浅议包头市大气环境中苯并(a)芘的污染

苯并(a)芘(Bap)是强致癌物之一，主要来源为煤、石油等矿物性燃料及其他有机物的不完全燃烧。本文通过对包头市1991～2000年大气苯并芘监测结果的统计分析，揭示了其污染状况及变化趋势，从而说明包头市大气环境中Bap主要来源于燃煤。     

阳离子丹宁絮凝剂的制备及其性能评价

利用曼尼希(Mannich)反应制备阳离子丹宁絮凝剂。影响阳离子化反应的主要因素是:原料配比、pH值、水溶剂用量,反应温度和时间。用正交试验设计法确定了最佳反应条件。通过烧杯实验证实,该絮凝剂与其它混凝剂复配处理钻井废水,可以降低处理费用,提高处理效果。     

煤矸石制取铝盐的条件试验

煤矸石作为一种来源广泛的铝资源利用愈来愈受重视，如何提高铝的溶出率是充分利用的关系。文中提出了采用回流可使煤矸石中Ａｌ２Ｏ３的溶出率达９５％以上。     

永荣矿区煤矸石的多途径综合利用

本文叙述了永荣矿务局开发利用煤矸石及其二次废渣的多项途径和方法，利用煤矸石生产矸石砖，发电，利用发电炉渣生产水泥和蒸养砖，改良土壤等，同时，提出一些探讨性意见。     

陕西渭北煤矿区地质灾害浅析

渭北煤矿区是陕西省的重要煤炭生产基地,随着矿区的开发,地质环境日趋恶化,地质灾害亦日渐增多。矿区地质灾害既普遍又严重,主要类型有:地震、活动断裂、滑坡、地面裂陷、泥石流及土壤侵蚀等。其内力型地质灾害主要受新构造运动所控制,而外力型地质灾害多与人类活动有关,即与矿区开发有关。     

论燃煤过程中的放射性污染

国内煤层中普遍存在的天然放射性核素，通过燃煤产生的烟气、煤灰渣等介质进入空气、土壤和水环境中。公众健康危害评价结果证明燃煤排放的放射性污染物通过吸入途径对人体的总危害危险大于二氧化硫、氨氧化物等一般污染物。鉴于我国近几年火电厂等煤炭消耗量大，并且不断增长的现状，指出对燃煤造成的放射性环境污染应予足够的重视。     

煤吸附氧的过程特性研究

分析了煤吸附氧的动态变化过程并将其划分为活性吸附阶段、变能级吸附阶段和趋势化吸附阶段 ;测试了不同变质程度典型煤样的吸氧过程曲线 ,得出了滞后时间和斜率常数是煤表面位置能分布及空隙结构特性的表征量。分别由吸附动力学理论及煤氧吸附过程曲线推导了煤吸氧速度方程 ,建立了煤吸氧过程特性的数学描述模型 ,得出了煤的吸附活化能与覆盖度之间存在着对数关系。特别指出吸氧速度是煤表面与氧结合性质的度量因子 ,在一定程度上量化了煤的自燃活化性能。     

Optimization and implementation of a foam system to suppress dust in coal mine excavation face

Foam technology is more efficient than water sprays for dust control in coal mines, but the traditional foam system is complex and poses problems related to foam production and spraying application, with high water consumption, unstable equipment and relatively low utilization efficiency of foam. This paper describes an optimized foam system which overcomes these disadvantages. The proposed foam generator has a self-suction unit that uses a turbulent-flow water jet to automatically draw in ambient air and foaming agent, thereby eliminating the need for compressed-air hoses and pipes. As well as simplifying the system, it solves the current problem of water backflow created by high-pressure compressed air. A refined foam spraying structure was developed for use in conjunction with an operating roadheader as it produces and diffuses dust. The structure consists of foam distribution supports and arc-fan nozzles. It can produce a more focused, continuous and uniform coverage at the source of the dust. The optimized system consumes less water and foaming agent, and achieves greater dust-suppression efficiency than methods in current use.     

Structure and flame speed of dilute and dense layered coal-dust explosions

Multidimensional time-dependent simulations were performed to study the interaction of a stoichiometric methane–air detonation with layers of coal dust. The simulations solved equations representing a Eulerian kinetic-theory-based granular multiphase model applicable to dense and dilute particle volume fractions. These equations were solved using a high-order Godunov-based method for compressible fluid dynamics. Two dust layer concentrations were considered: loose with an initial volume fraction of 1%, and dense with an initial volume fraction of 47%. Each layer was simulated with two types of dust: reactive coal and inert ash. Burning of the coal particles results in a coupled complex consisting of an accelerating shock leading a coal-dust flame. The overall structure of the shock–flame complex resembles that of a premixed fast flame with length scales on the order of several meters. The large length scales are direct results of time needed to lift, mix, heat, and autoignite the particle. The flame speeds are large and much larger than the gas-phase velocity. Large spikes of flame speed are characteristic of the 47% case. These spikes and high flame speed are caused by pockets of coal dust autoigniting ahead of the flame. The flame is choked in the 1% case due to the gas-phase products exceeding the sonic velocity with respect to the flame. The 47% case is choked due to attenuation of pressure waves as they propagate through particles. Inert layers of dust substantially reduce the overpressure, impulse, and speed produced by propagating blast wave. The results also show that loose layers of dust are far more dangerous than dense layers. The shock and flame are more strongly coupled for loose layers, propagate at higher velocity, and produce large overpressures and impulses.     

Study on the preparation of novel NiB/Hβ-Al2O3 micro-mesoporous suppressant and its inhibition mechanism of coal dust explosion flame

Coal dust explosion is one of the serious accidents in the coal industry. It is of great significance to study the flame suppression of coal dust explosions. In this paper, a novel active component NiB with amorphous structure for explosion suppression was synthesized by the chemical reduction method. Furthermore, the novel explosion suppressant NiB/Hβ-Al₂O₃ was prepared through the kneading method by loading novel amorphous NiB nanoparticles on Hβ-Al₂O₃ with the micro-mesoporous structure as the carrier. The morphology and structure of NiB/Hβ-Al₂O₃ were characterized by XRD, BET, SEM, and FTIR, which showed that the NiB/Hβ-Al₂O₃ has proper pore structure and NiB nanoparticles are uniformly distributed as active components for explosion suppression in suppressant. Hartmann tube was used to evaluate the inhibition of coal dust deflagration. The results showed that the flame propagation distance and velocity decreased with the increase of the explosion suppressant. When the addition of explosion suppressant was 30 wt%, the explosion of coal dust was suppressed effectively. Furthermore, combing with the analysis results of the products after coal dust deflagration, the physical and chemical inhibition mechanism of the novel NiB/Hβ-Al₂O₃ explosion suppressant on coal dust deflagration was put forward.