scholarly journals Characterization of Strength and Quality of Cemented Mine Backfill Made up of Lead-Zinc Processing Tailings

2021 ◽  
Vol 8 ◽  
Author(s):  
Ufuk Gokhan Akkaya ◽  
Kenan Cinku ◽  
Erol Yilmaz

Predicting the reactions of the backfill materials exposed to the effects of air and groundwater will eventually ensure an efficient and accurate mine fill system for sustainable mining operations. This paper reveals the effect of the mobility of sulfur ions within lead-zinc processing tailings on strength and quality of cemented mine backfills. Some laboratory tests such as X-ray diffraction, ion chromatography, scanning electron microscopy, combustion tests, chemical analysis, pH and zeta potential measurements were performed to better characterize the backfill’s mechanical and microstructural properties. Moreover, CEM II/A-P Portland pozzolan and CEM IV/A pozzolanic cements as ready-to-use cement products were used for cemented mine backfill preparation. To ensure the carrier of the lead-zinc tailings and to prevent the mobility of the sulfurous components, a binder content ranging from 3 to 7 wt% were employed in mine backfills. The experimental findings demonstrate that the used cement type and proportions were insufficient and some fractures are occurred in the samples due to the sulfur ion mobility. Accordingly, one can state clearly that the elemental analysis through the combustion test method can provide fast and reliable results in the determination of sulfur within lead-zinc processing tailings.

Author(s):  
Tran Minh Hieu ◽  
Nguyen Duong Ngoc Mai Chi

This study applied SERVQUAL scale of Parasuraman et al to measure factors affecting customer satisfaction on service quality at Vietnam Technological and Commercial Joint Stock Bank - An Giang Branch (Techcombank An Giang). The study was conducted to survey 207 customers who have been using the service at Techcombank An Giang. The survey results were analyzed by the Cronbach's Alpha reliability test method, then used Exploratory factor analysis (EFA) to verify and evaluate the scale of service quality. The results of the regression analysis show that customer's satisfaction about service quality at Techcombank An Giang includes four factors: The factor with the highest level is the Empathy with Beta = 0.253, the second of factor is the Responsibility with Beta = 0.248, ranked third in the influence level is the Tangible with Beta = 0.235, and the lowest impact level is the Reliability with Beta = 0.144. The research also uses statistical methods to describe and test the differences of demographic factors with customer's satisfactionon service quality.The analysis results show that there is no difference between customer's satisfaction on service quality and factors such as gender, age, income, number of transaction banks, regular transaction banks, and time to use the service at Techcombank An Giang. Through the research results, the author would like to propose some ideas to improve the quality of services, thereby attracting new customers and importantly, keeping traditional customers because the development orientation of Techcombank is to take care of old customers to cross sell other products of the bank. The Stud results offer a basis for the branch to identify the factors influencing customer satisfaction on their service quality, thereby having an appropriate strategy to improve customer satisfaction.


Author(s):  
V. V. Agafonov ◽  
V. Yu. Zalyadinov ◽  
M. E. Yusupov ◽  
N. S. Bikteeva

Sustainability of mining companies is of of high concern. The problem is specifically acute at companies that are monotownor monosettlement-forming. Sustainability of a mine depends in many ways on product quality and production resource-intensity. This article discusses formation of mineral quality indexes in terms of an open pit chrysotile mine. The studies took into account specific features of operation procedures implemented by each structural division of the mine. The analysis has found managerial and technological inconsistencies which affect quality and marketable product output, as well as efficiency of the mine in whole. The background for efficiency enhancement at a company is, by the authors’ opinion, consolidation of personnel subject to the single development strategy, namely: improvement of production and control efficiency, as well as use of available reserves and resources by means of better setup for production. The proposed approaches to planning mining operations and forming mineral quality allow higher quality of processing stock. In addition, a new model proposed for interaction between structural divisions of a mining company ensures improvement of general production indexes.


2013 ◽  
Vol 483 ◽  
pp. 166-169
Author(s):  
Jia Lun Qiu ◽  
Rui Rong Zhao ◽  
Ying Jie Wang ◽  
Wei Zhao ◽  
Jing Cai Li

The V / H inspection method is analyzed, including its basic definition, purpose and V / H inspection technical process of Gleason Company. In order to improve the quality of the contact region, Gleasons V / H test method is conducted for V/H inspection of spiral bevel gear before heat treatment, and analysis of experimental data is given.


2017 ◽  
Vol 726 ◽  
pp. 414-418
Author(s):  
Bo Fu ◽  
Hui Wang ◽  
Zhu Feng Shao

The optical quartz glass is widely applied in optical system , photo communications,inertial navigation,etc.It must have high optical homogeneity. Optical homogeneity of the optical quartz glass directly affects the wavefront quality of the optical transmission system, and changes the wavefront aberration of the system. How to accurately determine the optical homogeneity of the quartz glass is especially important. Currently,the method of test for optical homogeneity mainly used by interference principle. This paper analyzes various existing interference measurement method and test equipment. Summarized the advantages and disadvantages of various test methods,using range and measurement accuracy.


Author(s):  
E. Yu. Kulikova ◽  
Ju. A. Sergeeva

One of the problems of functioning of coal industry enterprises is the formation of mine waters, which are discharged into water bodies and cause their dangerous pollution. The total volume of water pumped by the enterprise includes up to 15 % for the recycling cycle, the remaining 85% is discharged to surface water bodies. As a result, the ecological balance of coal regions is disturbed, their sanitary and hygienic state on the environment worsens, and the quality of coal is reduced due to the intake of polluted water for technological operations. The volume of mine water contamination increases during mining operations at deeper horizons and in difficult mining and hydrogeological conditions. In turn, this leads to pollution and depletion of underground aquifers and the formation of environmental risk factors. In Kuzbass, all these factors contribute to the development of water crisis, since the state of surface reservoirs has already reached a critical limit. Especially dangerous is the process of liquidation of mines. Closing mines and sections disrupt natural water flows, resulting in all water from the aquifers going to deeper horizons. More pollutants enter the water, which poison the underground hydrosphere of the regions. The paper analyzes the pollutants entering the underground and surface hydro grid at coal-fired plants and offers a Conceptual model for minimizing the risk of water pollution.


MTZ worldwide ◽  
2013 ◽  
Vol 74 (11) ◽  
pp. 54-61
Author(s):  
Karl Huber ◽  
Johann Hauber

2020 ◽  
pp. 096452842094604
Author(s):  
O Sang Kwon ◽  
Seong Jin Cho ◽  
Kwang-Ho Choi ◽  
Suk-Yun Kang ◽  
Suyeon Seo ◽  
...  

Background: Moxibustion treatment involves a combination of thermal and chemical stimulation applied by the combustion of moxa wool. The quality of moxa wool is considered to be an important factor in moxibustion treatment traditionally and clinically. However, despite its importance, quantitative and objective methods for determining moxa wool quality are lacking. Methods: Moxa wool and commercial indirect moxibustion (CIM) device specimens were randomly collected, dried and strained through sieves of various sizes for 10 h. After sieving, the residues remaining on each sieve were collected. The collected samples were weighed and microscopically observed. Results: In this study, we observed that fibres mainly remained on sieves sized 425 μm, and particles were smaller than 300 μm. The residues between 425 and 300 μm varied between the products. In addition, moxa wool for direct moxibustion (DMW) exhibited significantly more fibres than moxa wool for indirect moxibustion (IMW). Most of the CIM devices using moxa wool had a quality similar to IMW, except for one CIM brand using moxa wool that contained three times more waste particles than IMW. Conclusion: Based on the results of this study, we conclude that the sieving method is useful for testing the quality of moxa wool even after the CIM manufacturing process. The sieve sizes of 425 and 300 μm could be used as a yardstick to determine the quality of moxa wool. Although this approach requires larger scale validation against existing standard methodologies, we believe it has great potential to be used to improve and safeguard the quality of moxa wool contained in commercial moxibustion devices.


2019 ◽  
Vol 27 (5) ◽  
pp. 237-252
Author(s):  
RH Gaarder ◽  
J Smith ◽  
Øyvind Welgaard ◽  
Ivar Brovold ◽  
André Duus

This article presents a feasibility study where fibre-reinforced structural elements are assembled into long slender columns using adhesive bonding. The columns are intended to be part of an externally guyed high-voltage transmission tower where they are subjected to a combination of compressive and transverse loads. The article has shown that 25-m long poles can be made with small tolerances in both angularity and concentricity. Previous published scientific work on buckling of composite columns was applied to predict the behaviour of the pole as it was being loaded in compression to 1200 kN or within 5% of its critical load in a bespoke horizontal test jig. The confidence in the material, the structural elements, the analysis method and the quality of the test equipment has shown that there is a potential in further optimization of the structure that will ultimately be a part of a high-voltage composite tower.


2001 ◽  
Vol 23 (2) ◽  
pp. 51-59 ◽  
Author(s):  
N. A. Motsoane ◽  
E. Pretorius ◽  
M. J. Bester ◽  
P. J. Becker

Latex products have long been recognized as a cause of latex protein allergy. The increased usage of latex gloves, with the consequent increased occurrence of latex allergies appears to have escalated with increasing awareness of the transmission of HIV–AIDS and other infections. The use of condoms as a means to prevent the transmission of STD's (sexually transmitted diseases) and HIV–AIDS has been widely promoted. Although extensive testing is done to evaluate the physical quality of condoms, no information is available regarding the biological safety of condoms. This study was undertaken to determine the effects of short‐term exposure to physiological levels of condom surface material on cell viability (MTT assay) and cell growth (crystal violet assay). A direct contact cell culture testing method (FDA test method F813‐83 used to evaluate the cytotoxic potential of medical materials and devices) was used. The modified test method was found to be a sensitive test system for the evaluation of the biological safety of condoms. This study reveals the importance of evaluating the biological safety of all condoms that are commercially available, because of the potential health risk that may be associated with prolonged use of certain types of condoms.


1979 ◽  
Vol 36 (9) ◽  
pp. 1023-1028 ◽  
Author(s):  
H. J. Bollingberg ◽  
P. Johansen

Lead concentrations in spotted wolffish (Anarhichas minor) collected from the vicinity of a sphalerite–galena mine and an ore concentration plant in West Greenland have been measured through a period of 2 yr before and 4 yr after mining operations started. Lead levels increased significantly since mining started, and accumulation takes place in liver and kidney, not in muscle tissue. The increased lead levels are not a risk to public health. Small fish have higher lead concentrations than larger ones. Key words: wolffish, arctic, liver, muscle, kidney, lead, zinc–lead mining


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