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Continuous preparation method of sodium dicyanamide

A technology of dicyandiamide sodium and cyanogen halide, applied in the field of continuous preparation of dicyandiamide sodium, can solve the problems of dicyandiamide sodium production process with many impurities, low yield, unstable quality, etc., and achieve simple post-treatment process, Easy to get raw materials and stable product quality

Active Publication Date: 2018-03-06
上海奥萝拉医药科技有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] Aiming at problems such as many impurities, low yield and unstable quality in the existing production process of sodium dicyandiamide, the invention provides a continuous preparation method of sodium dicyandiamide

Method used

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preparation example Construction

[0017] The embodiment of the present invention provides a continuous preparation method of sodium dicyandiamide, the preparation method at least includes the following steps:

[0018] Step 1, ammonia water and cyanogen halide are mixed in a pre-reactor under the condition of 0-20° C. to react to obtain a mixed material, and the pH value of the mixed material is 6-9;

[0019] Step 2, providing a reactor, the reactor is provided with a reactor connected to each other, a condensation tube reactor and a liquid caustic storage tank, the mixed material is transported to the reactor of the reactor, and the mixed material is mixed in the reactor The temperature is between 0-50°C;

[0020] Step 3, pump the mixed material and sodium hydroxide solution into the condensing tube reactor, adjust the pH value of the mixed material to 7-10, and at the same time pass the halogenation into the condensing tube reactor Cyanide is reacted, and the reaction solution falls back into the reaction ke...

Embodiment 1

[0042] The present embodiment provides a kind of continuous preparation method of sodium dicyandiamide, process flow diagram refers to attached figure 1 , the preparation method at least includes the following steps:

[0043] Step 1, adopt metering pump to mass concentration in tubular reactor to be 1000g of ammoniacal liquor 15%, ammoniacal liquor feed rate is 10g / min, when starting to add ammoniacal liquor, feed cyanogen chloride gas in tubular reactor at 0 Reaction under the condition of -5°C to obtain the mixed material, adjust the speed of the introduction of cyanogen chloride, and when the pH value of the mixed solution is 7.5-8, transport the mixed material to the intermediate tank;

[0044] Step 2. The temperature of the mixed material in the intermediate tank is kept at 40-50° C., and the mixed material is passed through the intermediate tank by a peristaltic pump into a tube condenser connected to the intermediate tank, and in the tube condenser Carry out circulatio...

Embodiment 2

[0048]The present embodiment provides a kind of continuous preparation method of sodium dicyandiamide, process flow diagram refers to attached figure 1 , the preparation method at least includes the following steps:

[0049] Step 1, adopt metering pump to mass concentration in tubular reactor to be 1000g of ammoniacal liquor 15%, ammoniacal liquor feed rate is 15g / min, when beginning to add ammoniacal liquor, feed cyanogen chloride gas in tubular reactor at 10 Reaction under the condition of -15°C to obtain the mixed material, adjust the speed of the introduction of cyanogen chloride, and when the pH value of the mixed solution is 6-7.5, transport the mixed material to the intermediate tank;

[0050] Step 2. The temperature of the mixed material in the intermediate tank is kept at 30-40° C., and the mixed material is passed through the intermediate tank into a tube condenser connected to the intermediate tank with a peristaltic pump, and is cooled in the tube condenser. Carry...

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Abstract

The invention relates to the technical field of sodium dicyanamide synthesis, and specifically discloses a continuous preparation method of sodium dicyanamide. The continuous preparation method comprises the following steps: mixing ammonium hydroxide and halogeno-cyanogen at the temperature of 0 to 20 DEG C in a pre-reactor to obtain a mixed material; providing a reactor, and transferring the mixed material to a reaction kettle of the reactor, wherein the reactor is provided with the reaction kettle, a condensing tube reactor and a liquid-alkali storage tank which are communicated with one another; pumping the mixed material and a sodium hydroxide solution into the condensing tube reactor, adjusting the pH value of the mixed material, meanwhile introducing halogeno-cyanogen into the condensing tube reactor, making reaction liquid flow through the condensing tube reactor and drop back into the reaction kettle, and carrying out the next step when the pH value of the reaction liquid is stabilized at 7.5 to 10; repeating the circular reaction steps to prepare the sodium dicyanamide. The continuous preparation method is easy to operate, is 80 percent or more in yield, is 98 percent oremore in product content, is stable in product quality, and is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of dicyandiamide sodium synthesis, in particular to a continuous preparation method of dicyandiamide sodium. Background technique [0002] Sodium dicyanamide (Sodium dicyanamide), also known as sodium dicyanamide, is an important chemical raw material and is widely used in medicine, dyestuffs and pesticide industries. Its most important application is the synthesis of antibacterial agent chlorhexidine hydrochloride and Synthesis of intermediate triazine ring of sulfuron herbicides. There are mainly two synthesis processes reported so far, namely the cyanamide process and the ammonia water process. In addition, they are divided into continuous synthesis and batch synthesis according to the degree of continuity. [0003] Currently foreign countries mainly use cyanamide, cyanogen chloride and sodium hydroxide as raw materials for continuous synthesis. Not only the labor cost is greatly reduced, but also becau...

Claims

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Application Information

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IPC IPC(8): C07C277/08C07C279/28
CPCC07C277/08C07C279/28
Inventor 杨国忠郭婷婷董璞曹彤彤时叶强
Owner 上海奥萝拉医药科技有限公司
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