Inclined Layered Solid-Filling Mining for Ultrathick Coal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mining methods for ultra-thick coal layers under surface constructions, railroads, or water bodies face issues such as surface subsidence, environmental damage, low mechanization, low recovery ratio, high production costs, and low efficiency due to spontaneous roof caving and limited mechanization in existing methods like layered mining and strip mining.
Innovation Solution
The inclined layered solid-filling mining method involves dividing coal layers into inclined sections, constructing an artificial roof using metal meshes and bamboo fences, and filling the mine goaf with solid materials to control subsidence and improve recovery efficiency, ensuring safe surface use and enhanced coal extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spontaneous caving approach is used to manage coal roofs, then mining efficiency is improved, but surface subsidence and damages to surface constructions occur
Solution Approach 1:
The ultra-thick coal layer is divided into multiple inclined layers (typically 3-5 layers) with each layer thickness controlled at 2.5-4.5m. This segmentation allows controlled mining of each layer with independent solid filling, preventing uncontrolled spontaneous caving that would cause surface subsidence while maintaining mining efficiency through systematic layer-by-layer extraction.
Solution Approach 2:
Solid filling material (gangue mixed with binding agents) is introduced as an intermediary substance to replace the natural roof support function. The solid filling is compacted in layers to form artificial support structures that prevent strata collapse and surface subsidence, while allowing continuous mining operations to proceed without interruption from roof management issues.
2Object-affected harmful factors
If strip mining or large area coordinated mining is used, then surface subsidence is controlled, but mechanization level and production efficiency decrease
Solution Approach 1:
The mining system is made dynamic through the use of movable hydraulic supports and conveyor systems that can advance continuously during mining operations. The hydraulic supports dynamically adjust to maintain roof support while the conveyor system continuously transports coal, enabling high-speed mechanized mining that maintains production efficiency while the solid filling provides static subsidence control.
Solution Approach 2:
The coal layer thickness parameter is changed from the natural ultra-thick state (8-20m) to divided layer thickness (2.5-4.5m each layer). This parameter change enables the use of standard mechanized mining equipment and solid filling techniques that maintain both subsidence control and high production efficiency, unlike traditional strip mining which requires much wider excavation areas.
3Quantity of substance
If conventional mining methods are used, then coal extraction is achieved, but coal recovery ratio is low
Solution Approach 1:
Solid filling is performed preliminarily in each mined layer before moving to the next layer. This preliminary action of filling creates stable artificial roofs that allow subsequent mining operations to access and extract coal from adjacent areas that would otherwise be lost to roof collapse or require leaving as large safety pillars, thereby improving overall coal recovery ratio.
Solution Approach 2:
The mining approach transitions from horizontal strip mining to vertical/inclined layered mining with solid filling. This dimensional change allows coal to be extracted from multiple layers stacked vertically, with solid filling providing support in the vertical dimension, enabling recovery of coal that would be inaccessible or too risky to extract using conventional horizontal mining methods.
Data Source
AI summary
In an inclined layered solid-filling mining method in an ultrathick coal layer, tunnels and equipment are arranged according to a solid-filling mining method. An artificial roof for a lower layer is formed by metal meshes and bamboo fences of a first layer a solid-filling mining method. The method is repeated, until the entire ultrathick coal layer is finished. The method is repeated forming additional roofs for subsequent layers.