Adhesion In Rocks

The objective was to ascertain the magnitude of forces responsible for coherency of rock by quantifying the strength of the attractive forces operating between minerals in rock. These forces oppose stresses set up in various rock gragmentation processes, hence strength measurements of these forces might prove useful in designing more efficient rock fragmentation methods. Methods were developed for estimating strength of intergranular adhesion in rock. Examination of bicrystals broken at the crystalline interfaces reveals that bonds responsible for this adhesion operate only over a portion of the interfacial area. This work demonstrated that strength tests can be conducted on small selected areas, i.e., grain boundaries in rock. This permits a determination of small scale zones of strength or weakness which may be related to the overall strength of the rock.

This book focuses on the mineral deposits from the mining complex of Kazakhstan, including copper ores from the Nikolayevsky and Shemonaikhinsky open-pit quarries, and from the Kazchrome and Konyrat mines in Balkhash. This study assesses the geomechanical conditions of the rock massive, as well as strengthening and reinforcing processes. It develops methods for their assessment and provides detailed instructions on applying the methods. The book also summarizes the latest research and developments in formulating cement solutions to reinforce slopes and suppress dust on the roads of the quarry. The book’s overarching goal is to promote geological and mining engineering conditions that ensure the ecologically safe development of the mineral resource fields. Given its scope, the book will be of interest to mining engineers, researchers, and students in a broad range of geomechanical, geodesic, mining and environmental fields.

A direct method has been developed for estimating the strength of intergranular adhesion in rock. It involves the separation of a bicrystal from the rock and a determination of the tensile strength at the solid-solid interface. This technique has been successfully applied to the study of quartz-feldspar interfaces separated from pegmatites, graphic granite, and the Rockville granite yielding average tensile strengths of 5.86, 8.62, and 10.65 MN/msq (850, 1,250, and 1,524 psi) respectively. The data generated by this technique indicate that the members of these bicrystals are strongly adhernet. Examination of bicrystals broken at the crystalline interfaces indicates that the bonds responsible for this adhesion operate only over a protion of the interfacial area. The significance of this work is that it demonstrates that tensile strength tests can be conducted on small selected areas, e.g. grain boundaries in rock. This permits a determination of small scale zones of strength or weakness which may be related to the overall strength of the rock. Selected area microindentation hardness testing has also been performed to probe hardness variations near phase boundaries.

At the beginning of the twentieth century, engineers and technologists would have recognized the importance of adhesion in two main aspects: First, in the display of friction between surfaces — at the time a topic of growing importance to engineers; the second in crafts requiring the joining of materials — principally wood—to form engineering structures. While physical scientists would have admitted the adhesive properties of glues, gels, and certain pastes, they regarded them as materials of uncertain formulation, too impure to be amenable to precise experiment. Biological scientists were aware also of adhesive phenomena, but the science was supported by documentation rather than understanding. By the end of the century, adhesion and adhesives were playing a crucial and deliberate role in the formulation of materials, in the design and manufacture of engineering structures without weakening rivets or pins, and in the use of thin sections and intricate shapes. Miniaturization down to the micro- and now to the nano-level of mechanical, electrical, electronic, and optical devices relied heavily on the understanding and the technology of adhesion. For most of the century, physical scientists were aware that the states of matter, whether gas, liquid, or solid, were determined by the competition between thermal energy and int- molecular binding forces. Then the solid state had to be differentiated into crystals, amorphous glasses, metals, etc. , so the importance of the molecular attractions in determining stiffness and strength became clearer.