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Study on the law of compressive rebound modulus of liquid soil materials
Published in Xianhua Chen, Jun Yang, Markus Oeser, Haopeng Wang, Functional Pavements, 2020
Yi Zhang, Dandan Guo, Chongwei Huang*, Meixuan Zhu
Cement is a kind of powdery, gray black inorganic cementitious material, which hardens when meeting water or air. The chemical composition of cement is shown in Table 2. After adding water to the cement, the slurry is formed. Sand and other materials are added into the paste and mixed again. If it is left standing, the cement will harden in air or water. Among them, cement can improve the strength and strengthen the setting of liquid soil materials.
Anaerobic and Anoxic Biotreatment of Waste
Published in Volodymyr Ivanov, Environmental Microbiology for Engineers, 2020
Slurry is a mixture of soil, clay, sludge, and manure with water. Usually, the content of solids is 10–30% (w/) but for clay slurry the content of solids is 30–40% (w/v) of solids. The advantages of slurry-phase cultivation are as follows: Microorganisms and particles remain suspended and in contact, and do not settled down due to the high viscosity of slurry.The bulk of the slurry remains anaerobic due to the consumption of dissolved oxygen in the upper layer of slurry; so, this system is most suitable for the anaerobic treatment of dredged sediments or excavated soil polluted with halogenated aromatic hydrocarbons, pesticides, and ordnance compounds. However, for the cases of these and other biotreatments of chemically polluted soil, slurry-phase cultivation can be performed under aeration as a second stage of the treatment.In many cases, the slurry can be separated for water and solid particles upon completion of cultivation.
Design of the support medium for Slurry Pressure Balance (SPB) shield tunnelling in demanding ground conditions
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
B. Schoesser, M. Straesser, M. Thewes
The aim of slurry assessment is to specify the requirements concerning the suspension rheology (yield point τ0) depending on the geotechnical conditions (characteristic grain size d10). The standardised approaches for determination of slurry properties can be found in DIN 4127 (2014) and are summarized in the DAUB recommendation (DAUB 2016).
Coupled effect of sulphate and temperature on the reactivity of cemented tailings backfill
Published in International Journal of Mining, Reclamation and Environment, 2021
As the world’s population increases in size, the global demand for mining products (minerals and metals) also increases, and projected to increase by about 25% between 2000 and 2050 [1]. To meet this demand, lower grade ores and deeper deposits are beginning to be mined due to significant advancements in mining technologies. This development in the mining industry has several challenges. One of the greatest challenges is the management of mine wastes, in particular tailings, that are generated yearly in large volume. Tailings are a by-product waste disposed in the slurry form that consists of processing water, finely grounded rock and mineral waste products. Generally, they are disposed and stored in conventional tailings storage facilities, such as dams, embankments and other types of surface impoundments [2–4]. These conventional methods can have many economic, technical and environmental issues. Therefore, several alternative tailing management methods have been proposed and practised by mining engineers and researchers, such as thickening tailings and using cement paste in tailings [2,5,6].
Erosion tribo performance of HVOF deposited WC-10Co-4Cr and WC-10Co-4Cr + 2%Y2O3 micron layers on pump impeller steel
Published in Particulate Science and Technology, 2020
Gurmeet Singh, Satish Kumar, Satbir S. Sehgal
Slurry pumps are utilized worldwide for transportation of fluid and in addition solids through pipeline. Slurry pumps have wide applications in mining, thermal power plants, and so forth. In present day applications, slurry transportation through pipeline with the assistance of high and low concentration slurry pumps is additionally in trend. The transportation of slurry through ash handling system is the ecological and economical operation. Many of the researchers like Postlethwaite et al. (1974), Neville et al. (1995), Gandhi et al. (1999), and Desale et al. (2008) have reported that solid particle erosion is caused by the interaction between material surface and solid particles suspended in a liquid. The surface encounters loss of mass by the repeated impacts of solid particles. Due to the damaging effects of slurry erosion, it is undesirable in machinery mainly associated with the mining, thermal plants, oil gas industries as it unfavorably influences the reliability and performance of the system. The slurry erosion is a complex phenomenon and it is not yet fully understood due to involvement of many factors such as target material properties, erodent particle characteristics and flow field parameters.
An insight into failure of iron ore mine tailings dams
Published in International Journal of Mining, Reclamation and Environment, 2023
Francis Otieno, Sanjay Kumar Shukla
Tailings are the waste products resulting from ore-dressing processes at mine sites and they are usually stored by pumping in a slurry form into sedimentation ponds surrounded by natural or artificial barriers, called tailings dams [1–5]. During the extraction of economic minerals, the volume of tailings is normally far in excess of the liberated resource, and tailings often contain potentially hazardous contaminants [1–8]. Iron ore accounts for 5% of the earth’s crust and the estimated world reserve of this mineral is approximately 170, 000 million tonnes [9]. Tailings from iron ore mining are mostly composed of haematite (Fe2O3) or magnetite (Fe3O4) and quartz (SiO2) [10] as shown in Figure 1. During the milling process, silica is removed, resulting in tailings (primarily SiO2) and concentrate (mainly Fe2O3), which is sent to the secondary grinding for adjustment of the final particle size. This process involves the use of chemicals, which lead to the generation of industrial effluents that have negative impacts on the environment [9]. In the past, many tailings dams failures have been reported [6,11–17]. Robinson and Toland [11] investigated case histories of different seepage problems for nine tailings dams spread across Europe, America, and Canada, and involved among other minerals, iron, uranium, silver, and soda ash. On the other hand, a total of 221 tailings dam failure incidents were reported by International Commission on Large Dams (ICOLD) [14] while Villavicencio et al [6]. investigated failures of sand tailings dams in Chile, a country known to be highly seismic.