Method for recovering lithium, silicon and aluminum in clay lithium ore by alkaline process
Through the alkaline method, the problem of more solid waste residue and unrecycled silicon and aluminum during the recycling of lithium, silicon and aluminum in clay lithium ore was solved, and efficient recycling and environmentally friendly results were achieved, and a high leachate lithium-containing solution and silicon were obtained. Aluminum compounds.
Patent Information
- Application Number
- CN202411169333.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2025-02-07
AI Technical Summary
In the prior art, when recycling lithium, silicon and aluminum in clay lithium ore, there is a lot of solid waste residue, which is unfriendly to the environment, and it is not effective to recover high-content silicon and aluminum.
The alkali process is adopted, and the lithium-containing solution and silicon-aluminum compound are obtained by pulverizing and mixing and calcining, acid leaching, suction filtration, evaporation and concentration, and the lithium phosphate and silicon-aluminum compound are finally obtained.
A lithium-containing solution with a high leaching rate of 95.8% was achieved, with a small amount of leaching residue, which was environmentally friendly. The high content of silicon and aluminum in clay lithium ore was successfully recovered to obtain the silicon-aluminum compound Al2 (Al2.8Si1.2)O9. 6.
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Figure CN119391973A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for recovering lithium, silicon and aluminum from clay lithium ore using an alkali method, belonging to the field of element recovery. Background Art
[0002] As a hot new energy metal in the 21st century, lithium has been widely used in electronic products, mobile devices, electric vehicles and other fields. With the continuous development of new energy and modern technology, the demand for lithium in countries around the world has increased rapidly. Relevant statistics show that there were 168 lithium mining mergers and acquisitions projects in the world in 2021, a year-on-year increase of nearly 3 times; the transaction volume was US$4.68 billion, a year-on-year increase of 1.5 times.
[0003] At present, the research on the development and utilization of lithium resources at home and abroad is mainly focused on brine lithium resources and pegmatite lithium resources, but there are relatively few studies on the development and utilization of clay-type lithium resources. In recent years, due to the sharp increase in demand for lithium resources, many researchers have begun to pay attention to the development and utilization of clay-type lithium resources to alleviate the long-term resource shortage problem faced by the development of my country's lithium industry. The clay lithium ore reserves in Yuxi City, Yunnan Province are high and are regarded as potential lithium resources. How to develop and utilize the lithium resources has become a hot topic.
[0004] At present, for clay-type lithium resources, sulfuric acid method, sulfate method, chlorination roasting method, limestone roasting method. According to the existing methods, although the lithium leaching rate is above 80%, the solid waste residue is large, which is not friendly to the environment, and the high content of silicon and aluminum in the clay lithium ore is not recovered. Summary of the invention
[0005] In view of this, the present invention provides a method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method, which obtains a lithium-containing solution with a high leaching rate of 95.8%, has a small amount of leaching residue, is environmentally friendly, retains lithium to the greatest extent during the solid silica gel elution process, and recovers high-content silicon and aluminum in the clay lithium ore to obtain a silicon-aluminum compound Al 2 (Al 2.8 Si 1.2 ) 9.6 ,
[0006] In order to achieve the above object, the present invention adopts the following technical solution:
[0007] A method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method, comprising the following steps:
[0008] (1) crushing and sieving clay lithium ore, mixing with alkali and then roasting to obtain clinker;
[0009] (2) acid leaching the clinker and then filtering it to obtain a filtrate and a filter residue;
[0010] (3) evaporating and concentrating the filtrate, drying, and calcining to obtain solid silica gel;
[0011] (4) eluting the solid silica gel to obtain a lithium-containing solution and a silicon-aluminum compound;
[0012] (5) adjusting the pH of the lithium-containing solution with a sodium phosphate solution to remove impurities, and after solid-liquid separation, evaporating and concentrating the filtrate and washing it with water multiple times to obtain lithium phosphate;
[0013] (6) Aluminum-silicon compound is pickled to obtain Al 2 (Al 2.8 Si 1.2 ) 9.6 .
[0014] On the basis of the above technical solution, the present invention is further limited as follows:
[0015] Furthermore, in step (1), the mineral-alkali ratio is 10:7; the screening is through a 200-mesh sieve; and the roasting is at 800° C. for 2 hours.
[0016] Furthermore, the acid leaching in step (2) is performed by immersing the mixture in 1.5 mol / L sulfuric acid for 1.5 h, with an immersion speed of 600 rpm, and a mass ratio of clinker to acid of 1:10.
[0017] Furthermore, in step (3), the evaporation concentration temperature is 110° C.; the drying temperature is 90° C.; and the calcination is performed at 800° C. for 2 h.
[0018] Furthermore, the elution conditions in step (4) are oil bath at 70° C., solid-liquid ratio 1:10, and time 1.5 h.
[0019] Furthermore, in step (5), the mass fraction of sodium phosphate is 10%; the end point of adjusting the pH value is 6.5; the evaporation temperature is 110° C.; the water washing temperature is 50° C.; and the water washing times are 5 times.
[0020] Furthermore, the pickling in step (6) is carried out with 1.5 mol / L sulfuric acid, an oil bath at 85° C., a rotation speed of 600 rpm, and pickling for 1 hour, with a liquid-to-solid ratio of 10:1.
[0021] The beneficial effects of the present invention are as follows:
[0022] 1. Compared with the traditional method, the present invention can obtain a higher leaching rate, and the amount of leached residue is only 8% of the original ore;
[0023] 2. Recover the high content of silicon and aluminum in clay lithium ore to obtain silicon-aluminum compound Al 2 (Al 2.8 Si 1.2 ) 9.6 ;
[0024] 3. Sodium phosphate is used for impurity removal, which causes very little loss of lithium ions, at 7.52%. Lithium phosphate can be obtained by direct evaporation and concentration.
[0025] 4. Under the condition of reducing environmental pollution, the elements in clay lithium ore can be efficiently recovered. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 This is a process flow chart of alkali recovery process of the present invention;
[0027] Figure 2 The XRD diagram of clay lithium ore and alkali roasting in Example 1 of the present invention;
[0028] Figure 3 The silicon-aluminum compound Al in Example 1 of the present invention 2 (Al 2.8 Si 1.2 ) 9.6 XRD pattern of
[0029] Figure 4 This is the XRD diagram of lithium phosphate of Example 1 of the present invention; DETAILED DESCRIPTION
[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0031] The following examples take the clay lithium ore in Yuxi, Yunnan as an example. The main components of the clay lithium ore are shown in Table 1 below:
[0032] Table 1 Main element composition of lithium clay ore in Yuxi, Yunnan
[0033] Ca / % Mg / % <![CDATA[Li / μg·g -1 ]]> Al / ％ Fe / % Na / % <![CDATA[Ga / μg·g -1 ]]> 0.4 0.14 1170 25.9 4.72 0.05 74.6
[0034] Example 1
[0035] The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method comprises the following steps:
[0036] 1. Activated roasting of clay lithium ore mixed with alkali
[0037] The clay lithium ore was crushed with a pulverizer and then sieved with a 200-mesh standard sieve. 10 g of the sieved concentrate was mixed with 7 g of sodium hydroxide and calcined in a muffle furnace at 800°C for 2 hours, with a loss on ignition of 17.3%.
[0038] 2. Roasting clinker for acid leaching
[0039] The roasted clinker and 1.5 mol / L sulfuric acid were uniformly mixed at a mass ratio of 1:10, and the stirring rate was maintained at 600 rpm for 1.5 hours at room temperature. The obtained solution was filtered to obtain acid leaching filtrate and filter residue. The parallel experiment was repeated 5 times, and the average leaching rate of lithium was 95.8%.
[0040] 3. Pretreatment of acid leaching filtrate
[0041] The extract was evaporated and concentrated in an oil bath at 110°C. When it became a gel, it was taken out and placed in a blast drying oven for drying. The dried gel was placed in a crucible and calcined at 800°C for 2h to obtain solid silica gel.
[0042] 4. Solid silica gel elution experiment
[0043] The solid silica gel was subjected to a water washing experiment, and the elution experimental conditions were an oil bath at 70°C, a solid-liquid ratio of 1:10, and a time of 1.5 hours. After elution, the eluate and the silicon-aluminum compound were obtained by suction filtration, and the retention rate of lithium ions was 88.7%.
[0044] 5. Eluent impurity removal
[0045] At this time, the eluent still contains a small amount of iron ions and aluminum ions, so a removal experiment is required. The impurity removal agent used is a 10% by mass sodium phosphate solution. The iron ions and aluminum ions are removed by adjusting the pH value. When the pH is 6.5, the removal rate of aluminum ions and iron ions is 99.9%, and the lithium ion retention rate is 81.7%.
[0046] 6. Purification of silicon-aluminum compounds
[0047] Considering that the eluted silicon-aluminum compound still contains trace amounts of iron, 1.5 mol / L sulfuric acid was used to remove iron. The experimental conditions were a liquid-to-solid ratio of 10:1, an oil bath of 85°C, 600 rpm, and 1 h. The acid-washed product was filtered, and the filtered solid obtained was Al 2 (Al 2.8 Si 1.2 ) 9.6 .
[0048] 7. Preparation of lithium phosphate
[0049] The impurity removal liquid is evaporated and concentrated in an oil bath environment at 110°C to obtain a solid, which is then washed with 50°C water to remove soluble impurities. After five repeated water washings, the washing liquid does not contain sodium ions, and the washed solid obtained at this time is pure lithium phosphate.
[0050] Example 2
[0051] The following experiment was conducted on the mixed roasting of clay lithium ore and alkali:
[0052] Experimental Example 1
[0053] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of calcium hydroxide, put it into a muffle furnace and roast it at 600°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0054] Experimental Example 2
[0055] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of calcium chloride, put it into a muffle furnace and roast it at 600°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0056] Experimental Example 3
[0057] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of calcium oxide, put it into a muffle furnace and roast it at 600°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0058] Experimental Example 4
[0059] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of sodium hydroxide, put it into a muffle furnace and roast it at 600°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0060] Experimental Example 5
[0061] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of sodium carbonate, put it into a muffle furnace and roast it at 600°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0062] The results of the above experimental examples 1-5 are shown in Table 2 below:
[0063] Table 2 Results of experimental examples 1-5 of mixed roasting and acid leaching of clay lithium ore and alkali
[0064]
[0065]
[0066] From the data in Table 2, it can be seen that the leaching rates of lithium ions vary with the addition of different roasting aids. When sodium hydroxide is added as a roasting aid, the leaching rate of lithium ions reaches 74.4%, which is much higher than other roasting aids. Therefore, sodium hydroxide is considered to be the best roasting aid for clay lithium ore.
[0067] Example 3
[0068] The following experiments were conducted on the optimization experimental conditions of sodium hydroxide roasting aid:
[0069] Experimental Example 6
[0070] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of sodium hydroxide, put it into a muffle furnace and roast it at 200°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0071] Experimental Example 7
[0072] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of sodium hydroxide, put it into a muffle furnace and roast it at 400°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0073] Experimental Example 8
[0074] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of sodium hydroxide, put it into a muffle furnace and roast it at 600°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0075] Experimental Example 9
[0076] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 7g of sodium hydroxide, put it into a muffle furnace and roast it at 800°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0077] Experimental Example 10
[0078] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 6g of sodium hydroxide, put it into a muffle furnace and roast it at 800°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0079] Experimental Example 11
[0080] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 5g of sodium hydroxide, put it into a muffle furnace and roast it at 800°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0081] Experimental Example 12
[0082] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 4g of sodium hydroxide, put it into a muffle furnace and roast it at 800°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0083] Experimental Example 13
[0084] Take 10g of clay lithium ore concentrate passed through a 200-mesh sieve and mix it evenly with 0g of sodium hydroxide, put it into a muffle furnace and roast it at 800°C for 2h, and take the roasted clinker and leaching it in 100g of 1.5mol / L sulfuric acid at room temperature for 1h and 600rpm.
[0085] The results of the above experimental examples 6-13 are shown in Table 3 below:
[0086] Table 3 Results of experimental examples 6-13 of mixed roasting and acid leaching of clay lithium ore and sodium hydroxide
[0087] Loss on ignition Residue rate Leaching rate Experimental Example 6 9.78％ 23.29％ 78.5％ Experimental Example 7 11.85％ 17.92％ 80.38％ Experimental Example 8 15.4％ 15.94％ 83.07 Experimental Example 9 17.3％ 8.2％ 95.8％ Experimental Example 10 17.2％ 11.6％ 93.8％ Experimental Example 11 16.42％ 13.7％ 92.45％ Experimental Example 12 15.87％ 15.8％ 90.7％ Experimental Example 13 14.93％ 87.8％ 8.38％
[0088] From the data in Table 3, we can know that with the increase of roasting temperature and alkali ratio, the lithium ion leaching rate and burn-off rate are constantly increasing, and the residue rate is constantly decreasing. Therefore, when the alkali ratio is 10:7 and the roasting temperature is 800°C, the leaching rate is 95.8% and the residue rate is 8.2%. A higher leaching rate is obtained with an extremely low residue rate, which is environmentally friendly.
[0089] Example 4
[0090] The following experiment was performed for solid colloid elution:
[0091] Experimental Example 14
[0092] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 4:1, for an elution experiment.
[0093] Experimental Example 15
[0094] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 6:1, for an elution experiment.
[0095] Experimental Example 16
[0096] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 8:1, for an elution experiment.
[0097] Experimental Example 17
[0098] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 10:1, for an elution experiment.
[0099] Experimental Example 18
[0100] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0101] Experimental Example 19
[0102] The solid colloid was placed in an oil bath at 50°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0103] Experimental Example 20
[0104] The solid colloid was placed in an oil bath at 70°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0105] Experimental Example 21
[0106] The solid colloid was placed in an oil bath at 90°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0107] Experimental Example 22
[0108] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 0.5 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0109] Experimental Example 23
[0110] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0111] Experimental Example 24
[0112] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 1.5 h, maintaining a liquid-to-solid ratio of 5:1, for an elution experiment.
[0113] Experimental Example 25
[0114] The solid colloid was placed in an oil bath at 30°C, 600 rpm, for 2 h, with the liquid-to-solid ratio maintained at 5:1, for an elution experiment.
[0115] Experimental Example 26
[0116] The solid colloid was placed in an oil bath at 70°C, 600 rpm, for 1.5 h, maintaining a liquid-to-solid ratio of 10:1, for an elution experiment.
[0117] The results of the above experimental examples 14-25 are shown in Table 4 below:
[0118] Table 4 Results of solid colloid water-washed lithium ion experiments 14-25
[0119]
[0120]
[0121] From the experimental data in Table 4, it can be seen that with the increase of elution temperature, liquid-to-solid ratio and elution time, the elution rate of lithium ions is also increasing. Among them, the elution temperature has the greatest impact. The best experimental conditions are elution temperature of 70°C, elution time of 1.5h, and liquid-to-solid ratio of 10. At this time, the elution rate is 88.7%.
[0122] Example 5
[0123] Use 10% sodium phosphate to remove impurities from the eluate
[0124] Table 5 Concentration of various ions in lithium eluent in an environment of pH 2.55-7.53
[0125]
[0126] It can be seen from Table 5 that when the impurity removal pH value is about 6.5, the impurity ions are basically completely removed. When the pH is raised, it is found that the loss of lithium ions increases, which is not conducive to the recovery of lithium. When the impurity removal pH value is about 6.5, the removal rates of aluminum ions and iron ions are both about 99.9%, and the retention rate of lithium ions is 81.7%. The present invention obtains a result at a pH value of about 6.5, and the obtained lithium-containing solution has a high purity and has practical application value. Subsequently, the pure lithium-rich solution is evaporated and concentrated to obtain a solid containing lithium phosphate, and the solid is washed with water for multiple times to remove excess soluble impurities to obtain pure lithium phosphate.
Claims
1. A method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method, characterized in that: Here are the steps: (1) crushing and sieving clay lithium ore, mixing with alkali and then roasting to obtain clinker; (2) acid leaching the clinker and then filtering it to obtain a filtrate and a filter residue; (3) evaporating and concentrating the filtrate, drying, and calcining to obtain solid silica gel; (4) eluting the solid silica gel to obtain a lithium-containing solution and a silicon-aluminum compound; (5) adjusting the pH value of the lithium-containing solution with a sodium phosphate solution to remove impurities, separate the solid from the liquid, evaporate and concentrate the filtrate, and then wash it with water several times to obtain lithium phosphate; (6) Aluminum-silicon compound is pickled to obtain Al2(Al 2.8 Si 1.2 ) 9.6 .
2. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1, characterized in that: In step (1), the mineral-alkali ratio is 10:
7.
3. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1 or 2, characterized in that: The sieving in step (1) is through a 200-mesh sieve; and the calcining is at 800° C. for 2 hours.
4. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1, characterized in that: The acid leaching in step (2) is performed by immersing in 1.5 mol / L sulfuric acid for 1.5 h, the immersion speed is 600 rpm, and the mass ratio of clinker to acid is 1:
10.
5. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1, characterized in that: The evaporation and concentration temperature in step (3) is 110° C.; the drying temperature is 90° C.; and the calcination is performed at 800° C. for 2 h.
6. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1, characterized in that: The elution conditions in step (4) are oil bath at 70° C., solid-liquid ratio 1:10, and time 1.5 h.
7. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1, characterized in that: The mass fraction of the sodium phosphate in step (5) is 10%; the end point of adjusting the pH value is 6.5; the evaporation temperature is 110° C.; the water washing temperature is 50° C.; and the water washing times are 5 times.
8. The method for recovering lithium, silicon and aluminum from clay lithium ore by alkaline method according to claim 1, characterized in that: The pickling in step (6) is carried out with 1.5 mol / L sulfuric acid, an oil bath at 85° C., a rotation speed of 600 rpm, and pickling for 1 hour, with a liquid-to-solid ratio of 10:1.