Widisinghe, sankha, sivakugan, nagaratnam, and wang, vincent z. Basic principles for stable gullies in the gold and. A word of warning to those who have not read black and are thinking of starting with red, dont. Stoping is the process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Loads on barricades in hydraulically backfilled underground mine. Backfilled stope in french englishfrench dictionary glosbe.
When mined, primary stope strike lengths are 15 to 17 m, strike lengths for secondary stopes are to 15 m. Mcguiness, m pipeline wear and the hydraulic performance of pas. Red picks up where it left of, all action, suspense, and exciting plot developments. In ore widths exceeding 4 m, stopes are mined transversely. Pdf arching within hydraulic fill stopes researchgate. To date, a limited number of mines have implemented paste backfill systems. Stress developments within a backfilled mine stope and the. The trajectory of minor principal stress in the fill from the centerline to the wall was assumed to be either a circulararc, parabola, or catenary.
For the final three years 2003, 2004, and 2005, 25% of production will be coming from the sill pillars largely under paste backfilled stopes. When a stope is ready to be backfilled, the classified tailings are mixed with water to form a slurry. Assessment of hydraulic backfilling in metal mines within the. Issn 15323641 wang, vincent and sivakugan, n 2014 an expectationmaximization algorithm embedded framework for safety assessment of reinforced concrete systems. Paper presented at the 12th international conference on mining with backfill 2017 minefill 2017, denver, co, united states pp. So if you dont get the plumbing right from the start you dont have to pull it apart, and rebleed the system. The vertical stresses at the bottom of the stope, near the wall, and the horizontal stresses on the drive were measured using earth pressure cells. Loads on barricades in hydraulically backfilled underground mine stopes. Beneficial experience from teaching and education to. Landriault d, brown r, counter d 2000 paste backfill study for deep mining at kidd creek. Numerical modeling constitutes a powerful and flexible approach to evaluate the response of backfilled stopes, as these tools can consider various factors, such as geometry of the openings, filling sequence, and material properties li et al.
The postprocessed tailings are directed back into the mine stopes as backfill, with barricades in place to retain the backfills. Mcguiness, m pipeline wear and the hydraulic performance of pastefill. The ram is engaged, and the piling is pressed into the ground. Hydraulic fill is one of the most popular backfill materials used to fill these underground voids, and is generally placed. Mine backfilling, filling of underground mined voids with processed tailings, is an integral process within the mining cycle and brings multiple benefits. Nov 01, 2015 alternatively, drain tubes can also be used in backfilled stopes to accelerate the drainage and consolidation of cpb. Many efforts have been devoted to reducing the segregation by adding flocculent substance 53,57,63,65,66. The backfill material used can be a mixture of sand and rocks, waste rock with cement, or dewatered mill tailings rejected low grade ore from processing, usually fine and sandy. The trench is then backfilled and any necessary protection constructed above. Each of our solutions starts with a free, written foundation repair quote, and includes a personal consultation with a foundation expert, an inperson inspection by a licensed engineer, and a free copy of our 90page foundation repair book.
Underground mine backfilling in australia using paste fills. Geotechnical aspects of hydraulic filling of underground mine stopes. Final report, author thomson, b m and heggen, r j, abstractnote backfilling, the disposal of spent uranium mill tailings in empty mine stopes, has been practiced in the grants mineral belt of new mexico for nearly 20 years. Next, stopes tunnels that have direct access to mining the ore are mined to gain access to the ore. The large underground voids created by the ore removal are backfilled with the waste tailings in the form of paste fills, hydraulic fills, and others. Gravity, coupled with velocity control, is used to effect the selected deposition of the material borrow pits containing suitable material are accessible at an elevation such that the earth can be sluiced to the fill after being. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, although in most cases artificial support is also provided. Minedout stopes are hydraulically backfilled with tailings, and the next slice is mined by machines working from the fill surface. Jan 01, 2019 this paper presents an analytical solution to estimate the stress state in vertical backfilled stopes with stress patterns of distribution in the fill considered.
Cemented paste backfill pressure monitoring and field testing. Underground mine backfilling in australia using paste. The remaining fine fraction of the tailings or slimes is discharged to the tailings pond. Assessment of hydraulic backfilling in metal mines within. A rationale specifically for paste backfill system design has been developed.
This paper examines stope design approaches employed at a metal mining operation in canada for extraction of transverse primary, transverse secondary, and. Two stopes were instrumented at different locations. Horizontal pressure on barricades for backfilled stopes. This is not one of those books where what happened in the previous book is backfilled in the current book. Slab foundation repair fort worth, tx structured foundation. The backfill slurry is then hydraulically transported to the stope, usually by. Irrespective of this value, all hydraulic fills are placed into the stope at water contents of 3045%. Backfill practices for sublevel stoping system springerlink. Sivakugan, n vu research repository victoria university. The total, pore pressures and temperature of paste backfill during and after stope filling were monitored for both instope and barricade. May 25, 2015 failures of backfilled stopes are not unknown. The arching effect has to be considered to evaluate the effective and total stresses in the backfilled stopes. The backfill material used can be a mixture of sand and. In this paper, a pseudoanalytical solution is proposed to evaluate the effective and total stresses in backfilled stopes during the backfill deposition on a permeable base, by considering the selfweight consolidation and arching effect.
In contrast to the carletonville goldfield, 89% of gully fatalities in the orange. When shipping or traveling on the job, the strikeoff can be swung flush with the side of the machine to limit overall width to 11 11 3. In mine backfilled stopes, the heterogeneity of hydraulic backfill associated with the segregation has been frequently reported 22,52,53,54,55,56,57,58,59,60,61,62,63,64. Sandfill provides the possibility of modifying the stope layout and adapting the postpillar method to variations in rock conditions and ore boundaries. Flow rate computations in hydraulic fill mine stopes. Feb 17, 2009 the book presented mine backfill design concepts and procedures, physical and mechanical properties of backfill and their measurement. Production blastinduced vibrations in longhole open stoping. In current underground mining using open stoping methods, it is. Tunnelling, methods of tunnelling and safety engineering. In this practice, primary stopes are initially excavated and then backfilled in a twostage pour.
A novel laboratory model was developed to identify the factors affecting lateral. All tunnels are excavated by drilling and blasting. Analytical solution for estimating the stress state in. During the first stage plug, a cpb material with increased cementitious content is placed at the bottom of the stope providing a strong base from which to build a backfill structure as well as protect mine works from. Acknowledgments this is the fourth edition of the water system design manual. There is increasing use of hydraulically placed tailings backfill in minedout voids stopes in underground mining, with the backfill being. The noncemented fill would have relatively high hydraulic conductivity and not provide a water seal. Cyclic shear response of fibrereinforced cemented paste. Sivakugan, n, widisinghe, s and wang, vincent 2014 vertical stress determination within backfilled mine stopes. Minerals free fulltext experimental tests on a small. Bd thompson, wf bawden, mine design engineering, canada. Experimental study of uniaxial compressive strength ucs. Characterisation of tailings for paste backfill system. An investigation into the drainage characteristics and.
Drainage is of primary concern with underground hydraulic fill mining, and therefore permeability is a key parameter in the design of hydraulic filling of mine stopes. Backfilling underground mine stopes with mine wastes has become a. A university professor should thus not only play the role of. A thorough investigation of the drainage characteristics of hydraulically backfilled mines has been undertaken at james cook university townsville, australia through numerical modelling\ud using the finite difference package flac, laboratory testing, scaled modelling, and insitu instrumentation of a backfilled stopes. Gravity, coupled with velocity control, is used to effect the selected deposition of the material. Total and effective stresses in backfilled stopes during. Engineered barricades are constructed, to retain the backfill within the mined void stope, across the horizontal drives before backfilling. Dilution and recovery are measured using a cavity monitoring system cms.
Sd widisinghe, n sivakugan, vz wang, james cook university, australia. A novel laboratory apparatus was developed where a cylindrical container with a horizontal drive, filled with dry hydraulic fill, was loaded by the mts machine. Sandfill provides the possibility of modifying the stope layout and adapting the postpillar. Many department of health doh employees provided valuable insights and suggestions to this publication. Some aspects of the mechanics of arching in backfilled stopes. Total and effective stresses in backfilled stopes during the. Loads on barricades in hydraulically backfilled underground mine stopes sd widisinghe et al. Our geotech library provides links to useful publications such as papers, books, manuals, theses, that are available online for free. Production blastinduced vibrations in longhole open. Basic principles for stable gullies in the gold and platinum. The backfilling provides ground support and regional stability, thus facilitating ore removal from nearby regions. The arching theory was adapted to geotechnical problems by marston 1930, who developed a solution to evaluate vertical loads on conduits in trenches. Effect of drainage and sequential filling on the behavior.
The company is primarily engaged in producing from its three operating gold mines. A solution to estimate the total and effective stresses in backfilled stopes with an impervious base during the filling operation of cohesionless backfill jian zheng, li li and yu. In the recent past, there has been significant growth in underground mining due to the ever increasing demand for resources and the advancement in technologies. Minimum working pressure of 1,000 pounds per square inch at a 50 gpm rate. The numerical simulations show that continuous filling of a 30 m high stope at a rising rate of 0. Once a slice of ore has been completely mined from the stope, the empty space left behind is backfilled hydraulically. Characterisation of tailings for paste backfill system design.
A hydraulic ram is placed between the bottom of the grade beam and the top of the concrete cylinder. The focus of this work has been to investigate the status of backfill technology, in particular paste backfill, a relatively new technology. Underground mine backfilling is a form of ground improvement that has to be carried out in the mine sites. Chapter 18 geotechnical aspects of hydraulic filling of. Three out of five gully fatalities in the carletonville goldfield occur either in a winch chamber or at the intersection of strike and dip gullies, where spans are greatest2. Jun 21, 2020 study of cemented pastefill and rockmass interaction and behavior in backfilled stopes the focus of this work has been to investigate the status of backfill technology, in particular paste backfill, a relatively new technology.
Numerical analyses of the stress distribution in backfilled stopes considering planar and nonplanar interfaces between the backfill and rock walls. In mine backfilled stopes, the heterogeneity of hydraulic backfill associated with the. A numerical evaluation of continuous backfilling in cemented. A research was performed by yao and sun 2012 to study a novel silica. Stability assessment for stopeandfill mining operations. I like the fact that you can switch the port and starboard control can be switched by the head unit. A hydraulic fill is an embankment or other fill in which the materials are deposited in place by a flowing stream of water, with the deposition being selective. Effect of drainage and sequential filling on the behavior of. A numerical evaluation of continuous backfilling in. The main ore zone is divided into a grid of 15 m wide stopes with sublevels located at 30 m vertical intervals. Analyzed are backfilled stope stability analysis and design and is presented the research on new method for minimizing the amount of cement used in backfilled stopes. Effect of segregation on the geotechnical properties of a hydraulic. Backfilled stope in french englishfrench dictionary. Pipejacking is a trenchless technology in which a drive pit is constructed and then sections of steel or concrete tube are hydraulically jacked forward from the pit to form the tunnel lining.
What is charge valve cutout pressure in an internal wet disc brake system. Widisinghe, sankha, and sivakugan, nagaratnam 2014 vertical stress isobars for trenches and mine stopes containing granular backfills. Mw grabinsky, d cheung, e bentz, university of toronto, canada. Once a slice is completely mined out, the empty space is partially backfilled hydraulically. The additional 7000 m 3 of water that has to be drained can mean a few additional weeks before the drainage stops so that the adjacent stopes can be excavated. Welcome to the main entrance of the online geotechnical engineering library. Rebar is added along with another cylinder and the process is repeated until the piling reaches a point of refusal the piling stops going into the ground and the house starts to. Aurelia metals limited is an australiabased gold and base metals mining and exploration company. Widisinghe, sd, sivakugan, n and wang, vincent 2014 loads on barricades in hydraulically backfilled underground mine stopes. Strength ucs distribution of hydraulic backfill associated with segregation. Examples of hydraulic backfill in open stope potvin et al, 2005. Since 1995, over 300 stopes have been measured using cms representing more than 90% of all mined out stopes. The principal objective of backfilling is the prevention of roof collapse and hydraulic connection with overlying. Chao li 27 april 2020 international journal for numerical and analytical methods in geomechanics, vol.
Stress developments within a backfilled mine stope and the lateral. However, few studies have focused on the characterization of. Failure of the barricades can be catastrophic and several accidents have been reported in australia and. Failure of such a slurry retaining barricade not only endangers the miners lives but also has led. Beneficial experience from teaching and education to research. Sometimes ore waste is mixed with other materials such as sand, cement, waste rock, or dewatered mill tailingsa lowgrade ore that has been rejected for processingto make the backfill.
Strikeoff is raised, lowered, extended and retracted hydraulically with manual stops for fine adjustment of elevation and slope. Pdf loads on barricades in hydraulically backfilled. Cleaning precautions during sewer cleaning operations, satisfactory precautions shall be taken in the. Subsequently, this theory has been extended to other geotechnical problems e. When cemented paste backfill cpb is used to fill underground stopes opened. Between december 2003 and december 2004, there were reportedly at least six paste fill barricade failures worldwide, with each of these failures resulting in an inrush of fill to the mine workings helinski et al. Numerical modeling is another approach commonly used to evaluate the stress state in backfilled stopes and to study the influence of different parameters, such as backfill properties, characteristics of the fillwall interface, the rate of the filling, and pores water pressures 31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51. Minerals free fulltext experimental study of uniaxial. A subsurface plug would be placed in each of the four ventilation shafts, and portions of the shafts would be backfilled with noncemented reclamation fill. To assess the overall structural stability of cpb as regional and local support, the strength development of paste backfilled stopes is measured by core.
573 750 152 68 797 251 1148 195 654 1369 1056 958 843 391 863 1465 1241 600 974 856 1533 1000 1088 97 1150 1291 1237 678