Yu Minggao

The Effect of Sample Size on Smoldering and the Transition to Flaming Combustion

Smoldering experiments and thermal analysis experiment were conducted to investigate the characteristics of smoldering maintenance and heat release. Polyurethane foam samples with different width were used in experiments and temperature histories were recorded. Smoldering just self-sustained and typically propagated to the end in natural convection as the sample width was 10cm. When sample width was less than 10cm, smoldering gradually quenched after ignited by cigarette. When sample width was larger than 10cm, smoldering propagated forwards with peak temperature gradually promoting to higher value, even transition from smoldering to flaming. TG and DSC analysis showed that heat released by solid reaction reached its high value at temperature scope of 400 - 500¿, rapidly decreased as temperature less than 400¿, and turned to be zero as temperature higher than 620¿. The analysis and result could well explain the phenomena in smoldering propagation, extinguishment, and transition to flaming combustion.

Research on the Harmful of Coal Solid Waste and Its Recycling Technology

Coal gangue is solid waste, which is all kinds of rocks and residual abandoned coal produced in the process of mining and washing in machining, its composition is very complicated. The paper is based on the data collection and field investigation, and discusses the harm of coal solid waste from different angles, especially the harm of spontaneous combustion gangue, it can make the air pollution of the environment, water quality and soil damage, the collapse, and take up valuable land resources and other hazards. Based on the collection of coal solid waste samples from different parts, we analyze the samples of material composition in detail by experimental methods, and point out the importance of the technology for coal solid waste recycling, it has strategic significance for making circular economy, reducing resource depletion, and realizing the coordinated development of the economy and the environment. At the same time, through research, we can enable the companies to realize the dangers of coal solid waste, and its available ingredients, so as to speedup the solid waste recycling quick, healthy and efficient development.