Jian Zhang

University of Wollongong | UOW · School of Civil Mining and Environmental Engineering

The pressure drop characteristics of negative pressure sampling drill pipe were studied experimentally in this work. The pressure drop was measured by a customized designed negative pressure sampling test system. The effects of the inner diameter of the drill pipe, the solid-gas rate and the inlet air velocity on the internal pressure drop of the d...

Spontaneous combustion of coal has long been a thermal dynamic hazard during coal mining, storage, and transport, posing a great threat to coal mine safety. Especially coal spontaneous combustion in longwall goaf poses a great threat to underground working crew. To investigate such a mine safety issue with more insights and “what if” scenarios, thi...

Coal mine dust continues to be a health and safety issue in underground coal mines. Coal seam water infusion was developed and widely applied in European coal mines for dust control, and was also a common practice in most Chinese coal mines. This method typically involves the infusion of water into the coal seam to increase its moisture content, an...

Spontaneous combustion of coal in underground coal mine is a long-standing thermal dynamic hazard. The hazard is harmful in diverse aspects: causing loss of coal resource, raising safety concerns, and giving off noxious/greenhouse effect gases. Detection and trending analysis of a few particular gaseous products liberated during coal oxidation is t...

Mine ventilation has always been critical for underground mining operations to ensure operational efficiency and compliance with safety and health statutory requirements. To obtain a thorough understanding of the ventilation flow characteristics on a longwall face, innovative three dimensional (3D) models, incorporating key features of the longwall...

Dust management at longwall faces has always been a concern for mine operators. Recent respirable dust monitoring at a longwall top coal caving (LTCC) face indicated that extremely high dust exposure levels have been experienced at the face. Dust contamination from intake ventilation and the incorrect use of ventilation arrangements (i.e. curtains)...

In the theory of spontaneous combustion, identifying the critical value of the Frank-Kamenetskii parameter corresponds to solving a bifurcation point problem. There are two different numerical methods used to solve this problem—the direct and indirect numerical methods. The latter finds the bifurcation point by solving a partial differential equati...

Nitrocellulose was an extremely dangerous explosive substance which would decompose at relatively low temperature. This paper studied the thermal properties transformed from thermal decomposition to thermal explosion for a less violent nitrocellulose sample (nitrogen content: 10.92%). Four experiments were implemented: XPS analysis and SEM analysis...

Spontaneous combustion of residual coal in longwall goaf is a long standing hazard. Airflow leakage into goaf is a major driver to the hazard and this issue deteriorates where longwalls are operating in multiple seams and shallow covers because mining-induced cracks are very likely to draw fresh airflow into goaf due to presence of pressure differe...

Gas management at longwall faces has always been a challenging issue to mine operators. Along a longwall face of an Australian colliery where CO2 is the dominant coal seam gas, frequent power trip off occurred due to the high goaf gas (CO2) emission, which significantly affected the normal longwall production and brought about safety threats to the...

Abstract Sodium dithionite and thiourea dioxide are two typical reducing agents commonly used in industry. This paper compared the thermal hazards of sodium dithionite and thiourea dioxide based on DSC-TG (Differential Scanning Calorimetry and Thermogravimetry) thermal analysis, small-scale self-heating experiments and FTIR smoke gas analysis. From...

Determining gas diffusion coefficient from experimental data is a key step of reproducing and predicting the diffusion process in coal. Previously analytical solution, including the unipore diffusion model and the bidisperse diffusion model, has been used extensively to estimate the gas diffusion coefficient(s) in coal. The utilization of analytica...

Cotton is a flammable material and some cottons would decompose or even self-ignite at bad storage and transport conditions. This paper studied the spontaneous combustion of cotton from the aspect of thermal decomposition temperature (TDT) and critical ambient temperature (CAT). From Fourier transform infrared spectroscopy analysis and chromatograp...

Self-heating or even spontaneous combustion of stockpiled coal, which is likely to outbreak under favourable circumstances during its transport, process, and storage, is a long-standing thermal dynamic hazard. This hazard is harmful in diverse aspects: causing loss of coal resource and caking property, raising safety concerns upon occurrence of ope...

Self-heating or even spontaneous combustion of stockpiled coal, which is likely to outbreak under favourable circumstances during its transport, process, and storage, is a long-standing thermal dynamic hazard. This hazard is harmful in diverse aspects: causing loss of coal resource and caking property, raising safety concerns upon occurrence of ope...

Spontaneous heating of coal stockpile has long been a thermal dynamic hazard during coal storage, processing, and transport. A transient non-equilibrium thermal CFD model has been developed to study the low-temperature self-heating behaviour of coal in multiple stockpiles under different prevailing wind conditions. Modelling results from the initia...