澳大利亚煤矿瓦斯治理及利用

本文对澳大利亚煤矿及其主采煤层的瓦斯赋存情况、矿井瓦斯的主要来源及其排放方式、矿井主要瓦斯治理技术进行了介绍,对澳大利亚煤矿产量与瓦斯排放量之间的关系进行了对比分析,综述了矿井瓦斯利用技术、方式、瓦斯发电场所分布和发电能力等基本情况,对澳大利亚未来矿井瓦斯治理及综合利用进行了展望。

在澳大利亚采用综放采煤工艺“一通三防”技术可行性研究

本文根据国内大型煤矿企业集团多年采用综放开采工艺的技术实践,结合澳大利亚煤矿的实际情况,对在澳大利亚煤矿实际条件下采用综放采煤工艺,其“一通三防”技术是否可行,进行了深入的探讨与研究,为国内矿业集团实施“走出去”战略,开展与澳方的技术交流与合作,提供了参考意见。

A review of the geomechanics aspects of a double fatality coal burst at Austar Colliery in NSW,Australia in April 2014

A coal burst occurred on 15 April, 2014 at the Austar Coal Mine, located west of Newcastle, NSW,Australia. The burst resulted in fatal injuries to two men working as part of the mining crew at the development face. At the time, a continuous miner was being used to mine a longwall development gate road through heavily structured coal, at a depth of approximately 550 m. A number of pre-cursor bumps had occurred on previous shifts, emanating from the coal ribs of the roadway, in proximity to the coal face.This paper reviews the geological, geotechnical and mining conditions and circumstances leading up to the coal burst event; and presents and discusses the available evidence and possible interpretations relating to the geomechanical behaviour mechanisms that may have been critical factors in this incident. The paper also discusses some key technical and operational considerations of ground support systems and mining practices and strategies needed for operating in such conditions in the future.

Investigations into the corrosive environments contributing to premature failure of Australian coal mine rock bolts

University of New South Wales(UNSW Australia) had been involved in the study of premature failure of rock bolts in Australia coal mines from the initial identification of the problem in 1999. Rock bolt steel changes over the last decade appear to have not reduced the incidence of failures. A broadened UNSW research project funded by the Australian Research Council(ARC) and Industry has targeted finding the environmental causes through extensive field and laboratory experiments. This paper describes the field studies conducted in underground coal mines,in particular attempts to measure the contribution to corrosion from groundwater,mineralogy and microbial activity. Various underground survey techniques were used to determine the extent of broken bolts,with the presence of both stress corrosion cracking(SCC) and localized deep pitting making no single technique suitable on their own.Groundwater found dripping from bolts across various coalfields in Australia were found to be not aggressive and known groundwater corrosivity classification systems did not correlate to where broken bolts were found. In-hole coupon bolts placed in roof strata containing claystone bands confirmed the clay as being a major contributor to corrosion. Microbes capable of contributing to steel corrosion were found to be present in groundwater,and culturing of the microbes taken from in-situ coupon bolts proved that the bacteria was present on the bolt surface. An ‘in-hole bolt corrosion coupon' development by the project may have multiple benefits of (1) helping quantify newly developed corrosivity classification systems,(2) providing an in-situ ground support corrosion monitoring tool,and (3) for testing possible corrosion protection solutions.

A comparative study of dust control practices in Chinese and Australian longwall coal mines

Mine dust is one of the main hazards in underground longwall mines worldwide.In order to solve the mine dust problem,a significant number of studies have been carried out regarding longwall mine dust control,both in China and Australia.This paper presents a comparative study of dust control practices in Chinese and Australian longwall mines,with particular references to statutory limits,dust monitoring methods and dust management practices,followed by a brief discussion on the research status of longwall mine dust control in both countries.The study shows that water infusion,face ventilation controls,water sprays,and deep and wet cutting in longwall shearer operations are commonly practiced in almost all underground longwall mines and that both Chinese and Australian longwall mine dust control practices have their own advantages and disadvantages.It is concluded that there is a need for further development and innovative design of more effective dust mitigation products or systems despite the development of various dust control technologies.Based on the examinations and discussions,the authors have made some recommendations for further research and development in dust control in longwall mines.It is hoped that this comparative study will provide beneficial guidance for scholars and engineers who are engaging in longwall mine dust control research and practice.

Development of a spontaneous combustion TARPs system based on BP neural network

Spontaneous combustion of coal is a major cause of coal mine fires.It not only poses a severe hazard to the safe extraction of coal resources,but also jeopardizes the safety of mine workers.The development of a scientific management system of coal spontaneous combustion is of vital importance to the safe production of coal mine.This paper provides a comparative analysis of a range of worldwide prediction techniques and methods for coal spontaneous combustion,and systematically introduces the trigger action response plans(TARPs)system used in Australian coal mines for managing the spontaneous heating of coal.An artificial neural network model has been established on the basis of real coal mine operational conditions.Through studying and training the neural network model,prediction errors can be controlled within the allowable range.The trained model is then applied to the conditions of Nos.1 and 3 coal seams located in Weijiadi Coal Mine to demonstrate its feasibility for spontaneous combustion assessment.Based upon the TARPs system which is commonly used in Australian longwall mines,a TARPs system has been developed for Weijiadi Coal Mine to assist the management of spontaneous combustion hazard and ensure the safe operation of its mining activities.

Design of primary ground support during roadway development using empirical databases

There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical use of empirical databases, and focuses on the main drivers for ground support as demonstrated in conceptual models. （;older Associates＇ empirical databases used for ground support include a primary roof support database and a primary fib support database. Both are based on successful ground support designs installed in mines in Australia, the US, the LIK, South Africa, New Zealand, and Europe. The term ＂successful＂ refers to those designs that were used on a repeated basis for the purpose of roadway devel- opment. The primary roof support database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the coal mine roof rating （CMRR）, and in situ stress. In regard to the primary rib support database, it is evident from the current database that the primary factors affecting the capacity of rib support required for a successful design are roadway height and depth of cover. These databases have been used to help determine the minimum primary ground support designs required at many mine sites in Australasia, Europe, and the US. This paper will demonstrate the effectiveness and practicality of these databases at two selected mines in Australia and the US. In order to improve the primary rib support database, this paper will also propose a new rib deformation rating based on the addition of site specific coal strength data for the Australian mines. The proposed rat- ing attempts to capture the main variables that define the behaviour of a buckling column.

DETERMINATION OF EQUILIBRIUM MOISTURE OF SOME CHINESE AND AUSTRALIAN COALS BY PULSE PROTON NMR

The varying temperature pulse proton NMR method was adopted to determine the e-quilibrium moisture content of several Chinese and Australian coals. The pulse proton NMR spec-trometry is sensible to the hydrogen at different physical state which occurs for water when temperature changes through 273 K. The equilibrium water,with some interactions to the coal surface, will not transform from one phase to another while the free water does. The measured results are reasonable comparing to the conventional gravimetric method.