Model Test And Application Study On Water Stemming Mechanism

ABSTRACT:Blasting method is often used in underground mining in Metal mine. Based on the engineering background of down hole blasting operation in Fankou lead-zinc Mine and the model test of water stemming, this paper analyze and investigate the results of model test to apply for different block way through the theoretical research, experimental verification, modeling calculation methods and indicators judge. Sums up the test conclusion, and give guidance in the engineering application. The main research contents and conclusions are as follows:(1) Employing reasonable length of water stemming in blasting holes can effectively replace sand stemming, and has better effect to reduce the blasting dust, whose explosion energy utilization and the blasting effect is better too.(2) Employing water stemming clogging on the sand of combined structure in blasting hole can achieve better blockage operability and satisfactory blasting effect.(3) According to the research results of Griffith theory and damage mechanics, set up calculation model of reasonable length of stemming and crack propagation length. The calculating reasonable length of stemming of model blasting is7.75cm length of water stemming, or5.3cm length of sand stemming, or5.1cm length of water stemming plus3.4cm length of sand stemming for the combined structure. Calculating the main crack extension average length is25.18cm. Define the length of stemming and the length of crack extension as the judging indexes of explosion energy utilization. Use FM-AHP theory to evaluate comprehensively the test results, which shows that the preferable blocking ways are8cm length of water stemming and combined structure I(4) Based on computer image processing technology, develop blasting fragmentation analysis system in the MATLAB (GUI) platform to deal with test results, draw distribution curve and output block size statistics. Calculating reasonable blasting block size is4.7cm, according to the fractal theory, calculating reasonable fragmentation distribution index (fractal dimension) is1.3. Define the foregoing two as the evaluation index of blasting effect, and use FM-AHP theory to evaluate comprehensively the test results, which shows that the preferable blocking ways are combined structure I and8cm length of water stemming.(5) Accord the test results to determine the blocking scheme of blasting hole in a mine. The application effect of blocking scheme in mine stope is satisfactory, and the engineering effect and test results is mutual authentication.