CN1754630A

CN1754630A - Hydrolysis method for lithium slag from lithium alkyl synthesis

Info

Publication number: CN1754630A
Application number: CN 200410085401
Authority: CN
Inventors: 朱铁辉; 陈邵文; 刘勇
Original assignee: Baling Petrochemical Co Ltd
Current assignee: Baling Petrochemical Co Ltd
Priority date: 2004-10-01
Filing date: 2004-10-01
Publication date: 2006-04-05
Anticipated expiration: 2024-10-01
Also published as: CN1326640C

Abstract

This invention provides one hydrolysis method to synthesize lithium alkyl, which comprises the following steps: containing the lithium powder filtered by lithium alkyl into its buffer tar; then pressing the lithium powder into hydrolysis tar through lithium powder metering pump to react with large amount of water under temperature of sixty degrees to control lithium powder quantative through hydrolysis temperature; the reaction temperature can be taken away by cooling water and thehydrocarbon solvent sent out are recycled by air condensation device. The method can prevent super heat without large range wave to realize the industry automatic control.

Description

Hydrolysis method of lithium slag obtained by synthesizing lithium alkyl

Technical Field

The invention relates to a hydrolysis method of lithium slag obtained by synthesizing lithium alkyl.

Background

The synthesis of alkyl lithium adopts the reaction of chloralkane and metallic lithium sand in hydrocarbon solvent, the obtained alkyl lithium mixed solution is settled and filtered to remove the lithium nitride, lithium chloride and the solid insoluble substances such as fine metallic lithium particles coated by lithium chloride, etc. contained in the mixed solution, and the solid insoluble substances and the cyclohexane mixture containing alkyl lithium, white oil, etc. are commonly called as lithium slag. In the existing production process of the alkyl lithium, no method for efficiently and safely treating the lithium slag generated in the production process of the alkyl lithium exists. In the prior art, the method for hydrolyzing the lithium slag comprises the steps of putting the lithium slag obtained after the lithium alkyl is filtered and produced into a hydrolysis kettle at one time, then hydrolyzing with quantitative water, taking away reaction heat by cooling a jacket in the hydrolysis process, and recovering a hydrocarbon solvent contained in the vented gas by using a vented condenser. The main reaction is as follows:

meanwhile, the LiCl is dissolved in water during the reaction process, and the heat of dissolution is released.

The method has two obvious phenomena of temperature rise and pressure rise in the hydrolysis process, wherein the first temperature rise and pressure rise mainly come from the heat released by the reaction of a large amount of high-concentration alkyl lithium contained in the lithium slag and water. The second temperature rise and pressure rise mainly come from that in the first temperature rise and pressure rise period, the added water reacts with alkyl lithium and a small amount of water dissolves lithium chloride on the surface of the metal lithium continuously, when the lithium chloride is dissolved to a certain degree, a large amount of metal lithium coated by the lithium chloride is exposed in water suddenly and reacts with the water suddenly, so that the second temperature rise and pressure rise phenomena occur, the process lasts for only 5-10 seconds, but the temperature and pressure rise is rapid, the temperature rise can reach 10-15 ℃/S, once the process is out of control, the reaction temperature can exceed 100 ℃, and the boiling point of hydrocarbon solvents in the lithium slag is far exceeded, so that a large amount of solvents volatilize, and the pressure rise of the hydrolysis kettle occurs. Finally, combustible gas breaks through the weak part of the kettle body and flashes in space to cause personal injury accidents. Therefore, this method has serious unsafe factors.

Disclosure of Invention

The invention aims to provide a lithium slag hydrolysis method which avoids the phenomena of over-temperature and over-pressure of the two reactions, does not generate large fluctuation of hydrolysis temperature and is easy to realize industrial automatic control.

In order to achieve the purpose, the invention adopts the following technical scheme:

lithium slag obtained by filtering lithium alkyl is collected into a lithium slag buffer tank, and stirring is assisted, so that the lithium slag and a solvent in the lithium slag are fully mixed; slowly pressing the lithium slag into a hydrolysis kettle through a lithium slag metering pump, carrying out hydrolysis reaction with a large amount of water in the hydrolysis kettle, and adding the water in the hydrolysis kettlethrough a water metering tank; the reaction temperature is controlled below 60 ℃, and the adding amount of the lithium slag is controlled by the temperature of the hydrolysis kettle; reaction heat is taken away by cooling water in a kettle jacket, and gases such as hydrocarbon solvents and the like evaporated in the reaction process are cooled and recovered by an emptying condenser; and after the hydrolysis reaction is finished, continuously stirring for 1-2 hours, standing, layering oil and water, recovering the oil phase, and feeding the water phase into a lithium water recovery treatment process.

In the specific implementation process of the invention, the process flow schematic diagram of the lithium slag hydrolysis is shown in the attached figure 1, and the hydrolysis process is as follows:

a. discharging the filtered lithium slag into a lithium slag buffer tank (1) with stirring at one time;

b. adding water into the hydrolysis kettle (3) through a water metering tank (4), and replacing air in the hydrolysis kettle (3) with nitrogen; opening the emptying flow of the hydrolysis kettle, and opening jacket cooling water;

c. slowly pressing the lithium slag into a hydrolysis kettle (3) through a lithium slag metering pump (2) to perform hydrolysis reaction, controlling the adding amount of the lithium slag through the temperature of the hydrolysis kettle (3), and controlling the reaction temperature below 60 ℃;

d. and after the hydrolysis is finished, continuously stirring the hydrolysis kettle (3) for 1-2 hours, standing, layering the oil phase, recovering the oil phase, and sending the water phase into a lithium water recovery treatment process.

Compared with the prior art, the invention has the following obvious advantages:

1. the hydrolysis process is safe and stable. Because the adding amount of the lithium slag is controlled by the temperature of the hydrolysis kettle, the hydrolysis process is extremely stable, two times of obvious temperature fluctuation do not exist, the highest temperature in the hydrolysis process does not exceed 60 ℃, and the temperature is generally controlled to be about 45 ℃. Once the temperature is too high, the lithium slag metering pump stops feeding, the hydrolysis temperature is quickly reduced, and the temperature controllability is very good.

2. Convenient operation, short hydrolysis time and convenient control by adopting an automatic means. Because the temperature rises slowly, the secondary reaction peak period does not occur, the metering pump is favorable for realizing automatic control, and the hydrolysis reaction time and the labor intensity of operators are greatly reduced.

3. Before the hydrolysis reaction is carried out, a large amount of water is in the hydrolysis kettle, and compared with the prior art, a large amount of lithium slag is in the hydrolysis kettle, so that the hydrolysis kettle is much safer; the application of the technology better solves the problems of over-temperature and over-pressure easily occurring in the lithium slag treatment process, and fundamentally ensures the stable production of the device.

Drawings

FIG. 1: the process flow schematic diagram of the lithium slag hydrolysis.

1-lithium slag buffer tank, 2-lithium slag metering pump, 3-hydrolysis kettle and 4-water metering tank.

Detailed Description

The present invention is described in detail below with reference to examples.

Example 1:

1) discharging slag and collecting materials. Discharging about 500L of filtered lithium slag into a lithium slag buffer tank with a stirrer at one time;

2) adding the measured 600L of water into the hydrolysis kettle through a water metering tank, then maintaining the pressure with 0.3MPa of nitrogen, replacing for three times, and discharging the air in the hydrolysis kettle.

3) Checking and opening the emptying flow of the hydrolysis kettle, and opening the jacket cooling water. And starting the lithium slag buffer tank for stirring, controlling the flow rate of the lithium slag to be about 300L/h by using a lithium slag metering pump, controlling the reaction temperature to be less than or equal to 60 ℃ until the lithium slag in the lithium slag buffer tank is completely added into the hydrolysis kettle, and continuing the charging process for about 2 hours.

4) And after hydrolysis is finished, continuously stirring for 1-2 hours, standing for 2 hours, after oil-water layering, recovering an oil phase, and sending a water phase into a lithium water recovery treatment process.

In the hydrolysis process, the temperature of the hydrolysis kettle is stably controlled, and the phenomena of over-temperature and over-pressure are avoided.

Claims

1. A hydrolysis method of lithium slag obtained by synthesizing lithium alkyl is characterized in that: lithium slag obtained by filtering lithium alkyl is collected into a lithium slag buffer tank, and stirring is assisted, so that the lithium slag and a solvent in the lithium slag are fully mixed; slowly pressing the lithium slag into a hydrolysis kettle through a lithium slag metering pump, carrying out hydrolysis reaction with a large amount of water in the hydrolysis kettle, and adding the water in the hydrolysis kettle through a water metering tank; the reaction temperature is controlled below 60 ℃, and the adding amount of the lithium slag is controlled by the temperature of the hydrolysis kettle; reaction heat is taken away by cooling water in a kettle jacket, and gases such as hydrocarbon solvents and the like evaporated in the reaction process are cooled and recovered by an emptying condenser; and after the hydrolysis reaction is finished, continuously stirring for 1-2 hours, standing, layering oil and water, recovering the oil phase, and feeding the water phase into a lithium water recovery treatment process.