Blassting On The Original Slope And The Optimization Of Its Parameter In The Wulongquan Limestone Mine

Because of the reasons that slope of landforms in original side slope in western section in WuLong Fount Mine is slow and slope angle is between 25?and 45? it is difficult to form normal production bench during the exploitation in this section if ordinary blasting method is adopted, so it is necessary to research blasting method and related work in order to deal with large numbers of slow original side slope and form regular production bench.There are many methods for dealing with original side slope that are summed up by consulting correlative national and oversea technology and documents, such as omnibus blasting composed of charged chambers and deep holes, blasting with changeable blasthole inclination, deep hole blasting with expansion hole caused by machinery and changeable diameter, accessorial blasting, blasting with bulled hole, and so on. On the basis of compare and analysis on advantages and disadvantages among above-mentioned methods, the conclusion that it is suitable and effective to adopt the blasting with bulled hole is drawn, at the same time, simple summarization that is related to the theory and practical application on expanding cavity with the blasting with bulled hole is done.In order to ensure it will succeed to adopt the blasting with bulled hole, the key is to adopt rational blasting method and to obtain suitable loading space. Concentrated couple charge is used in the first expanding cavity with the blasting, while decouple charge is used in the sequent ones during the course of repetitious expanding cavity with the large-diameter deep hole blasting, because there are different effect on the formation of bulled hole when adopting couple charge and decouple charge, sp, expanding cavity with the blasting is made up of the first one and sequent ones, and corrective expanding cavity mechanism with the blasting is researched. At the same time, according to breaking mechanism of rock, the radiuses of cavity, shatter and crush zone, and crack zone that are caused by first expanding cavity with the blasting are computed, and the best charge weight, , that is used in the first expanding cavity with the blasting is confirmed. Moreover, according to damage mechanics, the subsequent expanding cavity with the blasting is analyzed, and theconclusion that cavity of bulled hole can not be expanded when damage accumulation Ds <1, while rock will be broken fully and cavity of bulled hole still can be expanded when Ds =1 is drawn. And, some of laws on expanding cavity with the large-diameter deep hole blasting, such as cavity of bulled hole that forms has the shape of irregular wooden club, is also drawn.Applying the theory of expanding cavity with the large-diameter deep hole blasting, also combining the characteristic of deep hole blasting with bulled hole, different blasting plans with different side slope angles are drawn, the parameters for blasting with bulled hole that tally with spot fact are put forward; also, technics for expanding cavity with the blasting is researched through 12 corrective experimentations, and aiming at different rock character, the suitable technologic parameters for expanding cavity with the blasting are drawn, that is, expanding cavity should be carried out 4 times in soft rock, the total charge weight for expanding cavity should be 42 kg, distribution rate of charge weight should be 6: 9: 12: 15; while expanding cavity should be carried out 5 times in hard rock, the total charge weight for expanding cavity should be 60 kg, distribution rate of charge weight should be 6: 9: 12: 15: 18.The factors that affect the blasting with bulled hole are also discussed in the paper, through the optimization selections on the parameters for the blasting with bulled hole, the special parameters for the blasting with bulled hole, which is suitable for original side slope in WuLong Fount Mine, are drawn and validated through spot industry experimentations. On the basis of above-mentioned experimentations, the technical economy indexes on the blasting with bulled hole are analyzed...