Low Ca/Mg Cement Curing with Organic Acids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional concrete production is energy-intensive and emits significant CO2 due to the calcination of limestone in ordinary portland cement (OPC) manufacturing, and existing low-Ca cement solutions face challenges in environments with limited CO2 availability for curing.
Innovation Solution
A method involving a low Ca/Mg cement composition that reacts with a reagent chemical, such as citric acid, to form insoluble calcium or magnesium compounds and SiO2/Al2O3 complexes, reducing CO2 emissions by approximately 30% and allowing curing without requiring a CO2-rich atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If ordinary portland cement (OPC) is used to produce concrete, then the concrete achieves high strength and durability, but the CO2 emissions increase significantly due to limestone calcination
Solution Approach 1:
The patent changes the chemical composition parameters of cement by using low Ca/Mg content cements (such as lithium aluminosilicate glass, fly ash, or slag) instead of traditional high-calcium OPC. This parameter change reduces the amount of calcium carbonate needed, thereby reducing CO2 emissions from calcination while maintaining concrete strength through alternative binding mechanisms
Solution Approach 2:
The patent employs composite material systems combining low Ca/Mg cement with supplementary cementitious materials (SCMs) like fly ash, slag, and lithium aluminosilicate glass. These composites achieve the required strength and durability through synergistic effects of multiple materials, replacing high-calcium OPC and reducing CO2 emissions
2Object-generated harmful factors
If low Ca content cement is used to reduce CO2 emissions, then the CO2 footprint decreases, but the cement requires CO2-rich atmosphere for curing which is impractical in many environments
Solution Approach 1:
The patent introduces alternative curing mechanisms that use intermediaries such as water-based chemical reactions (e.g., hydration of aluminosilicates, pozzolanic reactions with fly ash or slag) instead of direct CO2 carbonation. These intermediary reactions enable curing in normal atmospheric conditions without requiring CO2-rich environments
Solution Approach 2:
The patent substitutes the chemical mechanism of CO2 carbonation with alternative chemical mechanisms such as hydration reactions and pozzolanic reactions. These alternative mechanisms operate effectively in ambient air conditions, replacing the need for controlled CO2 atmospheres and simplifying the curing process
3Object-generated harmful factors
If supplementary cementitious materials (SCM) are blended with cement to reduce CO2 emissions, then the environmental impact decreases, but the material availability becomes geographically dependent and variable
Solution Approach 1:
The patent develops universal low Ca/Mg cement formulations that can function effectively with various types of supplementary materials (fly ash, slag, lithium aluminosilicate glass) depending on local availability. The base cement composition is designed to be adaptable and work synergistically with different SCM types, making the system universally applicable across different geographical regions
Solution Approach 2:
The patent segments the cement system into a stable low Ca/Mg base cement component and a variable supplementary cementitious material component. The base cement provides consistent performance and binding capability, while the SCM component can be varied based on local material availability, allowing flexibility and adaptability across different regions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach decreases CO2 emissions in cement production and provides a more sustainable concrete curing method by forming insoluble products with low water solubility, enhancing environmental sustainability and practicality across various applications.
Implementation Method 1
reacts with a reagent chemical, such as citric acid, to form insoluble calcium or magnesium compounds
Implementation Method 2
a reagent chemical (e.g., that may be synthesized from CO2)
Data Source
AI summary
A method of curing a low Ca/Mg cement composition is described that includes providing a predetermined quantity of the low Ca/Mg cement composition in uncured form; and reacting the uncured low Ca/Mg cement composition with a reagent chemical for a time sufficient to cure said cementitious material, wherein said reagent chemical is a compound synthesized from CO2 and comprises dicarboxylic acids, tricarboxylic acids, or alpha-hydroxycarboxylic acids.