contents of 0.1-20g / L and 1-50g / L respectively.

[0003] Aluminum in the sulfuric acid leaching solution of lithium ore is usually not taken as a recycling object, but is removed as an impurity, mainly by neutralization precipitation. By adding limestone and lime, the aluminum is precipitated and stored as aluminum hydroxide slag, and is not recycled. In addition, due to the strong adsorption of aluminum hydroxide slag in conventional precipitation methods, the Li loss rate during the precipitation process is 5-10%, which not only affects the recovery rate of lithium, but also increases the amount of solid waste emissions, affecting the environment.

[0004] In view of this, the present application proposes to separate and recover aluminum from lithium ore acid leaching solution to prepare aluminum hydroxide by-product, which can not only comprehensively utilize the aluminum in the solution and reduce the emission of lithium extraction process slag, but also improve the recovery rate of lithium. Summary of the invention

[0005] The purpose of this application is to provide a method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore to solve the above-mentioned problems.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] A method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore, comprising:

[0008] De-ironizing the aluminum-lithium ore acid leaching solution to obtain a de-ironized solution;

[0009] The iron-removed liquid is mixed with an additive to obtain a mixed liquid, and then the mixed liquid is mixed with a precipitant to obtain a mixed slurry; the additive comprises one or more of dodecanol, ethylenediaminetetraacetic acid, citric acid, and polyethylene glycol;

[0010] The mixed slurry is mixed with aluminum hydroxide seed crystals, and then aged and subjected to a first solid-liquid separation to obtain a first solid and a first liquid; the first solid is used to prepare an aluminum hydroxide product;

[0011] The liquid is mixed with a causticizing agent and then causticized and evaporated to obtain a mixed gas and a causticized evaporated slurry; the mixed gas is used to prepare the precipitant;

[0012] The causticized evaporated slurry is subjected to a second solid-liquid separation to obtain a second solid and a second liquid; the second solid is calcium sulfate slag, and the second liquid is a lithium-containing solution.

[0013] Preferably, in the acid leaching solution of the aluminum-lithium ore, the lithium content is 0.5-20 g / L, the total iron content is less than or equal to 0.1 g / L, the aluminum content is 5-50 g / L, and the pH value is 0.2-2.5.

[0014] Preferably, the amount of the additive is 1-2000 g / m 3 .

[0015] Preferably, the precipitant comprises aqueous ammonia and / or aqueous ammonium carbonate solution;

[0016] The method satisfies one or more of the following conditions:

[0017] (1) The concentrations of the aqueous ammonia and the aqueous ammonium carbonate solution are independently 50-500 g / L;

[0018] (2) The amount of the precipitant is 1-10 times the molar amount of aluminum in the mixed solution;

[0019] (3) The flow ratio of the mixed liquid to the precipitant is (1-20):1;

[0020] (4) The mixed liquid and the precipitant are mixed by using a pipeline mixer and / or a venturi ejector.

[0021] Preferably, the method satisfies one or more of the following conditions:

[0022] (1) The amount of the seed crystal is 1-20 times the amount of aluminum hydroxide precipitation per unit time;

[0023] (2) The aging temperature is 0-100° C. and the aging time is 0.1-24 h;

[0024] (3) The aging is carried out under sealed conditions;

[0025] (4) The aging is carried out in 2-10 aging tanks connected in series, and the height difference between two adjacent aging tanks is 200-2000 mm;

[0026] (5) The end point pH of the aging is 3.5-8.

[0027] Preferably, the method satisfies one or more of the following conditions:

[0028] (1) The first solid-liquid separation is performed by one or more of a vacuum belt filter, a disc vacuum filter, a vertical filter press, a horizontal diaphragm filter press, and a thickener;

[0029] (2) after the first solid-liquid separation, the first solid matter may be washed and dried;

[0030] (3) The aluminum content of the first liquid is lower than 0.1 g / L.

[0031] Preferably, the method satisfies one or more of the following conditions:

[0032] (1) The causticizing agent includes one or more of calcium oxide, calcium hydroxide, sodium hydroxide, and lithium hydroxide;

[0033] (2) the amount of the causticizing agent is 0.2-5 times the molar amount of ammonia in the first liquid;

[0034] (3) The temperature of the causticizing evaporation is 50-120°C and the time is 0.1-24h.

[0035] Preferably, the method satisfies one or more of the following conditions:

[0036] (1) The mixed gas is a mixed gas of ammonia and water vapor;

[0037] (2) The mixed gas is absorbed by an absorption tower to prepare an aluminum precipitant with an ammonia concentration of 20-250 g / L.

[0038] Preferably, the method satisfies one or more of the following conditions:

[0039] (1) The second solid-liquid separation is performed by using one or more of a vacuum belt filter, a vacuum drum filter, a horizontal spiral centrifuge, and a horizontal diaphragm filter press;

[0040] (2) The calcium sulfate content in the calcium sulfate slag is 60-100%.

[0041] Preferably, the lithium carbonate product is prepared from the lithium-containing solution after impurities are removed.

[0042] Compared with the prior art, the beneficial effects of this application include:

[0043] The method for separating and recovering aluminum from the acid leaching solution of aluminum-containing lithium ore provided by the present application has removed iron before aluminum precipitation, so that the aluminum hydroxide product obtained by aluminum precipitation has a high purity, and the aluminum can be used to prepare aluminum hydroxide products that meet the national standard GB / T4294-2010 for recovery. Compared with the traditional precipitation method for aluminum removal (iron and aluminum are precipitated together with the leaching residue), it not only avoids the discharge of waste aluminum slag during lithium extraction, but also realizes the waste utilization of aluminum in the solution. By using additives, aging and adding crystal seeds, the prepared aluminum hydroxide has a coarse particle size, a stable crystal morphology, and a lithium loss rate in the solution of less than 1%; compared with the lithium loss rate of 5-10% in the traditional precipitation method for aluminum removal, the loss of lithium in the aluminum separation process is reduced. The precipitant used is combined with caustic evaporation to achieve the renewable recycling of the precipitant, low material consumption and low cost.

[0044] The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore provided in the present application is simple to operate and has a stable process, and can be applied to industrial-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0046] Figure 1 A schematic process flow diagram of a method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore provided in an embodiment. DETAILED DESCRIPTION

[0047] In order to better explain the technical solution provided by this application, before the embodiments, the technical solution is first described as a whole, as follows:

[0048] A method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore, comprising:

[0049] De-ironizing the aluminum-lithium ore acid leaching solution to obtain a de-ironized solution;

[0050] The iron-removed liquid is mixed with an additive to obtain a mixed liquid, and then the mixed liquid is mixed with a precipitant to obtain a mixed slurry; the additive comprises one or more of dodecanol, ethylenediaminetetraacetic acid, citric acid, and polyethylene glycol;

[0051] The mixed slurry is mixed with aluminum hydroxide seed crystals (a portion of which is taken from the first solid and used as seed crystals), and then aged and subjected to a first solid-liquid separation to obtain a first solid and a first liquid; the first solid is used to prepare an aluminum hydroxide product;

[0052] The liquid is mixed with a causticizing agent and then causticized and evaporated to obtain a mixed gas and a causticized evaporated slurry; the mixed gas is used to prepare the precipitant;

[0053] The causticized evaporated slurry is subjected to a second solid-liquid separation to obtain a second solid and a second liquid; the second solid is calcium sulfate slag, and the second liquid is a lithium-containing solution.

[0054] The function of additives is to reduce the surface tension of the solution and weaken its hindrance to the aggregation of aluminum hydroxide particles, thereby accelerating the rate at which the seeds adsorb aluminum ions, which is beneficial to the growth of the seeds and thus increases the number of aluminum hydroxide particles; at the same time, some will change the growth direction of aluminum hydroxide and form a certain morphology.

[0055] In an optional embodiment, the aluminum-lithium ore acid leaching solution has a lithium content of 0.5-20 g / L, a total iron content of less than or equal to 0.1 g / L, an aluminum content of 5-50 g / L, and a pH value of 0.2-2.5.

[0056] Optionally, in the aluminum-containing lithium ore acid leaching solution, the lithium content can be 0.5 g / L, 1 g / L, 5 g / L, 10 g / L, 15 g / L, 20 g / L or any value between 0.5-20 g / L, the total iron content can be 0.01 g / L, 0.05 g / L, 0.1 g / L or any value less than or equal to 0.1 g / L, the aluminum content can be 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L or any value between 5-50 g / L, and the pH value can be 0.2, 0.5, 1.0, 1.5, 2.0, 2.5 or any value between 0.2-2.5.

[0057] In an optional embodiment, the amount of the additive is 1-2000 g / m 3 .

[0058] Optionally, the amount of the additive can be 1 g / m 3 , 10g / m 3 , 50g / m 3 , 100g / m 3 , 500g / m 3 , 1000g / m 3 , 1500g / m 3 , 2000g / m 3 Or 1-2000g / m 3 Any value in between.

[0059] It should be noted that g / m 3 It refers to the amount of additives per cubic meter of iron-removing liquid.

[0060] In an optional embodiment, the precipitant includes aqueous ammonia and / or aqueous ammonium carbonate solution;

[0061] Ammonia water and / or ammonium carbonate aqueous solution are used as precipitants, and other impurity ions that affect lithium extraction are not introduced while aluminum in the solution is precipitated and separated.

[0062] The method satisfies one or more of the following conditions:

[0063] (1) The concentrations of the aqueous ammonia and the aqueous ammonium carbonate solution are independently 50-500 g / L;

[0064] Optionally, the concentrations of the aqueous ammonia and the aqueous ammonium carbonate solution may be independently 50 g / L, 100 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 350 g / L, 400 g / L, 450 g / L, 500 g / L or any value between 50 and 500 g / L;

[0065] (2) The amount of the precipitant is 1-10 times the molar amount of aluminum in the mixed solution;

[0066] Optionally, the amount of the precipitant may be 1 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times or any value between 1 and 10 times the molar amount of aluminum in the mixed liquid;

[0067] (3) The flow ratio of the mixed liquid to the precipitant is (1-20):1;

[0068] Optionally, the flow ratio of the mixed liquid to the precipitant may be 1:1, 5:1, 10:1, 15:1, 20:1 or any value between (1-20):1;

[0069] (4) The mixed liquid and the precipitant are mixed by using a pipeline mixer and / or a venturi ejector.

[0070] The use of the above equipment for rapid mixing is also one of the factors affecting the preparation of aluminum hydroxide with stable crystalline morphology and coarse particle size (D50 is 20 to 75 microns); among them, rapid mixing is mainly used to form a stable morphology, and adding seeds and aging are mainly used to increase the particle size.

[0071] In an optional embodiment, the method satisfies one or more of the following conditions:

[0072] (1) The amount of the seed crystal is 1-20 times the amount of aluminum hydroxide precipitation per unit time;

[0073] Optionally, the amount of the seed crystal can be 1 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, 16 times, 17 times, 18 times, 19 times, 20 times the amount of aluminum hydroxide precipitation per unit time, or any value between 1-20 times;

[0074] (2) The aging temperature is 0-100° C. and the aging time is 0.1-24 h;

[0075] Optionally, the aging temperature may be 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C or any value between 0-100°C, and the aging time may be 0.1h, 1h, 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h or any value between 0.1-24h;

[0076] (3) The aging is carried out under sealed conditions;

[0077] (4) The aging is carried out in 2-10 aging tanks connected in series, and the height difference between two adjacent aging tanks is 200-2000 mm;

[0078] The number of aging tanks can be any value among 2, 3, 4, 5, 6, 7, 8, 9, and 10; the height difference between two adjacent aging tanks can be 200mm, 500mm, 1000mm, 1500mm, 2000mm, or any value between 200-2000mm;

[0079] There is a height difference between the tanks, and the slurry flows by gravity between the aging tanks using the difference in liquid levels. Each aging tank discharges slurry from the bottom and introduces slurry from the top, and the slurry flows by gravity from the first tank to the last tank.

[0080] (5) The end point pH of the aging is 3.5-8.

[0081] Optionally, the endpoint pH of the aging can be 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or any value between 3.5 and 8.

[0082] In an optional embodiment, the method satisfies one or more of the following conditions:

[0083] (1) The first solid-liquid separation is performed by one or more of a vacuum belt filter, a disc vacuum filter, a vertical filter press, a horizontal diaphragm filter press, and a thickener;

[0084] (2) after the first solid-liquid separation, the first solid matter may be washed and dried;

[0085] (3) The aluminum content of the first liquid is lower than 0.1 g / L.

[0086] In an optional embodiment, the method satisfies one or more of the following conditions:

[0087] (1) The causticizing agent includes one or more of calcium oxide, calcium hydroxide, sodium hydroxide, and lithium hydroxide;

[0088] (2) the amount of the causticizing agent is 0.2-5 times the molar amount of ammonia in the first liquid;

[0089] Optionally, the amount of the causticizing agent may be 0.2 times, 0.5 times, 1 times, 2 times, 3 times, 4 times, 5 times, or any value between 0.2 and 5 times the molar amount of ammonia in the first liquid;

[0090] (3) The temperature of the causticizing evaporation is 50-120°C and the time is 0.1-24h.

[0091] Optionally, the temperature of the causticizing evaporation can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or any value between 50-120°C, and the time can be 0.1h, 1h, 6h, 12h, 18h, 24h or any value between 0.1-24h.

[0092] In an optional embodiment, the method satisfies one or more of the following conditions:

[0093] (1) The mixed gas is a mixed gas of ammonia and water vapor;

[0094] (2) The mixed gas is absorbed by an absorption tower to prepare an aluminum precipitant with an ammonia concentration of 20-250 g / L.

[0095] Optionally, the ammonia concentration of the aluminum precipitant prepared by absorbing the mixed gas in an absorption tower can be 20g / L, 50g / L, 100g / L, 150g / L, 200g / L, 250g / L or any value between 20-250g / L.

[0096] In an optional embodiment, the method satisfies one or more of the following conditions:

[0097] (1) The second solid-liquid separation is performed by using one or more of a vacuum belt filter, a vacuum drum filter, a horizontal spiral centrifuge, and a horizontal diaphragm filter press;

[0098] (2) The calcium sulfate content in the calcium sulfate slag is 60-100%.

[0099] Optionally, the calcium sulfate content in the calcium sulfate slag may be 60%, 70%, 80%, 90%, 100% or any value between 60-100%.

[0100] In an optional embodiment, the lithium carbonate product is prepared after removing impurities from the lithium-containing solution.

[0101] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0102] Example 1

[0103] like Figure 1 As shown, the present application provides a method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore, and the specific steps are as follows:

[0104] The solution after acid leaching and iron removal of a clay-type lithium ore contains 2.5 / L lithium, 0.01g / L iron, 25g / L aluminum, and the pH value of the solution is 2.0. 100g of polyethylene glycol is added to each cubic solution, and the solution is dissolved and mixed evenly to obtain the aluminum solution to be precipitated; the aluminum solution to be precipitated is pumped into the A inlet of the rapid mixer at a flow rate of Q1 by a metering device, and at the same time, ammonia water (precipitant) with a prepared concentration of 150g / L and a molar amount of 3.1 times the molar amount of aluminum in the solution is pumped into the B inlet of the rapid mixer at a flow rate of Q2 by a metering device to quickly mix the aluminum solution to be precipitated with the precipitant; the rapid mixer is 2 pipeline mixers connected in series, and the flow ratio of Q1 to Q2 during aluminum precipitation is 3.1:1. The slurry mixed by the rapid mixer flows by gravity into a closed stirring aging tank with stirring. The amount of seed crystals returned is 6 times the amount of aluminum hydroxide precipitation per unit time, the aging temperature is 45°C, the aging time is 6 hours, and the aging tanks are connected in series with 3 tanks. The height difference between the tanks is 600mm. The slurry flows by gravity between the aging tanks using the liquid level difference of the slurry. Each aging tank adopts the method of discharging slurry from the bottom and feeding slurry from the top. The slurry flows by gravity from the first tank to the last tank, and the pH value of the slurry at the end of aging is controlled to be 5.5. The slurry discharged from aging is filtered and washed by a vertical filter press to separate the filter cake and filtrate in the slurry; the filter cake is dried by a dryer to prepare a product that meets the national standard GB / T The AH-2 aluminum hydroxide product of 4294-2010 has an aluminum hydroxide particle size D50 of 45 microns; the aluminum precipitation rate in the solution is 99.8%, and the aluminum content in the filtrate is 0.06 g / L; the filtrate is added with a calcium oxide causticizer for causticization and evaporation, the amount of the causticizer added is 0.6 times the molar amount of ammonia in the filtrate, the causticization evaporation temperature is 95°C, and the causticization evaporation time is 1 hour; the gas formed by the causticization evaporation is a mixed gas of ammonia and water vapor, which is absorbed by a spray absorption tower to obtain an aluminum precipitant with an ammonia concentration of 150 g / L, and is returned for aluminum precipitation; the slurry formed by the causticization evaporation is filtered / washed by a vacuum belt filter, and the filter residue is a calcium sulfate residue with a calcium sulfate content (dry basis) of 77%, which can be used as a cement building raw material after treatment; the lithium loss rate of the solution during the aluminum precipitation process is 0.35%; the filtrate is a lithium-containing solution, and the impurities are removed by conventional methods to prepare a lithium precipitant that meets the national standard (GB / T 11075-2013) 2 CO 3 -No. 0 lithium carbonate product requirements.

[0105] Example 2

[0106] The present application provides a method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore, and the specific steps are as follows:

[0107] After calcination, acidification, roasting, water leaching and iron removal, the solution of a spodumene concentrate contains 21g / L lithium, 0.006g / L iron, 14g / L aluminum, and the pH value of the solution is 1.5. 50g of ethylenediaminetetraacetic acid is added to each cubic solution, and the solution is dissolved and mixed evenly to obtain the aluminum solution to be precipitated; the aluminum solution to be precipitated is pumped into the A inlet of the rapid mixer at a flow rate of Q1 by a metering device, and at the same time, the prepared ammonia precipitant with a concentration of 120g / L and a molar amount of 3.1 times the molar amount of aluminum in the solution is pumped into the B inlet of the rapid mixer at a flow rate of Q2 by a metering device, and the aluminum solution to be precipitated and the precipitant are quickly mixed; the rapid mixer is 2 parallel venturi ejector mixers, and the flow ratio of Q1 to Q2 during aluminum precipitation is 4.4:1. The slurry mixed by the rapid mixer flows by gravity into a closed stirring aging tank with stirring. The amount of returned seed crystals is 3 times the amount of aluminum hydroxide precipitation per unit time, the aging temperature is 40°C, the aging time is 4 hours, and the aging tanks are connected in series with two tanks. The height difference between the tanks is 800mm. The slurry flows by gravity between the aging tanks using the liquid level difference of the slurry. Each aging tank adopts the method of discharging slurry from the bottom and feeding slurry from the top. The slurry flows by gravity from the first tank to the last tank, and the pH value of the slurry at the end of aging is controlled to be 5.0. The slurry discharged from the aging was filtered and washed by a horizontal diaphragm filter press to separate the filter cake and filtrate in the slurry; the filter cake was dried by a dryer to prepare the AH-2 aluminum hydroxide product that meets the national standard GB / T4294-2010, and the aluminum hydroxide particle size D50 was 34 microns; the aluminum precipitation rate in the solution was 99.6%, and the aluminum content in the filtrate was 0.05g / L; calcium oxide causticizing agent was added to the filtrate for caustic evaporation, the amount of causticizing agent added was 0.7 times the molar amount of ammonium in the filtrate, the caustic evaporation temperature was 90°C, and the caustic evaporation temperature was 90°C. The causticization evaporation gas is a mixed gas of ammonia and water vapor, which is absorbed by a spray absorption tower to obtain an aluminum precipitant with an ammonia concentration of 120g / L, and is returned for aluminum precipitation; the slurry formed by causticization evaporation is filtered / washed by a vacuum belt filter, and the filter residue is a calcium sulfate residue with a calcium sulfate content (dry basis) of 76%, which can be used as a cement building raw material after treatment; the lithium loss rate of the solution during aluminum precipitation is 0.2%; the filtrate is a lithium-containing solution, which is prepared by conventional methods after impurities are removed to meet the national standard (GB / T 11075-2013) Li 2 CO 3 -No. 0 lithium carbonate product requirements.

[0108] Example 3

[0109] The present application provides a method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore, and the specific steps are as follows:

[0110] The solution after calcination, acid leaching and iron removal of a mixed lithium ore contains 10g / L lithium, 0.004g / L iron, 10g / L aluminum, and the pH value of the solution is 1.2. 200g of citric acid is added to each cubic solution, and dissolved and mixed evenly to obtain the aluminum solution to be precipitated; the aluminum solution to be precipitated is pumped into the A inlet of the rapid mixer at a flow rate of Q1 by a metering device, and at the same time, the prepared ammonium carbonate precipitant with a concentration of 300g / L and a molar amount of 1.6 times the molar amount of aluminum in the solution is pumped into the B inlet of the rapid mixer at a flow rate of Q2 by a metering device, and the aluminum solution to be precipitated and the precipitant are quickly mixed; the rapid mixer is 3 pipeline mixers connected in series, and the flow ratio of Q1 to Q2 during aluminum precipitation is 5.3:1. The slurry mixed by the rapid mixer flows by gravity into a closed stirring aging tank with stirring. The amount of seed crystals returned is 4 times the amount of aluminum hydroxide precipitation per unit time, the aging temperature is 60°C, the aging time is 8 hours, and the aging tanks are connected in series with 4 tanks. The height difference between the tanks is 400mm. The slurry flows by gravity between the aging tanks using the liquid level difference of the slurry. Each aging tank adopts the method of discharging slurry from the bottom and feeding slurry from the top. The slurry flows by gravity from the first tank to the last tank, and the pH value of the slurry at the end of aging is controlled to be 6.0. The slurry discharged from the aging is filtered and washed by a horizontal diaphragm filter press to separate the filter cake and filtrate in the slurry; the filter cake is dried by a dryer to prepare a product that meets the national standard GB / T AH-2 aluminum hydroxide product of 4294-2010, aluminum hydroxide particle size D50 is 40 microns; aluminum precipitation rate in solution is 99.6%, and aluminum content in filtrate is 0.04g / L; calcium oxide causticizing agent is added to the filtrate for causticizing evaporation, the amount of causticizing agent added is 0.75 times the molar amount of ammonium in the filtrate, the causticizing evaporation temperature is 85°C, and the causticizing evaporation time is 3 hours; the gas formed by causticizing evaporation is a mixed gas of ammonia and water vapor, which is absorbed by a packed absorption tower, and carbon dioxide is introduced to obtain an aluminum precipitant with an ammonium carbonate concentration of 300g / L, and is returned for aluminum precipitation; the slurry formed by causticizing evaporation is filtered / washed by a vacuum belt filter, and the filter residue is a calcium sulfate residue with a calcium sulfate content (dry basis) of 78%, which can be used as a cement building raw material after treatment; the lithium loss rate of the solution during aluminum precipitation is 0.18%; the filtrate is a lithium-containing solution, and the conventional method is used to remove impurities to prepare an aluminum precipitant that meets the national standard (GB / T11075-2013) Li 2 CO 3 -No. 0 lithium carbonate product requirements.

[0111] Comparative Example 1

[0112] The solution after acid leaching and iron removal of a clay-type lithium ore contains 2.5 / L lithium, 0.01g / L iron, 25g / L aluminum, and the pH value of the solution is 2.0. 100g of polyethylene glycol is added to each cubic solution, and dissolved and mixed evenly to obtain the aluminum solution to be precipitated; the aluminum solution to be precipitated is pumped into the A inlet of the rapid mixer at a flow rate of Q1 by a metering device, and at the same time, the prepared sodium hydroxide (precipitant) with a concentration of 200g / L and a molar amount of 3.1 times the molar amount of aluminum in the solution is pumped into the B inlet of the rapid mixer at a flow rate of Q2 by a metering device, and the aluminum solution to be precipitated and the precipitant are quickly mixed; the rapid mixer is 2 pipeline mixers connected in series, and the flow ratio of Q1 to Q2 during aluminum precipitation is 3.1:1. The slurry mixed by the rapid mixer flows by gravity into a closed stirring aging tank with stirring. The amount of returned seed crystals is 6 times the amount of aluminum hydroxide precipitation per unit time, the aging temperature is 45°C, the aging time is 6 hours, and the aging tanks are connected in series with three tanks. The height difference between the tanks is 600mm. The slurry flows by gravity between the aging tanks using the liquid level difference of the slurry. Each aging tank adopts the method of discharging slurry from the bottom and feeding slurry from the top. The slurry flows by gravity from the first tank to the last tank, and the pH value of the slurry at the end of aging is controlled to be 5.5. The slurry discharged from the aging is filtered and washed by a vertical filter press to separate the filter cake and the filtrate in the slurry; the filter cake is dried by a dryer to prepare an AH-2 aluminum hydroxide product that meets the national standard GB / T 4294-2010, and the aluminum hydroxide particle size D50 is 10 microns; the aluminum precipitation rate in the solution is 99.8%, and the aluminum content in the filtrate is 0.05g / L; the lithium loss rate of the solution during the aluminum precipitation process is 8.9%; although the precipitation and recovery of aluminum in the solution can also be achieved by using sodium hydroxide to precipitate aluminum, since sodium hydroxide is a strong base, aluminum hydroxide colloid is easily formed during the aluminum precipitation process to adsorb lithium in the solution, resulting in an increase in the lithium loss rate; in addition, a large amount of sodium ions are introduced into the solution during the aluminum precipitation with sodium hydroxide, and the sodium sulfate content in the solution after the aluminum precipitation reaches 190g / L. In the process of solution concentration, sodium sulfate is easily crystallized and precipitated, which is not conducive to the subsequent recovery of lithium in the filtrate; and the sodium hydroxide precipitant is difficult to regenerate and recycle during the aluminum precipitation process, and the consumption is high, the aluminum precipitation cost is high, and it is not conducive to industrial application.

[0113] Comparative Example 2

[0114] The solution after acid leaching and iron removal of a clay-type lithium ore contains 2.5 / L lithium, 0.01g / L iron, 25g / L aluminum, and the pH value of the solution is 2.0. The solution is directly pumped into the A inlet of the rapid mixer at a flow rate of Q1 by a metering device without adding additives. At the same time, ammonia water (precipitant) with a prepared concentration of 150g / L and a molar amount of 3.1 times the molar amount of aluminum in the solution is pumped into the B inlet of the rapid mixer by a metering device at a flow rate of Q2 to quickly mix the aluminum solution to be precipitated with the precipitant; the rapid mixer is 2 pipeline mixers connected in series, and the flow ratio of Q1 to Q2 during aluminum precipitation is 3.1:1. The slurry mixed by the rapid mixer flows by gravity into a closed stirring aging tank with stirring. The amount of returned seed crystals is 6 times the amount of aluminum hydroxide precipitation per unit time, the aging temperature is 45°C, the aging time is 6 hours, and the aging tanks are connected in series with three tanks. The height difference between the tanks is 600mm. The slurry flows by gravity between the aging tanks using the liquid level difference of the slurry. Each aging tank adopts the method of discharging slurry from the bottom and feeding slurry from the top. The slurry flows by gravity from the first tank to the last tank, and the pH value of the slurry at the end of aging is controlled to be 5.5. The slurry discharged from aging is filtered and washed by a vertical filter press to separate the filter cake and filtrate in the slurry; the filter cake is dried by a dryer to prepare an AH-2 aluminum hydroxide product that meets the national standard GB / T 4294-2010, and the aluminum hydroxide particle size D50 is 18 microns; the aluminum precipitation rate in the solution is 99.7%, and the aluminum content in the filtrate is 0.07 g / L; the aluminum hydroxide particle size obtained by aluminum precipitation without adding additives is small, and the lithium loss rate of the solution during the aluminum precipitation process is 1.2% (caused by aluminum hydroxide adsorption), which is higher than the lithium loss rate (0.35%) of aluminum precipitation with the addition of additives.

[0115] Comparative Example 3

[0116] The solution after acid leaching and iron removal of a clay-type lithium ore contains 2.5 / L lithium, 0.01g / L iron, 25g / L aluminum, and the pH value of the solution is 2.0. 100g of polyethylene glycol is added to each cubic solution, and dissolved and mixed evenly to obtain the aluminum precipitation solution; the aluminum precipitation solution is pumped into the aluminum precipitation stirring tank at a flow rate of Q1 by a metering device, and at the same time, ammonia water (precipitant) with a concentration of 150g / L and a molar amount of 3.1 times the molar amount of aluminum in the solution is pumped into the aluminum precipitation stirring tank by a metering device at a flow rate of Q2. During the process, the flow ratio of Q1 to Q2 is 3.1:1. The aluminum precipitation slurry flows by gravity into a closed stirring aging tank with stirring. The amount of returned seed crystals is 6 times the amount of aluminum hydroxide precipitation per unit time, the aging temperature is 45°C, the aging time is 6 hours, and the aging tanks are connected in series with three tanks. The height difference between the tanks is 600mm. The slurry flows by gravity between the aging tanks using the liquid level difference of the slurry. Each aging tank adopts the method of discharging slurry from the bottom and feeding slurry from the top. The slurry flows by gravity from the first tank to the last tank, and the pH value of the slurry at the end of aging is controlled to be 5.5. The slurry discharged from aging is filtered and washed by a vertical filter press to separate the filter cake and filtrate in the slurry; the filter cake is dried by a dryer to prepare AH-2 aluminum hydroxide product that meets the national standard GB / T 4294-2010, and the aluminum hydroxide particle size D50 is 42 microns; the aluminum precipitation rate in the solution is 99.8%, and the aluminum content in the filtrate is 0.06g / L; however, the lithium loss rate of the solution during the aluminum precipitation process is 2.3%; since the aluminum precipitation liquid and the precipitant are directly added to the aluminum precipitation stirring tank, the mixing intensity is limited, and the rapid diffusion mixing and reaction of the solution and the precipitant cannot be achieved, a small amount of amorphous aluminum hydroxide is formed, resulting in an increase in the lithium adsorption loss of the solution.

[0117] Comparative Example 4

[0118] The solution after acid leaching and iron removal of a clay-type lithium ore contains 2.5 / L lithium, 0.01g / L iron, 25g / L aluminum, and the pH value of the solution is 2.0. 100g of polyethylene glycol is added to each cubic solution, and the solution is dissolved and mixed evenly to obtain the aluminum solution to be precipitated; the aluminum solution to be precipitated is pumped into the A inlet of the rapid mixer at a flow rate of Q1 by a metering device, and at the same time, ammonia water (precipitant) with a prepared concentration of 150g / L and a molar amount of 3.1 times the molar amount of aluminum in the solution is pumped into the B inlet of the rapid mixer at a flow rate of Q2 by a metering device to quickly mix the aluminum solution to be precipitated with the precipitant; the rapid mixer is 2 pipeline mixers connected in series, and the flow ratio of Q1 to Q2 during aluminum precipitation is 3.1:1. The slurry mixed by the rapid mixer flows by gravity into a closed stirring tank with stirring, and the precipitation pH value is controlled to be 5.5. After stirring for 1 hour, the slurry is discharged, and a vertical filter press is used for filtering and washing to separate the filter cake and filtrate in the slurry; the filter cake is dried by a dryer, and the prepared aluminum hydroxide particle size D50 is 15 microns, the particle size is fine, and the filtering performance of aluminum hydroxide is significantly reduced; the aluminum precipitation rate in the solution is 99.5%, the aluminum content in the filtrate is 0.12 g / L, and the aluminum precipitation rate is lower than that in Example 1; in addition, the lithium loss rate of the solution during the aluminum precipitation process is 5.7%, which is higher than that in Example 1.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore, characterized in that: include: De-ironizing the aluminum-lithium ore acid leaching solution to obtain a de-ironized solution; The iron-removed liquid is mixed with an additive to obtain a mixed liquid, and then the mixed liquid is mixed with a precipitant to obtain a mixed slurry; the additive comprises one or more of dodecanol, ethylenediaminetetraacetic acid, citric acid, and polyethylene glycol; The mixed slurry is mixed with aluminum hydroxide seed crystals, and then aged and subjected to a first solid-liquid separation to obtain a first solid and a first liquid; the first solid is used to prepare an aluminum hydroxide product; The liquid is mixed with a causticizing agent and then causticized and evaporated to obtain a mixed gas and a causticized evaporated slurry; the mixed gas is used to prepare the precipitant; The causticized evaporated slurry is subjected to a second solid-liquid separation to obtain a second solid and a second liquid; the second solid is calcium sulfate slag, and the second liquid is a lithium-containing solution.

2. The method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore according to claim 1, characterized in that: The aluminum-containing lithium ore acid leaching solution has a lithium content of 0.5-20 g / L, a total iron content of less than or equal to 0.1 g / L, an aluminum content of 5-50 g / L, and a pH value of 0.2-2.

5.

3. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: The dosage of the additive is 1-2000g / m 3 .

4. The method for separating and recovering aluminum from an acid leaching solution of an aluminum-containing lithium ore according to claim 1, characterized in that: The precipitant includes aqueous ammonia and / or aqueous ammonium carbonate solution; The method satisfies one or more of the following conditions: (1) The concentrations of the aqueous ammonia and the aqueous ammonium carbonate solution are independently 50-500 g / L; (2) The amount of the precipitant is 1-10 times the molar amount of aluminum in the mixed solution; (3) The flow ratio of the mixed liquid to the precipitant is (1-20):1; (4) The mixed liquid and the precipitant are mixed by using a pipeline mixer and / or a venturi ejector.

5. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: The method satisfies one or more of the following conditions: (1) The amount of the seed crystal is 1-20 times the amount of aluminum hydroxide precipitation per unit time; (2) The aging temperature is 0-100° C. and the aging time is 0.1-24 h; (3) The aging is carried out under sealed conditions; (4) The aging is carried out in 2-10 aging tanks connected in series, and the height difference between two adjacent aging tanks is 200-2000 mm; (5) The end point pH of the aging is 3.5-8.

6. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: One or more of the following conditions are met: (1) The first solid-liquid separation is performed by one or more of a vacuum belt filter, a disc vacuum filter, a vertical filter press, a horizontal diaphragm filter press, and a thickener; (2) after the first solid-liquid separation, the first solid matter may be washed and dried; (3) The aluminum content of the first liquid is lower than 0.1 g / L.

7. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: The method satisfies one or more of the following conditions: (1) The causticizing agent includes one or more of calcium oxide, calcium hydroxide, sodium hydroxide, and lithium hydroxide; (2) the amount of the causticizing agent is 0.2-5 times the molar amount of ammonia in the first liquid; (3) The temperature of the causticizing evaporation is 50-120°C and the time is 0.1-24h.

8. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: The method satisfies one or more of the following conditions: (1) The mixed gas is a mixed gas of ammonia and water vapor; (2) The mixed gas is absorbed by an absorption tower to prepare an aluminum precipitant with an ammonia concentration of 20-250 g / L.

9. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: The method satisfies one or more of the following conditions: (1) The second solid-liquid separation is performed by using one or more of a vacuum belt filter, a vacuum drum filter, a horizontal spiral centrifuge, and a horizontal diaphragm filter press; (2) The calcium sulfate content in the calcium sulfate slag is 60-100%.

10. The method for separating and recovering aluminum from an acid leaching solution of aluminum-containing lithium ore according to claim 1, characterized in that: The lithium carbonate product is prepared by removing impurities from the lithium-containing solution.

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