The initial raw material for the production of crushed rock is blasted rock, which is subject to processing at crushing and screening plants. The granulometric composition of the rock mass depends on a number of factors, in particular: the method of drilling and blasting, physical and mechanical properties of minerals, etc.
Solid minerals are extracted by three methods: underground, surface (open pit) and underwater. The first two methods are widely developed, the third is beginning to develop.When designing and planning the development of a deposit, it is necessary to take into account the main features of mining methods. All factors affecting the efficiency of work are useful to categorize into two parts: objective and subjective. ...
In the second half of the 18th century, the rapid development of iron and copper works, as well as gold and salt mining in Russia, created the necessary prerequisites for the organization of a domestic school to train mining and technical personnel, which was urgently needed by industry. The Mining Cadet Corps, now the Leningrad Mining Institute, established in St. Petersburg in 1773, became such a school - the oldest technical educational institution of our country. Over its 200-year history, the Mining Institute has educated a large army of talented scientists, production organizers, engineers, whose work contributed to progress in various branches of science and technology. A significant contribution was made by the Institute's students to the development and improvement of the open-pit mining method - a method that has always been of great importance, and in our time has become the most widespread in the mining industry of the country.
One of the most important decisions in the design of open pits is the choice of direction and intensity of movement of mining operations in the horizontal direction and in depth. These issues are usually solved when establishing the method of opening the open pit field and the calendar plan of mining operations. Implemented in the field opening for a long time, and sometimes forever, predetermines the order and efficiency of the open pit.
Two methods of development of mineral deposits - underground and open (surface) - are constantly improving and competing with each other. Recently, there is a tendency to isolate the third method of development - underwater. Since the beginning of the XX century, the most developed is the open pit method of development, and in the following decades, the area of its application will continuously expand. In this connection both theory and practice of open pit operations have been improved and the most complete and accurate classifications of those methods, which are created for surface development of deposits, are more and more urgently required. This article attempts to improve the classifications of stripping methods and development systems by utilizing all, in our opinion, the most valuable information given by other researchers, and some of the author's suggestions.