Process method for extracting lithium and rubidium from calcium oxide calcined lepidolite and synthesizing calcium sulfate whiskers

Abstract

The invention discloses a process method for extracting lithium and rubidium by calcining lepidolite with calcium oxide and synthesizing calcium sulfate whiskers. The process method comprises the following steps: mixing lepidolite and calcium oxide; roasting the mixed material to obtain lepidolite clinker; taking out the clinker, and performing water quenching cooling to obtain water-quenched slag; drying and ball-milling the water-quenched slag to obtain powder slag; adding hydrochloric acid into the powder slag, and mixing to obtain a leaching solution and leaching slag; mixing sodium chloride, ferric chloride and tributyl phosphate to obtain a loaded extraction agent; mixing the leach liquor with a loaded extractant, oscillating and separating to obtain a lithium-containing organic phase and a rubidium chloride-containing solution; performing back extraction separation on the lithium-containing organic phase and hydrochloric acid to obtain lithium chloride, and adding a sodium carbonate solution to react to obtain lithium carbonate; evaporating and crystallizing the rubidium chloride solution to obtain a rubidium chloride solid; and mixing the leaching residues with deionized water, adding sulfuric acid, and stirring to obtain the calcium sulfate whiskers. According to the method, a lepidolite production process and a calcium sulfate whisker production process are combined for joint production, so that the added value of the product is increased, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of lithium mica treatment processes, and particularly to a process method for extracting lithium and rubidium from calcined lithium mica with calcium oxide and synthesizing calcium sulfate whiskers. Background Art

[0002] Currently, with the increasingly strict carbon emission requirements and the rapid development of the new energy industry, the strategic status of lithium and rubidium has been enhanced unprecedentedly. Improving the extraction rates of lithium and rubidium from lithium mica minerals is of great significance for improving the production efficiency of their related chemicals from the source. Among them, lithium, as the metal element with the smallest atomic radius and the lowest density, has an irreplaceable position in modern power batteries and future thermonuclear fusion reactors. And rubidium is an alkaline metal similar to lithium, and its excellent optoelectronic properties gradually show strong vitality in emerging applications such as perovskite solar cells and gradually show strong vitality in emerging applications such as quantum heat engines. Therefore, with the increasing importance of rubidium, the co-extraction of lithium and rubidium is also of great significance. In order to effectively utilize lithium mica, researchers have conducted some studies, mainly divided into three methods: salt roasting, alkali leaching, and low-temperature acid roasting, but they have not efficiently co-extracted lithium and rubidium, and have not treated solid waste. Summary of the Invention

[0003] The main object of the present invention is to provide a process method for extracting lithium and rubidium from calcined lithium mica with calcium oxide and synthesizing calcium sulfate whiskers, aiming to solve the above technical problems.

[0004] To achieve the above object, a process method for extracting lithium and rubidium from calcined lithium mica with calcium oxide and synthesizing calcium sulfate whiskers proposed by the present invention includes:

[0005] Step 1: Uniformly mix lithium mica and calcium oxide in a corundum crucible according to a certain mass ratio;

[0006] Step 2: Place the uniformly mixed mixture in a muffle furnace and roast it under a certain environment to obtain calcined lithium mica clinker;

[0007] Step 3: After the roasting is completed, take out the calcined lithium mica clinker and quickly put it into a water quenching tank for water quenching and cooling to obtain water quenched slag;

[0008] Step 4: Place the cooled water quenched slag in an electrothermal blast drying oven for drying, and ball mill it in a ball mill for 2 hours to obtain powdered slag;

[0009] Step 5: Take a certain amount of the powdered slag, add hydrochloric acid, mix it at a certain temperature, stir and filter to obtain leaching solution and leaching residue;

[0010] Step 6: Uniformly mix sodium chloride, ferric chloride with a certain concentration and tributyl phosphate to obtain a loaded extractant.

[0011] Step 7: Mix the leaching solution and the loaded extractant in a certain proportion, then shake and separate them, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution;

[0012] Step 8: Perform back-extraction on the lithium-containing organic phase with hydrochloric acid, separate to obtain lithium chloride, add an excessive amount of sodium carbonate solution to react to obtain lithium carbonate, and return the separated organic phase to Step 6 for recycling;

[0013] Step 9: Take the rubidium chloride solution and evaporate it to crystallize to obtain rubidium chloride solid.

[0014] Step 10: Mix the leaching residue and deionized water according to a certain solid-liquid ratio, add sulfuric acid to a certain pH, stir, add sodium dodecylbenzenesulfonate as a surfactant, then transfer the slurry to a reaction kettle to react at a certain temperature, and filter after the reaction to obtain calcium sulfate whiskers.

[0015] In one embodiment, the step of uniformly mixing lepidolite and calcium oxide in a corundum crucible according to a certain mass ratio is specifically as follows:

[0016] Uniformly mix lepidolite and calcium oxide in a corundum crucible according to a mass ratio of 5:1.

[0017] In one embodiment, the step of placing the uniformly mixed mixture in a muffle furnace and roasting it in a certain environment to obtain lepidolite clinker is specifically as follows:

[0018] Place the uniformly mixed mixture in a muffle furnace and heat and roast it at a temperature of 1300 °C at a heating rate of 5 °C / min for 0.5 h to obtain lepidolite clinker.

[0019] In one embodiment, the step of taking a certain amount of the powdered furnace slag, adding hydrochloric acid, mixing at a certain temperature, stirring and filtering to obtain a leaching solution and a leaching residue is specifically as follows:

[0020] Take the powdered furnace slag, add hydrochloric acid with a concentration of 600 g / L, mix at a temperature of 80 °C with a liquid-solid ratio of 6 mL / g, stir for 2 h, and filter to obtain a leaching solution and a leaching residue.

[0021] In one embodiment, the step of uniformly mixing sodium chloride, ferric chloride with a certain concentration and tributyl phosphate to obtain a loaded extractant is specifically as follows:

[0022] Uniformly mix 4.5 mol / L sodium chloride, 0.4 mol / L ferric chloride and tributyl phosphate to obtain a loaded extractant, and the volume concentration ratio of tributyl phosphate is 60%.

[0023] In one embodiment, the step of taking the leaching solution and the loaded extractant, mixing them in a certain proportion, then shaking and separating them, and performing countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution is specifically as follows:

[0024] Mix the leaching solution and the loaded extractant in a ratio of 1:3, shake for 5 min and separate, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution.

[0025] In one embodiment, the step of performing back extraction on the lithium-containing organic phase with hydrochloric acid includes:

[0026] Perform back extraction on the lithium-containing organic phase and 6 mol / L hydrochloric acid in a ratio of 5:1.

[0027] In one embodiment, the step of mixing the leaching residue with deionized water according to a certain solid-liquid ratio, adding sulfuric acid to a certain pH, stirring, adding sodium dodecylbenzenesulfonate as a surfactant, and then transferring the slurry to a reaction kettle to react at a certain temperature, and filtering after the reaction to obtain calcium sulfate whiskers is specifically as follows:

[0028] Mix the leaching residue with deionized water according to a solid-liquid ratio of 10:1, add sulfuric acid until the pH is 5, stir for 0.5 h, add sodium dodecylbenzenesulfonate as a surfactant, then transfer the slurry to a reaction kettle to react at a certain temperature, and filter after the reaction to obtain calcium sulfate whiskers.

[0029] The technical solution of the present invention includes:

[0030] Step 1: Uniformly mix lepidolite and calcium oxide in a corundum crucible according to a certain mass ratio;

[0031] Step 2: Place the uniformly mixed mixture in a muffle furnace and calcine it under a certain environment to obtain lepidolite clinker;

[0032] Step 3: After the calcination is completed, take out the lepidolite clinker and quickly put it into a water quenching tank for water quenching and cooling to obtain water quenched slag;

[0033] Step 4: Place the cooled water quenched slag in an electrothermal blast drying oven for drying, and ball mill it in a ball mill for 2 hours to obtain powdered slag;

[0034] Step 5: Take a certain amount of the powdered slag, add hydrochloric acid, mix it at a certain temperature, stir and filter to obtain a leaching solution and a leaching residue;

[0035] Step 6: Uniformly mix sodium chloride, ferric chloride with a certain concentration and tributyl phosphate to obtain a loaded extractant.

[0036] Step 7: Take the leaching solution and the loaded extractant, mix them according to a certain ratio, shake and separate, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution;

[0037] Step 8: Perform back extraction on the lithium-containing organic phase with hydrochloric acid. After separation, lithium chloride is obtained. Add an excessive amount of sodium carbonate solution to react to obtain lithium carbonate. The separated organic phase is returned to Step 6 for recycling.

[0038] Step 9: Take the rubidium chloride solution and evaporate it to crystallize to obtain solid rubidium chloride.

[0039] Step 10: Mix the leaching residue with deionized water according to a certain solid-liquid ratio. Add sulfuric acid until a certain pH is reached and then stir. Add sodium dodecylbenzenesulfonate as a surfactant. Then transfer the slurry to a reaction kettle and react at a certain temperature. After the reaction ends, filter to obtain calcium sulfate whiskers.

[0040] The beneficial effects of the present invention are as follows: Combine the production process of lepidolite with the production process of calcium sulfate whiskers for combined production, learn from each other's strengths and weaknesses, increase utilization, achieve energy conservation and consumption reduction, increase the added value of products, and reduce production costs. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0042] Figure 1 It is a process flow diagram of a process method for calcining lepidolite to extract lithium and rubidium and synthesize calcium sulfate whiskers according to an embodiment of the present invention.

[0043] The realization, functional features, and advantages of the object of the present invention will be further described with reference to the embodiments and the drawings. Detailed Embodiments

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0045] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, in the present invention, descriptions such as "first" and "second" are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0047] Moreover, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] The present invention provides a process method for extracting lithium and rubidium from lepidolite by calcining with calcium oxide and synthesizing calcium sulfate whiskers.

[0049] As Figure 1 shown, the process method for extracting lithium and rubidium from lepidolite by calcining with calcium oxide and synthesizing calcium sulfate whiskers provided by the embodiments of the present invention includes:

[0050] Step 1: Uniformly mix lepidolite and calcium oxide in a corundum crucible according to a certain mass ratio;

[0051] Step 2: Place the uniformly mixed mixture in a muffle furnace and calcine it under a certain environment to obtain lepidolite clinker;

[0052] Step 3: After the calcination is completed, take out the lepidolite clinker and quickly put it into a water quenching tank for water quenching and cooling to obtain water quenched slag;

[0053] Step 4: Place the cooled water quenched slag in an electrothermal blast drying oven for drying, and ball mill it in a ball mill for 2 hours to obtain powdered slag;

[0054] Step 5: Take a certain amount of the powdered slag, add hydrochloric acid, mix it at a certain temperature, stir and filter to obtain a leaching solution and leaching residue;

[0055] Step 6: Uniformly mix sodium chloride, ferric chloride with a certain concentration and tributyl phosphate to obtain a loaded extractant;

[0056] Step 7: Take the leaching solution and mix it with the loaded extractant according to a certain ratio, oscillate and separate it, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution;

[0057] Step 8: Perform back extraction on the lithium-containing organic phase with hydrochloric acid, separate to obtain lithium chloride, add an excessive amount of sodium carbonate solution to react to obtain lithium carbonate, and return the separated organic phase to Step 6 for recycling;

[0058] Step 9: Evaporate and crystallize the rubidium chloride solution to obtain rubidium chloride solid;

[0059] Step 10: Mix the leaching residue with deionized water according to a certain solid-liquid ratio, add sulfuric acid until a certain pH is reached, stir, add sodium dodecylbenzenesulfonate as a surfactant, then transfer the slurry to a reaction kettle and react at a certain temperature. After the reaction, filter to obtain calcium sulfate whiskers.

[0060] This application combines the production process of lepidolite with the production process of calcium sulfate whiskers for joint production, making up for each other's advantages, increasing utilization, achieving energy conservation and consumption reduction, increasing the added value of products, and reducing production costs.

[0061] The following further describes the embodiments of the present invention with reference to the accompanying drawings. Except for the following descriptions, the rest in the embodiments are the same as those in Embodiment 1. As Figure 1 shown, it includes the following steps:

[0062] Embodiment 1

[0063] Mix lepidolite and calcium oxide evenly in a corundum crucible according to a mass ratio of 5:1.

[0064] Place the evenly mixed mixture in a muffle furnace and heat and roast it at a temperature of 1300 °C for 0.5 h at a heating rate of 5 °C / min to obtain lepidolite clinker.

[0065] After the roasting is completed, take out the roasted lepidolite clinker and quickly put it into a water quenching tank for water quenching and cooling, so that it is in full contact with water and quickly cooled at a cooling rate of 20 °C / min to obtain water quenched slag.

[0066] After cooling, place the water quenched slag in an electrothermal blast drying oven for drying, and then ball mill it in a ball mill for 2 hours to obtain powdered slag.

[0067] Further, take the powdered slag, add 600 g / L hydrochloric acid, mix it at a liquid-solid ratio of 6 mL / g at a temperature of 80 °C, stir continuously at a certain rotation speed for 2 h, and filter to obtain leaching solution and leaching residue.

[0068] Mix 4.5 mol / L sodium chloride, 0.4 mol / L iron chloride and tributyl phosphate evenly to prepare a loaded Fe 3+ organic extractant (NaFeCl4·3H2O·2TBP), and the volume concentration ratio of tributyl phosphate accounts for 60%.

[0069] Take the leaching solution and the loaded Fe 3+ organic extractant and mix them according to a fixed ratio of 1:3, oscillate for 5 min for physical separation, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution.

[0070] The lithium-containing organic phase is subjected to counter-extraction with 6 mol / L hydrochloric acid in a ratio of 5:1. After separation, lithium chloride is obtained. An excessive amount of sodium carbonate solution is added for reaction to obtain lithium carbonate, and the separated organic phase is returned for recycling.

[0071] The rubidium chloride solution is evaporated and crystallized to obtain solid rubidium chloride.

[0072] The leaching residue obtained by filtration is mixed with deionized water at a certain solid-liquid ratio of 10:1. Sulfuric acid is added until the fixed pH = 5, and it is stirred for 0.5 h. Sodium dodecylbenzenesulfonate is added as a surfactant, and then the slurry is transferred to a reaction kettle to react at a certain temperature for 4 h. After the reaction is completed, calcium sulfate whiskers are obtained by filtration.

[0073] After detection, the recovery rate of lithium reaches 98.03%.

[0074] Example 2

[0075] Lepidolite and calcium oxide are uniformly mixed in a corundum crucible at a mass ratio of 8:1.

[0076] The uniformly mixed mixture is placed in a muffle furnace and heated and calcined at a heating rate of 5 °C / min at a temperature of 1200 °C for 0.5 h to obtain lepidolite clinker.

[0077] Take the leaching solution and the loaded Fe 3+ The organic extractant is mixed in a fixed ratio of 1:2, oscillated for 5 min for physical separation, and subjected to countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution.

[0078] After detection, the recovery rate of lithium reaches 95.15%.

[0079] Example 3

[0080] Lepidolite and calcium oxide are uniformly mixed in a corundum crucible at a mass ratio of 10:1.

[0081] The uniformly mixed mixture is placed in a muffle furnace and heated and calcined at a heating rate of 5 °C / min at a temperature of 1100 °C for 0.5 h to obtain lepidolite clinker.

[0082] Take the leaching solution and the loaded Fe 3+ The organic extractant is mixed in a fixed ratio of 1:1, oscillated for 5 min for physical separation, and subjected to countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution.

[0083] After detection, the recovery rate of lithium reaches 90.07%.

[0084] The main reasons for the low lithium recovery rates in Examples 2 and 3 are the differences in roasting temperature, calcium oxide proportion, and organic extractant proportion. As the temperature rises to the required value, the flaky structure is rapidly destroyed, and more and more lepidolite is converted into an active state. Various ions in the mineral are easily separated, and the recovery rate also increases, reaching the maximum value at 1300 °C; the addition of calcium oxide reduces the melting point of the raw material, making it easier to reach the activation state. As the proportion of calcium oxide increases, the recovery rate also increases; when the content of the extractant increases, the number of extractant molecules available for binding in the solution increases, and more lithium ions can react, thereby improving the extraction efficiency of lithium.

[0085] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A process for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers, characterized in that, The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers includes: Step 1: Uniformly mix lepidolite and calcium oxide in a corundum crucible according to a certain mass ratio; Step 2: Place the uniformly mixed mixture in a muffle furnace and roast it under certain conditions to obtain lepidolite clinker; Step 3: After the roasting is completed, take out the lepidolite clinker and quickly put it into a water quenching tank for water quenching and cooling to obtain water quenched slag; Step 4: Place the cooled water quenched slag in an electrothermal blast drying oven for drying, and ball mill it in a ball mill for 2 hours to obtain powdered slag; Step 5: Take a certain amount of the powdered slag, add hydrochloric acid, mix at a certain temperature, stir and filter to obtain leaching solution and leaching residue; Step 6: Uniformly mix sodium chloride, ferric chloride with a certain concentration and tributyl phosphate to obtain a loaded extractant; Step 7: Take the leaching solution and mix it with the loaded extractant according to a certain ratio, then oscillate and separate, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution; Step 8: Perform back extraction on the lithium-containing organic phase with hydrochloric acid, separate to obtain lithium chloride, add an excessive amount of sodium carbonate solution to react to obtain lithium carbonate, and return the separated organic phase to Step 6 for recycling; Step 9: Take the rubidium chloride solution and evaporate and crystallize to obtain solid rubidium chloride; Step 10: Take the leaching residue and mix it with deionized water according to a certain solid-liquid ratio, add sulfuric acid until a certain pH value, stir, add sodium dodecylbenzenesulfonate as a surfactant, then transfer the slurry to a reaction kettle and react at a certain temperature, and filter after the reaction is completed to obtain calcium sulfate whiskers.

2. The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of uniformly mixing lepidolite and calcium oxide in a corundum crucible according to a certain mass ratio is specifically as follows: Uniformly mix lepidolite and calcium oxide in a corundum crucible according to a mass ratio of 5:

1.

3. The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of placing the uniformly mixed mixture in a muffle furnace and roasting it under certain conditions to obtain lepidolite clinker is specifically as follows: Place the uniformly mixed mixture in a muffle furnace and heat and roast it at a temperature of 1300 °C for 0.5 h with a heating rate of 5 °C / min to obtain lepidolite clinker.

4. The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of taking a certain amount of the powdered slag, adding hydrochloric acid, mixing at a certain temperature, stirring and filtering to obtain leaching solution and leaching residue is specifically as follows: Take powdered slag, add hydrochloric acid with a concentration of 600 g / L, mix at a temperature of 80 °C with a liquid-solid ratio of 6 mL / g, stir for 2 h, and filter to obtain leaching solution and leaching residue.

5. The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of uniformly mixing sodium chloride, ferric chloride with a certain concentration and tributyl phosphate to obtain a loaded extractant is specifically as follows: Uniformly mix sodium chloride with a concentration of 4.5 mol / L, ferric chloride with a concentration of 0.4 mol / L and tributyl phosphate to obtain a loaded extractant, and the volume concentration ratio of tributyl phosphate is 60%.

6. The process method for extracting lithium and rubidium from calcined lepidolite with calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of taking the leaching solution and mixing it with the loaded extractant according to a certain ratio, then oscillating and separating, and performing countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution is specifically as follows: Take the leaching solution and mix it with the loaded extractant according to a ratio of 1:3, oscillate for 5 min and separate, and perform countercurrent washing four times to obtain a lithium-containing organic phase and a rubidium chloride solution.

7. The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of performing back extraction on the lithium-containing organic phase with hydrochloric acid includes: The lithium-containing organic phase is subjected to back extraction with 6 mol / L hydrochloric acid at a ratio of 5:

1.

8. The process method for extracting lithium and rubidium from lepidolite by calcining calcium oxide and synthesizing calcium sulfate whiskers according to claim 1, characterized in that, The step of taking the leaching residue and mixing it with deionized water according to a certain solid-liquid ratio, adding sulfuric acid until a certain pH is reached and then stirring, adding sodium dodecylbenzenesulfonate as a surfactant, and then transferring the slurry to a reaction kettle to react at a certain temperature, and filtering after the reaction to obtain calcium sulfate whiskers is specifically as follows: Take the leaching residue and mix it with deionized water according to a solid-liquid ratio of 10:1, add sulfuric acid until the pH is 5 and then stir for 0.5 h, add sodium dodecylbenzenesulfonate as a surfactant, and then transfer the slurry to a reaction kettle to react at a certain temperature, and filter after the reaction to obtain calcium sulfate whiskers.

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