Carbonated slurry production system

A carbonated slurry production system for producing a carbonated slurry formed by carbonation of a slurry containing calcium-containing powder and water by a carbon dioxide-containing gas, the carbonated slurry production system comprising:

• a slurry tank configured to store the slurry;
• a slurry supply device configured to continuously supply the slurry to the slurry tank;
• a carbon dioxide-containing gas supply device configured to supply the carbon dioxide-containing gas;
• a carbonated slurry discharge device configured to continuously discharge the carbonated slurry from the slurry tank;
• a liquid surface measurement unit configured to measure a height of a liquid surface of the slurry in the slurry tank;
• and
• a slurry control device configured to control an average retention time of the slurry,
• wherein the slurry tank includes
• a first slurry storage portion configured to store the slurry and the carbon dioxide-containing gas so that a gas phase formed of the carbon dioxide-containing gas is positioned above a first liquid surface of the slurry, to bring the slurry and the carbon dioxide-containing gas into contact with each other, and
• a second slurry storage portion configured to store the slurry and a gas so that a gas phase formed of the gas is positioned above a second liquid surface of the slurry, and a contact surface between the slurry and the carbon dioxide-containing gas is absent,
• wherein the carbon dioxide-containing gas supply device is configured to supply the carbon dioxide-containing gas to the gas phase formed of the carbon dioxide-containing gas in the first slurry storage portion at a pressure larger than an atmospheric pressure,
• wherein the liquid surface measurement unit is configured to measure a height of each of the first liquid surface of the first slurry storage portion and the second liquid surface of the second slurry storage portion, and
• wherein the slurry control device is configured to control the average retention time of the slurry by adjusting an amount of the slurry to be supplied from the slurry supply device per unit time and an amount of the carbonated slurry to be discharged from the carbonated slurry discharge device per unit time based on the height of each of the first liquid surface of the first slurry storage portion and the second liquid surface of the second slurry storage portion measured with the liquid surface measurement unit.