CN101428840B - Method for synthetic production of nano-calcium carbonate, calcium carbide fuel gas - Google Patents

Abstract

The invention provides a method for comprehensively preparing nanometer calcium carbonate, calcium carbide and fuel gas through taking limestone and coke as main raw materials. The method mainly comprises the following steps: calcining the limestone to obtain large granular CaO and CaO2; preparing the calcium carbide and the fuel gas containing CO, H2 and CH4 through water reaction; causing fine granular CaO after being digested to generate carburizing reaction with the CO2 generated under the existence of various crystal-shaped control agents when the limestone is calcined to obtain the calcium carbonate; and finally obtaining nanometer calcium carbonate powder which mainly comprises cubical-shaped particles and spherical particles through controlling technological conditions. Compared with the prior art, because CaO has various purposes after being graded in granularity, the invention can avoid the defects of low thermal efficiency, arching and the like caused by the superfine granularity of the CaO during the production process of the traditional calcium carbide, thereby reducing the crushing process during the production process of the nanometer calcium carbonate. The CO2 can be recycled in a reactor for preparing the calcium carbide and the calcium carbonate during the preparation process, so that the purity of the fuel gas and the availability of raw materials are improved.

Description

The method of a kind of synthetic production of nano-calcium carbonate, calcium carbide, fuel gas

Technical field

The present invention relates to the method for a kind of synthetic production of nano-calcium carbonate, calcium carbide, fuel gas.

Background technology

Lime carbonate is one of important inorganic chemical industry basic raw material, because the raw material limestone aboundresources, characteristics such as it is simple to have production technique, and energy consumption is little, and performance is more stable are widely used in industries such as rubber, plastics, printing ink, papermaking, food and medicine.In recent years, along with the super-refinement of lime carbonate, the development of structure complicated and process for modifying surface thereof has greatly improved its using value.Difform lime carbonate can be applicable to different, can be used for industries such as rubber, tackiness agent, coating, printing ink as cube and spheric lime carbonate; Fibrous, fusiform can be used for industries such as rubber, papermaking.Therefore, the preparation of the lime carbonate of nano level and variform and production have very large practical significance.

Produce the method for calcium carbonate superfine powder both at home and abroad, adopt usually carbon dioxide is fed the reactor that fills calcium hydroxide emulsion, in carburizing reagent, add the crystal growth control agent, obtain calcium carbonate superfine powder.By controlling different reaction conditionss, can make a plurality of kinds such as the sphere that is fit to different industries and requires, cube, needle-like, sheet, chain.In concrete operations, the lime carbonate of different shape depends on strict reaction conditions, and main controlling factor has the kind of crystal control agent and consumption, the joining day of control agent, Ca (OH) ₂Concentration, CO ₂Adding mode and flow, stir speed (S.S.), temperature of reaction etc.By controlling different conditions, prepared the multiple nano-calcium carbonate calcium product of monomer particle diameter (or minor axis) at present greater than 10nm, crystal shape has chain, needle-like, sphere, cube, sheet etc.

Yet in the prior art, document mostly is the single shape lime carbonate of preparation, is essentially the corresponding a kind of lime carbonate shape or amorphous of a kind of preparation method, rarely have in a kind of preparation method, obtain respectively variform lime carbonate.

The present invention is exactly the applicant on the basis of before Chinese patent application (CN101195776A), to the comprehensive utilization of the various raw materials in the petrifaction gas preparation process and intermediate product and development obtains, specifically, be with Wingdale, coke is a main raw material, synthetic production of nano-calcium carbonate, calcium carbide, fuel gas, particularly prepare spherical and cuboidal nano-calcium carbonate particles, a series of problems of avoiding single shape to cause, therefore, the scientific research personnel of our company is through a large amount of experiment and data analysis, grope a kind of by changing the technological achievement that the carbonization technique condition obtains the lime carbonate of variform, for having core competitiveness, enterprise provides more strong support, simultaneously, also reduce enterprise cost, saved available resources.

Summary of the invention

It is main raw material with Wingdale, coke that purpose of the present invention just provides a kind of, the method that comprehensively prepares cube and spherical nano-calcium carbonate, calcium carbide, fuel gas, cube that obtains and spherical nano-calcium carbonate calcium product can be widely used in industries such as being used for rubber, tackiness agent, coating, printing ink, a series of problems of having avoided single shape to be produced in causing using.Concrete steps comprise:

A. calcined limestone at high temperature obtains CaO and CO ₂

B. with CO ₂Separated into two parts CO ₂(I), CO ₂(II);

C. the CaO that obtains among the step a being crushed to below the 5-40mm, is the sieve of 2-4mm after the aperture, and with the CaO separated into two parts, raw granulate fraction is CaO (I), and fine fraction is CaO (II);

D. with CO ₂(I) and CaO (I) feed in the Reaktionsofen that wet coke or coal are housed, 900-1300 ℃ down reaction obtain calcium carbide and comprise CO, H ₂, CH ₄Fuel gas;

E. in CaO (II), add the water of 5 times of its quality, stir digestion, sieve after reaction is finished, the elimination coarse particles, with the slurry thin up after filtering to Ca (OH) ₂Concentration is 40wt%;

F.. the slurry that obtains among the whipping step e feeds CO ₂(II), add the crystal formation control agent, described crystal formation control agent comprises first kind of control agent and second kind of control agent, wherein, and CO ₂(II) feeding processing condition are according to the adding of first control agent and second control agent and different, when adding first kind of control agent, and CO ₂The feeding mode be the bubbling mode, flow is 200L/h; After reaction 1 hour, add second kind of control agent, at this moment CO ₂The feeding mode be intermittently alr mode of bubbling, flow is 400L/h, stir speed (S.S.) was reacted 2 hours 200 rev/mins and 400 rev/mins of transformations, described first kind of crystal formation control agent is AlCl ₃, its total add-on is Ca in the slurry (OH) ₂0.5% of quality, described second kind of crystal formation control agent is γ-An Bingjisanyiyangjiguiwan, its total add-on is Ca in the slurry (OH) ₂0.8% of quality; Temperature of reaction is controlled between 30-40 ℃.

G. the product that obtains among the step f is carried out solid-liquid separation, with the solid product drying, obtain the main nano-calcium carbonate powder of being made up of cube particle and spherical particle, wherein, the particle average particle size range is 30-40nm.

Optionally, in step f, collect expellant gas, and CO ₂(I) feed together in the Reaktionsofen in the steps d.

Second kind of crystal formation control agent is γ-An Bingjisanyiyangjiguiwan, is the KH-550 silane coupling agent.

Compared with prior art, the present invention has following tangible advantage:

1. feeding CO ₂On the mode, on traditional mode, carry out bold innovation, adopted for two steps fed the mode of adding control agent respectively first, added AlCl first ₃After, because the Al (OH) that hydrolysis is produced ₃Cohesive action lime carbonate small-particle is one by one connected into chain, add the control agent γ-An Bingjisanyiyangjiguiwan once more after, and the intermittent type that carries out under the specific rotation speeds stirs, then with Al (OH) ₃Agglutinating lime carbonate chain is opened, owing under the effect of intermittent mode that stirs and crystal formation control agent, when stirring velocity is big, can form sphere, stirring velocity hour can the shape cube, and the product that obtains at last promptly is mainly cube and globular CaCO ₃As seen, time, the CO that control agent adds in moulding process ₂Difference such as feeding amount, mode, thereby obtained cube and globular CaCO simultaneously ₃, this is of the present invention one innovation greatly;

2. owing to inevitably have certain reunion after the nano-powder drying, therefore, than single shape blended nano-calcium carbonate, present method is owing to directly mix nano-calcium carbonate in reaction process, can access mixed effect more uniformly, avoid the variety of problems that is produced in actual applications;

3. CaO is carried out being used for different purposes after the classification, can avoid shortcomings such as the meticulous thermo-efficiency that brings of CaO granularity in traditional calcium carbide production is low, scaffold, also reduced the broken disintegrating process in the nano-calcium carbonate production process.

4.CO ₂Mutual circulation utilization in the reactor of preparation calcium carbide and lime carbonate has improved the purity and the utilization ratio of raw materials of fuel gas product, the maximized available resources of utilizing, just saved the existing energy, have better technique effect,, have obvious improvement than prior art.

Description of drawings

Fig. 1 is the cube TEM photo of Nano particles of calcium carbonate prepared among the present invention

Fig. 2 is that the cube of Nano particles of calcium carbonate prepared among the present invention changes the TEM photo to sphere

Embodiment

Embodiment 1: a kind of is main raw material with Wingdale, coke, and the method for synthetic production of nano-calcium carbonate, calcium carbide, fuel gas comprises the steps:

A. calcined limestone at high temperature obtains CaO and CO ₂

B. with CO ₂Separated into two parts CO ₂(I), CO ₂(II);

C. the CaO that obtains among the step a being crushed to below the 5-40mm, is the sieve of 2-4mm after the aperture, and with the CaO separated into two parts, raw granulate fraction is CaO (I), and fine fraction is CaO (II);

D. with CO ₂(I) and CaO (I) feed in the Reaktionsofen that wet coke or coal are housed, 900-1300 ℃ down reaction obtain calcium carbide and comprise CO, H ₂, CH ₄Fuel gas;

E. in CaO (II), add the water of 5 times of its quality, stir digestion, sieve after reaction is finished, the elimination coarse particles, with the slurry thin up after filtering to Ca (OH) ₂Concentration is 40wt%;

F. the slurry that obtains among the whipping step e feeds CO ₂(II), add the crystal formation control agent, described crystal formation control agent comprises first kind of control agent and second kind of control agent, wherein, and CO ₂(II) feeding processing condition are according to the adding of first control agent and second control agent and different, when adding first kind of control agent, and CO ₂The feeding mode be the bubbling mode, flow is 200L/h; After reaction 1 hour, add second kind of control agent, at this moment CO ₂The feeding mode be intermittently alr mode of bubbling, flow is 400L/h, stir speed (S.S.) was reacted 2 hours 200 rev/mins and 400 rev/mins of transformations, described first kind of crystal formation control agent is AlCl ₃, its total add-on is Ca in the slurry (OH) ₂0.5% of quality, described second kind of crystal formation control agent is γ-An Bingjisanyiyangjiguiwan, its total add-on is Ca in the slurry (OH) ₂0.8% of quality; Temperature of reaction is controlled between 30-40 ℃.At last, collect expellant gas, and CO ₂(I) feed together in the Reaktionsofen in the steps d.

G. the product that obtains among the step f is carried out solid-liquid separation, with the solid product drying, obtain the main nano-calcium carbonate powder of being made up of cube particle and spherical particle, wherein, the particle average particle size range is 30-40nm.

Claims (2)

1. one kind is main raw material with Wingdale, coke, and the method for synthetic production of nano-calcium carbonate, calcium carbide, fuel gas comprises the steps:

A. calcined limestone at high temperature obtains CaO and CO ₂

B. with CO ₂Separated into two parts part i CO ₂, part ii CO ₂

C. the CaO that obtains among the step a being crushed to below the 5-40mm, is the sieve of 2-4mm after the aperture, and with the CaO separated into two parts, raw granulate fraction is part i CaO, and fine fraction is part ii CaO;

D. with part i CO ₂Feed in the Reaktionsofen that wet coke is housed with part i CaO, reaction obtains calcium carbide and comprises CO, H under 900-1300 ℃ ₂, CH ₄Fuel gas;

E. in part ii CaO, add the water of 5 times of its quality, stir digestion, sieve after reaction is finished, the elimination coarse particles, with the slurry thin up after filtering to Ca (OH) ₂Concentration is 40wt%;

F. the slurry that obtains among the whipping step e feeds part ii CO ₂, adding the crystal formation control agent, described crystal formation control agent comprises first kind of control agent and second kind of control agent, wherein, part ii CO ₂The feeding processing condition according to the adding of first control agent and second control agent and different, when adding first kind of control agent, CO ₂The feeding mode be the bubbling mode, flow is 200L/h; After reaction 1 hour, add second kind of control agent, at this moment CO ₂The feeding mode be intermittently alr mode of bubbling, flow is 400L/h, stir speed (S.S.) was reacted 2 hours 200 rev/mins and 400 rev/mins of transformations, described first kind of crystal formation control agent is AlCl ₃, its total add-on is Ca in the slurry (OH) ₂0.5% of quality, described second kind of crystal formation control agent is γ-An Bingjisanyiyangjiguiwan, its total add-on is Ca in the slurry (OH) ₂0.8% of quality; Temperature of reaction is controlled between 30-40 ℃;

G. the product that obtains among the step f is carried out solid-liquid separation, with the solid product drying, obtain the main nano-calcium carbonate powder of being made up of cube particle and spherical particle, wherein, the particle average particle size range is 30-40nm.

2. the method for claim 1 is characterized in that: in step f, collect expellant gas and part i CO ₂Feed together in the Reaktionsofen in the steps d.

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