scholarly journals Properties and Application of Backfill Materials in Coal Mines in China

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
Jixiong Zhang ◽  
Meng Li ◽  
Abbas Taheri ◽  
Weiqing Zhang ◽  
Zhongya Wu ◽  
...  
Keyword(s):  
Large Scale ◽  
Coal Mines ◽  
High Stress ◽  
High Water ◽  
High Water Content ◽  
Environmental Aspects ◽  
Coal Resources ◽  
Mining Areas ◽  
Mining Depth ◽  
Backfill Materials

Coal is the basic resource underpinning energy generation in China, however, constant, large-scale mining of coal results in many problems such as ecological destruction of mining areas. As a result, backfilling of solid waste underground is proposed to control strata and surface subsidence and to protect the environment. At present, these materials, such as granular material, cemented material and high-water-content materials are mainly used for backfilling. This study summarised the types of backfill materials that are used in coal mines in China along with the backfilling process. Moreover, distribution and characteristics of mines backfilled with these backfill materials were obtained and analysed. Considering the socio-environmental aspects that affect backfilling, this research proposed a guideline for the selection of backfill materials and then analysed specific engineering cases of three backfill materials. In addition, the future development of backfill materials was discussed. With extensive extraction of shallow coal resources in China and, therefore, rapid depletion of coal resources in eastern regions of China, coal mining depth is increasing significantly. As a result, it is required to investigate new backfill materials suited for the deep high-stress environment.

Environmental impacts of a large-scale incinerator with mixed MSW of high water content from a LCA perspective

2015 ◽  
Vol 30 ◽  
pp. 173-179 ◽  
Author(s):  
Ziyang Lou ◽  
Bernd Bilitewski ◽  
Nanwen Zhu ◽  
Xiaoli Chai ◽  
Bing Li ◽  
...  
Keyword(s):  
Water Content ◽  
Environmental Impacts ◽  
Large Scale ◽  
High Water ◽  
High Water Content

Fiber Filled Hybrid Hydrogel for Bio-Manufacturing

2020 ◽  
pp. 1-38
Author(s):  
MD Habib ◽  
Bashir Khoda
Keyword(s):  
Cell Viability ◽  
Large Scale ◽  
Three Dimensional ◽  
High Water ◽  
Solid Content ◽  
Design Stage ◽  
High Water Content ◽  
Cellulose Derivatives ◽  
Hybrid Hydrogel ◽  
Low Cytotoxicity

Abstract The extrusion based three-dimensional (3D) bio-printing deposits cell-laden bio-ink with high spatial resolution and may offer living tissue regeneration. Due to the biocompatibility, very low cytotoxicity, and high-water content, natural hydrogels are commonly considered as the cell-laden bio-ink for scaffold fabrication. However, due to the low mechanical integrity, a large-scale scaffold (> 10 layers) with intricate architecture is a challenge. In this paper, we developed and characterize a novel bio-ink consisting of alginate, CMC, and TO-NFC for bio-printing applications. The potential of cellulose derivatives in terms of rheological property to satisfy scaffold architecture and cell viability is explored with a relatively small amount of solid content (<5%). By combining alginate, CMC, and TO-NFC as a hybrid hydrogel, we design to overcome their individual challenges as bio-ink. At the design stage, we have considered two main characteristics, printability and shape fidelity with quantitative indices. We studied the rheological characteristics for determining the suitable composition for extrusion bio-printing. Our investigation suggests an optimal material composition that can print 42 layers and a 9 mm tall scaffold structure. The proposed hybrid hydrogel is used to prepare bio-ink encapsulating cells and cell viability is measured as 90% after 10 days of incubation.

Rapid Consolidation Behavior of Dredged Clays at High Water Content

2011 ◽  
Vol 368-373 ◽  
pp. 2966-2970
Author(s):  
Yu Peng Cao ◽  
Jian Wen Ding ◽  
Xia Bian ◽  
Feng Ji ◽  
Gui Zhong Xu
Keyword(s):  
Large Scale ◽  
High Water ◽  
Laboratory Model ◽  
High Water Content ◽  
Vertical Drains ◽  
Drainage Rate ◽  
Horizontal Drains ◽  
The Stability ◽  
Stability Time ◽  
Consolidation Behavior

Consolidation of dredged clays with a system of horizontal and vertical drains is considered. Horizontal drains in the system are made of sand layers, while vertical drains are plastic vertical drains (PVD). Laboratory model tests are performed to study the rapid consolidation behavior of layered clay-sand and clay with PVD. Special cares are given to settlement and the drainage rate of dredged clays with radial and vertical drain system. Numerical analysis is also used to identify the stability time of consolidation, and to verify which method is better suitable for handling large-scale dredged clays.

Aqueous two-phase systems as a tool for bioseparation – emphasis on organic acids

2020 ◽  
Vol 5 (9) ◽  
Author(s):  
Dragomir Yankov
Keyword(s):  
Organic Acids ◽  
Protein Separation ◽  
Large Scale ◽  
Process Integration ◽  
Scale Up ◽  
High Water ◽  
High Water Content ◽  
Two Phase ◽  
Aqueous Two Phase Systems ◽  
Phase Systems

AbstractAqueous two-phase systems (ATPS) are universally recognized as an excellent alternative to the conventional separation techniques in the biotechnology, because of their undoubted advantages such as mild and biocompatible conditions, high water content, low interfacial tension, ease of process integration and scale up, etc. The formation of ATPS is due to the incompatibility of two polymers in a common solution. Other types of ATPS are formed by polymer/salt, ionic and/or non-ionic surfactants, inorganic salt/short-chain alcohols, and based on room temperature ionic liquids. ATPS are successfully used (even in large scale) for cells, enzyme and protein separation, while their application for recovery of small molecules such as organic acids, antibiotics, alcohols is more complicated as they are usually hydrophilic and tend to distribute evenly between the phases. The purpose of this paper is to overview and summarize the efforts made for the application of different types of ATPS for the separation of organic acids.

Application of Vibrating Fluidized Bed in Low Rank Coal Drying Process

2013 ◽  
Vol 788 ◽  
pp. 233-236
Author(s):  
Yong Jie Zhao ◽  
Xiang Wei Kong ◽  
Bin Li ◽  
Zi Cheng Zhang
Keyword(s):  
Fluidized Bed ◽  
High Speed ◽  
Large Scale ◽  
Energy Resource ◽  
High Water ◽  
Low Rank ◽  
High Water Content ◽  
Drying Process ◽  
Low Rank Coal ◽  
Coal Drying

Low rank coal is an important energy resource in the world, particularly in the developing countries. But its high water content causes a waste of energy and serious environmental pollution, which restricts its applications. In order to improve the efficiency of the low rank coal and reduce pollution, the drying processes for low rank coal are urgently needed. This paper presented a review of the general drying processes for low rank coal. In the review, the newly-developed vibrating fluidized bed (VFB) drying process was emphasized. This novel VFB drying process which can be used in large-scale industrial production has several advantages, such as high speed, high drying intensity and low pollution. Moreover, two VFB researches reported by the authors were also introduced. In these researches, the dynamic behavior of VFB was simulated by two commercial codes of ADAMS and ANSYS separately. According to the simulation results, the exciting force and the structure of sieve box were optimized.

scholarly journals Investigation of the Optimization of Unloading Mining Scheme in Large Deep Deposit Based on Vague Set Theory and Its Application

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jia Sheng ◽  
Wen Wan ◽  
Dongrui Liu ◽  
Feifei Jiang ◽  
Xiangdong Li ◽  
...  
Keyword(s):  
Set Theory ◽  
Large Scale ◽  
High Stress ◽  
Mining Area ◽  
Technical Problems ◽  
Deep Mining ◽  
Vague Set ◽  
Mining Depth ◽  
Metal Mines ◽  
Selection Of

With the development of shallow surface mineral resources in metal mines, it is gradually turning to the stage of deep mining. According to the current mining depth and the average annual depth, during the period of “14th Five-Year Plan,” one-third of the underground metal mines will reach or exceed the mining depth of 1,000 m, with the deepest being 2,000 m. In the stage of deep mining, mines will face the conditions of high stress, high temperature, high well depth, and strong mining disturbance, which will greatly increase the difficulty of large-scale deep mining. Among them, the high ground stress environment is the principal problem of many technical problems in deep mining. The selection of mining method has become a prerequisite for solving the problem of efficient and safe mining of deep deposits. In this paper, the vague set theory was introduced into the selection of mining methods and a vague set model for deep unloading mining schemes was established. Taking the Jinchuan No. 2 mining area as the engineering background, four unloading schemes for deep mining were proposed, and the Vague set model was used for optimization. It is concluded that the mining approach with large-section unloading is the optimal unloading mining plan. The application shows that it has the advantages of high unloading efficiency, large production capacity, and low loss index. It has been fully promoted in the deep mining of the mining area. It is feasible and effective to use the vague set theory in the selection of deep unloading mining schemes, which provides a proper approach in the selection of deep unloading mining schemes.

Research on Surface-Layer Improvement Technology for Dredger Fill by Vacuum Preloading

2012 ◽  
Vol 256-259 ◽  
pp. 1703-1706
Author(s):  
Yan Hua Yang ◽  
Fu Quan Ji ◽  
Zhao Yang
Keyword(s):  
Large Scale ◽  
Soft Soil ◽  
Soft Clay ◽  
Drainage System ◽  
High Water ◽  
Soil Improvement ◽  
High Water Content ◽  
Construction Technology ◽  
Vacuum Preloading ◽  
Reclaimed Land

The surface-layers have very high water content and low bearing capacity, so far to be the very soft clay foundation, which come from the reclaimed land in project of reclamation. It is difficult to improve the very soft clay foundation by traditional vacuum preloading. A new method named surface soft soil improvement is presented in this paper, which can make the soft clay foundation to be improved in preliminary. Once forming the hard coat layer, the foundation may reach the needs of further construction. In the construction technology, the horizontal filter pipe net is used to instead of the sand bedding course. By laying of woven cloth and non-woven geotextile over the surface of reclaimed silt, installing PVDs by manpower becomes possible. Besides, the vertical PVDs all are connected with the horizontal filter pipe net directly, that makes a whole spatial drainage system. The loss of the degree of vacuum is decreased, and the improvement is increased. Thus, this construction technology is as a reference to the large scale engineering construction and similar projects.

Fiber Filled Hybrid Hydrogel for Bio-Manufacturing

2020 ◽  
Author(s):  
Ahasan Habib ◽  
Bashir Khoda
Keyword(s):  
Tissue Regeneration ◽  
Large Scale ◽  
High Spatial Resolution ◽  
Three Dimensional ◽  
High Water ◽  
Solid Content ◽  
High Water Content ◽  
Living Tissue ◽  
Hybrid Hydrogel ◽  
Nano Fiber

Abstract The extrusion based three-dimensional (3D) bio-printing deposits cell-laden bio-ink with high spatial resolution and may offer living tissue regeneration. Due to the biocompatibility, less cytotoxicity and high water content, natural hydrogels are commonly considered as the bio-ink for scaffold fabrication. However, due to the low mechanical integrity, a large scale scaffold (> 10 layers) with intricate architecture is a challenge. In this paper, Cellulose-based nano-fiber and CMC are added with alginate material to improve the rheological behavior of the hybrid hydrogel. Shear-thinning behavior, shape fidelity, printability of the composition are investigated and evaluated for various compositions. Finally, both regular and freeform 3D scaffolds are fabricated with the proposed hybrid hydrogel to validate its printability and shape fidelity. The required properties of bio-ink are highly dependent upon the percentage composition and the solid content.

Anatomy of a volcanic island inferred from a multiphysics approach

2021 ◽  
Author(s):  
Marceau Gresse ◽  
Makoto Uyeshima ◽  
Takao Koyama ◽  
Hideaki Hase ◽  
Koki Aizawa ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Large Scale ◽  
Geophysical Methods ◽  
High Water ◽  
Rock Properties ◽  
High Water Content ◽  
Complex Interactions ◽  
Tectonic Events ◽  
Magmatic Reservoir ◽  
Flow Circulation

<p>Phreatic and phreatomagmatic eruptions are difficult to predict with accuracy on volcanoes due to complex interactions at depth between heat, water, and magmatic fluids. To better understand such multifaceted interactions, we present here a multidisciplinary geophysical approach performed on Miyakejima, a 10-km wide stratovolcano in the Izu Bonin arc. Its plumbing system was highlighted by combining four geophysical methods: magnetotellurics, seismicity (hypocenters), self-potential, and thermal image (remote sensing). We thus propose the first large-scale interpretation of the volcanic structure in terms of rock properties, temperature, fluid content, and fluid flow. Our findings indicate that hot volatiles released from a <em>deep</em> magmatic reservoir (> 350°C, 2.5–4.5 km depth) rise through a narrow permeable path, interact with the conductive hydrothermal system beneath the 2000 A.D. caldera (<250°C, 0–2 km depth). This mixture of fluid is finally released in the fumarolic area in the southern part of the caldera at 181°C. This combined approach allow us to: 1) delineate the water table of the volcano (300–700 m depth), 2) determine the general fluid flow circulation beneath the island, 3) characterize seismic signatures of long-period and volcano-tectonic events, and 4) elucidate the origin of the high water content of fumaroles developed since the last eruption in A.D. 2000.</p>

Sign in / Sign up

Export Citation Format

Share Document