Apparatus for carbonation of a cement mix

An apparatus for carbonating a cement mix comprising a cement binder and aggregate in a cement mix apparatus during a mix operation, comprising

• (i) a mixer for mixing the cement mix, wherein the mixer is an open mixer;
• (ii) a system for contacting the cement mix in the mixer with carbon dioxide operably connected to the mixer and comprising a first actuator for modulating a flow of carbon dioxide to the mixer through a conduit comprising an opening directed to the mixer;
• (iii) a first sensor positioned at a first location and configured to monitor a characteristic of the mix operation, wherein the characteristic comprises a carbon dioxide content of a gas mixture exiting from the mixer;
• and to transmit information regarding the characteristic to a controller;
• (iv) the controller, wherein the controller is operably connected to the sensor and the actuator and configured to process the information and determine whether or not and/or to what degree to modulate the flow of carbon dioxide to the mixer, based at least in part on receiving information from the sensor regarding the carbon dioxide content of the gas mixture exiting from the mixer at the first location and comparing the carbon dioxide content of the gas mixture exiting from the mixer at the first location with a predetermined threshold level, and to transmit a signal to the actuator to modulate the flow of carbon dioxide to the mixer if the carbon dioxide content of the gas mixture exiting the mixer exceeds the threshold.