Sulfo-aluminous Clinker with Boron Doping for Low-Temperature Production
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Solution Overview
Problem
The cement industry faces challenges in reducing CO2 emissions during the production of Portland cement, and achieving the simultaneous presence of reactive belite (C2S α polymorph) and 'yee'limit calcium sulfoaluminate phase in clinkers, which is currently impossible at temperatures above 1425°C due to high energy consumption and environmental concerns.
Innovation Solution
A sulpho-aluminous clinker composition comprising 5-25% calcium aluminoferrite, 15-35% calcium sulfoaluminate, 10-50% belite with at least 3% C2S α polymorph, and 2-25% boron-doped calcium silicate, prepared at temperatures below 1350°C to reduce CO2 emissions and prevent phase destruction, while allowing the use of iron-rich raw materials without sticking phenomena.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clinker is prepared at temperatures above 1425°C to achieve simultaneous presence of reactive belite (C2S α polymorph) and 'yee'limit calcium sulfoaluminate phase, then hydraulic reactivity and strength are improved, but CO2 emissions increase and energy consumption increases
Solution Approach 1:
The patent changes the chemical composition parameters of the raw material mixture by incorporating specific mineralizers (boron, sodium, potassium, lead) and controlling the stoichiometry of calcium aluminate phases. This allows the desired phasic composition with C2S α polymorph and C4A3-yFy phase to be achieved at lower cooking temperatures (below 1425°C), thereby reducing energy consumption and CO2 emissions while maintaining hydraulic reactivity.
Solution Approach 2:
The patent introduces minor elements (boron, sodium, potassium, lead) as intermediaries or mineralizers that facilitate the formation of reactive belite (C2S α) and calcium sulfoaluminate phases at lower temperatures. These minor elements act as mediators that enable the simultaneous presence of C2S α and C4A3-yFy phases without requiring high temperature processing, thus resolving the contradiction between achieving desired phases and reducing energy consumption.
2Reliability
If clinker is prepared at temperatures above 1425°C to achieve simultaneous presence of reactive belite (C2S α polymorph) and 'yee'limit calcium sulfoaluminate phase, then hydraulic reactivity and strength are improved, but CO2 emissions increase
Solution Approach 1:
The patent modifies the chemical composition parameters by incorporating specific mineralizers (boron, sodium, potassium, lead) and controlling raw material stoichiometry. This enables the formation of C2S α polymorph and C4A3-yFy phase at lower cooking temperatures (below 1425°C), which directly reduces CO2 emissions while maintaining the hydraulic reactivity required for high-performance cement.
Solution Approach 2:
The patent introduces minor elements (boron, sodium, potassium, lead) as intermediaries that facilitate phase formation at lower temperatures. These mineralizers act as mediators that enable the simultaneous presence of reactive belite and calcium sulfoaluminate phases without requiring high temperature processing, thereby reducing CO2 emissions while preserving hydraulic reactivity.
3Adaptability or versatility
If iron-rich raw materials are used to reduce costs and increase availability, then material versatility is improved, but sticking phenomena occur during kiln cooking
Solution Approach 1:
The patent introduces boron and other minor elements (sodium, potassium, lead) as intermediaries that act as anti-sticking agents. These mineralizers modify the surface properties of the raw material mixture and the formed phases, preventing adhesion to kiln walls and reducing sticking phenomena. This allows the use of iron-rich raw materials without the harmful sticking effects that would otherwise occur.
Solution Approach 2:
The patent changes the chemical composition parameters by incorporating boron and other minor elements that alter the melting behavior and surface properties of the raw material mixture. This modification of compositional parameters prevents sticking phenomena during kiln cooking, enabling the use of iron-rich raw materials while maintaining material versatility.
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 results in cements with reduced setting time, maintained hydraulic reactivity, and increased strength, achieving a 35% reduction in CO2 emissions compared to Portland cement production, while enabling the use of a wider range of materials and avoiding sticking issues during kiln cooking.
Implementation Method 1
The manufacture of hydraulic binders, and in particular that of cements, essentially consists of the calcination of a mixture of judiciously chosen and measured raw materials
Implementation Method 2
The polymorphism of belite (C2S) governs its reactivity or its hydraulicity. Solid solutions with minor elements such as boron, sodium or potassium lead, to a certain extent, to vary the crystallographic nature of the belite
Implementation Method 3
calcium silicate doped with boron C11S4B
Implementation Method 4
Clinkers allowing the preparation of sulfo-aluminous cements or sulfo-belitic cements relate to a process for manufacturing a clinker from a raw material
Data Source
AI summary
The invention relates to a novel sulfoaluminous clinker, to a method for preparing said clinker, and to the use of said clinker for preparing a hydraulic binder and subsequently grout, concrete, or mortar.