Apparatus and method for pipeline continuous carbonization of calcium and magnesium

Abstract

The invention relates to an apparatus and a method for pipeline continuous carbonization of calcium and magnesium. The apparatus comprises a tubular reactor. The tubular reactor comprises an inner cavity and a heat-insulation layer; a fold fin or a spiral unit is arranged in the inner cavity of the tubular reactor; a slurry and carbon dioxide inlet is arranged at the front end of the tubular reactor. The method comprises the following steps: stirring and uniformly beating to-be-carbonized slurry containing at least one solid selected from the group consisting of calcium oxide, calcium hydrate, magnesium oxide and magnesium hydroxide, wherein the concentration of the slurry is 2 to 30 g / L in terms of an oxide, pumping the slurry and carbon dioxide into the tubular reactor and allowing the slurry and carbon dioxide to converge and contact; retaining the slurry in a pipeline for 10 to 60 min; and discharging the slurry having undergone carbonization out from a rear end of the tubular reactor and carrying out solid-liquid separation to obtain at least one selected from the group consisting of a magnesium bicarbonate solution, a calcium bicarbonate solution and calcium carbonate. According to the invention, increase of a contact surface between gas and the slurry is realized under the action of local high-speed turbulent flow of fluid in the pipeline, the amount of mixed flows in a whole system is small, and integral carbonization efficiency is high.

Description

technical field [0001] The invention relates to a device and method for continuous carbonization of calcium and magnesium in pipelines, in particular to a device and method for continuous carbonization of magnesium hydroxide / calcium hydroxide slurry in pipelines, in which the continuous carbonization of pipelines with flaps or spirals is used instead of the commonly used carbonization tower Realize the carbonization of magnesium / calcium oxide or hydroxide slurry to obtain magnesium bicarbonate / calcium bicarbonate solution, so as to improve the carbonization efficiency and the utilization rate of carbon dioxide, and reduce the greenhouse effect. Background technique [0002] At present, when calcium-magnesium-containing minerals are used as raw materials at home and abroad, when calcium-magnesium carbonate products are produced by carbonization, the carbonization process actually contains Mg(OH) 2 or Ca(OH) 2 , Mg(OH) 2 and Ca(OH) 2 Mixed alkaline slurry with CO dissolved ...

AI Technical Summary

Problems solved by technology

This tubular reactor utilizes the form of Venturi to achieve strong stirring. This method is very suitable for the carbonization process of producing ultra-fine calcium carbonate particles, but the mechanical efficiency is low, the pressure drop is large, and the energy consumption is high. The effect needs to be improved to a limited extent.

This is mainly because the gas-liquid mixing effect is good at the moment of entering the pipeline during the carbonization process, but with the long-distance flow of the slurry in the pipeline, the gas-liquid-solid separation gradually occurs, lacking the driving force for further mixing, and the carbonization efficiency is limited.

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