Some recent studies arising in the kinetic theory of chemically reactive mixtures will be revisited here, with the aim of describing some methods and tools of the kinetic theory used to model reactive mixtures and investigate some mathematical and physical problems.
Environmental issues have evolved considerably over the last two decades. The main contributing factors, to name a few, have been the changing values of modern societies, the globalization of trade and its linkage to en-vi ronment, evolution and accessibility of information/communication technologies, better educated populations, climate change, long-range transport of toxics, and the increasing influence of non-governmental organizations (NGOs) and multistakeholders. As well, environmental management of mining operations had to he realigned in order to meet these new realities and to respond to more elaborated regulations oriented towards sustainability, Environmental management systems (EMS) have been introduced not to meet the assurance of conformance to regulations but also to prevent pollution and to apply continuous improvement of mining processes. EMS models have been developed and certification to international standards (e,g. ISO 14 001) is a common practice. Globalization has imposed challenges anti additional requirements to environmental management. Developing a mine in emerging countries implies dealing with international agencies, local communities, and a variety of government infrastructures to obtain a "license to operate," This paper presents the structure of Cambior's EMS and how it was adapted and implemented in the company's operations in South America.
A series of small-scale tests was conducted to evaluate the effect of microstructure development, imposed by blasting, on the mateiial properties of the rock as well as its resistance to crushing and grinding. The uniaxial compressive strength, tensile strength, Poisson's ratio, P-wave, S-wave velocity, point load test index, crushing, and grinding work indices were evaluated for samples without any blasting load and for samples which had received a variety of blast loads ranging from 8 single impact with a low-strength detonating cord to a combination of impacts at different times and significant impacts with powder factors close to those used in practical blasts. It was shown that the rock mechanics parameters change even at low impacts, suggesting easier crushing of the rock. Damage values appear to be affected by timing as stress wave superposition affects the damage process. Fragmentation is achieved at higher impact levels while, work index modification of the fragments is also observed when high powder factors are used. suggesting improvements in grinding.
Evidence in support of an iron-gold corrosion cell during the high-temperature/high-pressure elution of loaded carbon is presented herein including, but not limited to, its discovery, mode of genesis, and confirmatory laboratory testwork. A discussion of metallurgical and economic impacts, remedial investigations, plant design considerations, and future work including mitigative possibilities is presented.
Fragmentation analysis of blast or crushed rock material is a time-consuming and costly process. During the last two decades, the mining industry has been investigating image-based analysis systems as an alternative to generate fragmentation results. Many image-based techniques and commercial products have emerged during the last few years, and the mining industry has recently begun using these tools for real-time estimation of size distributions. Some existing systems require manual, image editing to add or delete edges (or net) before executing the fragmentation analysis routine, This manual procedure may take hours of time for each image analyzed. Reliable and robust image segmentation should be able to handle a wide range of rock textures and sizes under a variety of lighting conditions. This paper describes novel software application, which has the capability to autonomously capture images and analyze them to generate the particle size distribution. The system can also process a batch of images captured during a fixed duration of time and produce the overall particle size distribution. The new method has different layers of segmentation modules, which allows the system to operate under a wide range of rock textures and lighting conditions. A new grey-level slicing technique is developed which can perform under a range of illuminating conditions. The Canny-based edge detection technique is used to segment rocks appearing in dark regions.
A brief overview of rockburst control measures is presented. The paper then elaborates on one key rockburst control measure, which is known as destress blasting. A historical background of the technique is presented in order to understand different aspects of its field application. The publication enumerates key aspects of the technique as being used in practice in South Africa and North America. The paper also presents an analysis of three case studies in order to demonstrate difficulties associated with the field application of destress blasting in hard rock mines.
