CN100537421C - Method of preparing cyanamide aqueous solution and dicyandiamide and coproducing carbon and calcium carbonate by calcium cyanamide - Google Patents
Method of preparing cyanamide aqueous solution and dicyandiamide and coproducing carbon and calcium carbonate by calcium cyanamide Download PDFInfo
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- CN100537421C CN100537421C CNB2006100529063A CN200610052906A CN100537421C CN 100537421 C CN100537421 C CN 100537421C CN B2006100529063 A CNB2006100529063 A CN B2006100529063A CN 200610052906 A CN200610052906 A CN 200610052906A CN 100537421 C CN100537421 C CN 100537421C
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Abstract
The invention discloses a manufacturing method of mono-cyandiamide solution and di-cyandiamide and joint carbon and calcium carbonate, which comprises the following steps: adding limestone nitrogen into 3%-30% mono-cogeneration solution; stirring until reacting completely under 60 deg.c; separating insoluble matter to obtain carbon; making the effective nitrogen molar rate of mono-cogeneration and limestone nitrogen in the mono-cogeneration solution more than 1; aerating carbon dioxide into filtrate; evolving calcium carbonate with pH value below 10 under 60 deg.c; proceeding binary polymerization for mono-cogeneration to make di-cogeneration with high dissolving efficiency.
Description
Technical field
The present invention relates to the production method of the cyanamide aqueous solution and Dyhard RU 100, relate in particular to the method for the usefulness lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon, lime carbonate.
Background technology
Cyanamide and Dyhard RU 100 are applied to agricultural chemicals and medical material industry widely as industrial raw material, are used as epoxy curing agent, dye fixing agent, flocculation agent etc.The crystal cyanamide is mainly used in medicine, healthcare product, synthesizing of fodder additives and synthesizing of pesticide intermediate, and the cyanamide aqueous solution can be used as the defoliant of fruit fruit tree, nontoxic insecticide.Dyhard RU 100 can be used for making medicines such as guanidinesalt, Sulphadiazine Sodium, barbituric acid, moroxydine; Also can be used as Organic Chemicals is applied on the plastics industry to be used to make multiple nitrogenous organic chemical industry's products such as Xylitol, Liu Ni, Gua Ni, nitric acid to produce trimeric cyanamide, formaldehyde resin, glue paste, Resins, epoxy etc. in the organic chemical industry.In addition, Dyhard RU 100 still is a kind of high-quality and efficient nitrogenous fertilizer, adds the Dyhard RU 100 solution and the Ammonium bicarbonate food grade cocrystallization of certain concentration during Ammonium bicarbonate food grade is produced, and can be made into long-acting ammonium bicarbonate.And Dyhard RU 100 also can be used as the fire retardant that thick dose and fiber timber fall in rubber accelerator, synthetic detergent, viscose glue, and cyanamide and Dyhard RU 100 have great demand.
In the prior art, the production of cyanamide and Dyhard RU 100 is raw material with commercial lime nitrogen mostly.Commercial lime nitrogen generates by following nitrogenizing reaction.
CaC
2+N
2→CaCN
2+C
Therefore in lime nitrogen, inevitably sneak into the composition of carbon.
The preparation method of present cyanamide has multiple, as U.S. Pat 5017355, lime nitrogen is distributed to water or alcohol, then after solution feeds carbon dioxide, the suspension that forms obtains the cyanamide aqueous solution after filtering, and insolubles is the mixture of lime carbonate and carbon in the suspension.
U.S. Pat 3300281 has been put down in writing successive cyanamide aqueous solution production method, utilizes lime nitrogen to add and forms suspension in the entry, reacts with carbon dioxide then, obtains product.
Lime nitrogen is distributed in the water, and behind the feeding carbon dioxide, the chemical equation that generates cyanamide is as follows:
CaCN
2+C+CO
2+H
2O→CaCO
3+C+H
2NCN
Therefore, the lime carbonate of generation and carbon have formed mixture.
Polymerization takes place and obtains Dyhard RU 100 in the cyanamide aqueous solution under alkaline condition, reaction formula is:
2H
2NCN→H
2NC(NH
2)＝NCN。
Relevant is the report of the method for raw material production Dyhard RU 100 with the lime nitrogen, as Canadian Chemistry andProcess Industries, December 1944 P805, clear and the 30-3535 of Japan special permission, each is on the books for U.S. Pat P-3300281 etc., but all the time, in the initial period of reaction, all be that lime nitrogen is distributed in the water, feed carbon dioxide and react that the lime carbonate of generation and carbon form mixture.
In view of this, the production method of prior art can filter out a large amount of industrial filter residues when the manufacture order cyanamide aqueous solution.The industrial residue that this technology produces is the fine coal grey, is the mixture of lime carbonate and carbon and micro cyanide through analysis of components.According to 1 ton of Dyhard RU 100 of the every production of measuring and calculating, can produce about 4 tons and filter waste residue, because waste residue is the mixing of lime carbonate and carbon and other impurity, it utilizes the field to be restricted, and only can use as cement raw material or as soil improvement agent.
Once had and openly utilize the application of Dyhard RU 100 industrial residue to have: Chinese invention patent " is produced filler of high molecular synthetic products " (CN1071181), or produce light calcium carbonate (CN1100067), also have the dry powder after dicyandiamide sludge as material drying and the size classification is made plastic filler (CN1108273), or be to be mixed and made into haydite (CN1493537) with gelling material again after cyanate discharges carbonic acid gas and nitrogen the cyanide oxidation in the waste residue; Utilize dicyandiamide sludge as material to add vitrified bond common brick or production lime (CN1463948, CN1277164).The purpose of above-mentioned patent all is to administer the Dyhard RU 100 industrial residue, alleviate environmental pollution, but all there is the processing cost height in these methods, and perhaps made lime carbonate or lime quality are low, and therefore, existing Dyhard RU 100 manufacturer will handle as trade waste.
The industrial residue that the still unmatchful cyanamide aqueous solution and Dyhard RU 100 production process produce in the prior art carries out comprehensive utilization method.
Summary of the invention
In order to solve in the prior art with the lime nitrogen is the problem that the raw material production cyanamide aqueous solution and Dyhard RU 100 produce reluctant industrial residue, it is raw material with commercial lime nitrogen that the present invention aims to provide a kind of, to contain nitrogen element (available nitrogen), calcium, carbon of cyanamide state etc. in its moiety, each separates a kind of manufacture method of coproduction with the form of the cyanamide aqueous solution or Dyhard RU 100, lime carbonate, carbon
For achieving the above object, the present invention adopts following technical scheme:
Method with the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate is characterized in that comprising the steps:
(a): lime nitrogen adds the cyanamide aqueous solution, be stirred to and react completely, separation can not be dissolved part, obtain carbon, the weight percent concentration of the described cyanamide aqueous solution is 3%-30%, temperature of reaction is below 60 ℃, and the mol ratio of available nitrogen element is greater than 1 in cyanamide in the described cyanamide aqueous solution and the lime nitrogen;
(b): in step (a) gained filtrate, feed carbon dioxide, with precipitate filter lime carbonate, filtrate is the cyanamide aqueous solution, the pH value is below 10 during reaction, temperature of reaction is below 60 ℃;
With,
(c): the cyanamide aqueous solution that step (b) is obtained carries out the binary polymerization, obtains Dyhard RU 100.
Conventional art is that lime nitrogen is distributed in the filtrate after aqueous solvent or Dyhard RU 100 separate, this wherein the concentration of cyanamide all below 1%.Therefore, lime nitrogen is distributed in the water, and following reaction: CaCN just takes place later on
2+ C+H
2O → 1/2Ca (HNCN)
2+ C+1/2Ca (OH)
2
But the calcium hydroxide that reaction generates can not thoroughly carry out reaction to having reacted inhibition, and the nitrogen of cyanamide state much can not dissolve, and just exists with the insoluble solids form, and this route industrialization is impracticable.
Therefore, industrially directly in this suspension, feed carbon dioxide usually, when the nitrogen of the cyanamide state that exists with solid form is reduced, obtain the cyanamide aqueous solution as far as possible.
1/2Ca(HNCN)
2+C+1/2Ca(OH)
2+CO
2→CaCO
3+C+H
2NCN
Therefore, the lime carbonate of generation has just formed mixture with carbon.
People such as present inventor find, as step (a) reaction formula (formula-1), when lime nitrogen is distributed in the water, under the situation that cyanamide exists, can generate the acid calcium cyanamide that is dissolvable in water water extremely apace, i.e. step (a), in the aqueous solution, exist with the situation that adds the equimolar cyanamide of lime nitrogen under, following shown in reaction can very fast finishing, the cyanamide calcium in the lime nitrogen generates soluble acid calcium cyanamide.
CaCN
2+ C+H
2NCN → Ca (HNCN)
2+ C formula-1
Carbon in the lime nitrogen can not be water-soluble, and on the other hand, the acid calcium cyanamide can be water-soluble.Impurity such as the iron in the lime nitrogen, silicon remain in carbon one side, and the acid calcium cyanamide aqueous solution that filters the back gained just can prevent sneaking into of impurity effectively, after insoluble carbon filters out, obtains the clarifying acid calcium cyanamide aqueous solution.The carbon that obtains like this can be directly used in filler for plastic, fuel etc.; Process alkali, acid etc. can be used for pigment, electrode bar etc. after cleaning and making with extra care.
According to step (a) reaction formula, corresponding with the calcium cyanamide in the lime nitrogen, the amount of the cyanamide in the solution preferably wait the mole or more than.The total nitrogen of cyanamide attitude is 18%～24% in the industrial lime nitrogen of producing, if reaction solution uses the aqueous solution that contains cyanamide 1%, the lime nitrogen of 1Kg just needs 27 liters liquid, actual production equipment just needs very big, the treatment capacity of solution is also very many in addition, in fact can't carry out suitability for industrialized production; Conversely, if the cyanamide concentration of the reaction solution that uses surpasses 50%, the amount of liquid that consuming the 1Kg lime nitrogen needs just is kept to 0.6 liter, but the acid calcium cyanamide will separate out, just can't implement the present invention.In order successfully to implement the present invention, it is feasible that reaction solution uses the cyanamide aqueous solution of 3%～30% (weight ratio), the lime nitrogen that uses need be through the fine powder after pulverizing, ultra-finely also there is no need, recommending to use median size is 20～100 microns, when in the cyanamide aqueous solution, adding lime nitrogen, need stirring, temperature below 60 ℃.
Whether formula-1 reaction is finished, and can decide according to the mensuration to cyanamide, Dyhard RU 100 concentration in the solution.Usually, batch reaction just was through with internal reaction in 1 hour; If be successive reaction, the residence time, real reaction also finished in 1 hour.
After the acid calcium cyanamide aqueous solution of step (a) gained is handled with carbon dioxide, react, just can form the lime carbonate that is insoluble in water and cyanamide soluble in water respectively by following formula-2 (step (b) reaction formula).
Ca (HNCN)
2+ CO
2+ H
2O → CaCO
3↓+2H
2NCN formula-2
After the filtration, just obtain the transparent cyanamide aqueous solution, carbon dioxide and acid calcium cyanamide reactant aqueous solution, gas absorption is used tower or add the acid calcium cyanamide in retort, and feeding carbon dioxide from the bottom can.
The lime carbonate that step of the present invention (b) is generated at first is that the form with the acid calcium cyanamide is dissolved in the aqueous solution, therefore can remove impurities in raw materials, the lime carbonate based on very high purity that obtains, and purity can reach more than 99%.
The cyanamide aqueous solution carries out the binary polyreaction of formula-3 under alkaline condition, make Dyhard RU 100.
2H
2NCN → H
2NC (NH) NCN formula-3
Part or all of the gained cyanamide aqueous solution is back to step (a), and the aqueous solution as cyanamide in the step (a) carries out batch operation.Step (b) the gained cyanamide aqueous solution turns back to the cyanamide aqueous solution that step (a) can be produced greater concn.
If the part of step (b) the gained cyanamide aqueous solution is back to step (a),, carry out the continous way operation as the cyanamide aqueous solution in the step (a).
Industrial application is preferably, intermittent type or continous way production are produced the cyanamide aqueous solution, recoverable step (a) is reacted after can getting a part of dilute with water wherein, and the cyanamide aqueous solution Yi Shi-3 that stays reacts and produces Dyhard RU 100, and its filtrate turns back to step (b).
In pH8～11 binary polymerizations, polymerization is after the continuous crystallizer cleaning can be implemented the production of continous way Dyhard RU 100 with step (b) the gained cyanamide aqueous solution, and binary polymeric filtrate turns back to step (b).
If the continous way manufacture order cyanamide aqueous solution can adopt following steps:
(a): with the cyanamide aqueous solution with pulverize the back lime nitrogen and import reactor A continuously, filter the black insolubles, clean with water, carbon, merging filtrate;
The weight percent concentration of the described cyanamide aqueous solution is 3%-30%, and temperature of reaction is below 60 ℃, and the raw materials components mole ratio of available nitrogen element is 1～10 in cyanamide in the described cyanamide aqueous solution and the lime nitrogen;
(b): step (a) gained filtrate imports reactor B, and the bottom feeds carbon dioxide, the white slurries in the reactor B is directed in the filter B filters, and cleans through the filtering white filter cake water of filter B, gets lime carbonate, and filtrate is merged into the cyanamide aqueous solution;
When reactor B is overflowed lime carbonate, the cyanamide aqueous solution by the cyanamide filtrate alternative steps (a) of passing through filter B, the raw materials components mole ratio of available nitrogen in cyanamide in the adjusting cyanamide aqueous solution and the lime nitrogen, the pH value is below 10 during reaction, temperature of reaction is below 60 ℃;
When the concentration of strainer B cyanamide filtrate reaches aimed concn, dividing mass percent concentration wherein is that 10%～30% cyanamide filtrate is exported to storage tank, and simultaneously to the reactor A amount of makeup water.
If continuous production Dyhard RU 100, also comprise step (c): the continuous production Dyhard RU 100 also comprises step (c): through cyanamide in the filter B filtering cyanamide aqueous solution and Dyhard RU 100 total mass percent concentration greater than after 10%, add water to reactor A and keep entering that cyanamide is 10%～30% with Dyhard RU 100 total mass percent concentration in the cyanamide filtrate of reactor, the cyanamide filtrate of filter B is exported to storage tank simultaneously, and the cyanamide filtrate work output of filter B and the addition of reactor A water are about equally;
The cyanamide aqueous solution of storage tank imports reactor C 30 ℃～80 ℃ following binary polymerizations, and the reaction soln that overflows input continuous crystallizer is separated out the Dyhard RU 100 crystal, filters through filter C again, and filtrate merging is recycled to reactor B.
Aforesaid method, the weight percent concentration of step (a) the cyanamide aqueous solution is 5%-20%.
Aforesaid method, the temperature of reaction of step (a) is below 40 ℃, controlled step (b) temperature of reaction is below 40 ℃.
Can be according to the purpose decision reaction conditions of producing, if purely in order to produce the cyanamide aqueous solution, the temperature of reaction of step (a) need be controlled at below 20 ℃, step (b) pH value need remain on below 7, temperature needs below 40 ℃, if but temperature control is too low, will increase refrigeration costs, to industrial be disadvantageous.Therefore recommend to be controlled at more than 0 ℃.
The inventive method, being chosen as below 9 that maintenance pH value is preferable during step (b) reaction is preferred below 8, and as mentioned above, when only producing the cyanamide aqueous solution, the pH value need remain on below 7.
When the polymerization of step (c) cyanamide prepares Dyhard RU 100, need to keep pH value 8～11, the binary polymeric reaction temperature is 30 ℃～80 ℃,
The insoluble carbon of the inventive method step (a) gained cleans through alkali, acid, can make with extra care after the drying and obtain high purity graphite.
The density of carbon dioxide gas that step (b) is used is high more good more.If concentration has more than 10%, industrially just can use.Extract from the limestone kiln under the situation of carbon dioxide, concentration needs 20%～41%.In addition, refined concentration also can be used at the carbon dioxide more than 99%, but objectionable constituent such as hydrogen sulfide, sulfurous acid, ammonia need to reduce as much as possible, and the concentration that makes hydrogen sulfide, sulfurous acid and ammonia in the production control is less than 1%.
As the preferable mode of the inventive method, the weight percent concentration of step of the present invention (a) the cyanamide aqueous solution is 5%-20%, and temperature of reaction is below 20 ℃; Controlled step (b) temperature of reaction is below 20 ℃, and keeping pH during the reaction of step (b) is below 7, and the part of step (b) the gained cyanamide aqueous solution is back to step (a), as the cyanamide aqueous solution in the step (a), carries out the continous way operation;
Step (b) the gained cyanamide aqueous solution is remained in binary polymerization under pH8～11 conditions, carry out the production of continous way Dyhard RU 100, its filtrate turns back to step (b).
Method of producing the cyanamide aqueous solution and Dyhard RU 100 coproduction carbon, lime carbonate provided by the invention with lime nitrogen, compared to existing technology in lime nitrogen produce the cyanamide aqueous solution and Dyhard RU 100 method, have following technique effect:
(1), invention has solved the problem that the mixed industrial waste residue of indeterminable lime carbonate and carbon is brought in the conventional art.
The present invention carries out each to production carbon with lime carbonate and separates in the process of producing the Dyhard RU 100 or the cyanamide aqueous solution.
The lime carbonate that the present invention generated, because the form with the acid calcium cyanamide is dissolved in the aqueous solution earlier, therefore can remove the lime nitrogen impurities in raw materials, the lime carbonate purity that obtains can reach more than 99%, and highly purified lime carbonate can be used as weighting agent, the properties-correcting agent of plastics, rubber, pipeline etc.; Isolated carbon can be directly used in filler for plastic, fuel etc.; After process alkali, acid etc. are cleaned and made with extra care, can be used as the electrode materials of battery, perhaps field such as rubber, pigment has good economic benefit, environmental benefit and social benefit.
(2), method of the present invention is dispersed in lime nitrogen in the solution of cyanamide existence, can generate the acid calcium cyanamide that is dissolvable in water water fast, impurity such as the iron in the lime nitrogen, silicon residue in carbon one side and filter as insolubles, prevent that effectively impurity from sneaking into the acid calcium cyanamide aqueous solution, guaranteed the purity of the cyanamide aqueous solution and Dyhard RU 100.
(3) reaction times weak point, the dissolved efficiency height, batch production similarity condition, Dyhard RU 100 of the inventive method or cyanamide yield are higher more than 50% than art methods.
Figure of description
Fig. 1 is a quantity-produced industrial flow chart of the present invention
Embodiment
Below, illustrate the inventive method by embodiment.
Test is as follows with the quality index of lime nitrogen:
Cyanamide attitude nitrogen element (available nitrogen) 20.0%
Calcium component is converted to CaO 64.0%
100 microns of mean particle sizes
Embodiment 1 uses 5% the cyanamide aqueous solution, batch hydrolysis example
In the 500mL beaker that stirring is housed, add 5.00% cyanamide aqueous solution 200g (pH7.5), beaker cools off outward.Under condition of stirring, disposable adding 10g lime nitrogen.Temperature in the beaker remains on below 20 ℃.After 10 minutes, stirring stops, and gains carry out vacuum filtration with the B that is covered with filter paper diameter 10cm.Insolubles on the filter paper cleans merging filtrate with a spot of water.
The principal constituent of residual insolubles is a carbon on the filter paper, and heavy 2.83g is moisture 30%, contains the concentration 0.17% of available nitrogen.Black thing on the filter paper is used earlier 5% sodium-hydroxide treatment, and 5% nitric acid treatment after washing is used in washing more then, after this refining drying, obtains the carbon component 1.17g of black.Index is a moisture 0.5%, ash content 2.1%
Filtrate is transferred in the beaker, insert liquid with pipe and import carbon dioxide down, just the adularescent precipitation generates at once, and carbon dioxide one pH value in the solution is till 7, and the B that the lime carbonate usefulness of generation is covered with filter paper diameter 10cm carries out vacuum filtration.Lime carbonate on the filter paper cleans merging filtrate with a spot of water.After the lime carbonate drying that obtains, weight is 11.1g.
The analytical results of lime carbonate is as follows:
Purity 99.8%, dry loss of weight 0.1%, 20.7 microns of mean particle sizes, specific surface area 2100cm
2/ g, bulk specific gravity 0.65g/ml is a water-ground limestone.
Carbide raw material is to use the natural limestone that contains lime carbonate 95.6%, by the present invention, from inferior Wingdale, finally can obtain highly purified lime carbonate.
The filtrate of final gained has 210g, and wherein cyanamide concentration 5.85%, Dyhard RU 100 concentration 0.30%.
The material balance of cyanamide is to estimate by following calculating.
[advancing]
The mole number of cyanamide is in the lime nitrogen that uses:
10×20％÷28×1000＝71.43mmol
Lime nitrogen adds 10.00g
Available nitrogen in the lime nitrogen (cyanamide attitude nitrogen element) 20%
Molecular weight (the N of nitrogen
2) 28
The cyanamide mole number that exists in the cyanamide aqueous solution that uses
200×5％÷42×1000＝238.10mmol
Aqueous solution 200g
Concentration of aqueous solution 5%
Cyanamide molecular weight 42
[going out]
After the reaction, the cyanamide mole number that exists in the reaction solution
210×6.15％÷42×1000＝307.5mmol
Aqueous solution weight 210g
Cyanamide conversion concentration 5.85%+0.30%=6.15%
[material balance]
The increasing amount of cyanamide has 307.5-238.1=69.4mmol in the solution
Dissolved efficiency (yield) the 69.4 ÷ 71.43=97.16% that begin from lime nitrogen
Embodiment 2 uses the cyanamide aqueous solution of embodiment 1 gained, carries out a batch hydrolysis example
The cyanamide aqueous solution of usage example 1 gained according to the same working method of embodiment 2, finally can get cyanamide concentration 6.57%, the solution 220g of Dyhard RU 100 concentration 0.65%.The material balance method of calculation of example 1 above using, dissolved efficiency is 98.0%.
This batch operation method is implemented in circulation, can obtain the cyanamide aqueous solution of greater concn.
Embodiment 3 uses 25% the cyanamide aqueous solution, batch manufacture order cyanamide aqueous solution, Dyhard RU 100, coproduction carbon and lime carbonate
To the 500L reactor that stirring is housed, add 25.00% cyanamide aqueous solution 200Kg (pH10), the outer normal-temperature water circulation of reactor cooling, under condition of stirring, disposable adding 25Kg lime nitrogen.Temperature in the kettle remains on below 40 ℃, and pitch time, the cyanamide of abstraction reaction liquid judged whether reaction is complete, and after about 30 minutes, stirring stops, and gains are with being delivered to drum filter, and the black insolubles cleans with a spot of water, merging filtrate.
The principal constituent of insolubles be carbon after the acid-alkali refining drying, obtain the carbon component 235Kg of black.
Filtrate (being mainly the acid calcium cyanamide aqueous solution) is directed at another 500L reactor, feeding is 41% gas (hydrogen sulfide, sulfurous acid, ammonia total about 0.65%) from limestone kiln extraction carbonated concentration under the still, temperature of reaction is 40 ℃, white precipitate generates in the still, carbon dioxide one pH value in the solution is 8, the white slurries are directed at strainer, and the lime carbonate that obtains cleans with a spot of water, merging filtrate.
After the lime carbonate drying, weight is 15Kg.
Gained lime carbonate purity 99.7%.
The filtrate of final gained has 217Kg, and wherein cyanamide concentration 25.68%, Dyhard RU 100 concentration 0.68%.
The dissolved efficiency (yield) that begins from lime nitrogen is 92.32%
Get the cyanamide aqueous solution of gained, keep pH value 9, carry out the binary polyreaction in reactor, temperature is controlled to be 80 ℃, the binary polymerization.After about 6 hours, reaction solution overflows, and is input to xln in the continuous crystallizer again.The temperature of crystallizer remains on 40 ℃, the white Dyhard RU 100 crystal of generation, and the Dyhard RU 100 crystal washs with a spot of water, and the gained Dyhard RU 100 carried out drying 3 hours under 105 ℃, yield 94.72%.
Present embodiment uses 3% the cyanamide aqueous solution, lime nitrogen is added contain the cyanamide aqueous solution, is stirred to react completely, isolate carbon, filtrate is the acid calcium cyanamide aqueous solution, and temperature of reaction is 60 ℃, and the mol ratio of available nitrogen is 4 in cyanamide in the described cyanamide aqueous solution and the lime nitrogen.
Feed the gas contain carbonic acid gas in the acid calcium cyanamide aqueous solution, to reacting liquid pH value be 9, with precipitate filter lime carbonate, filtrate is the cyanamide aqueous solution, density of carbon dioxide gas is 12%, temperature of reaction is 60 ℃.Cyanamide concentration 4.39% in the cyanamide aqueous solution, Dyhard RU 100 concentration 0.4%.
It is 10 that the cyanamide aqueous solution that obtains is kept the pH value, and temperature is 75 ℃ of following binary polyreactions, can make Dyhard RU 100.
All the other are with embodiment 1.
Embodiment 5: the example of continuous production cyanamide aqueous solution coproduction carbon, lime carbonate (according to technical process shown in Figure 1, the manufacture order cyanamide aqueous solution)
Cyanamide concentration is that 5.00% the aqueous solution adds to broach hopper shown in Figure 12 with the speed of 200Kg/Hr.At the same time, lime nitrogen after crushed adds to this broach hopper with 20.00Kg/Hr speed, mixes.This broach hopper is directly connected to reactor A, and thrust-augmenting nozzle 1 shown in Figure 1 is inserted into below the mud liquid level of reactor A.The mud of reactor A (suspension) supplies to broach hopper 2 by pipe arrangement 3, circulates, and the temperature of reactor A must remain on below 15 ℃.
The liquid that reactor A overflows filters out insoluble solid (the filter cake main component is a carbon, therefore shows black) through strainer A, and the filter residue cake cleans the back with a spot of new water and merges with filtrate.Filter residue is the powder of black, carries out drying under 105 ℃, obtains carbon.
Clarifying filtrate imports to reactor B.In the reactor B, feed the carbon dioxide of concentration 35% from the bottom.Reactor B remains on below the pH7, and temperature of reaction is below 20 ℃.
Begin to overflow white slurries from reactor B, stop the interpolation of the 5.00% cyanamide aqueous solution, the clear filtrate that replaces filter B is supplied with to broach hopper with 200Kg/Hr by pipe arrangement 4, and the cyanamide aqueous solution just begins circulation and got up.
The white calcium carbonate that filter B filters out is washed with a spot of new water, and washings and filtrate merge.The lime carbonate that generates carries out drying under 105 ℃.
After 9 hours, pipe arrangement 4 effusive cyanamide concentration just should reach 12%, add new water with the speed of 42Kg/Hr to reactor A, simultaneously filtrate the exporting to storage tank with 46.72Kg/Hr of filter B.
So, just can successive have produced 12% the cyanamide aqueous solution.
Normal working condition
Raw material adds (advancing)
Lime nitrogen 20.00Kg/Hr
New water replenishes 42.00Kg/Hr
Produce (going out)
Cyanamide aqueous solution 46.72Kg/Hr
Cyanamide concentration 12.0%
Dyhard RU 100 concentration 0.2%
The yield of converting cyanamide with the lime nitrogen amount of adding is 92.2%.
Lime carbonate 22.5Kg/Hr
Purity 99.7%
Moisture 0.1%
Carbon component 3.6Kg/Hr
Moisture 0.5%
Above 12.0% the cyanamide aqueous solution pH is adjusted to 4～5, concentrate with turning round under 40 ℃ of the vaporizer negative pressure, just can obtain transparent clarifying 50% the cyanamide aqueous solution.Certainly simultaneously also can production part Dyhard RU 100.
After the analysis, the result is as follows:
Cyanamide concentration 50.0%
Dyhard RU 100 1.1%
Urea is below 0.1%
Thiocarbamide is below 0.1%
In the technology, strainer can adopt plate-and-frame filter press, drum filter, separating centrifuge, band filter, Nu Caishi strainer or the like; Drying machine can adopt Vibratingfluidbeddrier, fluid bed dryer, static drying machine, Vacuumdrier, pneumatic drier or the like; As long as meet efficient, satisfy economy principle, that can achieve the goal again can select for use.
Cyanamide concentration is that 5.00% the aqueous solution adds to the broach hopper shown in the figure 2 with the speed of 200Kg/Hr.At the same time, lime nitrogen after crushed adds to this broach hopper with 20.00Kg/Hr speed, mixes.This broach hopper is directly connected to reactor A, and thrust-augmenting nozzle 1 shown in Figure 1 is inserted into below the mud liquid level of reactor A.The mud of reactor A (suspension) supplies to broach hopper 2 by pipe arrangement 3, circulates.The temperature of reactor A must remain on below 15 ℃.
The liquid that reactor A overflows filters out insoluble solid (the filter cake main component is a carbon, therefore shows black) through strainer A.The filter residue cake cleans the back with a spot of new water and merges with filtrate.Filter residue is the powder of black, carries out drying under 105 ℃.
Clarifying filtrate imports to reactor B.In the reactor B, feed the carbon dioxide of concentration 35% from the bottom.Reactor B remains on below the pH7.5, and temperature of reaction is below 40 ℃.
Begin to overflow white slurries from reactor B, stop the interpolation of the 5.00% cyanamide aqueous solution, the clear filtrate that replaces filter B is supplied with to broach hopper with 200Kg/Hr by pipe arrangement 4, and the cyanamide aqueous solution just begins circulation and got up.
The white calcium carbonate that filter B filters out is washed with a spot of new water, and washings and filtrate merge.The lime carbonate that generates carries out drying under 105 ℃.
After 14 hours, pipe arrangement 4 effusive cyanamide concentration and Dyhard RU 100 concentration add up to regard to behind the should exceed 16%, add new water with the speed of 35～40Kg/Hr to reactor A, regulate making the total concentration of cyanamide and Dyhard RU 100 remain on 16%～18%.Filtrate the exporting of while filter B with 40Kg/Hr to storage tank.
From the clarified liq that the cyanamide storage tank overflows, be input to reactor C.The filtrate of strainer A is input to reactor C by pipe arrangement 6, regulates flow its pH value is remained between 9 to 11.
In addition, reactor C maintains 65～75 ℃, can promote the binary polymerization.After about 4 hours, reaction solution overflows from reactor C.The reaction solution that overflows is input in the continuous crystallizer, separates out crystal.The temperature of crystallizer remains on 30 ℃, the white Dyhard RU 100 crystal of generation, and successive filters by strainer C.Also contain 4.5% Dyhard RU 100 and 0.8% cyanamide in the filtrate.Filtrate is recycled to reactor B by pipe arrangement 7.
Filter cake Dyhard RU 100 crystal washs with a spot of water, and washings and filtrate merge.The Dyhard RU 100 of gained carries out drying under 105 ℃.
Raw material adds (advancing)
Lime nitrogen 20.00Kg/Hr
Available nitrogen 20.0%
Washing water add up to 6.3Kg/Hr
Produce (going out)
Dyhard RU 100 aqueous solution 5.68Kg/Hr
Purity 99.8%
Moisture 0.03%
Producing 1 part of Dyhard RU 100 needs 3.52 parts lime nitrogen, also is that unit consumption is 3.52.
Lime carbonate 22.6Kg/Hr
Purity 99.8%
Moisture 0.1%
Carbon component 3.6Kg/Hr
Moisture 0.5%
In the technology, strainer can adopt plate-and-frame filter press, drum filter, separating centrifuge, band filter, Nu Caishi strainer or the like; Drying machine can adopt Vibratingfluidbeddrier, fluid bed dryer, static drying machine, Vacuumdrier, pneumatic drier or the like; As long as meet efficient, satisfy economy principle, that can achieve the goal again can select for use.
Crystallizer, in order to obtain continuously crystal, can adopt Olso crystallization apparatus or be furnished with refrigerating unit to scratch the modus ponens crystallization apparatus continuously relatively good; Certainly can not be confined to abovely, can crystallizer be set plural number, also be reasonable concerning crystallization.
Embodiment 7: the example of continuous production cyanamide aqueous solution coproduction carbon, lime carbonate (according to technical process shown in Figure 1, the manufacture order cyanamide aqueous solution)
Being 15.00% the aqueous solution with cyanamide concentration adds with the broach hopper 2 of speed in Fig. 1 of 100Kg/Hr, pulverize the back lime nitrogen and import broach hopper 2 continuously with 15Kg/Hr, after the mixing, below the mud liquid level by thrust-augmenting nozzle 1 insertion reaction device A, the suspension of reactor A is by pipe arrangement 3 and broach hopper 2 circulations, and the reactor A temperature keeps 40 ℃, liquid that reactor A overflows through strainer A filter the insoluble object of black, clean with water, get carbon, merging filtrate;
Above-mentioned clear filtrate imports reactor B, and the bottom feeds the carbon dioxide of 20% concentration that extracts in the limestone kiln, passes to reactor B and reacts completely, and the pH value is about 8, keeps the reactor B temperature below 50 ℃.
The white slurries that reactor B is overflowed are directed at filter B and filter, the filtering white filter cake of filter B with water clean lime carbonate, filtrate is merged into the cyanamide aqueous solution;
When reactor B begins to overflow white calcium carbonate, stop to add to the cyanamide aqueous solution of broach hopper 2, alternative by the cyanamide filtrate of filter B with 80Kg/Hr;
About 5 hours, when the concentration of strainer B cyanamide filtrate reaches 20%, the cyanamide filtrate of filter B is exported to storage tank with 15Kg/Hr, and adds new water with the speed of 12.2Kg/Hr to reactor A.
But the cyanamide aqueous solution of continuous production 20% like this.
Embodiment 8: continuous production Dyhard RU 100 solution coproduction carbon, lime carbonate
After cyanamide and Dyhard RU 100 add up to concentration greater than 10% in the cyanamide aqueous solution that embodiment 7 middle filtrator B filter out,
Add water continuously to reactor A and keep entering in the cyanamide filtrate of reactor cyanamide to add up to concentration with Dyhard RU 100 be 10%～30%, the while cyanamide filtrate of filter B is exported to storage tank.
The cyanamide aqueous solution that overflows from storage tank imports reactor C 35 ℃ of following binary polymerizations, the filtrate of strainer A is by pipe arrangement 6 input reactor C, regulating flow makes the pH value between 8～11, reaction solution input continuous crystallizer, separate out the Dyhard RU 100 crystal, filter by strainer C, filtrate merga pass pipe arrangement 7 is recycled to reactor B again.
Comparative example
Except the cyanamide change in concentration of using the aqueous solution, other operations are identical with example 1.Get the 200g aqueous solution, under stirring state, the lime nitrogen of disposable adding 10.0g through behind the specific time, filters out insolubles, and after filter cake cleaned with less water, washings and filtrate merged.In the filtrate that obtains above, feed carbon dioxide, separate out lime carbonate.The lime carbonate of separating out is filtered out, clean lime carbonate, merge washings and filtrate, adjust to 205g, cyanamide in the assay filtrate and Dyhard RU 100 with a spot of water.Method of calculation are identical with embodiment 1.
The condition of comparative example
Shown below is experimental result
Experimental result 1
Experimental result 2
Experimental result 3
Cyanamide concentration is high more, and dissolved efficiency is high more, and evidence concentration is lower than 3%, DeGrain, and enforcement of the present invention is also relatively more difficult, and institute thinks enforcement the present invention, uses the cyanamide aqueous solution more than 3% relatively good.
In the embodiment of the invention 1 and embodiment 2, the cyanamide concentration of the solution that uses is respectively that 5.0% and 6.15%, 10 minute internal reaction is finished substantially, and dissolved efficiency can reach 97.16% and 98.8%.
Claims (14)
1, with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that comprising the steps:
(a): lime nitrogen adds the cyanamide aqueous solution, be stirred to and react completely, separation can not be dissolved part, obtain carbon, the weight percent concentration of the described cyanamide aqueous solution is 3%-30%, temperature of reaction is below 60 ℃, and the mol ratio of available nitrogen element is more than 1 in cyanamide in the described cyanamide aqueous solution and the lime nitrogen;
(b): in step (a) gained filtrate, feed carbon dioxide, with precipitate filter lime carbonate, filtrate is the cyanamide aqueous solution, the pH value is below 10 during reaction, temperature of reaction is below 60 ℃;
With,
(c): the cyanamide aqueous solution that step (b) is obtained carries out the binary polymerization, obtains Dyhard RU 100.
2, use the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate according to claim 1, it is characterized in that the part of step (b) the gained cyanamide aqueous solution is back to step (a), as the cyanamide aqueous solution in the step (a), implement continous way production.
3, use the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate according to claim 1, it is characterized in that the whole or part of step (b) the gained cyanamide aqueous solution is back to step (a), as the cyanamide aqueous solution in the step (a), implement batch production.
4, as described in the claim 2 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that step (b) the gained cyanamide aqueous solution in pH8～11 binary polymerizations, implement the production of continous way Dyhard RU 100, binary polymeric filtrate turns back to step (b).
5, as described in the claim 2 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that continous way cyanamide aqueous solution production stage is as follows:
(a): with the cyanamide aqueous solution with pulverize the back lime nitrogen and import reactor A continuously, be stirred to and react completely, filter the black insolubles, clean with water, carbon, merging filtrate;
The weight percent concentration of the described cyanamide aqueous solution is 3%-30%, and temperature of reaction is below 60 ℃, and the raw materials components mole ratio of available nitrogen element is 1～10 in cyanamide in the described cyanamide aqueous solution and the lime nitrogen;
(b): step (a) gained filtrate imports reactor B, and the bottom feeds carbon dioxide, the white slurries in the reactor B is directed in the filter B filters, and cleans through the filtering white filter cake water of filter B, gets lime carbonate, and filtrate is merged into the cyanamide aqueous solution;
When reactor B is overflowed lime carbonate, the cyanamide aqueous solution by the cyanamide filtrate alternative steps (a) of passing through filter B, the raw materials components mole ratio of available nitrogen element in cyanamide in the adjusting cyanamide aqueous solution and the lime nitrogen, the pH value is below 10 during reaction, temperature of reaction is below 60 ℃;
When the concentration of strainer B cyanamide filtrate reaches aimed concn, dividing the wherein wt percentage concentration is that 10%～30% cyanamide filtrate is exported to storage tank, and simultaneously to the reactor A amount of makeup water.
6, as as described in the claim 5 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that the continuous production Dyhard RU 100 also comprises step (c): through cyanamide in the filter B filtering cyanamide aqueous solution and Dyhard RU 100 total weight percent concentration greater than after 10%, add water to reactor A and keep entering that cyanamide is 10%～30% with Dyhard RU 100 total weight percent concentration in the cyanamide filtrate of reactor, the cyanamide filtrate of filter B is exported to storage tank simultaneously, and the cyanamide filtrate work output of filter B and the addition of reactor A water are about equally;
The cyanamide aqueous solution of storage tank imports reactor C 30 ℃～80 ℃ following binary polymerizations, and the reaction soln that overflows input continuous crystallizer is separated out the Dyhard RU 100 crystal, filters through filter C again, and filtrate merging is recycled to reactor B.
7, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that the weight percent concentration of step (a) the cyanamide aqueous solution is 5%-20%.
8, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, the temperature of reaction that it is characterized in that step (a) is below 40 ℃, controlled step (b) temperature of reaction is below 40 ℃.
9, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, the temperature of reaction that it is characterized in that step (a) is below 20 ℃, controlled step (b) temperature of reaction is below 20 ℃, and keeping pH during the reaction of step (b) is below 7.
10, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, keeping pH when it is characterized in that step (b) reaction is below 8.
11, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, when it is characterized in that step (c) preparation Dyhard RU 100, keep pH value 8～11, the binary polymeric reaction temperature is 30 ℃～80 ℃.
12, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that the insoluble carbon of step (a) gained, clean through alkali, acid, after the drying high purity graphite.
13, as described in one of claim 1～6 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that the carbonated gas concentration of step (b) is that to extract carbonated concentration more than 10% or from the limestone kiln be 20%～41% gas, wherein hydrogen sulfide, sulfurous acid and ammonia are less than 1%.
14, as described in the claim 13 with the method for the lime nitrogen manufacture order cyanamide aqueous solution and Dyhard RU 100 and coproduction carbon and lime carbonate, it is characterized in that the weight percent concentration of step (a) the cyanamide aqueous solution is 5%-20%, temperature of reaction is below 20 ℃; Controlled step (b) temperature of reaction is below 20 ℃, and keeping pH during the reaction of step (b) is below 7;
The part of step (b) the gained cyanamide aqueous solution is back to step (a),, implements the production operation of the continous way cyanamide aqueous solution as the cyanamide aqueous solution in the step (a);
Step (b) the gained cyanamide aqueous solution is remained in binary polymerization under pH8～11 conditions, carry out the production of continous way Dyhard RU 100, its filtrate turns back to step (b).
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