Diamond Pattern Pit Design for Strip Mining Efficiency
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Solution Overview
Problem
Conventional dozer push methods in strip mining are limited by the need to push waste rock uphill, which reduces efficiency and increases costs, as dozers are less effective at grades above 25-30% and require longer distances to lift material to higher heights, while trucks are restricted to 10% grades for loaded travel.
Innovation Solution
The method involves designing a diamond pattern pit with blocks oriented at 45 degrees to the advancing strike face, allowing for shorter push distances and strategic blasting to reduce waste material excavation, facilitating dozer operation with inclines of 10% or less, and combining dozer and truck/shovel operations to optimize waste removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dozers are used to push waste rock uphill, then waste rock can be moved to the dump area, but dozer efficiency decreases and fuel consumption increases when grades exceed 25-30%
Solution Approach 1:
The patent applies preliminary action by using strategic blasting to pre-loosen and cast waste rock into a more favorable position before dozing. The blasting creates a pre-conditioned material state and position that reduces the subsequent dozing effort and fuel consumption, allowing dozers to operate more efficiently at lower grades.
Solution Approach 2:
The patent changes the dimensional approach by transitioning from direct uphill pushing to a multi-dimensional workflow: blasting casts material laterally and partially upwards, then dozers complete the movement from a reduced height differential. This dimensional redistribution of the movement task reduces the energy required for the dozing portion.
2Weight of moving object
If dozers push waste rock longer distances to achieve greater lift heights, then more material can be moved vertically, but dozer effectiveness decreases with increasing push lengths
Solution Approach 1:
Strategic blasting performs the preliminary action of lifting and casting waste rock to an intermediate height position before dozing. This pre-elevation reduces the vertical distance the dozer must push, maintaining dozer effectiveness while achieving the required total lift height.
Solution Approach 2:
The waste rock movement is segmented into two distinct phases: blasting handles the initial vertical lift and lateral cast, while dozing handles the remaining horizontal and vertical movement from a reduced starting point. This segmentation allows each method to operate within its optimal performance range.
3Length of moving object
If trucks are used to transport waste rock, then they can carry material over longer distances, but they are restricted to 10% grades for loaded travel and require flat loading and unloading areas
Solution Approach 1:
Strategic blasting performs preliminary action by casting waste rock laterally toward the dump area, reducing the distance trucks need to travel and eliminating the need for long graded roadways. This pre-positioning allows trucks to operate on flatter terrain with greater grade adaptability.
Solution Approach 2:
The patent uses blasting to change the dimensional approach from linear truck hauling along graded roadways to a more direct three-dimensional material placement. Waste rock is cast closer to the final dump position, reducing the horizontal transport distance and grade requirements for truck operations.
4Productivity
If conventional strip mining methods are used with straight advancing faces, then ore can be extracted systematically, but waste rock must be moved over longer distances and higher grades
Solution Approach 1:
The patent introduces asymmetry by positioning blast holes at specific angles (30-60 degrees) relative to the dozing direction rather than using symmetric perpendicular blasting. This asymmetric blasting geometry casts waste rock more directly toward the dump area, reducing push distance while maintaining systematic ore extraction.
Solution Approach 2:
Strategic blasting performs preliminary action by pre-positioning waste rock closer to the dump area before dozing begins. This reduces the subsequent push distance required and allows the dozer to operate over shorter, more efficient distances while ore extraction continues systematically.
Data Source
AI summary
The invention is directed to a method of strip mining that involves dividing the pit into blocks in a diamond shape arrangement with an angular advancing strike face and removing waste material from each diagonally adjacent block so as to minimize the amount of waste material pushed by dozers and maintain the incline of ramps to gradients of 10% or less so that trucks can take mined ore from the pit.