Experimental Research and Application of Mining with Paste Material Stowing

2011 ◽  
Vol 121-126 ◽  
pp. 1416-1420
Author(s):  
Guang Peng Qin ◽  
Zhi Jie Wen ◽  
An Min Li ◽  
Zhu Wu Zhu ◽  
Peng Peng Sun
Keyword(s):  
Environmental Issues ◽  
Industrial Test ◽  
Filling Material ◽  
Stowing Material ◽  
Roof Stability ◽  
Early Strength ◽  
And Control ◽  
Cementing Material ◽  
Furnace Slag ◽  
The Ideal

Mining with filling technology is not only an important part of green mining but also the ideal methods to solve the environmental issues in coal mining. The coal gangue and fly ash and furnace slag were selected as the stowing material and the SL paste as cementing material. These two kinds of material were processed into a toothpaste-like slurry without dehydration on ground and transport to underground with the help of gravity or stowing pump in order to stowing the goaf and control the movement of superincumbent strata .Industrial test at Xinsan colliery showed that such kind of paste filling material has high early strength, when filling body was used for false roof of work-face, the post-strength requirement of paste filling material can ensuring false roof stability.

Research on Mining Water-Rich Fly-Ash-Based Filling Material

2014 ◽  
Vol 988 ◽  
pp. 201-206 ◽  
Author(s):  
Wei Xin Chen ◽  
Feng Yi Li ◽  
Xian Hua Guan ◽  
Lei Chen ◽  
Wen Bo Nie
Keyword(s):  
Fly Ash ◽  
Industrial Waste ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Filling Material ◽  
Metal Mine ◽  
Early Strength ◽  
The Cost ◽  
Cementing Material ◽  
Early Activity

It had decades of history that cementing material was used for filling in coal mine or metal mine goaf, which was a common filling material in recently filling mining. Paste and high water material have excellent performance, but the price was too high, which restricted the development of cemented filling technology severely. Later, fly ash and other industrial waste were mixed into the cementing material in order to reduce the cost, but because of which early activity was low, the early strength was reduced by mixing too much fly ash and other industrial waste, the setting time was extended, which affected the filling effect seriously. Therefore, it becomes a key problem that how to excite the early activity of fly ash. It was a breakthrough to select the appropriate activator and activation method, because of the difference mechanism of action and effects for different activators of fly ash, the complexity composition of filling material mixed with large number of fly ash, and the early and late physical and mechanical properties [1,2].Four salts are used for activators in this paper, which are mixed with fly ash and water, and a display method was selected to maximum activate the activity of fly ash, increase the early strength of the material, and reduce the cost of the material.

Study on Proportioning Test of Coal Solid Waste Paste Filling Material

2012 ◽  
Vol 524-527 ◽  
pp. 1086-1091
Author(s):  
Xin Guo Zhang ◽  
Ji Wen Bai ◽  
Heng Wang ◽  
Ning Jiang
Keyword(s):  
Fly Ash ◽  
Solid Waste ◽  
High Efficiency ◽  
Filling Material ◽  
Confined Water ◽  
Bleeding Rate ◽  
Mining Technique ◽  
Comprehensive Mechanization ◽  
Early Strength ◽  
Cementing Material

In order to excavate coal resourses which is under buildings, water bodies, railways and above confined water, a complete technology of new pumping paste comprehensive mechanization mining technique which is safety, high efficiency, high mining rate and environmental protection has been formed, the study on filling material is very important. In this thesis, the uniform experiment is used comprehensively on the proportioning test of mine solid waste such as coal gangue, fly ash etc. The results showed: (1) the collapsed slump of paste will increase obviously with the increase of the content of fly ash; (2) the paste stratified degree will decrease regularly with the increase of the content of fly ash; (3) the paste bleeding rate will reduce obviously with the increase of the content of fly ash; (4) the paste strength will increase gradually with the the increase of cementing material; (5) early strength agent can improve the early strength of filling test blocks to some extent, but the later strength growth is not obvious.

scholarly journals Thiruvalluvar’s Concept of Cultural Ecology

2020 ◽  
Vol 2 (3) ◽  
pp. 202-210
Author(s):  
Rajeswari G
Keyword(s):  
Social Issues ◽  
Environmental Issues ◽  
Modern World ◽  
Environmental Aspects ◽  
Global Literature ◽  
The Social ◽  
Local Areas ◽  
Man And Nature ◽  
The Relationship ◽  
The Ideal

Thirukkural, global literature does not only talk about human behaviours which are to be glorified. It also proposes bright cut ideas about the relationship between humans and nature. The attention of the modern world is on environmental issues. The fast developments due to science and technology resulted in destroying nature. Due to industrial-based products and for the sake of the sophisticated life of the modern man, we left the nature for destruction. And now humanity faces the consequences. It is a general truth that the literature reflects the social issues of that time of its outcome. One can notice that the recent creative literature of Tamil talks about environmental aspects of the globe and the local areas. Thirukkural also deals with the issues of nature and it proposes the ideal relationship between man and nature, which is the concern of this paper. Thiruvalluvar says that the whole world depends on water. All the activities in the world cannot be possible if the rain fails. All the activities of living creatures, including humans, depend on water. Start with food production and leading to every activity are depends on rain. So Tiruvalluvar concludes that the relationship between humans and nature depends on water i.e. is rain. The paper concludes that the concept of Thiukkural towards nature is the dependency of humanity.

Soil as a wastewater treatment system: historical development

2007 ◽  
Vol 7 (1) ◽  
pp. 67-75 ◽  
Author(s):  
V.E. Tzanakakis ◽  
N.V. Paranychianaki ◽  
A.N. Angelakis
Keyword(s):  
Wastewater Treatment ◽  
Rural Communities ◽  
Industrial Effluents ◽  
Polluted Water ◽  
Basic Principles ◽  
Energy Demands ◽  
Current Trends ◽  
Land Treatment ◽  
And Control ◽  
The Ideal

“Land treatment” refers to the application of wastewater to the soil to achieve treatment and to meet irrigation needs of the vegetation. Application of wastewater to the land was the first practice used to protect public health and control environmental pollution. This technology has gone through different stages of development with time but it was not until 1840s when the basic principles of this technology started to establish. The use of land treatment for wastewater treatment declined after the development of conventional treatment plants but a renewed interested occurred after the passage of Clean Water Act and especially, during the last two decades. Currently, its application has been expanded in the management of various types of wastewaters including dairy, meat, industrial effluents as well as and polluted water sources. It is recognized as the ideal technology for rural communities, clusters of homes and small industrial units due to low energy demands and low operation and maintenance costs. Furthermore, in conjunction with biomass production can contribute in the control of climate change. A brief historical overview along with an introduction to the fundamental processes the current trends and the future prospects are provided in this section.

Joseph Barthélémy et les Commissions permanentes de la Chambre des Représentants de Belgique

Res Publica ◽  
1980 ◽  
Vol 22 (4) ◽  
pp. 587-601
Author(s):  
Claude Courtoy
Keyword(s):  
House Of Representatives ◽  
Assembly System ◽  
Rules Of Procedure ◽  
And Control ◽  
The Ideal

Some French infiuences have to be found to explain how the two functions (legislative and control over the Cabinet) of the Standing Committees of the Belgian House of Representatives have evolved. In 1920, when the first Standing Committees system was introduced in the Belgian House of Representatives, a direct French contribution can already be noticed. As a matter of fact, the Speaker of the Committee of Parliamentary Procedures derives his report directly from one made a few months earlier by Joseph Barthélémy for the French House of Representatives.Again in 1935, the first total revision of the entire rules of procedure of the House of Representatives shows the ideal of some French statemen (Poincaré, Tardieu, Blum) to struggle against the assembly system withthe result of a limitation in the functions of the Standing Committees down to its legislative part. These functions were not altered during the second revision in 1962, but some sort of diffused control over theCabinet was still exerted. In 1979, this control was finally formalised.

Civic Patron as Ideal Citizen

The Lay Saint ◽  
2019 ◽  
pp. 83-125
Author(s):  
Mary Harvey Doyno
Keyword(s):  
Men And Women ◽  
Internal Focus ◽  
The Creation ◽  
Civic Community ◽  
New Equation ◽  
And Control ◽  
Contemplative Life ◽  
The Ideal

This chapter discusses the cult of Pier “Pettinaio” or Pier “the comb-maker” of Siena. Pier lived in Siena until his death in 1289, earning first a pious, and then a saintly reputation for his efforts to follow a rigorous schedule of prayer, to deliver charity to his fellow city-dwellers, and finally to resist the more aggressive commercial practices espoused by other urban artisans and merchants. One sees in Pier's vita how the celebration of a contemporary lay patron became an opportunity to think about the role everyday men and women played in the creation of an ideal civic community. As the vita repeatedly argues, Pier's extraordinary spiritual rigor produced the model of good communal citizenship. But one also sees in this vita an expanded understanding of the content and role of lay charisma. At the same time that the vita celebrates Pier's external actions, it also celebrates his internal focus: his embrace of the contemplative life, his prophetic powers, and his ecstatic states. Thus, in the years immediately before the mendicants took over guardianship and control of the lay penitential life, the cult of a pious Sienese comb-maker demonstrates not only a new equation between the ideal lay Christian and the ideal lay citizen but also an expanded notion of the content and power of lay spirituality.

Estimation of Secured Wireless Sensor Networks and Its Significant Observation for Improving Energy Efficiency Using Cross-Learning Algorithms

2021 ◽  
pp. 450-467
Author(s):  
Sirasani Srinivasa Rao ◽  
K. Butchi Raju ◽  
Sunanda Nalajala ◽  
Ramesh Vatambeti
Keyword(s):  
Energy Efficiency ◽  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Learning Algorithms ◽  
Base Station ◽  
Wireless Sensor ◽  
Control Applications ◽  
Symmetric Key ◽  
And Control ◽  
The Ideal

Wireless sensor networks (WSNs) have as of late been created as a stage for various significant observation and control applications. WSNs are continuously utilized in different applications, for example, therapeutic, military, and mechanical segments. Since the WSN is helpless against assaults, refined security administrations are required for verifying the information correspondence between hubs. Because of the asset limitations, the symmetric key foundation is considered as the ideal worldview for verifying the key trade in WSN. The sensor hubs in the WSN course gathered data to the base station. Despite the fact that the specially appointed system is adaptable with the variable foundation, they are exposed to different security dangers. Grouping is a successful way to deal with vitality productivity in the system. In bunching, information accumulation is utilized to diminish the measure of information that streams in the system.

The Study of the Beijing Traffic Noise Pollution Control Countermeasures

2014 ◽  
Vol 641-642 ◽  
pp. 853-859
Author(s):  
Wei Wang ◽  
Hui Zhao ◽  
Guan Xing Wang ◽  
Hua Zhen Zhou
Keyword(s):  
Road Traffic ◽  
Control Strategies ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Environmental Issues ◽  
Control Measures ◽  
Road Traffic Noise ◽  
Typical Time ◽  
The Status ◽  
And Control

Traffic noise is a major source of noise pollution in the urban environment, including road traffic noise and rail traffic noise, which has become one of the domestic large and medium cities in environmental issues to be solved. This paper analyzes the status of the Beijing traffic noise pollution and control strategies, and a typical apartment block selected as a case, analyzes its noise pollution elements, severity, time distribution, and draws a noise map of the plane area and a dormitory building in the noise conditions typical time. Last we discussed and gave the method based on noise control measures.

scholarly journals Optimization and Hydration Mechanism of Composite Cementing Material for Paste Filling in Coal Mines

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Jinxiao Liu ◽  
Wenxin Li ◽  
Feng Zhang ◽  
Xinguo Zhang ◽  
Lianjun Chen ◽  
...  
Keyword(s):  
Early Stage ◽  
Uniform Design ◽  
Setting Time ◽  
Coal Mines ◽  
Hydration Products ◽  
Hydrated Calcium Silicate ◽  
Sulphoaluminate Cement ◽  
Final Setting Time ◽  
Early Strength ◽  
Cementing Material

The low early strength of materials for paste filling in mines caused by low early strength of composite cementing material has been a severe issue. In this study, the effects of sulphoaluminate cement and gypsum on strengths of composite cementing material were investigated experimentally by employing the constrained formulation uniform design. With the content of the sulphoaluminate cement below 14% and the content of the gypsum below 16%, the compressive strengths of composite cementing materials increased, especially early strength. However, the initial and final setting time does not meet the engineering requirements in this case. Optimization tests of composite additives demonstrated that H2BO3(0.3%) + Na2SO4(0.1%) and H2BO3(0.3%) + NaNO2(0.1%) were ideal setting retarding and early strengthening composite additives as they can both reduce the initial and final setting time and enhance compressive strengths of composite cementing material. Investigations by XRD and SEM revealed that the hydration products of composite cementing material were dominated by AFt (ettringite) at the early stage and by C-S-H (hydrated calcium silicate) gel + CH (calcium hydroxide) gel at the middle and late stages. The hydration products of ratio-optimized composite cementing material do not restrain each other due to the generation sequence. Instead, they grew interactively and were coupled, thus facilitating the growth of the hardened body. This study can provide references for optimization of composite cementing material for paste filling in coal mines.

Effect of Type of Cement and Expansive Agent on the Hardening of Steam-Cured Concrete

2017 ◽  
Vol 744 ◽  
pp. 105-113 ◽  
Author(s):  
Takayoshi Maruyama ◽  
Hideaki Karasawa ◽  
Shigeyuki Date
Keyword(s):  
Early Stage ◽  
Precast Concrete ◽  
Curing Temperature ◽  
Steam Curing ◽  
Slag Powder ◽  
Expansive Agent ◽  
Cast Concrete ◽  
Increase Productivity ◽  
Early Strength ◽  
Furnace Slag

Pre-cast concrete products are sometimes manufactured in two cycles daily. It is ensured that they have the required strength at an early stage of demolding by increasing the steam curing temperature to reduce cost or increase productivity. However, the reduction in durability because of cracking due to thermal stress is a topic of concern. On the other hand, it has been known that fine blast-furnace-slag powder and expansive agents show high temperature dependence. Although they are used even in precast concrete products, the effect of steam curing on these materials is not known. Thus, in this study, the expression of compressive strength and expansion that are critical in improving the quality and productivity of precast concrete products was investigated, using high early-strength cement and two types of expansive agents, namely, ettringite-based and lime-based agents. Consequently, the strength expression was accelerated by the addition of expansive agent to ordinary cement and high early-strength cement. The extent of restrained expansion is greater for the lime-based expansive agent than for the ettringite-based expansive agent, and when an expansive agent is added to high early-strength cement, the extent of restrained expansion falls to a level lower than that in the case of ordinary cement.

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