Roof filling control technology and application to mine roadway damage in small pit goaf

To recover coal resources that have been damaged by traditional mining methods and ensure stability of the lower roadway in a small pit goaf,the goaf area must be filled and reinforced.In this research,the 1202 working face of the Hanzui mine is considered as an example for classifying the roof of the mining tunnel under the small kiln destruction zone,the effect of the goaf on the roadway is determined based on the radio tunnel penetration method,a mechanical model to determine the roof filling control mechanism was established,and the duct foaming system and roof filling process were designed.The results show that the scope and degree of influence of the goaf on the mining lane are large,but safe tunneling can be ensured through the use of a steel shed and advanced grouting techniques.When the roof conditions are not similar,materials with different filling heights and filling strengths can be used to control the roof filling of the roadway.By combining field experience and laboratory tests,it was determined that a high-foaming material with a water-cement ratio of 1:0.6,a suitable high-foaming additive,and a water volume ratio of 1:30 is cost-efficient for filling and meets the filling strength requirements.Finally,the reliability of the proposed technology was verified by field experiments,which provide a reference for filling operations in similar mines.

Fouling characteristics of cnidarians(Hydrozoa and Anthozoa)along the coast of China

Hydrozoans and anthozoans are an important component of a great variety of marine communities,particularly abundant and ubiquitous as part of the fouling assemblages around the globe.Several negative impacts have been associated to their occurrence on artificial substrata.In the coastal waters of China,a total of 76 species of fouling cnidarians were observed and classified.According to the occurrence frequency or biomass,the major species in the Bohai and Yellow Seas were Ectopleura marina,Bougainvillia sp.,and Eudendrium capillare;in the East China Sea Anthopleura nigrescens,Diadumene lineata,and Ectopleura crocea;and in the South China Sea Clytia sp.,Obelia sp.,and Actiniaria spp.The peak period of settlement of most species was mainly in summer and autumn.With the decrease of latitude,species number increased greatly and even cnidarian fouling was observed all year round in the East and South China Seas.Salinity was another factor aff ecting species distribution.Naturally,immersion time of substrata also directly aff ects the characteristics of cnidarians in fouling communities.

耦合酸气提浓的脱硫脱碳工艺

针对高碳硫比的酸性天然气的净化,提出了一种耦合酸气提浓的脱硫脱碳新工艺.以某高碳硫比原料气为例,采用PROMAX和AMSIM模拟软件进行工艺模拟和参数分析.结果表明,二级闪蒸压力为300 k Pa、闪蒸温度为118℃时,闪蒸气量和二次吸收塔顶的尾气量均较大,再生后的酸气浓度较高,能耗比常规工艺低.该工艺在满足产品质量要求的同时能将再生后的酸气浓度由20.65vol%提升至30.16vol%,提高了天然气处理单元操作的稳定性,降低了一次性投资和操作运行成本.