Method for synthesizing ultrafine calcium carbonate by utilizing carbide slag

[0024] Example 1

[0025] Mix the calcium carbide slag with a water content of 35% and water in a mass ratio of 1:10 to make the calcium carbide slag fully dissolve into a suspension. In the suspension of the calcium carbide slag, add ammonium chloride to fully react and control the solution The pH value is greater than or equal to 7, the mass ratio of calcium carbide slag and ammonium chloride is 1:0.78, after removing the residue, add the crystal shape control agent N-methylpyrrolidone and sodium dodecylbenzene sulfonate (the mass ratio is 1:1 ), control the addition of the crystal form control agent to 1% of the weight of calcium carbonate produced by the carbonization reaction, and then pass it into the purified CO 2 Gas (CO 2 The volume percentage of the cement plant kiln exhaust gas or power plant flue gas is carbonized, and the temperature of the carbonization reaction is controlled at 10-25°C until the pH value of the solution is less than or equal to 7. The fine calcium carbonate slurry is subjected to liquid-phase surface activation treatment, the activation temperature is 80°C, the activation time is 2 hours, the activator is sodium stearate, and the addition amount is 2% of the weight of calcium carbonate produced by the carbonization reaction. After dehydration, washing, and drying Light calcium carbonate powder can be obtained, the conversion rate of calcium carbide slag is 72%, and the test results of calcium carbonate products show that the crystal form is spherical calcium carbonate, the average particle size of single particles is 60-80nm, the content of calcium oxide obtained is 53.2%, and the specific surface area is 35m. 2 /g, oil absorption value 30DOP/100CaCO 3 , Other properties meet the requirements of the industrial ultrafine activated calcium carbonate (HG/T2776-1996) standard.

[0026] Example 2

[0027] Mix the calcium carbide slag with a water content of 35% and water in a mass ratio of 1:10 to make the calcium carbide slag fully dissolve into a suspension. In the suspension of the calcium carbide slag, add ammonium chloride to fully react and control the solution The pH value is greater than or equal to 7, the mass ratio of calcium carbide slag and ammonium chloride is 1:0.78, after removing the residue, add the crystal shape control agent N-methylpyrrolidone and sodium dodecylbenzene sulfonate (the mass ratio is 1:1 ), control the addition of the crystal form control agent to 1% of the weight of calcium carbonate produced by the carbonization reaction, and then pass it into the purified CO 2 Gas (CO 2 The volume percentage is 30%) of cement plant kiln tail gas or power plant flue gas for carbonization, and the reaction temperature is controlled at 10-25 ℃, until the pH value of the solution is less than or equal to 7, the ultrafine after carbonization reaction The calcium carbonate slurry is subjected to liquid-phase surface activation treatment, the activation temperature is 50°C, the activation time is 2 hours, the activator is sodium stearate, and the amount added is 1% of the weight of calcium carbonate formed by the carbonization reaction, and it can be dehydrated, washed, and dried. Obtained light calcium carbonate powder, the conversion rate of calcium carbide slag is 72%, the test result of calcium carbonate product shows that the crystal form is chain calcium carbonate, the average particle size of single particles is 70-90nm, the content of calcium oxide obtained is 52%, and the specific surface area is 28m 2 /g, oil absorption value 32DOP/100CaCO 3 , Other properties meet the requirements of the industrial ultrafine activated calcium carbonate (HG/T2776-1996) standard.

[0028] Example 3

[0029] The calcium carbide slag with a water content of 35% and water are mixed uniformly in a mass ratio of 1:9 to fully dissolve the calcium carbide slag into a suspension. In the suspension of the calcium carbide slag, add ammonium chloride to fully react and control the solution The pH value is greater than or equal to 7, the mass ratio of calcium carbide slag and ammonium chloride is 1:0.78, after removing the residue, add the crystal shape control agent potassium pyrophosphate and sodium dodecylbenzene sulfonate (the mass ratio is 2:1), The addition amount of the control crystal form control agent is 1% of the weight of calcium carbonate produced by the carbonization reaction, and then it is passed into the purified and contains CO 2 Gas (CO 2 The volume percentage is 30%) of cement plant kiln tail gas or power plant flue gas for carbonization, and the reaction temperature is controlled at 10-25 ℃, until the pH value of the solution is less than or equal to 7, the ultrafine after carbonization reaction The calcium carbonate slurry is subjected to liquid-phase surface activation treatment, the activation temperature is 70°C, the activation time is 2 hours, the activator is water-soluble silane coupling agent CG-151 (Jiangsu Chenguang Coupling Agent Co., Ltd.), and the amount of activator added is carbonization reaction To generate 1% of calcium carbonate by weight, the activator is first formulated into an aqueous solution with a concentration of 5% and then added. After dehydration, washing, and drying, light calcium carbonate powder can be obtained. The calcium carbonate slag conversion rate is 75%. The calcium carbonate product test result It shows that the crystal form is chain calcium carbonate, the average particle size of single particles is 50-80nm, the content of calcium oxide obtained is 54.3%, and the specific surface area is 25m. 2 /g, oil absorption value 25DOP/100CaCO 3 , Other properties meet the requirements of the industrial ultrafine activated calcium carbonate (HG/T2776-1996) standard.