The classification of igneous rocks approved in Petrographic code is not quite good, as well as the classification offered by the commission of the International Union of geological sciences. The rational and practically convenient classification of igneous rocks must take into account positive aspects of existing systematics. The division of igneous rocks into three classes (plutonic, volcanic and hypabissal) according to criteria stated in Petrographic code is well founded. The further division should be based on mineral contents; chemical composition should be used only if mineral contents can not be determined. Chemical composition must be recalculated to contents of normative minerals for classification purposes.
The Mineralogical Society, founded in 1817 in St. Petersburg, united lovers of nature with a variety of interests, covering in addition to mineralogy itself also geology, petrography, paleontology, volcanology, etc. Already in the first decades the members of the Mineralogical society have contributed much to the knowledge of Russian geology. Beginning from the 60s of the 19th century and up to the organization of the Geological Committee, the Mineralogical Society led the study of the geological structure of Russia in order to compile a geological map of Russia. The results of these studies and the methodology developed by the Mineralogical Society formed the basis for the subsequent activities of the Geological Committee established in 1882.
An essential aspect of the physical and chemical theory of the processes of magmatic petrogenesis is the comparison of data on the material composition of rocks - members of natural associations - and experimental data on the composition of products of evolution and crystallization of melts in model silicate systems.
The name of Academician A.N. Zavaritsky, one of the greatest scientists of our country, is associated with a significant stage in the development of Soviet petrography and geology of ore deposits.
The general principles of selecting selectively acting solvents, setting up tests and interpreting their results for the technical and economic assessment of mineral leaching processes have long been known and described in detail in many hydrometallurgy courses. With regard to the specific problems of selectivity of dissolution in phase chemical analysis, these issues are also covered quite fully ...
The dependences linking the degree of decomposition of a solid substance with the initial amount and concentration of a solvent through an equilibrium constant are described more simply if the equation of the chemical dissolution reaction, accompanied by the formation of complex or difficult-to-dissolve products, is attributed to one mole of solvent. The equilibrium constant of such a reaction ...
Studies on the kinetics of apatite dissolution in sulfuric acid have shown that the formation of films of insoluble compounds on the surface of the solid phase makes it difficult for solvent to access it and leads to a slowdown and even complete cessation of the dissolution process. In the concentration range of 16-25 n. H2SO4, the dissolution reaction slows down sharply. At concentrations above 25 n., apatite dissolves quickly. This is due to the different physical structure of the calcium sulfate film, which depends on the concentration of the solvent...
Molybdenum and tungsten can be extracted with alkylamines from acidic solutions obtained during the chemical refinement of scheelite concentrate at the Tyrnyauz Processing Plant. These solutions contain 5-8 g/l of molybdenum and tungsten. Each is present in both oxidized and reduced forms. The solution also contains significant amounts of phosphorus and silicon. Apparently, molybdenum and tungsten are found in these solutions in the form of phosphoric and silicic heteropoly acids, since these metals are excellently extracted by solutions of amines in nonpolar diluents. To determine the state of molybdenum and tungsten in these solutions, the behavior of metals during extraction by their amines from hydrochloric acid solutions in the presence of phosphorus and silicon in a wide range of hydrochloric acid concentrations was studied...
The flotation capacity of a mineral is influenced by the electrical characteristic of the boundary layer in the mineral-solution system. Therefore, it is important to correctly determine the zero charge point, which characterizes the absence of a double electric layer. It can be found by measuring the capacity of this layer ...
The Snider Nunataks are located at coordinates 107°41' E and 66°03' S on the Knox Coast in East Antarctica. They are several rocky outcrops among the mainland ice, located in an area of about 0.15 km^2. The sizes of nunataks vary from 10-15 to 120-150 m across. Nunataks are located 200-250 m from the coastal barrier of the ice sheet.
The year 1962 marked the 75th anniversary of the completion of the works of I. G. Bogusky, which laid the foundation for the study of the kinetics of solid-liquid dissolution. The question of the dissolution rate was raised by Wenzel and then by some French scientists in the middle and even at the beginning of the XIX century. However, the first systematic studies of the regularities of the dissolution process of a solid were the works of I. G. Bogusky, one of the pupils of D. I. Mendeleev. Bogusky found that the dissolution rate is proportional to the concentration of the solvent and the size of the solid surface. Subsequent work by Shpring and other researchers on a variety of objects confirmed the conclusions of I. G. Bogusky, but did not give exhaustive results that would allow to express the observed regularities in the form of mathematical formulations.
