Search

A great share of workers employed at polymetallic ores mining have to face harmful working conditions at their workplaces. To provide safe working conditions for them and to preserve their health is a vital task occupational medicine has to tackle. Polymetallic ore mining enterprises employ certain common technological processes; nevertheless, there are specific features depending on ore mining techniques and the mineralogical composition of different ores. These features determine differences both in working conditions and in occupational risks of developing occupational morbidity (OM) and work-related morbidity (WRM). By now, there have been enough studies on peculiarities of occupational health risks for workers employed at sulfide ore mines, copper-nickel ore mines and ferruginous quartzite mines. Considerably less attention has been given to assessing occupational risks for workers dealing with mining and processing copper-zinc ores. We performed complex clinical and hygienic examinations at a major copper-zinc ore mining enterprise located in the Southern Urals. The research results gave grounds for determining a category of working conditions, establishing formation peculiarities and the structure of occupational and work-related diseases among workers from various occupational groups. Occupational risks were assessed considering hygienic and medical-biological indicators. We established the highest occupational health risks for shaft sinkers, followed by drilling unit operators, timberers, excavator drivers, load haul dumper (LHD) operators and underground self-propelled machine (USPM) operators. The research results gave grounds for developing a conceptual model of assessing and managing occupational risks in the branch. The urgency of developing and implementing activities aimed at risk mitigation should be determined depending on how validated a risk is and on its rates established for specific occupational groups.

Novel rapid determination of copper-zinc ore elemental composition by total reflection X-ray fluorescence (TXRF) is proposed. Approaches for solid state sample analysis by TXRF are provided. The sample preparation is chosen to obtain the suspensions in ethylene glycol. The optimum suspension preparation conditions (sample mass, volume of dispersion medium) and the measurement conditions (internal standard element, spectra acquisition time) were determined. The sedimentation stability of suspensions was studied. It was found that the suspensions remain stable for approximately 2 min, which is sufficiently long for the sampling the suspension. The proposed technique allows determining the elemental composition of solid ore samples without sample digestion. The sample preparation time takes approximately 20 min. The relative standard deviation of the analytical results did not exceed 10%. [ABSTRACT FROM AUTHOR]

• The pyrite, Cu-Zn, and polymetallic ores are hydrothermal, associated with metasomatic alteration. • The ore mineral compositions, variety of Ag and Au minerals of ores correspond to the Kuroko type deposits. • The pyrite ores were formed due to Na-Mg chloride fluid with a salinity of 7.8–11.3 wt% NaCl eq. at not less than 260–300 °C. The Cu-Zn and Cu ores on the orebody flanks were formed at lower temperatures (180–140 °C). • The polymetallic ores were formed due to Na and K chloride fluid with a salinity of 4–8.8 wt% NaCl eq. at 220–150 °C. The paper is devoted to the mineralogical and geochemical peculiarities and ore-forming conditions of the formation of the Kyzyl-Tashtyg pyrite-polymetallic deposit in Eastern Tuva. The ore mineral assemblages of the deposit were formed due to aqueous fluids containing Na, Mg, and K chlorides at the pressure of 900 bar and the variations of f O 2 , f S 2 , f Se 2, and f Te 2. The earliest pyrite ores in the central parts of the ore bodies were formed at relatively high temperatures of 400–260 °C due to a fluid of the composition NaCl-H 2 O and MgCl 2 -NaCl-H 2 O with the salinity of 4–11.3 wt% NaCl eq. The copper-zinc ores were deposited at 377–145 °C from the NaCl-H 2 O fluid with the salinity of 2.6–10 NaCl eq. and the copper ores – at 200–165 °C from the NaCl-KCl-H 2 O fluid with the salinity of 3.5–6.5 NaCl eq. The latest polymetallic and barite-polymetallic ores were formed at 330–130 and 270–140 °C, from the NaCl-KCl-H 2 O ± MgCl 2 -H 2 O fluid with the salinity of 3.5–8.8 and 2–8.5 wt% NaCl eq., respectively. The calculated δ34S H2S values of the fluid range from + 0.2 to + 6.6 ‰, which indicates the participation of sulfur of magmatic origin and borrowed from the host rocks. The δ34O isotopic composition of the fluid suggests that the fluid of magmatic genesis (+8.7... + 7.1 ‰) participated in the early stages of ore mineralization, and at the final stages, it was mixed with meteoric waters (-4.0...-0.7 ‰). The temperature decrease of mineral formation and fluid salinity from early to latest stages confirms the participation of heated meteoric waters. The results of the study of the geological structure, mineral assemblages, fluid inclusions, and stable isotope ratios provided to conclude that the formation of the Kyzyl-Tashtyg deposit was initiated by hydrothermal-magmatic activity, associated with the introduction of subvolcanic bodies of rhyolite and rhyolite-dacite and involvement of fluids separated during crystallization of felsic magma, as well as heated meteoric waters enriched with oxygen, which contributed to the growth of fO 2 and variations fS 2 , fSe 2 , fTe 2 and determined the diversity of mineral types of ores. [ABSTRACT FROM AUTHOR]