Vol 13 Iss. 2

Engineer Smirnov, in the book "Sbornik Gipronemet" Nos. 1 and 2 (1932 edition), in the article "Theoretical Basis for the Calculation of Group Arrangements", presented his method of energy consumption by group consumers, which he derived based on the laws of probability theory. The incorrectness of his work consists of: 1) the fact that he starts from random conditions of the operation of mechanisms, which in reality is far from the case; 2) the fact that the laws of probability theory are not correctly applied by him.

The optical vernier is based on the principle of bringing into one plane two diametrically opposite, magnified graduations of the graduated circle. The reading accuracy of an optical vernier is twice as high compared to an ordinary vernier. The eccentricity error is automatically eliminated because diametrically opposite graduations of the graduated circle come into play in the formation of the vernier. A theodolite equipped with an optical vernier can be made in a more compact form than a conventional instrument and is much more convenient to handle, especially for surveying work underground.

Until recently, the micromanometer and Pitot tube were used only by a few, relatively few research institutes dealing with ventilation issues, but now these instruments are finding increasing application in mines and pits of the Soviet Union for solving various practical problems, such as: identifying ventilation "bottlenecks" by measuring the static pressure drop along a section of a working where a large pressure loss occurs; determining the total and static head of mine fans; determining friction coefficients or local resistances of particular mine workings of interest to the mine. The author has set himself the task, in a brief article, of providing a sufficiently detailed analysis of the operation of the micromanometer in conjunction with the Pitot tube for various cases encountered in practice. In conclusion, the consequences of measuring total vacuum instead of static vacuum when testing fans should be pointed out. When designing mine ventilation, the fan delivery and the (static) depression of the mine are determined. Then a fan type is selected based on individual fan characteristics. If the static head is measured incorrectly during fan testing, its characteristic will show an increased static head by the amount of the velocity head at the Pitot tube location, and instead of the required fan with capacity Q at static head h, we will select a fan with capacity Q at static head h – a, where a is the velocity head, which can reach 15–20 mm. Consequently, the fan we select will give a delivery at a lower depression.

Up to the present time the physical and chemical properties of cast-rock products as well as the technological process involved in their production has not been adequately discussed in literature. In this paper — „Chemically Resistant Cast-Rock Products“ — some wear-resisting features of molten rock are considered with regard to its chemical composition and mineralogical structure. As reagents the most common acids and alkali in various concentrations have been used. Some experimental data are given showing cast-rock as a material with wide industrial application, chemically resistant and as a good substitute for expensive non-ferrous metals and special corrosion-resisting alloys. Finally, a brief scheme of the technological process is supplied, where the important factors of temperature and time conditioning during a complete production circuit are determined with a view to obtaining the best results in the making of cast-rock products.

The resection (Pothenot problem) is a very common method for determining the position of a new point. The presence of a multiple resection always requires adjustment. The simplest and most illustrative method of adjustment in this case is the graphical method, in which, as is known, lines of position are used. Assuming the principles of this adjustment as known, the present article examines, without unnecessary detail, the error figure formed by the lines of position of the resection, without delving into the method of its construction; a particular case of the error figure is discussed. At the station, we measure directions to reference points and then adjust them. As is known, with such a preliminary adjustment, the error figure has a number of double and triple intersection points. The essence of graphical adjustment consists in adjusting the error figure, and this naturally explains the research that has been aimed at simplifying this process. Such research has led us to an important conclusion. Namely, it turned out that the point of application of the resultant of the double intersection points and the point of application of the resultant of the triple intersection points coincide with each other, and the sum of the weights of the triple points is in a simple ratio to the sum of the weights of the double points. Furthermore, from the Pothenot problem with four points, a transition is made to any number of given directions to points. By means of simple reasoning, the validity of our theorem is proved also for these cases.

The extraction of cassiterite from ores by flotation, despite numerous attempts, remains an unresolved problem in practice. The presented results convincingly show the following. Activation of cassiterite with hydrosulfites significantly increases the flotation activity of the mineral. High tin recovery into the concentrate is achieved at collector dosages lower than usual in flotation. The flotation rate of activated cassiterite does not differ from the flotation rate of sulfides under optimal reagent schemes. One of the tasks for subsequent research should be the selection of a collector more effective for activated cassiterite. The extraction of cassiterite from ores by flotation remains an unresolved problem in practice. Numerous proposals for the flotation of tin stone described in the literature (1936) have not found industrial application due to technological and economic difficulties. Tests of the method of preliminary activation of cassiterite proposed by Prof. K. F. Beloglazov have shown that the use of activation significantly increases the floatability of cassiterite. Flotation of the activated mineral from synthetic mixtures with quartz proceeds even at collector dosages lower than usual, with a flotation rate normal for sulfides.

As a petrologist of the geological expedition of the Central Asian Geological Administration, the author studied the Kirghiz and Talas Ala‑Tau ranges from the meridian of the village of Dmitrievskoye in the west (72°15′ east longitude from Greenwich) to the meridian of 73°45′ in the east. The region of the Kirghiz and Talas Ala‑Tau mountain ranges from the meridian 72°15′ east longitude from Greenwich in the west to the meridian 73°45′ in the east consists chiefly of various Proterozoic and Lower Paleozoic metamorphic shales, quartzites and marble limestones. Less developed are the Lower Silurian limestones and the so‑called “Toluk” tuffaceous‑limestone sequence of the Lower and partly Upper Silurian. The enumerated sequences are intensely dislocated and cut by enormous granite, diorite and other intrusions. On the above‑mentioned rocks, unconformably with them, lies the Lower Carboniferous sequence of red‑colored sandstones and conglomerates, containing in its lower part a limestone bed 70–500 m thick with abundant fauna. Above this lies the red‑colored sequence of arkose and tuffaceous sandstones and conglomerates — the so‑called “Aramin” sequence. All the above‑mentioned sequences are covered, unconformably with them, by Tertiary variegated formations.

The purpose of this work is to present a type of field universal comparator with a constant baseline. This comparator can be used by various production organizations (mine surveying services, geodetic organizations, etc.) as a simplest laboratory.

Западное Забайкалье, имея богатейшие месторождения редких металлов, ряд точек с полиметаллическими оруденениями и др., является одним из перспективных районов для развития горно-рудной промышленности. В связи с освоением этого нового горно-промышленного района разрешение вопросов водоснабжения промышленных предприятий и населенных пунктов становится в порядком дня со всей актуальностью. В настоящей статьей попытаемся дать общую характеристику условий залегания подземных вод в горных районах Западного Забайкалья на основе данных разведки и эксплуатации некоторых месторождений. В орографическом отношении Западное Забайкалье представляет среднегорную страну с довольно резко расчлененным рельефом. Водораздельные хребты, разделяющие бассейны главных рек, имеют в среднем абсолютные высоты 1800-2000 м, а относительные превышения их над уровнем речных долин находится в пределах от 600 до 800 м. Долины главных рек довольно хорошо разработаны, местами представляют обширные луга, а водораздельные хребты почти сплошь покрыты тайгой. Водораздельные хребты и речные долины имеют довольно выдержанное широтное направления. Эти основноые орогидрографические элементы в свою очередь расчленены эрозией на ряд второстепенных хребтов с крутыми склонами и плоскодонных речных долин (падей) меридиального направления. Здесь относительные превышения водораздельных гребней над речными долинами второго порядка колеблются в пределах 300-500 м.