花岗岩的黑火药爆炸切割技术

本文介绍了爆炸切割与光面爆破的区别；系统阐述了石材切割技术方案选择、黑火药爆炸切割参数的确定、切割工艺、起爆技术及切割实例。     

Ceramics composites from iron ore tailings and blast furnace slag

The search for materials and methods capable of reducing human impacts on the environment is of utmost importance nowadays. This study's primary purpose was to analyze the technical feasibility of ceramic composites production utilizing Fundão Dam's Iron Ore Tailings (IOT), Blast Furnace Slag (BFS) from charcoal, and Foundry Sand (FS) as partial substitutes for the traditional raw materials – sand and clay – for application in building industry materials. The composites were molded in rectangular specimens and fired at temperatures of 900, 950, 1000, 1050, and 1200 °C. The developed materials were analyzed and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Thermogravimetry (TGA), and Differential Thermal Analysis (DTA). The obtained materials had flexural strength modulus of up to 12.19 MPa, water absorption ranging from 2 to 22%, linear shrinkage ranging from 0.02 to 6.50%, and apparent density ranging from 2.03 to 1.63 g/cm³. The study of the internal structure formation process revealed the formation of amorphous structures in the composites. The results demonstrated that these waste materials may be jointly used in construction materials, contributing to the reduction of natural resource extraction, besides enabling their correct disposal, minimizing environmental impacts, and improving the life quality of the surrounding communities.     

Research on slag-resistance of ZrN-SiAlON-SiC-C composite refractory in different atmospheres

The ZrN-SiAlON composite powder was synthesized using low-grade zircon and bauxite by carbothermal reduction nitridation at first and then ZrN-SiAlON-SiC-C composite refractory were fabricated with the ZrN-SiAlON powder, SiC particles, and a small amount of Si powder as raw materials and sucrose as the binder. The slag resistance of these composites in O₂, N₂ and Ar atmosphere was investigated by X-ray diffraction, scanning electron microscopy, and energy dispersion spectra. The results show that the pores in the inside of ZrN-SiAlON-SiC-C composite refractory were enlarged in oxygen atmosphere due to oxidation, which leads to the decrease in slag resistance. In argon atmosphere, blast furnace slag destroyed the sintered body of zircon, corundum, and cristobalite with the formation of CaZrO₃, then infiltrated into and filled the pores inside the refractory to form a dense layer, which hindered the further erosion of the blast furnace slag. In the reducing atmosphere, the interfacial energy of the gas-liquid phases became larger due to the reactions between blast furnace slag liquid and the gas, resulting in a larger wetting angle which prevented the erosion.     

工程水压爆破在煤层爆破中的应用

通过黑岱沟露天煤矿的工程试验总结了工程水压爆破技术(水土复合填塞炮孔)的原理及在露天煤矿爆破施工中的应用效果。在露天煤矿爆破施工中采用工程水压爆破技术,可以提高煤层爆破的大块率,降低单位立方岩石耗药量,降低爆破气体的温度,同时可以降低煤层爆破失火率、粉尘排放量,有效地控制爆破飞石。     

基于多目标规划的抛掷爆破台阶参数优化

为了优化确定抛掷爆破台阶参数，采用回归分析等方法，构建了抛掷爆破台阶参数与采剥费用之间的关系模型，并从地质资源条件、设备线性尺寸、生产作业条件等方面提出了抛掷爆破台阶参数的约束条件，建立了抛掷爆破台阶参数多目标优化模型，提出了基于带精英策略的非支配排序遗传算法(NSGA-Ⅱ)的多目标优化模型求解方法。通过工程实例计算，得出以下结论:黑岱沟抛掷爆破台阶最优工作线长度为2 200 m，台阶高度为38 m，采掘带宽度为84 m，台阶坡面角为65°。在不考虑其他因素的影响下，露天矿采剥总费用随着工作线长度的增大先减小后增大，随着台阶高度的增大而减小。采掘带宽度在60~90 m范围内变化时，采剥总费用随着采掘带宽度的增大先降低后增大。露天矿采剥总费用随着台阶坡面角的增大而降低，但台阶坡面角对台阶稳定性影响较大，而台阶高度对采剥总费用的影响较大，相同稳定系数的情况下，取较小的台阶坡面角、较大的台阶高度时采剥总费用较小。     

Progressive fracture processes around tunnel triggered by blast disturbances under biaxial compression with different lateral pressure coefficients

To investigate the progressive fracture processes around a tunnel triggered by static stress and dynamic disturbance, experiments and numerical simulations were performed. The results show that the spatial distributions of acoustic emission (AE) events become very different as lateral pressure coefficients change. The combined effect of static stress and dynamic disturbance causes the damage around the tunnel, and initial stress conditions control the damage morphology. The blast disturbance cannot fundamentally change the damaged area but will deepen the extent of damage and accelerate the failure speed. The more significant the difference between the vertical and horizontal stresses is, the higher the impact on the tunnel by the dynamic disturbance is. The AE activity recovers to a relatively stable state within a short time after the blast and conforms to power-law characteristics.     

刚性地面对爆炸冲击波传播规律的影响

为研究刚性地面对爆炸冲击波传播特性的影响,采用ANSYS/LS-DYNA对TNT炸药在刚性地面工况下起爆后的整个过程进行了数值分析,得到了刚性地面工况下爆炸冲击波的传播规律以及特征参数,并将其与自由空气工况下爆炸冲击波的传播规律以及特征参数进行了对比分析。建立了TNT炸药在刚性地面工况下起爆后,比例距离在0.5 m/kg^1/3≤Z≤3 m/kg^1/3之间时的冲击波超压峰值简便计算公式,分析了起爆高度对刚性地面附近冲击波的影响规律,并得到了刚性地面反射增强效应作用范围的判别公式。数值分析所得结果可为结构或构件在刚性地面上发生爆炸时荷载的初步确定提供一定的参考。     

基于射流冲击作用的舰机适配性数值分析与优化

准确分析和控制射流冲击对航母甲板环境的影响是新型喷气偏流板设计和布局的关键所在。为了确定射流冲击影响最小的偏流板布局，运用有限体积法，采用分区混合网格方案，结合雷诺时均纳维斯托克斯（RANS）方程和SST k-ω湍流模型对喷气偏流板在不同布局下的射流冲击效应进行三维数值模拟。选取舰载机双发动机全加力状态时喷气偏流板与发动机距离不同、喷气偏流板倾角不同共12种布局组合进行射流冲击效应的对比计算,计算结果显示了喷气偏流板各布局下的流场参数、传热特性、尾喷口温升、冲击力和力矩等分布规律。定性和定量分析了燃气射流冲击下温度场和速度场的危险区域，结果表明，偏流板与发动机距离5 m、偏流板倾角45°时的布局更有利于将燃气射流向上引导。在此基础上，基于倾角最小化原则及二次导流原理优化设计了一种导流隔热性能好、工作稳定性高的被动隔热式喷气偏流板装置。     

碱度对包钢高炉渣物理性能的影响

摘要：为探明二元碱度对包钢高炉渣物理性能的影响机理，基于包钢7号高炉渣化学组成，添加纯试剂CaO、SiO2调整炉渣的二元碱度。通过实验研究二元碱度对包钢7号高炉渣熔化温度、黏度和熔化性温度的影响规律；同时采用Factsage70热力学软件，计算了不同碱度下炉渣的液相线温度和热焓值。结果表明：随着碱度升高，炉渣熔化温度不断升高，黏度和熔化性温度先降低后升高，碱度在1.1～1.3之间，碱度每提高0.1，炉渣半球温度提高4.67℃，软熔区间为3.33～4.60℃；碱度在1.1～1.4之间，1450℃以上炉渣黏度均低于0.5Pa·s，流动性良好；Factsage7.0计算结果表明：随着碱度的升高，炉渣的液相线温度不断升高，热焓值不断降低。综合考虑碱度对包钢炉渣熔化温度、熔化性温度、热焓和黏度的影响规律，建议包钢高炉渣的碱度应控制在1.1～1.3之间。     

Evaluation of air blast parameters in block cave mining using particle flow code

Air blast, a sudden mass movement of air, can occur in underground mining system where caving develops an extensive mass of unsupported rock spanning a large void. Air blast can result in injury to mine personnel, damage to equipment or disrupts mine operation. Evaluation of air blast parameters is, therefore, an essential part to develop strategies to mitigate the hazard. The properties of a muckpile or a caved zone are significant factors affecting the magnitude of air blast in particular on the undercut and extraction levels. This research investigates the effect of muckpile properties on air flow using the numerical code, PFC2D. The critical parameters such as thickness, block size and porosity (swell factor) of the muckpile have been studied to quantify how much they could change the magnitude of air pressures and velocities while the air flows through the muckpile. It was found that the porosity of the muckpile is the most effective parameter on the magnitude of air blast and by designing a thick layer of blasted rock with low porosity in the caved zone, the intensity of the air blast can be significantly reduced. The findings of this study can be used to design air blast plugs or bulkheads in order to isolate any potential air blast from the active workings, or to quantify the minimum thickness of the muckpile above extraction levels to manage air blast hazards.