Hygienic assessment of personnel working conditions in underground uranium mining

The aim of the study is to assess the main radiation-hazardous factors that determine the effective dose of personnel during underground uranium mining at the Priargunsky Industrial Mining and Chemical Association, and to summarize the data of the radiation control of the enterprise for 2016-2020. The main factors that create personnel dose loads are: the volume activity of short-lived daughter products of radon decay in the air, the dose rate of external gamma radiation, and the volume activity of long-lived alpha-emitting radionuclides of the uranium-radium series in industrial dust. Information on the structure and values of individual effective doses of workers is presented. Recommendations for improving the radiation monitoring system are given.

Tobacco Industry Agglomeration and Industrial Pollution Emission: Nonlinear Test Based on Panel Data

In the past 40 years, the agglomeration of tobacco industry plays a vital role in economic growth in China. Meanwhile, the rapid economic development has paid serious environmental and energy costs.Based on the panel data of 31 provinces in China from 2005 to 2015, this paper uses the differential GMM method to empirically test the relationship between the agglomeration of tobacco industry and industrial pollution emissions. The study found that the spatial agglomeration of the tobacco industry has a significant negative impact on industrial wastewater, sulfur dioxide and industrial dust emissions. Capital labor, enterprise scale, and pollution control investmentall have a significant impact on pollution emissions.Therefore, the increase in the agglomeration of China’s tobacco industry is conducive to reducing industrial pollution emissions.

Recovery of Copper(II) and Silver(I) from Nitrate Leaching Solution of Industrial Dust via Solvent Extraction with LIX63

A nitrate leachate containing Cu(II), Ag(I), Ni(II), Mg(II), and Al(III) was obtained during the leaching of industrial dust, which arises during the pyrometallurgy of spent camera modules. To separate and recover Cu(II) and Ag(I) from the leaching solution, solvent extraction experiments using 5,8-diethyl-7-hydroxydodecan-6-oxime (LIX63) were conducted. LIX63 was found to selectively extract Cu(II) and Ag(I) over other metal ions (Ni(II), Mg(II), and Al(III)) at low nitric acid concentrations. The extraction efficiency of Cu(II) was more affected than that of Ag(I) by the acidity of the feed solution and the LIX63 concentration in the organic phase. Cu(II) and Ag(I) were simultaneously extracted using 2 mol/L LIX63. Cu(II) was separated from the loaded LIX63 via stripping with 4 mol/L HNO3, whereas Ag(I) was recovered via stripping with 0.1 mol/L thiourea after the removal of Cu(II). McCabe–Thiele diagrams for the extraction and stripping of Cu(II) and Ag(I) were constructed. The complete extraction of Cu(II) and Ag(I) was confirmed via counter-current extraction. Moreover, stripping simulation tests confirmed that higher than 99.99% of Cu(II) and 99.2% of Ag(I) were stripped. The purities of Cu(II) and Ag(I) in the recovered solution were 95.2% and 99.993%, respectively. A process flow chart for the recovery of Cu(II) and Ag(I) from the nitrate leachate of the target industrial dust was also provided.

CFD and Laboratory Studies of Dust Cleaning Efficacy of an Efficient Four Stage Non-Clogging Impingement Filter for Flooded-Bed Dust Scrubbers

Fibrous-type filters are used to capture dust particles in mining and other occupations where personnel are exposed for prolonged periods. Dust cleansing systems including flooded-bed dust scrubbers use these mesh-type multi-layered filters. These filters trap dust particles efficiently on their surface and inside their mesh. However, their continued operation leads to dust build-up and subsequent clogging. This results in increased resistance of the filter and lowered airflow rate through the scrubber. This could potentially enhance the exposure of the miners. A non-clogging self-cleaning impingement screen type dust filter was designed by the authors for use in mining and industrial dust cleansing applications. The filter guides dirt-laden air through rapidly turning paths which forces it to shed heavier particles. The particles impact one of the impermeable solid metallic filter surfaces and are removed from the airstream. A full cone water spray installed upstream prevents any surface build-up of dust. This paper summaries the computer models generated to show the filter operations and laboratory experiments including optical particle counting to establish the cleaning efficiency.

Ecological Forecasting of Industrial Dust Emissions: Problems and Solutions

The results of the study of the levels of atmospheric air pollution by solid particles with different approaches to the accounting of dust and the analysis of the sufficiency and validity of permissible emission standards are presented. On the example of an operating enterprise, taking into account the current inventory, a comparative analysis of the levels of exposure to solid chemicals and the sum of all dusts (TSP) was performed. It is established that the dust factor at the total emission, forms the values of the maximum concentrations 2 times more than the individual chemical components. The presented results confirm the need to review the existing approaches to the regulation of emissions of solid components, including the inclusion in the system of the assessment of the sufficiency of emissions by the criterion of the total impact of dust in general. A correctly estimated level of total dust exposure will allow to exclude an unacceptable level of exposure to solid industrial emissions at the initial stage of the formation of project and environmental documentation (NDV projects).

Managing the Dust Degree –Related Risks in Valea Jiului Collieries: A Synthesis

The paper aims to make a synthesis regarding the risks associated with the presence of industrial dust in the underground atmosphere of the coal mines. Thus, in the first part of it are presented relevant aspects regarding the health risk associated with the exposure to silica dust, as well as the flammability and explosiveness of the coal dust, in correlation with the mechanism of the explosion. The second part is dedicated to identifying and substantiating measures to combat the explosiveness of coal dust. In presenting the mentioned measures, the emphasis is placed on highlighting the scope and the specific advantages and disadvantages of each measure, with particular emphasis on the possibilities offered by the use of less employed techniques in mining operations in the Jiu Valley, such as it is, for example, the treatment of mining works with hygroscopic substances. The purpose of the authors is to offer the experts in the field of management of occupational safety and health in the mining industry an overview, in conjunction with specific information elements that facilitate the decision-making processes regarding the minimization of the hazards associated with the degree of coal dustiness in the Jiu Valley collieries.

Simultaneous Determination and Preliminary Source Estimation of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Road Dust from Northern Vietnam

Concentrations of seven indicator polychlorinated biphenyls (Ʃ7PCBs) and eight predominant polybrominated diphenyl ethers (Ʃ8PBDEs) were examined in outdoor dust samples collected from some representative areas in northern Vietnam, including a core urban area of Hanoi City, an industrial park in Thai Nguyen Province, and a rural area in Bac Giang Province. Levels (median and range) of Ʃ7PCBs and Ʃ8PBDEs in our dust samples were 2.8 (0.028–22) and 11 (0.55–52) ng/g, respectively. Concentrations of PCBs and PBDEs in the urban and industrial dust samples were significantly higher than those measured in the rural ones, suggesting the role of urbanization-industrialization processes on the emission of these pollutants. PCBs exhibited specific profiles in the industrial dusts with significant proportions of low-chlorinated congeners such as CB-28 and CB-52, while the remaining samples were more contaminated by heavier compounds such as CB-118, CB-138, and CB-153. For PBDEs, BDE-209 was the most predominant congener in all the samples. Emission souces of PCBs and PBDEs in our dust samples were estimated to be household, traffic, and industrial activities. Human exposure to PCBs and PBDEs in outdoor dusts was estimated, implying relatively low health risk.

Ways to Improve the Operational Safety of Gas Adsorption Dehydration Unit

The problem of technological installations operational safety in the gas processing industry, which is currently subject to high requirements, is studied in the article. This is due to the circulation of harmful and hazardous substances at the installations, as well as the possibility of gas leakage when interacting with which air can create an explosive mixture. Statistical data is presented concerning the incidents in the oil and gas due to violations of safety rules and deviations from normal operating mode at gas dehydration units. The number of fires, emissions of hazardous substances and explosions is also noted. The object of research is presented — gas adsorption dehydration unit. Process flow diagram of adsorption gas dehydration with a brief description of the process is attached. Physical and chemical production factors of hazards arising during operation of the adsorption gas dehydration unit, the toxicity of substances and their effect on the human body are considered. During the research, the main focus is on the quality of the adsorbent used for gas dehydration. Due to the poor quality of the adsorbent (partial crushing and coking of the adsorbent layer), an increase in the pressure drop in the adsorber is possible, which may result in an additional load on the equipment parts, which can lead to destruction. It should also be noted that the quality of the adsorbent affects the amount of dust emitted. With repeated use, the adsorbent particles are reduced in size and carried away with the gas flow. Industrial dust is a particle of solid substances suspended in the air for a long time. In case of prolonged contact with industrial dust, there is a risk of chronic diseases of the respiratory tract, lungs. In the final part of the study, a new adsorbent NaLSX is proposed for use, which has improved characteristics than adsorbents used in industry. A comparative analysis of the characteristics of adsorbents affecting the operational safety and productivity of the gas adsorption dehydration unit is presented.

Industrial Dust Explosions. A Brief Review

This paper first addresses the question: what is a dust explosion? Afterwards, some specific issues are briefly reviewed: materials that can give dust explosions, factors influencing ignitability and explosibility of dust clouds, the combustion of dust clouds in air, ignition sources that can initiate dust explosions, primary and secondary dust explosions, dust flash fires, explosions of “hybrid mixtures”, and detonation of dust clouds. Subsequently, measures for dust explosion prevention and mitigation are reviewed. The next section presents the case history of an industrial dust explosion catastrophe in China in 2014. In the final section, a brief review is given of some current research issues that are related to the prevention and mitigation of dust explosions. There is a constant need for further research and development in all the areas elucidated in the paper.

Model-Based Evaluation of Air-Side Fouling in Closed-Circuit Cooling Towers

Fouling is a permanent problem in process technology and is estimated to cost 0.25% of the gross national product. Evaporative cooling systems are especially susceptible to air-side fouling: as they work with untreated outside air, they are exposed to both natural (e.g., pollen) and human-made (e.g., industrial dust) contaminants. In addition, suspended solid particles and dissolved salts in the spray water are an issue. In this study we analyzed an approach for fouling detection based on a semi-physical (grey-box) cooling tower model which we calibrated with measurement data. A test series with reliable laboratory data indicates good applicability of the model. In three datasets, the performance decreases due to fouling (scaling, which was provoked intentionally) in the range of 5–11% were clearly detected. When applied to measurement data of two cooling towers in real applications, the model also proved to be well calibratable with relatively little data (two to four operating days). For two data sets, the model yielded reasonable results when applied to long term data: a cooling tower cleaning could be retraced and nominal operation was verified during the remaining time. During the analysis of a third data set a temporary performance deviation was found, which could not be explained with the recorded data. Thus, the approach turned out to be generally applicable but requires further verification and refinement in order to increase the robustness. If successful, it can be transferred to a commercial product for need-oriented maintenance in order to reduce cooling tower operating costs and environmental impact.