A carbonization and activation integrated device and method for producing nano-calcium carbonate

Abstract

The invention relates to a carbonization and activation integration device and method for producing nano calcium carbonate. The carbonization and activation integration device comprises parts such as a heat conduction oil jacket, a refrigerating coil pipe, an acidometer, a thermocouple, a gas distributor, a variable-frequency speed regulation stirrer and a carbon dioxide buffer tank. The method comprises the steps: pumping calcium hydroxide refining plasma with mass percentage of 6 to 15 percent into the carbonization and activation integration device, stirring, cooling, introducing carbon dioxide-air mixed gas of a variable concentration, performing the carbonization at 10 to 50 DEG C, ending the carbonization when pH is lowered to 6 to 7, opening the jacket to heat by virtue of the heat conduction oil, increasing the stirring rotation speed, adding additives equivalent to 1 to 5 percent of a dry matrix amount of the calcium hydroxide, controlling the activation temperature at 60 to 90 DEG C, activating and modifying for 20 to 40 minutes, stopping heating and stirring, and ending the activation modification; and moving the carbonized and activated slurry out of the integration device, press filtering, dehydrating, and sufficiently drying at 110 to 130 DEG C to obtain a nano calcium carbonate product of different crystal forms.

Description

Technical field [0001] The invention relates to an integrated device and method for producing nanometer calcium carbonate carbonization and activation, and belongs to the field of inorganic chemical powder materials. Background technique [0002] Calcium carbonate is an inorganic powder material with a large amount and a wide range of uses. Due to its wide range of raw materials, low price, non-toxicity, and high whiteness, it is widely used in rubber, plastic, paper, paint, paint, wire, cable, and ink. , Food, daily chemical, feed and other industries as fillers or additives. As a new type of high-grade functional inorganic powder material, nano-calcium carbonate has been used more and more widely. However, there are still some problems of poor product crystal form consistency, integrity, product dispersion and quality stability. The distribution is not uniform enough, the product sedimentation volume is not well controllable, and the phenomenon of package alkali returning occu...

AI Technical Summary

Problems solved by technology

As a new type of high-grade functional inorganic powder material, nano-calcium carbonate has been more and more widely used, but there are still some problems of product crystal form consistency, integrity, poor product dispersibility and quality stability. The distribution is not uniform enough, the controllability of product sedimentation volume is not good, and the phenomenon of package return to alkali occurs from time to time

The usual way to produce nano-calcium carbonate is to carry out the carbonization reaction in the carbonization kettle. The gas distribution effect of the gas distributor in the traditional carbonization process is not ideal, and there are carbonization dead angles, which cause the product to return to alkali. , aging, cooling, thickening and other processes, and then transferred to the wet activation tank for activation treatment, activation modification requires heating, but at this time the calcium carbonate cooked pulp has been cooled to room temperature, heating needs to consume more energy, This not only takes a long time of more than 24 hours, reduces production efficiency, but also consumes more energy and increases production costs

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