阅读说明：本技术 一种纳米碳酸钙与拟薄水铝石或白炭黑的联合制备方法 (Combined preparation method of nano calcium carbonate and pseudo-boehmite or white carbon black ) 是由 唐平贵 李殿卿 冯拥军 于 2021-01-27 设计创作，主要内容包括：本发明以铝源、硅源、Ca(OH)-2和CO-2为原料,通过分步串联反应,联合制备纳米碳酸钙与拟薄水铝石或白炭黑,副产的Na-2CO-3循环使用。在纳米碳酸钙的制备过程中借助胶体磨的高剪切力强制Ca(OH)-2浆液和CO-2饱和的NaHCO-3溶液微观混合,极大地提高了混合效率,并抑制纳米碳酸钙的团聚,副产的NaOH与铝源或硅源反应制备NaAlO-2或Na-2SiO-3溶液。NaAlO-2或Na-2SiO-3与CO-2饱和的NaHCO-3溶液反应制备纳米拟薄水铝石或白炭黑。本发明实现了反应原料100％利用,反应条件温和,绿色环保,生产成本低,易于工业化生产。(The invention uses aluminum source, silicon source, Ca (OH) 2 And CO 2 The nano calcium carbonate and the pseudo-boehmite or the white carbon black are jointly prepared as raw materials through stepwise series reaction, and Na as a byproduct is produced 2 CO 3 Can be recycled. High shear forcing of Ca (OH) with a colloid mill during the preparation of nano calcium carbonate 2 Slurry and CO 2 Saturated NaHCO 3 The solution is micro-mixed, the mixing efficiency is greatly improved, the agglomeration of the nano calcium carbonate is inhibited, and the byproduct NaOH reacts with an aluminum source or a silicon source to prepare NaAlO 2 Or Na 2 SiO 3 And (3) solution. NaAlO 2 Or Na 2 SiO 3 With CO 2 Saturated NaHCO 3 The solution reacts to prepare the nano pseudo-boehmite or the white carbon black. The invention realizes 100 percent utilization of reaction raw materials, mild reaction conditions, environmental protection, low production cost and easy industrial production.)

1. A joint preparation method of nano calcium carbonate and pseudo-boehmite is characterized by comprising the following steps:

A. preparing Na with the concentration of 1-5 mol/L₂CO₃Solution to Na₂CO₃Introducing CO into the solution₂Gas to CO in solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃A solution;

B. reacting Ca (OH)₂Adding the mixture into deionized water with the mass of 3-20 times and grinding the mixture for 5-20 minutes by using a colloid mill to obtain Ca (OH)₂Slurry; control agent and NaHCO according to morphology₃The molar ratio is 0-0.2: 1 adding a morphology control agent, and adding the NaHCO prepared in the step A₃Solution with Ca (OH)₂The molar ratio of the serous fluid is 1: 1, simultaneously adding the mixture into a colloid mill for grinding reaction for 5-15 minutes; stirring and crystallizing for 0.5-3 hours at the temperature of 0-100 ℃ to obtain nano calcium carbonate precipitate and NaOH solution; the precipitate is filtered, washed and dried to obtain the nano CaCO₃(ii) a The filtered NaOH mother liquor can be directly used as a NaOH raw material in the step C, the washing liquor is repeatedly used until the concentration of NaOH reaches 0.5mol/L, and then the obtained solution is heated and concentrated to 1-5 mol/L and is used as a NaOH raw material solution in the step C;

the morphology control agent is any one or more of sodium sulfate, sodium citrate, sodium pyrophosphate, ethylene diamine tetraacetic acid tetrasodium salt, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium laurate, sodium stearate, sodium polyacrylate, sodium allyl sulfonate, polyacrylamide, dodecyl amino propionic acid, a silane coupling agent, polyethylene glycol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and hydroxypropyl methyl cellulose;

C. and B, adding an aluminum source into the NaOH raw material solution generated in the step B, wherein the adding amount of the aluminum source is as follows according to the molar ratio of Al to Na of 0.2-1: 1, uniformly stirring, heating to 90-200 ℃, reacting for 1-6 hours under stirring, cooling to room temperature after the reaction is finished, filtering, and removing insoluble impurities to obtain NaAlO₂A solution; according to the molar ratio of the modifier to the Al element of 0-0.5: 1, adding a modifier, stirring and dissolving to obtain NaAlO containing the modifier₂Mixing the solution;

the aluminum source is bauxite, Al (OH)₃、Al₂O₃Selecting aluminum ash, high-alumina fly ash and roasted Al₂O₃A base spent catalyst;

NaAlO₂the modifier added into the solution is any one or more of sodium silicate, disodium hydrogen phosphate, sodium tungstate, sodium vanadate, sodium molybdate, sodium niobate, sodium tantalate, sodium phosphotungstate, sodium phosphomolybdate, sodium phosphoniobate, sodium phosphotantalate and sodium phosphovanadate;

D. NaHCO prepared in the step A₃The solution is mixed with the NaAlO containing modifier prepared in the step C₂Mixing the solutions, wherein NaHCO₃With NaAlO₂The molar ratio is 1-2: 1, NaHCO₃Dissolved CO in solution₂The precipitation reaction can be promoted; crystallizing the mixed slurry at 20-100 ℃ for 0.5-6 hours to generate pseudo-boehmite precipitate and Na₂CO₃Filtering, washing and drying the solution and the precipitate to obtain nano pseudoboehmite; filtered Na₂CO₃The mother liquor can be used as Na in the step A₂CO₃The solution is used, and the washing solution can be reused until Na₂CO₃Is heated and concentrated to 1-5 mol/L, and then is used as Na in the step A₂CO₃The solution was used.

2. The method for jointly preparing nano calcium carbonate and pseudo-boehmite according to claim 1, wherein the morphology control agent in the step B is one of sodium pyrophosphate, sodium polyacrylate, a silane coupling agent and hydroxyethyl cellulose;

the aluminum source in the step C is Al (OH)₃And Al₂O₃；NaAlO₂The modifier added into the solution is any one of sodium silicate, disodium hydrogen phosphate and sodium tungstate.

3. A combined preparation method of nano calcium carbonate and white carbon black is characterized by comprising the following steps:

step A, B is the same as step A, B of claim 1;

C. and B, adding a silicon source into the NaOH raw material solution generated in the step B, wherein the adding amount of the silicon source is 0.2-0.5 according to the Si/Na molar ratio: 1, uniformly stirring, heating to 90-200 ℃, reacting for 1-6 hours under stirring, cooling to room temperature after the reaction is finished, filtering, removing insoluble impurities to obtain Na₂SiO₃A solution; according to the molar ratio of the modifier to the Si element of 0-0.5: 1, adding a modifier, stirring and dissolving to obtain Na containing the modifier₂SiO₃A solution;

the silicon source is quartz powder, protein powder, chalcedony powder, diatomite, rice hull ash and silicate mineral powder after acid treatment, preferably quartz powder and diatomite;

Na₂SiO₃the modifier added into the solution is any one or more of quaternary ammonium salt, polyethylene glycol, sodium polyacrylate, polyacrylamide, dodecyl amino propionic acid, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and hydroxypropyl methyl cellulose;

D. NaHCO prepared in the step A₃The solution is mixed with the Na containing modifier prepared in the step C₂SiO₃Mixing the solutions, wherein NaHCO₃With Na₂SiO₃The molar ratio is 2-4: 1, NaHCO₃Dissolved CO in solution₂The precipitation reaction can be promoted; performing crystallization reaction on the mixed slurry at the temperature of 20-100 ℃ for 0.5-6 hours to generate nano white carbon SiO₂And Na₂CO₃A solution; filtering, washing and drying the precipitate to obtain nano white carbon black; filtered Na₂CO₃The mother liquor can be used as Na in the step A₂CO₃The solution is used, and the washing solution can be reused until Na₂CO₃Is heated and concentrated to 1-5 mol/L, and then is used as Na in the step A₂CO₃The solution was used.

4. The joint preparation method of nano calcium carbonate and white carbon black according to claim 3, wherein the silicon source in the step C is quartz powder or diatomite; said Na₂SiO₃The modifier added into the solution is one of quaternary ammonium salt, sodium polyacrylate and hydroxyethyl cellulose.

Field of the invention

The invention relates to the field of preparation of inorganic non-metallic functional materials, in particular to a joint preparation method of nano calcium carbonate and pseudo-boehmite or white carbon black.

Background

The pseudoboehmite is boehmite which has incomplete crystallization and special spatial network structure, has physical characteristics of high specific surface area, large pore volume and the like and chemical characteristics of peptization and thixotropy under acidic conditions. The excellent characteristics of the pseudo-boehmite enable the pseudo-boehmite to be widely applied to the fields of petroleum industry, automobile industry, fire fighting field, paper making industry, environmental protection industry, building industry and the like as a catalyst, a carrier, a binder, a carrier coating, a fire retardant and an adsorbent. The nano white carbon black is non-toxic, tasteless and white silicon dioxide powder, and has the advantages of chemical inertness, high electrical insulation, large internal surface area, high temperature resistance, non-combustibility and the like. The white carbon black has small particle size and large specific surface area, has good reinforcing property on rubber materials, can obviously improve the mechanical properties of rubber products such as tensile strength, wear resistance, ageing resistance, tear resistance and the like, and is widely applied to a plurality of fields such as rubber industry, animal feed carriers, food, medicine, oral care, papermaking, coating, agriculture, silicon rubber and the like.

At present, the pseudo-boehmite is prepared by methods such as an aluminum alkoxide method, an aluminum salt neutralization method, a carbonization method and the like. The pseudo-boehmite prepared by the alcoaluminum method has high purity, good crystal form, concentrated pore diameter and large specific surface area, but the method has complex production process, the prepared pseudo-boehmite has small pore diameter, and the organic solvent used in the preparation process has certain toxicity, pollutes the environment and is not easy to recover. The aluminum salt neutralization method has mild reaction conditions, simple preparation steps, single crystal phase and high alumina content, and is an ideal method suitable for industrial production. However, the product prepared by the method has smaller particle size and wide pore size distribution range, and generates a large amount of sodium salt wastewater. The carbonization method is the process route with the lowest cost, but the method belongs to gas-liquid two-phase reaction in the gelling process, so that the raw materials are not uniformly mixed and are not mixed with CO₂The sodium metaaluminate in the reaction is easy to hydrolyze to generate gibbsite, so the method has strict requirements on gas introduction amount and pH; in addition, the method has the advantages of low strength of the sodium aluminate solution, low gelling concentration, difficult molding and poor quality.

The production process of the white carbon black can be divided into a gas phase method and a precipitation method, wherein the gas phase method mainly uses silicon halide as a basic raw material, the reaction conditions are harsh, the cost is high, and the white carbon black has small particle size and high purity. The precipitation method for synthesizing the white carbon black generally comprises the steps of uniformly mixing a sodium silicate solution and an acid in a liquid phase state to prepare a silicon dioxide precipitate, and then filtering, washing, drying and crushing the silicon dioxide precipitate to obtain a finished product of the white carbon black. The precipitation method is further classified into a hydrochloric acid precipitation method, a carbon dioxide precipitation method, a nitric acid precipitation method and a sulfuric acid precipitation method according to the kind of the acid used. The precipitated silica white is favored by people due to the characteristics of mild reaction conditions, simple production technology, low cost and the like, but the specific surface area of the product is small, the particle size is larger, a large amount of hydroxyl groups are arranged on the surface, aggregates are easy to form, and a large amount of sodium salt wastewater can be generated. The carbon dioxide precipitation method does not need strong acid and is a process route with the lowest cost, but the method belongs to gas-liquid two-phase reaction, has slow reaction rate, easily causes uneven mixing of raw materials, has strict requirements on gas introduction amount and pH value control, influences nucleation and growth of white carbon black, further seriously influences the quality of products, and has low utilization rate of carbon dioxide and large loss.

At present, the production of pseudo-boehmite and nano white carbon black is all faced with the problems of difficult control of reaction conditions, unstable product quality, discharge of a large amount of sodium salt wastewater and the like, so that the development of a novel preparation technology and a novel process with controllable conditions, low energy consumption and environmental protection has very important significance for the sustainable development of the pseudo-boehmite and nano white carbon black industry.

Disclosure of Invention

The invention aims to provide a joint preparation method of nano calcium carbonate and pseudo-boehmite or white carbon black, and the obtained nano calcium carbonate, pseudo-boehmite and nano white carbon black can be used in the fields of catalysis, adsorption, environmental protection, high polymer materials and the like.

The invention uses aluminum source or silicon source, Ca (OH)₂And CO₂The nano calcium carbonate and the pseudo-boehmite or the white carbon black are jointly prepared by the stepwise series reaction of the raw materials. Firstly preparing nano calcium carbonate, and preparing NaAlO by reacting the byproduct NaOH with an aluminum source or a silicon source₂Or Na₂SiO₃Reaction solution, NaAlO₂Or Na₂SiO₃Solution with CO₂Saturated NaHCO₃Solution reaction to prepare pseudo-boehmite or white carbon black and byproduct Na₂CO₃The solution is used for preparing the nano calcium carbonate again, and the recycling of byproducts is realized.

The combined preparation method of the nano calcium carbonate and the pseudo-boehmite comprises the following specific steps:

A. preparing Na with the concentration of 1-5 mol/L₂CO₃Solution to Na₂CO₃Introducing CO into the solution₂Gas to CO in solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃And (3) solution.

B. Reacting Ca (OH)₂Adding the mixture into deionized water with the mass of 3-20 times and grinding the mixture for 5-20 minutes by using a colloid mill to obtain Ca (OH)₂Slurry; control agent and NaHCO according to morphology₃The molar ratio is 0-0.2: 1 adding a morphology control agent, and adding the NaHCO prepared in the step A₃Solution with Ca (OH)₂The molar ratio of the serous fluid is 1: 1, simultaneously adding the mixture into a colloid mill for grinding reaction for 5-15 minutes; stirring and crystallizing for 0.5-3 hours at the temperature of 0-100 ℃ to obtain nano calcium carbonate precipitate and NaOH solution; the precipitate is filtered, washed and dried to obtain the nano CaCO₃(ii) a And D, directly using the filtered NaOH mother liquor as a NaOH raw material in the step C, repeatedly using washing liquor until the concentration of NaOH reaches 0.5mol/L, heating and concentrating to 1-5 mol/L, and using the concentrated NaOH mother liquor as a NaOH raw material solution in the step C.

The morphology control agent is any one or more of sodium sulfate, sodium citrate, sodium pyrophosphate, ethylene diamine tetraacetic acid tetrasodium salt, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium laurate, sodium stearate, sodium polyacrylate, sodium allyl sulfonate, polyacrylamide, dodecyl amino propionic acid, a silane coupling agent, polyethylene glycol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and hydroxypropyl methyl cellulose. Preferred are sodium pyrophosphate, sodium polyacrylate, a silane coupling agent and hydroxyethyl cellulose.

C. And B, adding an aluminum source into the NaOH raw material solution generated in the step B, wherein the adding amount of the aluminum source is as follows according to the molar ratio of Al to Na of 0.2-1: 1, determining, uniformly stirring, and heating to 90 toReacting for 1-6 hours at 200 ℃ under stirring, cooling to room temperature after the reaction is finished, filtering, and removing insoluble impurities to obtain NaAlO₂A solution; according to the molar ratio of the modifier to the Al element of 0-0.5: 1, adding a modifier, stirring and dissolving to obtain NaAlO containing the modifier₂The solution was mixed.

The aluminum source is bauxite, Al (OH)₃、Al₂O₃Selecting aluminum ash, high-alumina fly ash and roasted Al₂O₃Based on a spent catalyst, preferably Al (OH)₃And Al₂O₃。

NaAlO₂The modifier added into the solution is any one or more of sodium silicate, disodium hydrogen phosphate, sodium tungstate, sodium vanadate, sodium molybdate, sodium niobate, sodium tantalate, sodium phosphotungstate, sodium phosphomolybdate, sodium phosphoniobate, sodium phosphotantalate and sodium phosphovanadate, preferably any one of sodium silicate, disodium hydrogen phosphate and sodium tungstate, and has the function of adjusting the microstructure of the pseudo-boehmite.

D. NaHCO prepared in the step A₃The solution is mixed with the NaAlO containing modifier prepared in the step C₂Mixing the solutions, wherein NaHCO₃With NaAlO₂The molar ratio is 1-2: 1, NaHCO₃Dissolved CO in solution₂The precipitation reaction can be promoted; crystallizing the mixed slurry at 20-100 ℃ for 0.5-6 hours to generate pseudo-boehmite precipitate and Na₂CO₃Filtering, washing and drying the solution and the precipitate to obtain the nano pseudoboehmite. Filtered Na₂CO₃The mother liquor can be used as Na in the step A₂CO₃The solution is used, and the washing solution can be reused until Na₂CO₃The concentration reaches 0.5mol/L, then the mixture is heated and concentrated to 1-5 mol/L, and then the concentrated solution is used as Na in the step A₂CO₃The solution was used.

The preparation method is also suitable for the combined preparation of the nano calcium carbonate and the white carbon black, and comprises the following specific preparation steps:

A. same as step A, B above

C. Replacing the aluminum source in the step C with a silicon source, wherein the Si/Na molar ratio is 0.2-0.5: 1, modificationThe molar ratio of the agent to the Si element is 0-0.5: 1, then Na is obtained₂SiO₃And (3) solution.

The silicon source is quartz powder, protein powder, chalcedony powder, diatomite, rice hull ash and silicate mineral powder after acid treatment, and preferably quartz powder and diatomite.

Na₂SiO₃The modifier added into the solution is one or more of quaternary ammonium salt, polyethylene glycol, sodium polyacrylate, polyacrylamide, dodecyl amino propionic acid, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and hydroxypropyl methyl cellulose, preferably quaternary ammonium salt, sodium polyacrylate and hydroxyethyl cellulose, and has the function of adjusting the microstructure of the white carbon black.

D. The NaAlO in the step D is treated₂The solution is changed to Na₂SiO₃Solution, NaHCO₃With Na₂SiO₃The molar ratio is 2-4: 1, obtaining the nano white carbon black.

Fig. 1 is a schematic diagram of two combined preparation processes, wherein a is a schematic diagram of combined preparation of nano calcium carbonate and pseudo-boehmite, and b is a schematic diagram of combined preparation of nano calcium carbonate and white carbon black.

Fig. 2 and 3 are representations of the calcium carbonate obtained in example 1, the crystal form of which is calcite-type as can be seen in fig. 2 and the size of which is less than 100nm as can be seen in fig. 3.

FIGS. 4 and 5 are representations of the pseudoboehmite obtained in example 1, with FIG. 4 showing that the sample is pseudoboehmite and FIG. 5 showing that the pseudoboehmite size is in the order of nanometers.

Fig. 6 and 7 are representations of the white carbon black obtained in example 6, where fig. 6 illustrates that the white carbon black has an amorphous crystal structure, and fig. 7 illustrates that the white carbon black is in a nanometer size.

The invention has the beneficial effects that: the invention converts Ca, Al and Si elements in the raw materials into products, realizes 100 percent utilization of reaction raw materials, and obtains high-value nano calcium carbonate, pseudo-boehmite and white carbon black products; high shear forced Ca (OH) by means of a colloid mill₂And NaHCO₃The micro-mixing of the (a) and (b),greatly improves the mixing efficiency, promotes the smooth liquid-solid reaction, accelerates the formation and uniform growth of crystal nucleus, inhibits the agglomeration of the nano calcium carbonate and can conveniently obtain the high-value nano calcium carbonate. The invention converts CO into₂Dissolving in NaHCO₃In the solution, the defects of harsh reaction conditions, difficult control of reaction parameters, unstable product quality, large alkali consumption and large wastewater discharge in the preparation process of the pseudo-boehmite and the white carbon black are overcome. The method has the advantages of easily available raw materials, low price, high utilization rate of the raw materials, mild reaction conditions, high reaction rate, stable product quality, no wastewater, environmental protection, low production cost, easy industrial production and the like, and realizes the combined green preparation of the nano calcium carbonate, the pseudo-boehmite and the nano white carbon black under mild conditions.

Description of the drawings:

fig. 1 is a schematic diagram of two combined preparation processes, wherein a is a schematic diagram of combined preparation of nano calcium carbonate and pseudo-boehmite, and b is a schematic diagram of combined preparation of nano calcium carbonate and white carbon black.

Fig. 2 is an XRD spectrum of calcium carbonate prepared in example 1.

Fig. 3 is a scanning electron micrograph of the calcium carbonate prepared in example 1.

FIG. 4 is an XRD spectrum of pseudo-boehmite prepared in example 1.

FIG. 5 is a scanning electron micrograph of the pseudoboehmite prepared in example 1.

FIG. 6 is an XRD spectrum of the white carbon black prepared in example 6.

FIG. 7 is a scanning electron micrograph of the white carbon black prepared in example 6.

The specific implementation mode is as follows:

example 1:

step A: 106 g of Na are weighed out₂CO₃Adding into deionized water to prepare Na with the concentration of 1mol/L₂CO₃Solution then over Na₂CO₃Introducing CO into the solution₂CO in gas to solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃And (3) solution.

And B: 0.5L of NaHCO prepared in step A was taken₃Solution 5 g of sodium dodecyl sulfate are weighed into NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 74 g of Ca (OH)₂Adding into 600 g deionized water and grinding for 5 minutes by a colloid mill to obtain Ca (OH)₂Slurry, NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, grinding and reacting for 6 minutes to obtain nano calcium carbonate slurry, crystallizing the slurry at 90 ℃ for 1 hour, filtering the precipitate, washing with deionized water for 6 times, and drying in an oven at 100 ℃ for 3 hours to obtain nano CaCO₃And (5) producing the product. NaOH mother liquor is reserved for standby, and washing liquor is sequentially stored according to the washing sequence and is reused.

And C: 50 g of Al (OH)₃Adding the mixture into NaOH mother liquor obtained in the step B, stirring the mixture evenly, heating the mixture to 170 ℃, reacting the mixture for 2 hours under stirring, cooling the mixture to room temperature, weighing 1 g of sodium silicate, adding the sodium silicate into the solution, and stirring the solution to dissolve the sodium silicate to obtain NaAlO₂The solution was mixed.

Step D: with stirring, 0.5L of NaHCO prepared in step A was taken₃The solution was added dropwise to the NaAlO prepared in step C over 1 hour₂And crystallizing the obtained slurry at 85 ℃ for 2 hours in the solution, then filtering and washing for 8 times to obtain a pseudo-boehmite filter cake, and drying the filter cake in an oven at 95 ℃ for 4 hours to obtain a pseudo-boehmite product. Na (Na)₂CO₃The mother liquor is reserved, and the washing liquid is sequentially stored according to the washing sequence for repeated use.

Example 2:

step A: 0.5L of Na was obtained by applying step D1₂CO₃Mother liquor, introducing CO₂CO in gas to solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃And (3) solution.

And B: 0.25L of NaHCO prepared in step A was taken₃Solution 5 g of sodium dodecylbenzenesulfonate are weighed into NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 37 g of Ca (OH)₂Adding into 200 g deionized water and grinding for 8 minutes by a colloid mill to obtain Ca (OH)₂Slurry, NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, and grinding and reacting for 10 minutes to obtain the nano carbonCrystallizing the calcium carbonate slurry at 50 deg.C for 1 hr, filtering the precipitate, washing with NaOH solution from example 1, washing with deionized water for 1 time, and drying in oven at 95 deg.C for 6 hr to obtain nano CaCO₃And (5) producing the product. NaOH mother liquor is reserved for standby, and washing liquor is sequentially stored according to the washing sequence and is reused.

And C: 30 g of Al (OH)₃Adding the mixture into NaOH mother liquor obtained in the step B, stirring the mixture evenly, heating the mixture to 180 ℃, reacting the mixture for 1.5 hours under stirring, and cooling the mixture to room temperature to obtain NaAlO₂The solution was mixed.

Step D: with stirring, 0.25L of NaHCO prepared in step A was taken₃The solution was added dropwise to the NaAlO prepared in step C over 0.5 hour₂In solution, the resulting slurry was crystallized at 90 ℃ for 1.5 hours, then filtered, and sequentially treated with Na as in example 1₂CO₃Washing with washing solution, washing with deionized water for 1 time to obtain pseudoboehmite filter cake, drying the filter cake in a 120 deg.C oven for 4 hr to obtain pseudoboehmite product, Na₂CO₃The mother liquor is reserved, and the washing liquid is sequentially stored according to the washing sequence for repeated use.

Example 3:

step A: 159 g of Na are weighed out₂CO₃Adding the mixture into deionized water to prepare Na with the concentration of 1.5mol/L₂CO₃Solution then over Na₂CO₃Introducing CO into the solution₂CO in gas to solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃And (3) solution.

And B: 0.5L of NaHCO prepared in step A was taken₃The solution was weighed 10 grams of polyacrylamide into NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 111 g of Ca (OH)₂Adding to 1000 g of deionized water and milling with a colloid mill for 10 minutes to obtain Ca (OH)₂Slurry, NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, grinding and reacting for 10 minutes to obtain nano calcium carbonate slurry, crystallizing for 2 hours at 50 ℃, filtering the precipitate, washing for 6 times by deionized water, and drying for 2 hours in a 120 ℃ oven to obtain nano CaCO₃And (5) producing the product. NaOH mother liquor is reserved for standby, and the washing liquor can be reused.

And C: 80 g of Al (OH) are weighed out₃Adding the mixture into NaOH mother liquor obtained in the step B, stirring the mixture evenly, heating the mixture to 140 ℃, reacting the mixture for 2 hours under stirring, cooling the mixture to room temperature, weighing 2 grams of disodium hydrogen phosphate, adding the disodium hydrogen phosphate into the solution, and stirring the mixture to dissolve the disodium hydrogen phosphate to obtain NaAlO₂The solution was mixed.

Step D: under the stirring state, the NaAlO prepared in the step C₂The solution was added directly to 0.5L of NaHCO prepared in step A₃Crystallizing the obtained slurry at 95 deg.C for 2 hr, filtering, washing for 6 times to obtain pseudoboehmite filter cake, drying the filter cake in a 110 deg.C oven for 5 hr to obtain pseudoboehmite product, and adding Na₂CO₃Mother liquor is reserved, and washing liquor can be reused.

Example 4:

step A, B is the same as in example 3.

And C: weighing 70 g of Al (OH)₃Adding the obtained solution into NaOH mother liquor obtained in the step B, stirring the solution evenly, heating the solution to 150 ℃, reacting the solution for 3 hours under stirring, cooling the solution to room temperature, weighing 2 grams of sodium molybdate, adding the sodium molybdate into the solution, and stirring the solution to dissolve the sodium molybdate to obtain NaAlO₂The solution was mixed.

Step D: under the stirring state, the NaAlO prepared in the step C₂The solution was mixed with 0.5L of NaHCO prepared in step A₃Adding the solution into a reactor at the same time for reaction, after dropwise addition within 1 hour, crystallizing the obtained slurry for 1 hour at 100 ℃, then filtering and washing for 6 times to obtain a pseudo-boehmite filter cake, and drying the filter cake in a 100 ℃ oven for 8 hours to obtain a pseudo-boehmite product, wherein Na is added to the pseudo-boehmite product₂CO₃Mother liquor is reserved, and washing liquor can be reused.

Example 5:

step A: same as example 1

And B: 0.5L of NaHCO prepared in step A was taken₃The solution was weighed 12 grams of carboxymethyl cellulose to NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 74 g of Ca (OH)₂Adding into 800 g deionized water and grinding for 10 minutes by a colloid mill to obtain Ca (OH)₂Slurry liquidReacting NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, grinding and reacting for 10 minutes to obtain nano calcium carbonate slurry, crystallizing for 1 hour at 60 ℃, filtering the precipitate, washing with deionized water for 7 times, and drying in an oven at 110 ℃ for 2 hours to obtain nano CaCO₃And (5) producing the product. NaOH mother liquor is reserved for standby, and the washing liquor can be reused.

And C: 60 g of Al (OH)₃Adding the mixture into NaOH mother liquor obtained in the step B, stirring the mixture evenly, heating the mixture to 160 ℃, reacting the mixture for 1.5 hours under stirring, cooling the mixture to room temperature, weighing 3 grams of sodium phosphotungstate, adding the sodium phosphotungstate into the solution, and stirring the solution to dissolve the sodium phosphotungstate to obtain NaAlO₂The solution was mixed.

Step D: 0.5L of NaHCO prepared in step A was taken₃Solution and NaAlO prepared in step C₂Adding the solution into a colloid mill simultaneously for mixing reaction, crystallizing the obtained slurry for 3 hours at 90 ℃, then filtering and washing for 8 times to obtain a pseudo-boehmite filter cake, placing the filter cake in a 120 ℃ oven for drying for 4 hours to obtain a pseudo-boehmite product, and adding Na₂CO₃Mother liquor is reserved, and washing liquor can be reused.

Example 6:

step A: 106 g of Na are weighed out₂CO₃Adding into deionized water to prepare Na with the concentration of 1mol/L₂CO₃Solution then over Na₂CO₃Introducing CO into the solution₂Gas to CO in solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃And (3) solution.

And B: 0.5L of NaHCO prepared in step A was taken₃Solution 4 g of sodium dodecyl sulphate was added to NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 74 g of Ca (OH)₂Adding to 800 g of deionized water and milling with a colloid mill for 5 minutes to obtain Ca (OH)₂Slurry, NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, grinding and reacting for 8 minutes to obtain nano calcium carbonate slurry, crystallizing the slurry at 30 ℃ for 1 hour, filtering the precipitate, retaining the filtered NaOH mother liquor, washing the filter cake with deionized water for 6 times, and drying in an oven at 100 ℃ for 3 hours to obtain nano calcium carbonateCaCO of rice₃And (5) producing the product. NaOH mother liquor is reserved for standby, and the washing liquor can be reused.

And C: weighing 20 g of quartz powder, adding the quartz powder into the NaOH mother liquor obtained in the step B, uniformly stirring, heating to 120 ℃, reacting for 4 hours under stirring, cooling to room temperature, and filtering to obtain Na₂SiO₃A solution; 1 g of cetyltrimethylammonium bromide was weighed out and added to Na₂SiO₃Stirring and dissolving in the solution to obtain Na₂SiO₃The solution was mixed.

Step D: with stirring, 0.5L of NaHCO prepared in step A was taken₃The solution was added directly to the Na obtained in step C₂SiO₃And (3) reacting in the mixed solution, crystallizing the obtained slurry for 1 hour at the temperature of 100 ℃, and filtering, washing and drying to obtain the nano white carbon black product. Na (Na)₂CO₃Mother liquor is reserved, and washing liquor can be reused.

Example 7:

step A is the same as in example 6.

And B: 0.5L of NaHCO prepared in step A was taken₃Solution 5 g of sodium laurate are added to NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 74 g of Ca (OH)₂Adding into 400 g deionized water and grinding for 12 minutes by a colloid mill to obtain Ca (OH)₂Slurry, NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, grinding and reacting for 10 minutes to obtain nano calcium carbonate slurry, placing the nano calcium carbonate slurry at 50 ℃ for crystallization for 0.5 hour, filtering the precipitate, retaining the filtered NaOH mother liquor, washing the filter cake with deionized water for 6 times, and drying the filter cake in an oven at 95 ℃ for 6 hours to obtain nano CaCO₃And (5) producing the product.

And C: weighing 20 g of opal powder, adding into the NaOH mother liquor obtained in the step B, uniformly stirring, heating to 150 ℃, reacting for 3 hours under stirring, cooling to room temperature, and filtering to obtain Na₂SiO₃A solution; weighing 1 g of sodium polyacrylate and adding to Na₂SiO₃Stirring and dissolving in the solution to obtain Na₂SiO₃The solution was mixed.

Step D: stirring the Na obtained in the step C₂SiO₃The mixed solution was added dropwise over 15 minutes to 0.5L of NaHCO prepared in step A₃Reacting in solution, crystallizing the obtained slurry at 80 deg.C for 1 hr, filtering, washing, and drying to obtain nanometer white carbon black product, Na₂CO₃Mother liquor is reserved, and washing liquor can be reused.

Example 8:

step A: 159 g of Na are weighed out₂CO₃Adding the mixture into deionized water to prepare Na with the concentration of 1.5mol/L₂CO₃Solution then over Na₂CO₃Introducing CO into the solution₂CO in gas to solution₂Saturation is achieved to obtain CO₂Saturated NaHCO₃And (3) solution.

And B: 0.5L of NaHCO prepared in step A was taken₃Solution 10 g of hydroxyethyl cellulose are weighed into NaHCO₃Adding the mixture into the solution and stirring the mixture evenly; 111 g of Ca (OH)₂Adding into 1200 g deionized water and grinding for 5 minutes by a colloid mill to obtain Ca (OH)₂Slurry, NaHCO₃Solution with Ca (OH)₂Adding the slurry into a colloid mill at the same time, grinding and reacting for 6 minutes to obtain nano calcium carbonate slurry, crystallizing for 2 hours at 50 ℃, filtering the precipitate, washing with deionized water for 6 times, and drying in a 120 ℃ oven for 2 hours to obtain nano CaCO₃And (5) producing the product. NaOH mother liquor is reserved for standby, and the washing liquor can be reused.

And C: weighing 30 g of diatomite, adding the diatomite into the NaOH mother liquor obtained in the step B, uniformly stirring, heating to 150 ℃, reacting for 1.5 hours under stirring, cooling to room temperature, and filtering to obtain Na₂SiO₃A solution; 1.5 g of hydroxyethyl cellulose are weighed into Na₂SiO₃Stirring and dissolving in the solution to obtain Na₂SiO₃The solution was mixed.

Step D: the Na obtained in the step C is₂SiO₃Mixing the solution with 0.5L NaHCO₃The solution is directly mixed and reacted, the obtained slurry is crystallized for 1 hour at the temperature of 80 ℃, and the nano white carbon black product, Na, is obtained after filtration, washing and drying₂CO₃Mother liquor is reserved, and washing liquor can be reused.

Example 9:

step A, B is the same as in example 8.

And C: weighing 30 g of stone coal vanadium leaching slag, adding the stone coal vanadium leaching slag into the NaOH mother liquor obtained in the step B, uniformly stirring, heating to 160 ℃, reacting for 3 hours under stirring, cooling to room temperature, and filtering to obtain Na₂SiO₃A solution; 2 g of hydroxyethyl cellulose are weighed out and added to Na₂SiO₃Stirring and dissolving in the solution to obtain Na₂SiO₃The solution was mixed.

Step D: the Na obtained in the step C is₂SiO₃Mixing the solution with 0.5L NaHCO₃Mixing the solution with colloid mill, reacting for 5 min to obtain slurry, crystallizing at 90 deg.C for 0.5 hr, filtering, washing, and drying to obtain nanometer white carbon black product, Na₂CO₃Mother liquor is reserved, and washing liquor can be reused.