长九神山灰岩矿开采爆破试验研究

Experimental Study on Mining Blasting of Chang-jiu Limestone Mine

长九神山灰岩矿是世界上生产规模最大的砂石骨料场,爆破块度分布和粉矿率直接影响矿山的生产效益。为了控制爆破后块度分布同时降低爆破后岩粉含量,提高资源利用率,结合现场实际生产,在两个岩体节理发育程度不同的采区共进行了4次8组爆破试验,并在每次试验后取样进行筛分,研究爆破参数与爆破块度及岩粉含量的关系。筛分结果表明:地质因素和爆破参数因素均对爆破块度分布和粉矿率存在显著影响,现场8组试验平均块度在90-150mm,粉矿率均在4%以下。地质条件相对较差的采区平均块度较小,粉矿率较高。对于岩性相对较差的1#采区,可控制炸药单耗在0.33-0.36kg/m3,爆破后平均块度120-140mm以控制岩粉含量;岩性相对较好的2#采区,可适当增大炸药单耗至0.36-0.39 kg/m3,减小爆破后平均块度。在后续的生产过程中,需要结合具体生产需求和采区岩性条件对爆破参数进行调整。

Chang-jiu Shenshan limestone mine is the largest aggregate field in the world.The distribution of blasting fragmentation and powder ore rate directly affect the production efficiency of the mine.In order to control the fragmentation distribution after blasting,reduce the rock powder content after blasting and improve the utilization rate of resources,eight groups of blasting tests were carried out in two mining areas with different joint development degree of the rock mass combined with the actual production in the field.Samples were taken after each test for screening to study the relationship between the blasting parameters and the fragmentation and rock powder content of blasting.The screening results showed that geological factors and blasting parameters have a significant impact on the distribution of blasting block size and powder ore rate.The average block size of 8 groups of field tests was 90~150 mm,and the powder ore rate was below 4%.The average block size of the mining area with relatively poor geological conditions was smaller and the powder ore rate was higher.For 1# mining area with relatively poor lithology,the unit explosive consumption could be controlled at 0.33~0.36 kg/m^3,and the average block size after blasting was 120~140 mm to control the rock powder content.For 2# mining area with relatively good lithology,the unit explosive consumption could be increased to 0.36~0.39 kg/m^3,and the average block size after blasting could be reduced.In the follow-up production process,the blasting parameters need to be adjusted according to the specific production demands and the lithologic conditions of the mining area.