Volkov P. S. – The Ural State Mining University, Ekaterinburg, the Russian Federation. Е-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Random distribution of precious metals in the bulk of the reduced sample under its preparation for the analysis leads to
some divergence in the results of parallel analyses. The addition of the operation of concentration into the sample
preparation scheme, separate analysis of concentrate and tailings, and the calculation of the mass fraction of precious
metals with balance equation gives satisfactory convergence under the parallel analysis of samples containing precious
metals. To check the given fact the calculation of theoretical error of reduction has been fulfilled, the experiment over
the reduction of a sample of artificial mixture of quartz with sample weight getting has been fulfilled, mass fraction of lead
in sample weight has been determined. Lead panning and heavy fraction weighting are used as the method of analysis.
The acquired data make it possible to speak about convergence of theoretically calculated and experimentally obtained
relative error of reduction. As the result of artificial mixture concentration at self-cleaning centrifugal separator under low
intensity of gravitation field, the mass fraction in the concentrate and the tailings of the separator has been determined.
It has been determined that the use of model material under the estimation of the sample reduction error makes it possible
to acquire the result close to the theoretically determined one. The introduction of the operation of concentration into the
scheme of sample preparation leads to the decrease of the sample preparation relative error, which indicates high
efficiency of concentration during sample preparation.
Key words: sample preparation; reduction error; precious metals; heavy minerals; artificial mixture; centrifugal separator.
REFERENCES
1. Lokonov M. F., Petrova M. I., Reingardt E. P. [The methods of preparation for samples analysis of ore containing
intermetallic compounds of platinum metals]. Obogashchenie rud – Mineral Processing, 1984, no. 1, pp. 44–47.
(In Russ.)
2. Litvintsev V. S., Ponomarchuk G. P., Iatlukova N. G., Banshchikova T. S., Shokina L. N. [Some regularities in the
distribution of gold in silt-clay fractions of natural and technogenic formations]. Problemy osvoeniia georesursov
rossiiskogo Dal'nego Vostoka i stran ATR: mater. III Mezhdunar. nauch. konf. [Proc. 3rd Int. Sci. Conf. “The problems
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3. Hoffman E. L., Clark J. R., Yeager J. R. Gold analysis – fire assaying and alternative methods. Exploration and
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94 «Известия вузов. Горный журнал», № 5, 2017 ISSN 0536-1028
4. Petrov S. V., Bederova L. L., Borozdin A. P. [Regarding the methods of reliable determination of precious metals
content in the samples with large winning of virgin metals]. Obogashchenie rud – Mineral Processing, 2015, no. 4,
pp. 30–33. (In Russ.)
5. Kozin V. Z. Oprobovanie mineral'nogo syr'ia: nauch. monografiia [Scientific monograph “Mineral raw material
sampling”]. Ekaterinburg, UrSMU Publ., 2011. 316 p.
6. Morozov Iu. P., Falei E. A., Khamidulin I. Kh. [Development and testing of turbulization centrifugal separators].
Gornyi zhurnal – Mining Journal, 2015, no. 5, pp. 58–62. (In Russ.)
7. Falei E. A. [Optimization of laboratory turbulization centrifugal separator operation]. Nauchnye osnovy i praktika
pererabotki rud i tekhnogennogo syr'ia: mater. XIX Mezhdunar. nauch.-tekhn. konf. [Proc. 19th Int. Sci. and Pract. Conf.
“Scientific fundamentals and practice of ore and technogenic raw material processing”]. Ekaterinburg, Fort Dialog-Iset'
Publ., 2014, pp. 210–214. (In Russ.)

Kozin V. Z., Komlev A. S., Vodovozov K. A. – The Ural State Mining University, Ekaterinburg, the Russian Federation.
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Indices of technological balance are calculated by the results of sampling. Sampling is carried out with errors; it conditions
on balance indices errors. It has been shown that products separation contrast ratios in technological operations also
ISSN 0536-1028 «Известия вузов. Горный журнал», № 5, 2017 79
influence the output, extraction, and component mass calculating errors. Under low contrast ratio the calculation of
technological balance is carried out with raw errors, it leads to uncertain estimates of the situation at the factories. Real
separation contrast ratios at the copper-zinc factory are introduced. For the majority of operations separation contrast
ratios are within the limits of 1.1–2.0 but for the whole factory in general the contrast ratios for copper are equal to 7.0 and
7.4, for zinc – 16.0 and 5.4. The diagrams of determination of calculation errors depending on the contrast ratios are
introduced. Under the contrast ratios lower that 2 dependences rise sharply, it requires improving the quality of sampling
of input products in separate operations and factories as a whole.

Key words: technological balance indices; sampling errors; separation contrast ratios.

REFERENCES
1. Otrozhdennova L. A., Akkerman Iu. E., Kuchaev V. A., Aksenova G. Ia., Zavarina R. I. [The development of
the technology of copper-sulphide ore concentration at “Nurkazgan” deposit]. Obogashchenie rud – Mineral Processing,
2012, no. 6, pp. 18–22. (In Russ.)
2. Tsypin E. F. [Estimation of technological efficiency of concentration technology processes]. Izvestiya vysshikh
uchebnykh zavedenii. Gornyi zhurnal – News of the Higher Institutions. Mining Journal, 2001, no. 4–5, pp. 16–21.
(In Russ.)
3. Pelevin A. E. [Stage separation of iron concentrate]. Obogashchenie rud – Mineral Processing, 2007, no. 3,
pp. 10–15. (In Russ.)
4. Masalovich N. S., Ostroumov G. V., Ivanova I. D. [Confidence estimation of technological tests]. Razvedka i okhrana
nedr – Prospect and Protection of Mineral Resources, 1978, no. 8, pp. 34–38. (In Russ.)
5. Kozin V. Z. Kontrol' tekhnologicheskikh protsessov obogashcheniia [Control over the technological processes of
concentration]. Ekaterinburg, UrSMU Publ., 2010. 302 p.
6. Kozin V. Z., Komlev A. S. [Experimental determination of random sampling errors at concentrating mills].
Obogashchenie rud – Mineral Processing, 2017, no. 2, pp. 44–48. (In Russ.)
7. Kozin V. Z., Komlev A. S. [The influence of sample weight mass and the conditions of its selection on the error of the
sample analysis result]. Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal – News of the Higher Institutions.
Mining Journal, 2016, no. 5, pp. 76–83. (In Russ.)

Rakhmeev R. N., Voiloshnikov G. I., Fedorov Iu. O., Chikin A. Iu. – IRGIREDMET JSC, Irkutsk, the Russian
Federation. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
88 «Известия вузов. Горный журнал», № 5, 2017 ISSN 0536-1028
The article describes the results of the laboratory experiments for X-ray radiometrical method of separation of the –6+3 mm
size diamond-bearing gravity concentrate at the X-ray fluorescence separator with gas detector. In the result of the
laboratory experiments over the formed collection of diamond crystals and main associated minerals and rocks their
substantial difference within analytical areas of calcium, iron, and zircon has been revealed – chemical elements not
presented in diamond crystals and widely presented in other grains. At that, the scattered X-radiation level of diamonds
is significantly higher than the level of associated minerals and rocks. The specified differences are correct for all diamond
crystals regardless of their X-ray fluorescence capacity, and are used as a main indicator of separation. The said
experiments showed demonstratively that the proposed separation method and the identified separation indicator provide
recovery of all diamonds, including rejected in tailings of X-ray fluorescence separators, with high efficiency and selectivity.
Key words: diamond; upgrading; recovery; X-ray fluorescence separator; secondary X-ray spectrum; scattered radiation;
characteristic radiation; fluorescence.
REFERENCES
1. Separators manufactured by RRE “Bourevestnik”. Available at: www.bourevestnik.ru/products/separatory.html
(Access date March 31st, 2017). (In Russ.)
2. Makalin I. A. [Study of X-ray luminescent properties of minerals of “Arkhangelsk” tube]. Izvestiya vysshikh uchebnykh
zavedenii. Gornyi zhurnal – News of the Higher Institutions. Mining Journal, 2012, no. 7, pp. 80–84. (In Russ.)
3. Mironov V. P. [Raman scattering in diamonds from the concentrates and tailings of combined concentration scheme].
Materialy IV kongressa obogatitelei stran SNG, Moskva, 19.03–21.03.2003. [Proc. of the 4th CIS Сongress of mineral
processing engineers. Moscow, March 19th–21st, 2003]. Moscow, 2003, pp. 67–69.
4. Dementiev V. E., Fedorov Iu. O., Kononko R. V., Rakhmeev R. N. Sposob rentgenoradiometricheskoi separatsii
almazosoderzhashchikh materialov [The method of X-ray radiometrical separation of diamond-bearing materials].
Patent RF, no. 2551486.
5. Tsypin E. F. Informatsionnye metody obogashcheniia poleznykh iskopaemykh: ucheb. posobie [School book
“Information methods of minerals concentration”]. Ekaterinburg, UrSMU Publ., 2015. 206 p.
6. Mokrousov V. A., Lileev V. A. Radiometricheskoe obogashchenie neradioaktivnykh rud [Radiometrical concentration
of nonradioactive ore]. Moscow, Nedra Publ., 1979. 192 p.
7. Shemiakin V. S., Fedorov Iu. O., Fedorov M. Iu., and others. Osnovy rentgenoradiometricheskogo obogashcheniia
poleznykh iskopaemykh: nauch. monografiia [Scientific monograph “The fundamentals of X-ray radiometrical mineral
concentration”]. Ekaterinburg, Fort Dialog-Iset' Publ., 2015. 250 p.
8. Rakhmeev R. N., Chikin A. Iu., Fedorov Iu. O. [The use of X-ray radiometrical concentration to upgrade diamondbearing products]. Gornyi informatsionno-analiticheskii biulleten’ (nauchno-tekhnicheskii zhurnal) – Mining
Informational and Analytical Bulletin (scientific and technical journal), 2015, no. 19, pp. 37–42. (In Russ.)

Medvedeva M. L. – Expert center LLC, Ekaterinburg, the Russian Federation. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Kuz'min S. V., Kuz'min I. S., Shmanev V. D. – Research and Production Enterprise “Rutas” LLC, Ekaterinburg,
the Russian Federation. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
ISSN 0536-1028 «Известия вузов. Горный журнал», № 5, 2017 73
At the present stage of mining enterprises power supply development, the main reasons for emergency shutdowns are
connected with the emergence of single-phase ground faults (SPGF). SPGF occurs 3.88 times more often than the short
circuits (SC). In the article the causes of SPGF and SC in the networks of 6–10 kV of the mining enterprises are analyzed.
To the main reasons for emergence of SPGF and SC refer: the switching overstrain (SO), overstrain in SPGF mode, and
natural aging of isolation. It has been shown that from 2005 to 2015 switching overstrains transformed from minor factors
into the main reasons for SPGF and SC. It is connected with the growth of a share of vacuum switches in the total of the
switches used at mining enterprises and low efficiency of nonlinear surge arresters by means of which SO is limited.
The share of vacuum switches at mining enterprises changes from 57% to 67% from the total quantity of switches
depending on the type of the mining enterprise. Wide use of vacuum switches has led to the growth of SPGF and SC 1.9
and 1.8 times respectively. The article indicates the need of effective restriction of SO, whereas in order to reduce the
number of group shutdowns it is necessary to limit overstrain effectively in SPGF mode. Besides it has been indicated
that the natural aging of isolation connected with technology and climatic factors influences SPGF in the networks
of 6–10 kV in pits and coal mines.
Key words: single-phase ground faults; short circuits; switching overstrain; natural aging of isolation; overstrains of arc
single-phase ground faults.
REFERENCES
1. Kuz'min S. V., Zykov I. S., Mainagashev R. A., Iashchuk K. P. [The analysis of breakdown rate in the power supply
of 6–10 kV at the mining enterprises of Siberia]. Gornoe oborudovanie i elektromekhanika – Mining Equipment and
Electromechanics, 2009, no. 3, pp. 23–25. (In Russ.)
2. Kuz'min S. V., Gavrilova E. V., Baryshnikov D. V. [The influence of the process of arc suppression in high-voltage
switches on the value of switching overstrains in the networks of 6–10 kV of the mining enterprises]. Gornoe
oborudovanie i elektromekhanika – Mining Equipment and Electromechanics, 2009, no. 2, pp. 41–44. (In Russ.)
3. Serov V. I., Shchutskii V. I., Iakudaev B. M. Metody i sredstva bor'by s zamykaniiami na zemliu v vysokovol'tnykh
sistemakh gornykh predpriiatii [Methods and means of protection from ground faults in high-voltage networks of the
mining enterprises]. Moscow, Nauka Publ., 1985. 136 p.
4. Diagterev I. L., Kadomskaia K. P., Kopylov R. V. [The modes of neutral grounding and protection from overstrains
of electric networks with rotating electrical machines]. Ogranichenie perenapriazhenii v rezhime zazemleniia neitrali
seti 6–35 kV. Tr. III Vseros. nauch.-tekhn. konf. Pod. red. K. P. Kadomskoi i dr. [proc. 3rd All-Russ. Sci. and Pract. Conf.
"Overshoot suppression in mode of neutral grounding of the network 6–35 kV". Edited by K. P. Kadomskaia, and
others]. Novosibirsk, 2004. 200 p.