CN1195602C - Preparation method of lithium sand - Google Patents

Abstract

The present invention provides a preparation method of lithium sand and is characterized in that an inert medium with a water value 100 ppm to 300 ppm is used as a disperse medium and metallic lithium is completely melted at 200 to 250 DEC; the metallic lithium is dispersed into fine liquid droplets at speed of 1500 rpm to 3000 rpm; the stirring is stopped when the temperature of the metallic lithium drops to 150 DEC to 180 DEC within 10 to 30 minutes; at this point, the metallic lithium forms fine dispersion in the inert medium (the particle size is usually 10 microns to 400 microns); the lithium sand directly used to synthesize alkyl lithium is obtained when the temperature is continue to drop. The present invention overcomes technology prejudice that water contents of the dispersion medium is required below 200 ppm in the dispersion process and adopts the inert medium of which water content is 100 ppm to 300 ppm as the dispersion medium. Accordingly, complicated refining steps are omitted, after the water value is increased, a protecting layer of LiOH is formed on the lithium sand surface and the lithium sand is stable.

Description

A kind of preparation method of lithium sand

Technical field

The present invention relates to a kind of preparation method of lithium sand.

Background technology

Adopting lithium metal is the feedstock production lithium alkylide, is to improve reaction rate, must increase its specific area, promptly at first lithium metal is prepared into granularity and is 10～400 microns lithium sand.

To disperse to prepare lithium sand with high-speed stirred again after the lithium metal fusion, at present be a kind of comparative maturity and use general method industrial, is that people such as Ziegler proposed in nineteen thirty at first.Its process is lithium metal to be heated to make its whole fusions more than the fusing point in inert media, disperses 10min～30min with 3000rpm～15000rpm high-speed stirred again, is cooled to then to stop below the fusing point stirring, and continues cooling and can obtain lithium sand.Inert media is generally the higher boiling saturated hydrocarbons, requires wherein can not to contain the material that water, alcohol etc. can react with lithium.According to most patent introductions, as U.S3,293,313 (1966) or the like, with the lithium sand of method for preparing, also to higher yield be arranged when helping like this guaranteeing the synthesis of alkyl lithium usually with it with those high boiling hydrocarbon ils of flush away such as heptane, hexane or cyclohexanes.

The dispersion of lithium also usually needs to add dispersant except that requiring to carry out in inert media, seem even more important when especially sodium content is higher in the not high and lithium in decentralized medium viscosity, otherwise lithium disperses easy gelling of thing or caking.According to reported in literature, dispersant commonly used has dimerized linoleic acid, oleic acid, calcium stearate, lead naphthenate, Aluminum trilaurate and other fatty acid metal compounds.In addition, the colloid of lecithin, carbon sol and some polymer also can be used as dispersant.

Recent United States Patent (USP) U.S5,567,474 (1996), 5,776,369 (1998) reports are with anhydrous CO ₂Make dispersant, can produce one deck by Li on lithium sand surface ₂CO ₃, Li ₂The protective layer that O, LiOH and hydrocarbon ils are formed plays the effect that makes the lithium dispersion stable, and can not slow down the reaction of itself and halogenated hydrocarbons.More anhydrous simultaneously CO ₂The lithium sand that makes when making dispersant with oleic acid, it is lower to find to synthesize in the lithium alkylide product that obtains content of inorganic chlorine with the former.In addition, when making dispersant with oleic acid, sodium content can not be too much in the lithium, and general the requirement is lower than 0.88%, to prevent to disperse thing retrogradation or gelling.And use CO ₂When replacing oleic acid, without limits to the amount of sodium.

Summary of the invention

Though the fusion dispersion method of lithium metal is ripe, need add dispersant, lithium sand need wash and adopt high-speed stirred etc., increase operation link and implemented difficulty.The objective of the invention is to,, make it easier and easy to implement improving lithium dispersion thing stability, not losing under its active prerequisite the method is improved.

To achieve these goals, the present invention has adopted following technical scheme: with an airtight churned mechanically rustless steel container (can be referred to as Scattered Kettle) of being with argon replaces 1 time～3 times, add inert media and lithium metal ingot that water number is 100ppm～300ppm then, again with logical last 200 ℃～250 ℃ heating agent of Scattered Kettle chuck, heated 1 hour～2 hours, after confirming the complete fusion of lithium metal, start and stir, rotating speed is 1500rpm～3000rpm, it is separated into very thin drop, mixing time is not less than 10min, heating agent is switched to refrigerant, stop to stir when material in the still drops to 150 ℃～180 ℃ (below the lithium metal fusing point), this moment, lithium metal formed very tiny dispersion (particle diameter is 10 μ m～400 μ m usually) in inert media, continued can be directly used in the synthetic lithium sand of lithium alkylide after the logical refrigerant cooling.Inert media is white oil normally.

Increase the specific area of lithium sand, can promote itself and halohydrocarbons reaction to generate lithium alkylide, improve but lithium sand is active simultaneously, it is unfavorable that the long period is placed, stores even transport; If intermediate link too much makes technology become more complicated.Compared with prior art, our invention has following tangible advantage:

1, inert media requires its water content below 20ppm as decentralized medium usually.The present invention breaks conventional art prejudice, and to adopt water content be that the inert media of 100ppm～300ppm is as decentralized medium.Water number is 100ppm～300ppm inert media, can directly use, and saves complicated refining step; After the inert media water number increases, formed the protective layer of one deck, made lithium sand more stable, be used for the synthesis of alkyl lithium behind placement long period or the short-time contact air not influence of yield based on LiOH on lithium sand surface; Though the LiOH that lithium sand surface forms has changed the surface crystal structure of lithium particle, with the active no change of halohydrocarbons reaction even slightly rising.

2, do not need to add again in addition oleic acid, anhydrous CO among the present invention ₂Deng dispersant; It is synthetic promptly to can be used for lithium alkylide without the inert media on flush away lithium sand surface.

3, among the present invention, adopt rotating speed be 1500rpm～3000rpm than stirring at low speed, industrial easy to implement, and easy to maintenance.

The specific embodiment

Embodiment 1: with total volume be 250L the stainless steel Scattered Kettle with the 0.2MPa argon gas (oxygen content≤10ppm, water content≤10ppm, down with) displacement 2 times, adding water number again is the 26# technical white oil 70L of 9ppm.Open Scattered Kettle upslide lithium hand hole then under pressure-fired protection, dropping into 12.85kg rapidly, to contain the sodium amount be 1.44 (wt) the % lithium metal ingot and the hand hole that closes.Whether the airtight while replaces 2 times again to check Scattered Kettle with the 0.2MPa argon gas, and chuck begins with 231 ℃ of heat-conducting oil heating.Confirm the whole fusions of lithium metal in the still after 1 hour～2 hours, starting rotating speed then is the high shear stirring of 2960rpm.Behind the 10min deep fat is switched to cold oil rapidly, when temperature in the kettle is reduced to 170 ℃, stop to stir.The lithium sand that obtains is analyzed, found particle diameter between 20 μ m～500 μ m, but part lithium sand there is caking or assembles agglomerating phenomenon, also have on a small quantity and shift attached to being difficult on the still wall.

Embodiment 2 (synthetic n-BuLi): the stainless steel synthesis reactor (band multilayer mechanical agitation) that with total volume is 1500L is with 0.2MPa argon replaces 2 times, add the lithium sand 37.83Kg (using the white oil of its surface attachment of cyclohexane flush away earlier) that obtains among the embodiment 1, and water number is the cyclohexane 600L of 7ppm.Start the stirring back and drip 268L n-butyl chloride (lithium is than theoretical value excessive about 5%) with measuring pump in synthesis reactor, exothermic heat of reaction is taken away by the chuck cooling water.Reinforced finishing behind the 2h cut off cooling water and continues Synthetic 2 h, and controlling whole process reaction temperature is 70 ℃～85 ℃.Obtain light yellow n-butyllithium solution after the filtration, analyzing its concentration is 1.76M, is 91.7% with the chlorobutane rate of collecting.

Embodiment 3: with total volume is stainless steel Scattered Kettle 0.2MPa argon replaces 2 times of 250L, and adding water number again is the 26# technical white oil 70L of 153ppm.Open Scattered Kettle upslide lithium hand hole then under pressure-fired protection, dropping into 12.74kg rapidly, to contain the sodium amount be 1.44 (wt) the % lithium metal ingot and the hand hole that closes.Whether the airtight while replaces 2 times again to check Scattered Kettle with the 0.2MPa argon gas, and chuck begins with 236 ℃ of heat-conducting oil heating.Confirm the whole fusions of lithium metal in the still after 1 hour～2 hours, starting rotating speed then is the high shear stirring of 2960rpm.Behind the 10min deep fat is switched to cold oil rapidly, when temperature in the kettle is reduced to 170 ℃, stop to stir.The lithium sand that obtains is analyzed, found that particle diameter is between 10 μ m～350 μ m.The lithium sand of band white oil is directly put into synthesis reactor without washing, and the yield that obtains n-BuLi by embodiment 2 conditions is 91.9%.

Embodiment 4: with total volume is stainless steel Scattered Kettle 0.2MPa argon replaces 2 times of 250L, and adding water number again is the 26# technical white oil 70L of 209ppm.Open Scattered Kettle upslide lithium hand hole then under pressure-fired protection, dropping into 12.67kg rapidly, to contain the sodium amount be 1.58 (wt) the % lithium metal ingot and the hand hole that closes.Whether the airtight while replaces 2 times again to check Scattered Kettle with the 0.2MPa argon gas, and chuck begins with 235 ℃ of heat-conducting oil heating.Confirm the whole fusions of lithium metal in the still after 1 hour～2 hours, starting rotating speed then is the high shear stirring of 2960rpm.Behind the 10min deep fat is switched to cold oil rapidly, when temperature in the kettle is reduced to 170 ℃, stop to stir.The lithium sand that obtains is analyzed, found that particle diameter is between 15 μ m～400 μ m.With the white oil of its surface attachment of cyclohexane flush away, under without the situation of argon shield, to place 7 days, the yield that obtains n-BuLi by embodiment 2 conditions is 90.4%.

Embodiment 5: with total volume is stainless steel Scattered Kettle 0.2MPa argon replaces 2 times of 250L, and adding water number again is the 26# technical white oil 70L of 103ppm.Open Scattered Kettle upslide lithium hand hole then under pressure-fired protection, dropping into 12.79kg rapidly, to contain the sodium amount be 1.44 (wt) the % lithium metal ingot and the hand hole that closes.Whether the airtight while replaces 2 times again to check Scattered Kettle with the 0.2MPa argon gas, and chuck begins with 236 ℃ of heat-conducting oil heating.Confirm the whole fusions of lithium metal in the still after 1 hour～2 hours, starting rotating speed then is the high shear stirring of 2960rpm.Behind the 15min deep fat is switched to cold oil rapidly, when temperature in the kettle is reduced to 170 ℃, stop to stir.The lithium sand that obtains is analyzed, found that particle diameter is between 10 μ m～350 μ m.The lithium sand of band white oil is directly put into synthesis reactor without washing, and the yield that obtains n-BuLi by embodiment 2 conditions is 91.1%.

Embodiment 6: with total volume is stainless steel Scattered Kettle 0.2MPa argon replaces 2 times of 250L, and adding water number again is the 26# technical white oil 70L of 289ppm.Open Scattered Kettle upslide lithium hand hole then under pressure-fired protection, dropping into 12.69kg rapidly, to contain the sodium amount be 1.58 (wt) the % lithium metal ingot and the hand hole that closes.Whether the airtight while replaces 2 times again to check Scattered Kettle with the 0.2MPa argon gas, and chuck begins with 235 ℃ of heat-conducting oil heating.Confirm the whole fusions of lithium metal in the still after 1 hour～2 hours, starting rotating speed then is the high shear stirring of 2960rpm.Behind the 10min deep fat is switched to cold oil rapidly, when temperature in the kettle is reduced to 170 ℃, stop to stir.The lithium sand that obtains is analyzed, found that particle diameter is between 15 μ m～400 μ m.With the white oil of its surface attachment of cyclohexane flush away, under without the situation of argon shield, to place 7 days, the yield that obtains n-BuLi by embodiment 2 conditions is 90.6%.

Claims (1)

1, a kind of preparation method of lithium sand is characterized in that Scattered Kettle argon replaces 1 time～3 times are added white oil and lithium metal ingot that water number is 100ppm～300ppm then; With logical last 200 ℃～250 ℃ heating agent of Scattered Kettle chuck, heated 1 hour～2 hours, after the complete fusion of affirmation lithium metal, start and stir, rotating speed is 1500rpm～3000rpm, and it is separated into very thin drop; Mixing time is not less than 10min, heating agent is switched to refrigerant, stop to stir when material in the still drops to 150 ℃～180 ℃, this moment, lithium metal formed very tiny dispersion in inert media, continued to obtain being directly used in the synthetic lithium sand of lithium alkylide after the logical refrigerant cooling.