CN106699623B - A method of thiocarbamide is converted using ammonium thiocyanate - Google Patents
A method of thiocarbamide is converted using ammonium thiocyanate Download PDFInfo
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- CN106699623B CN106699623B CN201710026216.9A CN201710026216A CN106699623B CN 106699623 B CN106699623 B CN 106699623B CN 201710026216 A CN201710026216 A CN 201710026216A CN 106699623 B CN106699623 B CN 106699623B
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- thiocarbamide
- ammonium thiocyanate
- ammonium
- conversion
- purity
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C335/00—Thioureas, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C335/02—Thiourea
Abstract
The present invention provides a kind of methods using ammonium thiocyanate conversion thiocarbamide, using ammonium thiocyanate as raw material, it is reacted with the ammonium hydroxide of suitable certain mass ratio, when the conversion ratio of ammonium thiocyanate is to 78~95%, ammonia is removed, obtained solid is crude thiourea, and the purity of crude thiourea is 80~95%.Then it is sublimated the different principle of temperature using thiocarbamide and impurity, obtains the thiocarbamide of high-purity by way of distilling and repeatedly sublimating, yield can achieve 47.2%.The method using ammonium thiocyanate conversion thiocarbamide provided herein has the advantages that simple process, energy consumption, without secondary pollution and operating cost are low etc..Using the method for ammonium thiocyanate conversion thiocarbamide, the product that coking desulfurization waste liquor can be used to extract for ammonium thiocyanate extends the industrial chain of desulfurization waste liquor salt extraction, opened up a new way for the extraction of desulfurization waste liquor secondary salt.Thiocarbamide prepared by this method, product purity are up to 99%.
Description
Technical field
The present invention relates to chemical industry synthesis fields, in particular to a kind of method using ammonium thiocyanate conversion thiocarbamide.
Background technique
Currently, the method for industrial production thiocarbamide mainly has lime nitrogen-calcium sulfhydrate synthetic method and the synthesis of one hydrogen sulfide of cyanamide
Method.Lime nitrogen-calcium sulfhydrate synthetic method is suitable for extensive production mode, but lime nitrogen belongs to high energy consumption, high pollution product,
Therefore, high production cost, environmental cost are big.It is cyanamide-hydrogen sulfide synthetic method complex process, at high cost.
In view of this, the present invention is specifically proposed.
It is converted into thiocarbamide using ammonium thiocyanate, simple process, energy consumption and operating cost are low.Ammonium thiocyanate can utilize coke
Change the product that desulfurization waste liquor extracts, extend the industrial chain of desulfurization waste liquor salt extraction, opens new way for the extraction of desulfurization waste liquor secondary salt
Diameter.
Summary of the invention
The first object of the present invention is to provide a kind of method using ammonium thiocyanate conversion thiocarbamide, to solve existing preparation
The problems such as method and process of thiocarbamide is complicated, at high cost, high energy consumption, the method with ammonium thiocyanate conversion thiocarbamide utilizes sulphur
Ammonium cyanate is converted into thiocarbamide, has the advantages that simple process, energy consumption, without secondary pollution and operating cost are low etc..Ammonium thiocyanate
The product that coking desulfurization waste liquor can be used to extract, extends the industrial chain of desulfurization waste liquor salt extraction, opens for the extraction of desulfurization waste liquor secondary salt
New way is warded off.
The second object of the present invention is to provide sulphur made from the method described in one kind using ammonium thiocyanate conversion thiocarbamide
Urea, the thiocarbamide have many advantages, such as that purity is high, impurity are few.
In order to realize above-mentioned purpose of the invention, the following technical scheme is adopted:
A method of thiocarbamide is converted using ammonium thiocyanate, comprising the following steps:
(1), it is added in closed container and reacts after mixing ammonium thiocyanate and ammonium hydroxide, when the conversion ratio of ammonium thiocyanate arrives
When 78~95%, ammonia still process operation is carried out, remaining solid is crude thiourea in container；
(2), the crude thiourea in step (1) is distilled under the conditions of vacuum constant temperature, the gas of distillation carries out one section
It sublimates, obtains the thiocarbamide of high-purity, the gas that do not sublimate carries out two sections and sublimates, and obtains the mixture of thiocarbamide and ammonium thiocyanate, will
The mixture returns to sublimator and distils again, continues one section after distillation and sublimates；
(3), the gas that (2) two sections of step are not sublimated in sublimating is carried out three sections to sublimate, obtains the sulphur cyanogen of a small amount of high-purity
Sour ammonium.
It using ammonium thiocyanate as raw material, is reacted with the ammonium hydroxide of suitable certain mass ratio, when turning for ammonium thiocyanate
When rate is to 78~95%, ammonia is removed, obtained solid is crude thiourea, and the purity of crude thiourea is 80-95%, impurity
Main component be unconverted ammonium thiocyanate.Then it is sublimated the different principle of temperature using thiocarbamide and impurity, by distillation and more
The secondary mode sublimated obtains the thiocarbamide of high-purity.During sublimating, thiocarbamide, which is sublimated, makes the tiny powder fallen through rotation conveyer
Grain is contacted with sublimation gases and dynamic is sublimated, and effect of sublimating is good.The gas cooling that do not sublimate continues to sublimate, and obtains thiocarbamide and sulphur cyanogen
The thiocarbamide for being mixed with impurity is returned to sublimation apparatus and relays China of continuing rising, achievees the purpose that exist out by the mixture of sour ammonium.Three sections are sublimated,
Obtain the ammonium thiocyanate solid of high-purity.
The method for preparing thiocarbamide provided herein, uses ammonium thiocyanate as raw material, and coking can be used in ammonium thiocyanate
The product that desulfurization waste liquor extracts, extends the industrial chain of desulfurization waste liquor salt extraction, opened up a new way for the extraction of desulfurization waste liquor secondary salt.
Also, this method has the advantages that simple process, energy consumption, without secondary pollution and operating cost are low etc..
Preferably, in step (1), the purity > 96% of the ammonium thiocyanate, the concentration of the ammonium hydroxide is 20~30%.
It is furthermore preferred that the product that ammonium thiocyanate used by the application is extracted from coking desulfurization waste liquor, purity can
To reach 96% or more.
Preferably, the mass ratio of the ammonium thiocyanate and the ammonium hydroxide is (3~6): 1.
Under the conditions of usually used ammonia concn is 20~30%, the mass ratio of ammonium thiocyanate and ammonium hydroxide is carried out preferably,
Convenient for separation product and impurity, excess of ammonia shipwreck is also prevented to remove, influences product quality.
Preferably, in step (1), the temperature of the reaction is 65~90 DEG C, and reaction pressure is 0.1~1.0MPa, instead
It is 3~6 hours between seasonable；
It is furthermore preferred that heating while stirring during the reaction.
The condition of distillation preferably, obtain the mixed gas of thiocarbamide and impurity, be separately recovered in sublimating.
Preferably, in step (1), the purity of the crude thiourea is 80~95%.
Impurity in crude thiourea mainly from unconverted ammonium thiocyanate.
Preferably, in step (2), one section of temperature sublimated is 120~140 DEG C.
One section of temperature sublimated is controlled at 120~140 DEG C, is conducive to sublimating for thiocarbamide, obtains solid thiocarbamide convenient for separation.
Preferably, in step (2), two sections of temperature sublimated are 90~120 DEG C.
Two sections of controls of sublimating are at 90~120 DEG C, convenient for the common precipitation of thiocarbamide and impurity, further separate thiocarbamide and miscellaneous
Matter.
Preferably, in step (3), three sections of temperature sublimated are 60~90 DEG C.
Three sections of ammonium thiocyanate solids for sublimating to obtain high-purity.
The condition sublimated three times preferably, sublimate the purity and yield of thiocarbamide can be improved three times.It sublimates three times
Temperature it is different, it is also different for effect.It sublimates for one section and recycles thiocarbamide solid, two sections sublimate is the mixed of thiocarbamide and impurity
Object is closed, which, which returns to sublimation apparatus, continues to distil, and continues one section after distillation and sublimates.
Preferably, in step (1), after the ammonia still process operation, further comprising the steps of: ammonia is inhaled through spray absorber
It receives, obtained ammonia circulation utilizes, and is reacted with ammonium thiocyanate.
Ammonium hydroxide can recycle, save the cost.
Method preparation-obtained thiocarbamide as described above using ammonium thiocyanate conversion thiocarbamide, the purity of the thiocarbamide are big
In 99%.
Thiocarbamide obtained by the application has many advantages, such as that purity is high, impurity are few.
Compared with prior art, the invention has the benefit that
(1) method provided herein using ammonium thiocyanate conversion thiocarbamide, has simple process, energy consumption, nothing
The advantages such as secondary pollution and operating cost are low.
(2) method provided herein using ammonium thiocyanate conversion thiocarbamide, ammonium thiocyanate can be used coking desulfurization useless
The product that liquid extracts, extends the industrial chain of desulfurization waste liquor salt extraction, opened up a new way for the extraction of desulfurization waste liquor secondary salt.
(3) thiocarbamide prepared by the method provided herein using ammonium thiocyanate conversion thiocarbamide, has with high purity, miscellaneous
The advantages that matter is few.
Specific embodiment
Technical solution of the present invention is clearly and completely described below in conjunction with specific embodiment, but ability
Field technique personnel will be understood that following described embodiments are some of the embodiments of the present invention, instead of all the embodiments,
It is merely to illustrate the present invention, and is not construed as limiting the scope of the invention.Based on the embodiments of the present invention, the common skill in this field
Art personnel every other embodiment obtained without making creative work belongs to the model that the present invention protects
It encloses.The person that is not specified actual conditions in embodiment, carries out according to conventional conditions or manufacturer's recommended conditions.Agents useful for same or instrument
Production firm person is not specified, is the conventional products that can be obtained by commercially available purchase.
Embodiment 1
(1), by the ammonium hydroxide of the ammonium thiocyanate of mass content > 96% and concentration 20%, the ratio for being 3:1 according to mass ratio
Example mixing, and reacted in closed reaction kettle, 65 DEG C are warming up to, is heated while stirring, pressure in kettle is controlled and exists
Within the scope of 0.1MPa, react 3 hours；
(2), when the conversion ratio of assay ammonium thiocyanate is to 80%, ammonia still process operation is opened, ammonia is inhaled through spray absorber
It receives, is recycled in obtained ammonium hydroxide return step (1), remaining solid is released in kettle, and products obtained therefrom is crude thiourea, product
Purity 83%, the main component of impurity are unconverted ammonium thiocyanates；
(3), the thiocarbamide that step (2) obtains is heated in sublimator 150 DEG C, keeps vacuum constant temperature state, makes thiocarbamide
It distils, sublimation gases enter one section of device of sublimating by outlet, and at 120 DEG C, thiocarbamide is sublimated to be made to fall control constant temperature through rotation conveyer
Under tiny powder contacted with sublimation gases and dynamic sublimate, obtain product be 99% or more high-purity thiocarbamide；
(4), gas of not sublimating in step (3) enters two sections of devices of sublimating, and for control constant temperature at 90 DEG C, thiocarbamide and ammonium thiocyanate are solidifying
China, which is rotated conveyer, to be contacted the tiny powder fallen with sublimation gases and dynamically sublimates, and obtaining product is thiocarbamide and thiocyanic acid
Sublimator in the mixture return step (3) of ammonium, distils again；
(5), by gas of not sublimating remaining in step (4) into three sections of devices of sublimating, control constant temperature is at 60 DEG C, ammonium thiocyanate
Sublimate through rotate conveyer make the tiny powder fallen contact with sublimation gases and dynamically sublimate, obtain a small amount of product for 99% with
On high-purity ammonium thiocyanate.
Embodiment 2
(1), by the ammonium hydroxide of the ammonium thiocyanate of mass content > 96% and concentration 30%, the ratio for being 4:1 according to mass ratio
Example mixing, and reacted in closed reaction kettle, 90 DEG C are warming up to, is heated while stirring, pressure in kettle is controlled and exists
Within the scope of 1.0MPa, react 6 hours；
(2), when the conversion ratio of assay ammonium thiocyanate is to 88%, ammonia still process operation is opened, ammonia is inhaled through spray absorber
It receives, is recycled in obtained ammonium hydroxide return step (1), remaining solid is released in kettle, and products obtained therefrom is crude thiourea, product
Purity 80%, the main component of impurity are unconverted ammonium thiocyanates；
(3), the thiocarbamide that step (2) obtains is heated in sublimator 160 DEG C, keeps vacuum constant temperature state, makes thiocarbamide
Distillation, sublimation gases enter one section of device of sublimating by outlet, and control constant temperature at 120-140 DEG C, sublimate through rotating conveyer by thiocarbamide
It contacts the tiny powder fallen with sublimation gases and dynamically sublimates, obtain the high-purity thiocarbamide that product is 99% or more；
(4), gas of not sublimating in step (3) enters two sections of devices of sublimating, and control constant temperature is at 120 DEG C, thiocarbamide and ammonium thiocyanate
Sublimate makes the tiny powder fallen contact with sublimation gases and dynamically sublimate through rotation conveyer, and obtaining product is thiocarbamide and sulphur cyanogen
Sublimator in the mixture return step (3) of sour ammonium, distils again；
(5), by gas of not sublimating remaining in step (4) into three sections of devices of sublimating, control constant temperature is at 90 DEG C, ammonium thiocyanate
Sublimate through rotate conveyer make the tiny powder fallen contact with sublimation gases and dynamically sublimate, obtain a small amount of product for 99% with
On high-purity ammonium thiocyanate.
Embodiment 3
(1), by the ammonium hydroxide of the ammonium thiocyanate of mass content > 96% and concentration 25%, the ratio for being 5:1 according to mass ratio
Example mixing, and reacted in closed reaction kettle, 75 DEG C are warming up to, is heated while stirring, pressure in kettle is controlled and exists
Within the scope of 0.6MPa, react 4 hours；
(2), when the conversion ratio of assay ammonium thiocyanate is to 88~95%, ammonia still process operation is opened, ammonia is through spray-absorption
Tower absorbs, and recycles in obtained ammonium hydroxide return step (1), and remaining solid is released in kettle, and products obtained therefrom is crude thiourea,
Product purity 95%, the main component of impurity are unconverted ammonium thiocyanates；
(3), the thiocarbamide that step (2) obtains is heated in sublimator 155 DEG C, keeps vacuum constant temperature state, makes thiocarbamide
It distils, sublimation gases enter one section of device of sublimating by outlet, and at 130 DEG C, thiocarbamide is sublimated to be made to fall control constant temperature through rotation conveyer
Under tiny powder contacted with sublimation gases and dynamic sublimate, obtain product be 99% or more high-purity thiocarbamide；
(4), gas of not sublimating in step (3) enters two sections of devices of sublimating, and control constant temperature is at 100 DEG C, thiocarbamide and ammonium thiocyanate
Sublimate makes the tiny powder fallen contact with sublimation gases and dynamically sublimate through rotation conveyer, and obtaining product is thiocarbamide and sulphur cyanogen
Sublimator in the mixture return step (3) of sour ammonium, distils again；
(5), by gas of not sublimating remaining in step (4) into three sections of devices of sublimating, control constant temperature is at 70 DEG C, ammonium thiocyanate
Sublimate through rotate conveyer make the tiny powder fallen contact with sublimation gases and dynamically sublimate, obtain a small amount of product for 99% with
On high-purity ammonium thiocyanate.
Embodiment 4
(1), by the ammonium hydroxide of the ammonium thiocyanate of mass content > 96% and concentration 28%, the ratio for being 6:1 according to mass ratio
Example mixing, and reacted in closed reaction kettle, 80 DEG C are warming up to, is heated while stirring, pressure in kettle is controlled and exists
Within the scope of 0.8MPa, react 5 hours；
(2), when the conversion ratio of assay ammonium thiocyanate is to 78%, ammonia still process operation is opened, ammonia is inhaled through spray absorber
It receives, is recycled in obtained ammonium hydroxide return step (1), remaining solid is released in kettle, and products obtained therefrom is crude thiourea, product
Purity 92%, the main component of impurity are unconverted ammonium thiocyanates；
(3), the thiocarbamide that step (2) obtains is heated in sublimator 160 DEG C, keeps vacuum constant temperature state, makes thiocarbamide
It distils, sublimation gases enter one section of device of sublimating by outlet, and at 125 DEG C, thiocarbamide is sublimated to be made to fall control constant temperature through rotation conveyer
Under tiny powder contacted with sublimation gases and dynamic sublimate, obtain product be 99% or more high-purity thiocarbamide；
(4), gas of not sublimating in step (3) enters two sections of devices of sublimating, and control constant temperature is at 110 DEG C, thiocarbamide and ammonium thiocyanate
Sublimate makes the tiny powder fallen contact with sublimation gases and dynamically sublimate through rotation conveyer, and obtaining product is thiocarbamide and sulphur cyanogen
Sublimator in the mixture return step (3) of sour ammonium, distils again；
(5), by gas of not sublimating remaining in step (4) into three sections of devices of sublimating, control constant temperature is at 80 DEG C, ammonium thiocyanate
Sublimate through rotate conveyer make the tiny powder fallen contact with sublimation gases and dynamically sublimate, obtain a small amount of product for 99% with
On high-purity ammonium thiocyanate.
Experimental example product yield and purity test
To the method for utilizing ammonium thiocyanate conversion thiocarbamide provided by the embodiment of the present application 1-4, to the purity and receipts of product
Rate is tested, and experimental result is as shown in table 1.
1 product purity of table and yield test result
| Embodiment | Yield | Product purity |
| 1 | 41.5 | 99.2 |
| 2 | 44 | 99.3 |
| 3 | 45.8 | 99.6 |
| 4 | 47.2 | 99.5 |
The experimental results showed that the method provided herein using ammonium thiocyanate conversion thiocarbamide, yield can achieve
47.2%, product purity is greater than 99%, and product purity is high, impurity is few.
In conclusion the method provided herein using ammonium thiocyanate conversion thiocarbamide, there is simple process, the energy to disappear
Consumption, the advantages such as without secondary pollution and operating cost is low.Using the method for ammonium thiocyanate conversion thiocarbamide, coking is can be used in ammonium thiocyanate
The product that desulfurization waste liquor extracts, extends the industrial chain of desulfurization waste liquor salt extraction, opened up a new way for the extraction of desulfurization waste liquor secondary salt.
Thiocarbamide prepared by method using ammonium thiocyanate conversion thiocarbamide provided herein, has many advantages, such as that purity is high, impurity are few.
Although illustrate and describing the present invention with specific embodiment, it will be appreciated that the above various embodiments is only used
To illustrate technical solution of the present invention, rather than its limitations；Those skilled in the art should understand that: without departing substantially from this hair
It in the case where bright spirit and scope, is possible to modify the technical solutions described in the foregoing embodiments, or to wherein
Some or all of technical characteristic is equivalently replaced；And these are modified or replaceed, and do not make the essence of corresponding technical solution
It departs from the scope of the technical solutions of the embodiments of the present invention；It is, therefore, intended that in the following claims including belonging to the present invention
All these substitutions and modifications in range.
Claims (7)
1. a kind of method using ammonium thiocyanate conversion thiocarbamide, which comprises the following steps:
(1), it is added in closed container and reacts after mixing ammonium thiocyanate and ammonium hydroxide, when the conversion ratio of ammonium thiocyanate reaches 78
When~95%, ammonia still process operation is carried out, remaining solid is crude thiourea in container；
(2), the crude thiourea in step (1) being distilled under the conditions of vacuum constant temperature, the gas of distillation carries out one section and sublimates,
The thiocarbamide of high-purity is obtained, the gas that do not sublimate carries out two sections and sublimates, and the mixture of thiocarbamide and ammonium thiocyanate is obtained, by the mixing
Object returns to sublimator and distils again, continues one section after distillation and sublimates；
(3), the gas that (2) two sections of step are not sublimated in sublimating is carried out three sections to sublimate, obtains the ammonium thiocyanate of a small amount of high-purity；
In step (2), one section of temperature sublimated is 120~140 DEG C, and two sections of temperature sublimated are 90~120 DEG C；
In step (3), three sections of temperature sublimated are 60~90 DEG C.
2. the method according to claim 1 using ammonium thiocyanate conversion thiocarbamide, which is characterized in that in step (1), institute
The purity > 96% of ammonium thiocyanate is stated, the concentration of the ammonium hydroxide is 20~30%.
3. it is according to claim 2 using ammonium thiocyanate conversion thiocarbamide method, which is characterized in that the ammonium thiocyanate with
The mass ratio of the ammonium hydroxide is (3~6): 1.
4. the method according to claim 1 using ammonium thiocyanate conversion thiocarbamide, which is characterized in that in step (1), institute
The temperature for stating reaction is 65~90 DEG C, and reaction pressure is 0.1~1.0MPa, and the reaction time is 3~6 hours.
5. the method according to claim 4 using ammonium thiocyanate conversion thiocarbamide, which is characterized in that the process of the reaction
In heat while stirring.
6. the method according to claim 1 using ammonium thiocyanate conversion thiocarbamide, which is characterized in that in step (1), institute
The purity for stating crude thiourea is 80~95%.
7. the method according to claim 1 using ammonium thiocyanate conversion thiocarbamide, which is characterized in that in step (1), institute
After stating ammonia still process operation, further comprising the steps of: ammonia is absorbed through spray absorber, and obtained ammonia circulation utilizes, with sulphur cyanogen
Sour ammonium is reacted.
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| CN112409230A (en) * | 2020-11-23 | 2021-02-26 | 山东省科学院能源研究所 | Method for producing thiourea from ammonium thiocyanate |
| CN112876393A (en) * | 2021-01-19 | 2021-06-01 | 浙江工业大学 | Method for continuously synthesizing and purifying thiourea by using ammonium thiocyanate |
| CN114307359B (en) * | 2021-11-12 | 2023-05-12 | 格林智慧环保科技(山西)有限公司 | Thiourea and calcium thiocyanate membrane separation method |
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