Lime-Based Cement Extender Composition for Consistent Mine Backfill Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mine backfill solutions using fly ash as a cement extender face challenges due to varying unconfined compressive strength, diminishing supply, and increasing costs, necessitating an alternative that maintains strength and reduces environmental impact.
Innovation Solution
A lime-based cement extender composition comprising lime, limestone, and pozzolan particles, which are combined and milled to achieve a uniform particle size for enhanced strength and reduced moisture, forming a substitute for fly ash in mine backfill applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fly ash is used as a cement extender in mine backfill, then the cost is reduced and availability is maintained, but the unconfined compressive strength varies and supply is diminishing
Solution Approach 1:
The patent combines multiple materials (cement, lime, limestone, fly ash, and water) in specific proportions to create a composite backfill composition. This composite approach ensures consistent unconfined compressive strength by balancing the variable properties of individual components, particularly compensating for fly ash strength variations through the stabilizing effect of lime and limestone
2Ease of manufacture
If fly ash is used as a cement extender, then the immediate cost is lower, but the long-term availability decreases and costs increase
Solution Approach 1:
The patent modifies the compositional parameters of the backfill by specifying precise ranges of cement (10-30 parts), lime (1-10 parts), limestone (1-10 parts), and fly ash (5-20 parts). This parameter optimization allows the formulation to maintain cost-effectiveness while reducing dependency on fly ash availability, as the alternative materials (lime and limestone) are more readily available
3Device complexity
If conventional mine backfill solutions are used, then the process is simple, but the environmental impact increases due to greenhouse gas emissions
Solution Approach 1:
The patent utilizes lime and limestone as alternative materials that can be sourced from industrial by-products or local deposits, replacing a portion of fly ash and reducing the need for cement production. This approach discards the reliance on coal combustion by-products and recovers environmental benefits by using materials with lower carbon footprints, thereby reducing greenhouse gas emissions while maintaining process simplicity
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
The lime-based cement extender composition provides improved unconfined compressive strength, reduces material variability, and lowers greenhouse gas emissions, while being less dependent on the diminishing supply and rising costs of fly ash.
Implementation Method 1
lime-based cement extender composition comprising lime particles comprising calcium hydroxide and/or calcium oxide
Implementation Method 2
combined and milled to achieve a uniform particle size for enhanced strength and reduced moisture
Data Source
AI summary
A composition configured to be mixed with cement, and associated systems and methods are disclosed herein. In some embodiments, the composition includes at least 10% by weight lime particles, and at least 35% by weight pozzolan particles. Properties of the composition can include a magnesium oxide concentration of at least 0.5%, and an iron oxide concentration of at least 0.5-2.0%, an aluminum oxide concentration of 2-8%, a silicon dioxide concentration of 20-40%, a potassium oxide concentration of 20,000-30,000 ppm, and a sodium oxide concentration of 10,000-20,000 ppm. In some embodiments, the lime-based cement extender composition, or product, is combined with cement to produce a cement blend for use in the mining industry as mine backfill.