Research on the control technology of medium-length hole blasting fragmentation in underground mine

The scalloped medium-length hole blasting mining method used in Dahongshan Copper Mine accounted for more than 61%of the total amount of mining,but the large boulder yield restricted the intensity of ore supply for mines,and the average boulder yield was as high as 22.7%.In order to develop the mine production efficiency,the circular medium-length hole blasting technology was proposed and field tests were carried out.The test results showed that circular medium-length hole blasting mining can reduce the average boulder yield to 10.3%.Compared with the traditional scalloped medium-length hole blasting mining,the average boulder yield was decreased by 12.4%.The daily yield of ore for the panel on duty was increased by 152.29 t,and the growth rate was 51.1%.The new technology can reduce the time for the handling of boulder and the consumption of explosives and detonators for recrushing,and increase the efficiency of mining while reduce the mining cost,which has received good blasting effects.

根区穴施生物炭对烤烟生长及养分吸收的影响

为了探索生物炭在烟草生产中的应用效果,通过设置田间试验,选择水稻秸秆生物炭,采取穴施的方式,研究了其对烤烟生长及养分吸收的影响。结果表明,根区穴施生物炭后烟株株高、叶片面积等农艺指标表现较好,能够增加烟株的生物量,但随着生物炭施用量的增加,烟株生长发育受到了一定程度的抑制,其中在0.2 kg/株的生物炭用量下,烤烟整个生育期生长发育表现最好;根区穴施生物炭后,土壤pH以及阳离子交换量(CEC)具有升高趋势,并能够增加有机质、速效磷以及速效钾等养分含量,但随着穴施生物炭量的增加,土壤碱解氮含量呈下降趋势;根区穴施生物炭能够较好地促进烟株对钾元素的吸收,3个不同用量处理的烟株根、茎和叶3个部位的钾含量均有上升趋势,但在较高的生物炭施用量下(0.3 kg/株),烟株叶片氮的含量呈现出了一定的下降趋势。根区穴施生物炭也能够促进烟株根、茎和叶对磷的吸收,0.2 kg/株的施用量表现最好。因此,通过根区穴施生物炭能够促进烤烟生长以及对养分的吸收,综合考虑以0.2 kg/株的穴施生物炭用量较为适宜。

有序摆抛栽水稻的氮素吸收、利用与分配特征

有序化栽插是抛秧稻稳定高产和进一步超高产的基础,明确有序抛栽水稻氮素吸收利用及转运特点对其氮素高效利用有重要意义。本试验通过摆栽、点抛、撒抛3种抛栽方式以及对新型秧盘培育稻株氮素吸收利用特征的比较,研究水稻钵苗有序化栽插超高产的氮素吸收积累特性。试验结果表明:(1)水稻有序摆抛栽各生育时期全株含氮率低于撒抛,有效分蘖临界叶龄期和拔节期吸氮量相对较低,拔节后吸氮量显著或极显著高于撒抛,阶段吸氮量均表现为摆栽>点抛>撒抛。三连孔和二连孔植株各生育时期含氮率较高,且前期能保持适宜的吸氮量,拔节后吸氮能力显著增强,抽穗期、成熟期吸氮量和阶段吸氮量表现为二连孔>三连孔>单孔。(2)氮素农学利用率、生理利用率、偏生产力、氮素干物质生产效率、籽粒生产效率、氮素收获指数和产量均表现为摆栽>点抛>撒抛、机插,氮素利用率各指标、偏生产力、氮素收获指数在不同连孔处理间均表现为二连孔>三连孔、单孔,百千克籽粒需氮量表现为二连孔、三连孔>单孔,氮素干物质生产效率、籽粒生产效率为二连孔、三连孔<单孔。(3)不同抛栽方式处理穗后穗部含氮率和吸氮量均表现为摆栽>点抛>撒抛、机插,茎鞘和叶片呈现相反的趋势;不同连孔处理穗后叶片和穗部含氮率均表现为二连孔>三连孔>单孔,抽穗期茎鞘的含氮率差异不显著,各器官中的吸氮量亦表现为二连孔>三连孔>单孔。不同抛栽方式间氮素转运量和转运率表现摆栽>点抛>撒抛,而茎鞘和叶的氮素转运量和转运率在不同连孔处理间均表现为二连孔、三连孔<单孔。水稻有序摆抛栽,尤其是二连孔有序摆抛,前期有合理含氮量和积累量,抽穗后具有较高的氮素积累量、转运量和转运率,其氮素农学利用率、生理利用率、偏生产力、氮素干物质生产效率、籽粒生产效率、氮素收获指数相对较高,是水稻有序摆抛栽高产的营养生理基础。

Numerical simulation of blasting effect with divided charge structure

This paper numerically simulates the stress development and generates a three-dimensional model of the medium-length hole blasting in infinite rock mass for continuous charge and divided charge in blasting by using the large-scale nonlinear dynamic analysis software LS-DYNA and the elastic-plastic model ~*MAT_PLASTIC_KINEMATIC and JWO-EOS.The differences of the decreasing rate in Von Mises effective stress of blasting,element effective stress peak of free surface,bore wall stress and acceleration are investigated.It is shown that divided charge could greatly improve the blasting effect by engineering blasting practice.

中深孔分段落矿嗣后充填采矿实践

为提高三山岛金矿-600m以下中厚矿体采矿强度,采用上向中深孔分段落矿嗣后充填采矿法进行开采。首先,在采场上盘和顶柱下方分别施工支护巷道,进行长锚索预支护,有效保证了上盘围岩及采场顶柱的稳固性;其次,在分段采场开采分次爆破过程中,通过上分段上盘支护巷道进入采场,随后进行顶板处理,保证了采场顶板安全;最后,分段采场回采完毕,立即进行充填,缩短了采空区暴露时间,减少了围岩移动。实践证明,该采矿方法具有生产能力大、安全高效及采矿成本低的优点,满足了矿山生产规模扩张的需要,创造了巨大的经济效益和社会效益。