| The essence of large-scale open-pit coal mining is a huge earthwork space transportation project.The total annual stripping amount of a large-scale open-pit coal mine with a design capacity of 20 Mt/a is generally more than 100 million m~3.At present,the single bucket truck intermittent process is the main technology in large-scale open-pit coal mines in China,and the transportation cost accounts for 1/2-2/3 of the direct mining cost.The application range is greatly affected by the price fluctuation of tires and fuel oil,and the transportation has become the most significant link affecting the economic benefits of open-pit coal mines.From the perspective of mining process development,belt conveyor is gradually rising after single bucket-truck mining technology.The reason is that with the increasing mining depth of open-pit coal mine,limited by the slope(8%),the truck transportation distance in the single bucket truck process gradually exceeds the optimal economic transportation distance,and the replacement effect of belt conveyor for truck transportation is more obvious,The existing semi continuous mining technology in China basically uses belt conveyor instead of truck transportation,mainly on the surface,because of the limitation of climbing capacity of belt conveyor(18°).As well as the flexibility of moving and the constraints of Inner Dump follow-up,its advantages in deep and large open pit are no longer prominent.Combined with the resource occurrence conditions of open-pit coal mines in China and the specific characteristics of Ha'erwusu open-pit coal mine,the semi continuous technology of single bucket truck movable crushing station end slope self-moving large inclined belt conveyor is an alternative technology to solve the problems existing in the current semi continuous mining technology.Firstly,through the analysis of the application scenarios and operation characteristics of the end slope self-moving large inclined belt conveyor system,the paper determines the three core characteristics of the end slope self-moving large inclined belt conveyor(large inclined angle,self-moving type and adaptability).It is clear that the large inclined belt conveyor structure of the end slope large inclined belt conveyor is belt pressing type,and the crawler chassis is selected for the self-moving device.Combined with the shape of southern end wall and single machine structure of belt conveyor in Ha'erwusu open-pit coal mine,the two-point support multi machine combination lifting scheme and sectional self-moving scheme are determined,and the mechanical structure parameters of end wall self-moving large inclined belt conveyor are designed.In this paper,the mechanical simulation of end-help self-moving and large inclination belt conveyor is carried out by ANSYS software.The structural strength of belt conveyor and track plate is calculated.The transverse vibration model and modal parameters of belt are given.The stress distribution of belt at the roller of belt conveyor is analyzed.Combined with the coal seam occurrence characteristics and mining status of Ha'erwusu open-pit coal mine,the paper comprehensively compares the selection and location of the movable crushing station under the pit,and recommends the use of the working face self movable crushing station,with an hourly capacity of 2500t/h,crushing particle size of 300mm,moving step distance of 90m,and moving four times a year.Numerical analysis is carried out on the layout of single step and overall stability of large inclined belt conveyor,and the economic benefits of the end slope self-moving large inclined belt conveyor system in Ha'erwusu open pit coal mine are predicted and analyzed.The research results of this paper are of great significance for expanding the application scope of semi continuous process system,realizing"replacing oil with electricity"in open pit mine transportation and reducing carbon emissions.There are 68 pictures,13 tables and 56 references in this paper. |
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