Yoko–Dovyren Layered Massif: Composition, Mineralization, Overburden and Dump Rock Utilization

Ultramafic–mafic complexes are widely developed in the Earth’s crust. They contain deposits of various minerals. The Yoko–Dovyren intrusive in the North Baikal Region, Russia, is considered an example of an intrusive containing diverse mineralization: Ni-Cu, Platinum group elements, Cr, Zr, B, and blue diopside. During the development of the deposit, a huge amount of magnesium-containing rocks are moved to dumps and have a negative impact on the environment. To minimize this process, overburden and host rocks need to be involved in production, thereby avoiding the movement of rocks into dumps. The construction materials production is main industry using this rocks. Therefore, the purpose of these studies was to determine the quality of magnesium-containing rocks and the possibility of their use in construction. As a result of the complex works performed, it has been determined that these rocks have required physical and mechanical characteristics. Concretes in large and small aggregates from magnesium-containing rocks were obtained. It has been concluded that they are superior to concrete from granite rubble and quartz sand in terms of their strength indicators. The use of magnesium-containing rocks, without allowing them to fall into dumps, will allow us to create clean, environmentally safe mining enterprises

Nephrite of Bazhenovskoye Chrysotile–Asbestos Deposit, Middle Urals: Localization, Mineral Composition and Color

In the Bazhenovskoye chrysotile–asbestos deposit (Middle Urals), nephrite bodies of the serpentinite type were found on the contact of after gabbro rodingites and serpentinites. The color is uniform to non-uniform, green to light green, bluish green, greyish green, and whitish. Spots, streaks, lenticules of bright bluish-green or, on the contrary, light green color are sometimes noted. The nephrite is mostly comprised of tremolite. Chromite decreases the quality of the ornamental stone, but it is replaced by chrome grossular, which gives the nephrite a brighter bluish-green color locally. Crushed grains of chromite contain increased concentrations of Zn and Mn. The quality of the nephrite is decreased by serpentine and talc, as well as by fractures due to drilling and blasting works. The specific feature of the nephrite in the Bazhenovskoye deposit is the formation of nickeline, maucherite, and uvarovite. The green color is associated with Fe2+ ions. The nephrite of the Bazhenovskoye deposit meets the requirements for an ornamental stone. The origin of this nephrite includes a combination of metasomatic and metamorphic processes

Concretes Made of Magnesium–Silicate Rocks

At present, there is a shortage of high-quality feedstock to produce widely used building materials—concretes. Depletion of natural resources and growing restrictions on their extraction, in connection with environmental protection, necessitate the search for an equivalent replacement for conventional raw materials. Magnesium–silicate rocks are a waste of the mining industry. We researched the possibility of using these rocks as coarse and fine aggregates in heavy concrete production. Following the requirements of the national standards, we studied the physical and mechanical characteristics of the obtained material. It was found that the strength of concrete, made of magnesium–silicate rock coarse aggregate, at the age of 28 days of hardening is within 28 MPa, while the strength of the control sample is 27.3 MPa. Replacing quartz sand with dunite sand also leads to an increase in concrete strength (~4%). Complete replacement of aggregates facilitates an increase in strength by 15–20% than the control sample. At the same time, the density of the obtained materials becomes higher. Concretes have a dense structure that affects their quality. Concrete water absorption is within 6%. The fluxing coefficient is 0.85–0.87. The application of magnesium–silicate rocks in concrete production enables the complete replacement of conventional aggregates with mining waste without reducing the quality of the obtained materials. Furthermore, the issues of environmental protection in mineral deposit development are being addressed

Naryn-Gol Creek Sapphire Placer Deposit, Buryatia, Russia

A new gem corundum occurrence has been discovered in the Naryn-Gol Creek placer of the Dzhida volcanic field (Russia). In this placer deposit, sapphire associates with large crystals of garnet, spinel, augite, olivine, enstatite, ilmenite, Ti-magnetite, and alkali feldspar. Such a combination of minerals is typical for the placer deposits associated with alkali basalts widely distributed in Southeastern Asia and Australia. We have also found sapphire crystals in phonotephrites of the nearby Cenozoic alkali-basalt paleovolcano Barun Khobol Pravyi, and in basalt sample and trachybasalt from the valley flood basalts. The chemical composition of sapphire is generally typical for ‘basalt’ corundum: it is rich in Fe, and depleted in Ti and Cr. The δ18O SMOW values of corundum and related megacrysts range from 4.6 to 6.8 ‰, thus corresponding to the isotopic signature of igneous rocks. Etched and corroded surfaces of sapphire and other megacrysts indicate that they are in non-equilibrium with their host alkali basalts. Volatile components, CO2 in particular, played a significant role during sapphire formation as gas inclusions reveal

The Ways of Rational Nature Using Increasing on Example of North Baikal ore Region

Рассмотрены пути повышения рационального природопользования при освоении месторождений полезных ископаемых. Изучена возможность использования магнийсиликатных горных пород Йоко-Довыренского массива, находящихся среди вскрышных и отвальных пород, в производстве строительных материалов. Предлагается использовать данные породы в качестве крупного и мелкого заполнителя при производстве тяжелых бетонов. Показано, что по прочностным характеристикам эти бетоны не уступают традиционным видам на гранитном щебне. Полученные тяжелые бетоны имеют следующие физико-технические показатели: прочность при сжатии 28-32 МПа, средняя плотность 2400-2600 кг/м3, коэффициент водостойкости 0,85-0,87, морозостойкость - 50 циклов. Бетоны обладают повышенной сульфатостойкостью. Вовлечение данных пород в производство позволит решить проблемы создания экологически чистого горнодобывающего предприятия.The ways of rational nature using increasing during deposits development are considered. The possibility of Ioko-Dovyren massif overburden and spoil Mg-Si rocks in building materials production is studied. The using of these rocks as large and small filler at production of heavy concrete is offered. It is shown that such concretes do not yield to traditional type on granite rubble by durability feature. Got heavy concretes have following physics-technical factors: toughness at compression 28-32 MPA, average density 2400-2600 kg/m3, water-resistance factor 0.85-0.87, frost-resistance - 50 cycles. The concretes are characterized by increased sulphate-resistance. The involvement of this rocks in production will allow to solve the problems of the ecological clean enterprises mining creation

The Ways of Rational Nature Using Increasing on Example of North Baikal ore Region

Рассмотрены пути повышения рационального природопользования при освоении месторождений полезных ископаемых. Изучена возможность использования магнийсиликатных горных пород Йоко-Довыренского массива, находящихся среди вскрышных и отвальных пород, в производстве строительных материалов. Предлагается использовать данные породы в качестве крупного и мелкого заполнителя при производстве тяжелых бетонов. Показано, что по прочностным характеристикам эти бетоны не уступают традиционным видам на гранитном щебне. Полученные тяжелые бетоны имеют следующие физико-технические показатели: прочность при сжатии 28-32 МПа, средняя плотность 2400-2600 кг/м3, коэффициент водостойкости 0,85-0,87, морозостойкость - 50 циклов. Бетоны обладают повышенной сульфатостойкостью. Вовлечение данных пород в производство позволит решить проблемы создания экологически чистого горнодобывающего предприятия.The ways of rational nature using increasing during deposits development are considered. The possibility of Ioko-Dovyren massif overburden and spoil Mg-Si rocks in building materials production is studied. The using of these rocks as large and small filler at production of heavy concrete is offered. It is shown that such concretes do not yield to traditional type on granite rubble by durability feature. Got heavy concretes have following physics-technical factors: toughness at compression 28-32 MPA, average density 2400-2600 kg/m3, water-resistance factor 0.85-0.87, frost-resistance - 50 cycles. The concretes are characterized by increased sulphate-resistance. The involvement of this rocks in production will allow to solve the problems of the ecological clean enterprises mining creation