Search Documents

By W. K. Ting, A. Hasan

Mine stope is typically backfilled with cemented paste backfill, which provides a regional underground stability and also a reduction of aboveground tailings accumulation. During backfilling, a phenomenon known as arching occurs and affects the stress distribution of the cemented paste backfill. The change in temperature due to uncontrolled heat transfer from the surrounding rock mass and/or generation from hydration process complicates the stress distribution development of cemented paste backfill. This paper presents results of the investigation on the effects of hydration to cemented paste backfill behaviour when backfilled into a narrow wall model using uncemented paste backfill as controlled sample. The parameters considered include backfill type (cemented paste backfill vs uncemented paste backfill), curing temperature (30°C–60°C), and stress evolution during pouring, consolidation, and curing stages. Results show that uncemented paste backfill re-establishes arching effects more readily, with lower peak stresses and greater stress relaxation than cemented paste backfill, of which its behaviour is significantly influenced by hydration under elevated temperatures. The main outcome of this work is that hydration critically controls the stress-temperature response of cemented paste backfill, and the balance between hydration-driven strength gain and stress relaxation can be leveraged to optimise backfill mix design for safer and more efficient stope filling.

Jan 30, 2026

By W. W. Adams, T. D. Lawrence

"The National Safety Competition conducted by the Bureau of Mines, United States Department of the Interior for the promotion of safety in mines and quarries, has just been closed for seventeenth consecutive year. Enrollment covered more plants than in any previous contest. Moreover, a larger volume of employment was represented than in the contests of previous years, and several new plants were enrolled for the first time. Six safety trophies are awarded annually in these competitions one to the leading plant in each of six groups. An anthracite, mine in Pennsylvania, a bituminous-coal mine in West Virginia, a metal mine in Tennessee, a nonmetal mine in Virginia an open-cut mine in Minnesota, and a quarry in Alabama won the 1941 trophies.To be eligible to win a trophy, a mine or quarry must have had at least least 25 men working under ground or in the pit for not loss than 100 days. The number of man-hours worked must total 30,000 or more. Mines or quarries having no accidents during the year are rated according to the number of man-hours worked. If there are no plants with accident-free records, the mines and quarries in each of the six groups are rated according to their accident-severity rates; the plant having, the lowest rate is declared the winner.The Sentinls of safety trophies presented to the winning mines and quarries in the six groups were donated by the Explosives Engineer magazine to promote safety in the mineral industry. They are held by the winning companies for 1 year or until won by other mines and quarries."

Jul 1, 1942

Ammonium nitrate-fuel oil (ANFO) explosives are unstable in hot, reactive sulphide-rich ground at Mount Isa. Under certain conditions associated with background heat, moisture, and chemical impurities from natural oxidation, ANFO composites in contact with hot ground disproportionate and the ammonium nitrate can undergo rapid exothermic reactions with sulphide.Reactions can occur in confined charges from prolonged contact with reactive sulphides, or by contamination with sulphide in loading. Partial interaction can result in misfires or premature detonation. Spilt, scattered and unpropagated explosive will undergo further reaction in sulphide-rich environments. ANFO-sulphide interaction is invariably exothermic and causes an irreversible chemical transformation of the ore.The heat generated during reaction may be dissipated, heating the environment, or rapidly accumulated to yield hot spots or areas in excess of 400°C. These can result in forced ignition of bulk sulphide and sustained combustion.Thermal analysis was used to define the critical conditions for ANFO-sulphide interaction and sulphide combustion.The occurrence of incandescent ore is attributed to the thermal interaction between exothermic hydrolysis oxidation, ANFO-sulphide, and combustion processes.Chemical agents and control methods have been developed to prevent ANFO-induced oxidation and combustion.

Jan 1, 1968

By Jan E. Nesset, James A. Finch, Wei Zhang

"Bubbles are unquestionably the heart of the flotation process. Their size and combined surface area are largely what drive the recovery process. This suggests that plant engineers should be aware of where their plants are operating with respect to what is achievable for these key parameters. The paper presents a model of how the key operating variables of frother type and concentration, gas rate, altitude (above sea level) and viscosity affect the Sauter mean bubble size (D32) and bubble surface area flux (Sb). The results are compared to a set of plant measurements that demonstrate the benchmarking capability of the approach. A case study is used to link hydrodynamic change to improved metallurgical performance.INTRODUCTION At the beginning of the 20th Century the early practitioners of flotation were aware of the importance of understanding bubble behaviour (Rickard, 1916) but measurement of individual bubble and gas behaviour in the industrial environment was not possible due to a lack of adequate sensors. This situation was not rectified until three quarters of a century later with the advent of industrially-robust sensors developed, notably, at the University of Queensland’s Julius Kruttschnitt Mineral Research Centre (JKMRC) (Schwarz & Alexander, 2006) and McGill University (Gomez & Finch, 2002). What emerged was not the chaotic environment perhaps expected, but defined relationships between gas rate, gas holdup, bubble size and the total surface area of bubbles. These relationships could be defined by mathematical expressions and predicted from an understanding of the key process variables (Gorain, Franzidis & Manlapig, 1997; 1999) (Hernandez-Aguilar, Gomez & Finch, 2002) (Gomez, Cortes-Lopez & Finch, 2003) (Nesset, Gomez & Finch, 2007). The early JKMRC work focused on a large pilot cell (3 m3) installed in plant environments, while the McGill work was initiated on flotation columns (Finch & Dobby, 1990) (Xu, Finch & Uribe-Sales, 1991) and later adapted to industrial mechanical cells (Cooper, Scott, Dahlke, Finch & Gomez, 2004) (Dahlke, Gomez & Finch, 2005) (Nesset, Gomez, Finch, Hernandez-Aguilar & Difeo, 2005). Yianatos of Santa Maria University (Chile), a graduate of the McGill research team, carried the work to industrial settings in South and Central America (Yianatos, Bergh, Condori & Aguilera, 2001). The methods of gas dispersion measurement are now well accepted and most major research centres and flotation cell manufacturers have adopted the technology (Pyecha, Sim, Lacouture, Hope & Stradling, 2006) (Yañez et al., 2009) (Collins, Schwarz & Alexander, 2009)."

Jan 1, 2012

Resonance re-emission from nickel vapour affords a convenient method for isolating the resonance lines at 3415A, 3515A, and 3524A. The vapour is generated by cathodic sputtering and is illuminated by light from a nickel atomic spectral lamp. The resonance lines thus isolated can be usefully employed for absorption measurements on mineral samples where the nickel concentration is too high for measurements with the more sensitive line at 2320A. A spectrophotometer employing a resonance lamp as monochromator possesses several advantages where a great number of determinations are made under routine conditions. The wavelength setting is stable under even the most rigorous conditions and with the provision for automatic setting of full scale deflection the instrument requires virtually no adjustment. The instrument has been used under routine conditions for the determination of nickel (in the range O· 05-2 per cent) in mineral samples.

Jan 1, 1968

By Frank J. Wiebelt

Under a general program to extend the resources of mineral deposits, the Bureau of Mines examined the Quien Sabe antimony mine in October 1948. The preliminary evaluation demonstrated that a diamond-drill program was warranted co establish the tenor and persistence of the veins and permit an estimation of antimony reserves. The Bureau of Mines conducted a diamond-drilling program on the property from December 1949 to May 1950. Ten holes aggregating 2,483 feet were drilled. Nine of the holes encountered antimony-bearing vein material.

Jan 1, 1956

By S. L. Chen

Keywords: copper, concentrate drying, steam dryer, dryers By placing additional demands on energy and gas flow, the moisture content of a copper concentrate has an adverse effect on the smelting process. Different drying technologies, such as directly heated rotary dryers, flash dryers, and steam dryers, are available to solve this problem. The energy requirements of and off-gas generated from different dryer types are compared. The performance of the steam dryer was found to be superior to that of the others. In particular, the rotary steam dryer and its benefits are discussed. Structural properties confer an advantage on the rotary steam dryer, for wear on tube elements is eliminated, and drying efficiency is improved. If steam is available, the rotary steam dryer is an excellent choice for drying copper concentrates.

Jan 1, 2006

By Frederick H. Raab

The electromagnetic retransmission system is a new, automated method of locating trapped mine workers. This technique overcomes many 1 imitations inherent in electromagnetic direction finding by reducing the effects of the conducting ground to an acceptable maximum, by finding position accurately in the presence of antenna tilt, and by eliminating the need for the receiver to be located directly above the subsurface transmitter. Three transportable three-axis magnetic-dipole transmitters on the surface create a system of electronic grids in which the phases of the downlink Signals convey position information. The subsurface retransmitter modulates the uplink carrier of the existing beacon transmitter with the received downlink signal; the coal-pillar loop antenna is used for both receiving and transmitting. The uplink receiver uses a three-axis antenna and extensive digital signal processing. A small computer integrates data, estimates position, and controls system operation through VHF-FM communications. Both coal-mine and deep-mine operation are possible by selecting appropriate transmitting power and signal frequencies. This report shows such systems to be both feasible and practical.

Jan 1, 1980

Trans. No. Place Date Vol. Page 1. Wilkes-Barre Pa......May.71 1 3 2. Bethlehem, Pa.........Aug., '71 I 10 3. Troy, N.Y............Nov..: 71 1 13 4. Philadelphia, Pa........Feb., 72.. 1 17 5. New York. N. Y.*......May, '72.. 1 20 6. Pittsburgh. Pa.........Oct..' 72.. 1 25 7. Boston, Mesa..........Feb., '73.. 1 28 8. Philadelhia, Pa.*......May, '73.. 2 3 9. Easton, is............Oct..' 73.. 2 7 10. New York, N. Y.......Feb..' 74 . . 2 11 11. St. Louie. Mo.*........May,' 74 . . 3 3 12. Hazleton, Pa...........Oct., '74.. 3 8 13. New Haven Conn......Feb., '75.. 3 15 14. Dover,N.J.*..........May, 75.. 4 3 15. Cleveland,O...........Oct. 75. 4 0 16. Washington D. C......Feb.'' 76.: 4 18 17. philadelphia, Pa.......June,: 76.. 5 3 18. Philadelphia Pa........Oct 76.. 5 19 19. New York, N. Y.......Feb: '77.. 5 27 20. Wilkes-Barre. Pa.*.....Mag :77.. 0 3 21. Amenia N. Y..........Oct. 77.. 6 10 22. Philadeiphia Pa........Feb.;' 78. . 6 18 23. Chattanooga' Term.*. . . May' 78. . 7 3 24. Lake George: N. Y....: Oct. 78. . 7 103 25. Baltimore, Md.*.......Feb:' 79.. 7 217 26. ~ittsburgi, Pa.........~a;' 79.. 6 3 27. Montreal, Canada......~ept.;' 79.. 8 121 28. New York, N. Y.*......Feb., '80.. 8 275 29. Lake Superior, Mich....Aug., '80. . 9 1 30. Philadelphia, Pa.*......Feb., '81. 9 275 31. Staunton, Va..........May, '81. .10 1 32. Harrisburg, Pa.........Oct.. '81..10 119 33. Washington, I). C.*....Feb., '82. . 10 226 34. Denver. Colo..........Aug.. '82. . ll 1 35. Boston. Mass.*.........Feb.. '83..11 217 38. Roanoke, Va...........June, '83.. 12 3 37. Troy, N. Y...........Oct.. '83. .12 175 38. Cincinnati. O.*.... Feb, '84..12 4 39. Chicago Ill............May, '84. . 13 1 40. philadelphia, Pa........Sept., '84. . 13 285 41. New York, N. Y.*......Feb., '85. . 13 586 42. Chattanooga, Tenn.....May, '85..14 1 43. Halifax, N. S..........Sept., '85.. 14 307 44. Pittsburgh, Pa.*........Feb.. '86 . . 14 587 45. Bethlehem. Pa.........May, '86 .. 15 Ixiii. 46. St. Louis, Mo..........Oct, 86.. 15 Ixx. 47. Scranton, Pa.*.........Feb.', '87. . 15 lxxvi 48. Utah and Montana.....July '87.. 16 xvii. 49. Duluth, Minn...........July' '87. -16 xxiv. 50. Boston. Mass.*.........Feb.: '88. . 16 xxviii. 51. Birmingham, Ala.......May, '88. .17 xix. 52. Buffalo N. Y..........Oct. '88.. 17 xxiv. 53. New york, N.Y........feb.' ;89 . . 17 xxxi. 54. Colorado..............June' 89 . . 18 xvii. 55. Ottawa, Canada........Oct., 89. . 18 xxiv. 56. Washington, I). C.*. . . Feb. 90. .18 xxx. 57. New York, N. Y........sept:, '93. .19 vii. 58. New York, N. Y.*......Feb. '91. . 19 xxv. 59. Cleveland, O.......... June, :91 . .a xvi. 60. Glen Summit, Pa.......Oct, 111. . 20 lxi. 61. Baltimore, Md.*.......Feb.: '92. .21 xix. 62. Plattsburg, N. Y.......June, '02. . 21 xxxiii. 03. Reading. Pa...........Oct., :92. .21 xliv. 64. Montreal. Canada*.....Feb. 93..21 65. Chicago, Ill............aug.: '93..22 XI. 66. Virginia Reach. Va.*. ...Feb., '04. .24 xwl. 67. Bridgeport Coon.......Oct., '94..24 xxx?. 08. Florida ...'............Mar., '95. .25 xix 69 Atlanta. Ga......... Oct 95. 25 xi 70. Pittsburgh. Pa.*........Feb., '96.. 26 xvii. Trans. No. Place Date Vol. Page 71. Colorado..............Sept. '96. .26 xxix. 72. Chicago, Ill............Feb.. "97.. 27 xvii. 73. Lake Superior..........July '97. .27 xxx. 74. Atlantic City, N. J.*. ..Feb.: :98. .28 xvii. 75. Buffalo N. Y..........Oct. 08. .28 XXXVI. 76. New York,N. Y.*......Feb.: '99. .29 xvii. 77. California.............Sept., ;99. . 29 xlix. 78. Washington, D. C.*.....Feb., 00. .30 xix. 79. Canada...............Aug.. '00. .30 xlv. 80. Richmond. Va.*........Feb.. '01. . 31 xix. 81. Mexico................Nov..'01.. 32 cxviii. 82. Philadelphia Pa. $......May, :02. . 33 xxxv. 83. New Haven, Conn......Oct.. 02.. 33 xlvii. 84. Albany N. Y.*........Feb '03. .34 xxiii. 85. New York, N. Y........Oct.': '03. .34 xi. 86. Atlantic City. N. J.*....Feb., '04. .35 XXIII. 87. Lake Superior..........Sept.'04. .35 dii. 88. Washington. D. C......May' '05. .36 xlii. 89. British Columbia.......July, '05. . 36 90. Bethlehem. Pa.........Feb. '06. .37 xli. 91. London, England.......July: '06. .37 xlviii. 92. New York, N. Y........April, '07. . 38 lii. 93. Toronto, Canada.......July. '07. .38 lix. 94. New York, N. Y........Feb., :08. .39 xli. 95. Chattanooga, Tenn.....Oct.. 08..39 xlviii. 06. New Haven Conn......Feb. '09. .40 xli. 97. Spokane,Wash.........Sept:.'09. .40 xlviii. 98. Pittsburgh, Pa.........Mar.,'10. .41 xxxviii. 99. Canal Zone............Nov.,'10. .41 dv. 100. Wilkes-Barre, Pa.......June. ' 11. . 42 xxxiv. 101. San Francisco, Cal......Oct.. '11..42 xliv. 102. New York. N. Y.*......Feb 12. .43 Ixxvii. 103. Cleveland, Ohio........0ct;' '12.. 44 wii. 104. New York, N. Y.*......Feb.. '13. .45 xv. 105. Butte, Mont...........Aug., '13. .46 ?' 108. New York, N. Y........Oct., 13..47 vii 107. New York. N. Y.*......Feb.. '14..48 xv. 108 Salt Lake City. Otah Aug. :l. 49 5: 109. Pittsburgh, Pa.........Oct., 14. .50 vii. 110. New York, N. Y.*......Feb., '15. .51 xvi. 111. San Francisco, Cal......Sept., '15. .52 xii. 112. New York,N. Y.*......Feb., '16..54 xvi. 1 Arizona...............Sept.,'l6. .55 VII 114. New York, N. Y.*......Feb., '17: .56 vii. 115. St. Louis, Mo..........Oct.. '17..57 vii. 116. NewYork,N. Y.*......Feb.. '18..59 xvii 117. Colorado.....:........Sept.,'18. .60 vii. 118. Milwaukee, Wis........Oct.. '18. .60 x:!: 119. NewYork,N. Y.*......Feb., '19..61 xi. 120. Chicago...............Sept.,' l9.. 62 VII. 121. New York, N. T.*......Feb., '20..63 ix. 122. Lake Superior District. .Aug., '20.. 66 ix. 123. New York, N. Y.*......Feb., '21. .66 xiii. 124. Wilkes-Barre, Pa...... Sept.. : 21.. 66 xix. 125. New York, N. Y.*......Feb., 22. .67 ix. 126. San Francisco. Cal......Sept.,:22. .68 xxix. 127. New York, N.Y.*.....Feb., 23. .69 xxix 128. Canada...............Aug., '23. .69 xxxv! 128.129. New York, N. Y.*......Feb., ;24. .70 xxxi. 130. Birmingham, Ala.......Oct. 24. .71 xxxiii 131. NewYork.N Y.*......Feb.: '25.. 71 xxxviii. 132. 131.Salt Lake City, Utah .. .Sept., '25. .73 xvi 133. New York, N. Y.*......Feb., '26. .73 xxii. 134. Pittsburgh Pa ....... Oct.. '26. .74 xv. 135. New York,' N. Y.*............Feb., '27. .75 x::: 135.136. NewYork,N. Y.*......Feb., '28..76 104 137 NewYork.N. Y.*......Feb., '29. .291 116 138.San FranciscoYork,N.Y. Cal..........Oct. 29..308 406 139. New York, N. Y.*...Feb., '30..30H 1321

Jan 1, 1930

By Paul G. Marinos, Vassilis Marinos, Evert Hoek

The Geological Strength Index (GSI) is a system of rock mass characterization that has been developed in engineering rock mechanics to meet the need for reliable input data related to rock mass properties required as input for numerical analysis or closed-form solutions for designing tunnels, slopes, or foundations in rocks. The geological character of the rock material, together with the visual assessment of the mass it forms, is used as a direct input for the selection of parameters for predicting rock mass strength and deformability. This approach enables a rock mass to be considered as a mechanical continuum without losing the influence that geology has on its mechanical properties. It also provides a field method for characterizing difficult-to-describe rock masses. Recommendations on the use of GSI are given and, in addition, cases where the GSI is not applicable are discussed.

Jan 5, 2007

By James F. Devine

This Bureau of Mines report describes tests conducted at three sites to determine if, and to what extent, a vertical presplit fracture plane placed between a blast point and detection point will reduce vibration levels. Statistical analyses indicate that the presplit fracture plane did not reduce the vibration level.

Jan 1, 1965

By F. J. Sotillo

The reduction in energy consumption has been always important for beneficiation plants. Also gravity separation processes have gained lately great importance due to environmental concerns, especially in the gold and silver Industries. In this sense, the paper point out how to reduce the energy consumption in grinding, and increase efficiency in both grinding and gravity separation are of utmost importance to optimize the use of the country’s resources. For these purposes, chemical additives, such as rheology modifiers have shown great potential, and deserved careful consideration.

Sep 9, 2007

By Peter D. Bell

The paper describes the geology of the gold deposits of the Yanacocha district, Northern Perú. The Yanacocha District is located 20 km north of the city of Cajamarca, whose deposits are located in the Andes of norther in Perú. Gold production may have occurred as early as Incan times, but modern exploration that began in the 1960’s targeted only copper and silver. Current mining is entirely by open pit methods with heap leach recovery. Production in 2003 was from the Cerro Yanacocha deposit and the La Quinua fluvioglacial deposit. La Quinua is not discussed in detail in this report. However, Yanacocha is described as a high-sulfidation epithermal deposit occurring in pyroclastic rocks. The success of Yanacocha has made this type of target among the most sought after by exploration companies worldwide. The important characteristics of the geology of Yanacocha are reviewed below, along with some specifics of exploration techniques used in the district.

Sep 12, 2005

By Habib Zughbi, Paul Zulli

"A key step towards sustainability in iron and steelmaking is to optimise the use of raw materials and energy consumption, and consequently minimise CO2 emissions. Models based on a Process Integration (PI) approach play a key role in evaluating various scenarios and the impact of introducing changes in raw materials and operational conditions on the overall energy consumption and CO2 emissions. BlueScope uses a PI based comprehensive model for its Port Kembla Steelworks (PKSW), called the Integrated Steelworks Energy and Emissions Model (ISEEM). ISEEM is tightly coupled to the configuration of PKSW. It is based on mass and energy balances as well as thermodynamic relationships. ISEEM is a steady-state model and is used to predict overall and detailed unit-by-unit energy consumptions and CO2 emissions. It is also used for plant-based scenario modelling. This paper investigates the impact of major changes to PKSW configuration, including the shutting down of a blast furnace and cokemaking battery, on the energy consumption and CO2 emissions of the plant. It discusses some of the issues involved in updating the model and some identified opportunities."

Jan 1, 2015

Ground-water and tailings pond monitoring in the Upper Santa Cruz Basin Mines Task Force's Special Studies Area has been performed to determine the nature and extent of aquifer contamination from copper tailings pond's recharge in the basin. A monitoring program for each of three mining areas (Mines A, B, and D) was developed. Analysis of data shows that recharge from Mine A's ponds has caused increased hardness, sulfate and total dissolved solids in local ground water. However, pumpage in the area has controlled most of the water's movement. Pond recharge from Mine B has led to similar conditions, and the degraded water is moving towards a local public-supply well. Pumpage from Mine D's interceptor wells is controlling some, but not all, of the movement of recharge seepage from Mine D's ponds. Recommendations include the need for enhanced monitoring programs at each current mine site, development of a monitoring program for Mine C's area, development of water budgets for all mines, investigation of tailings pond compaction and sliming, establishment of mine closure plans for containment of recharged pond water, and the need for additional interceptor wells in several locations.

Jan 1, 1983

THE most important part of the routine survey work on a mine is the keeping up-to-date of plans and sections showing progress of stoping and development work, and the direction of the latter for the purpose of making necessary connections. Except in specialcircumstances, e.g., major horizoittal development, the exactitude required in this work is not extreme, and a method of survey in keeping with the demands of the work itself is all tbat is required.For example, no one would consider measuring the walls of a stope to a fraction of an inch; such extreme accuracy would be wasted.The stope walls being irregular, a mean is usually taken, and for ordinary purposes a survey with a limiting error of six inches is quite satisfactory for the purpose of plotting either stoping or development.It is the author's aim in this paper to describe the method in use at the North Broken Hill Oompany's British mine. This method, while being sufficiently accurate for the purpose in view, possesses the very great advantages of speed and simplicity of operation,with a minimum of necessary equipment. This latter is a very important item where several surveys on different levels have to be carried out on the one day.Let it be understood, however, that the use of this method does not dispense with the theodolite, but simply serves as a convenient adjunct to obtain details and to extend the accurate theodolite survey up rises and down winzes, and through ladderways orwinzes into stopes, where the use of a theodolite, if not actually impossible, is often exceedingly inconvenient. This is particularly so on the British mine, where a large proportion of the ore is won from narrow and complex-dipping lodes, and where vertical ore...

Jan 1, 1928

A quantitative chemical model of the rocks of the Broken Hill lode environment is presented to illustrate a stratiform orebody in a meaningful form to scientists interested in environmental control on the chemicalcomposition of sediments.Even though this study was restricted by the narrow range of rock analyses available it is obvious that significant chemical differences exist between the various rock units and also that some association of metallic sulphides with Ca, Mn, Fe, and P is indicated.Correlation of this evidence with that from other mining fields may point out more definite chemical relationships and elucidate the puzzle of the mode of formation of many stratiform orebodies.

Jan 1, 1968

The Functional Performance Equation for ball milling circuits provides plant staff with a new means to improve circuit performance. However, successful execution of a plant project, with verifiable circuit processing performance improvements, requires a significant number of accompanying steps beyond the equation alone. In order to identify and articulate all these steps, a study with plant staff from two milling operations and a grinding media supplier was undertaken. ?Task analysis? of improving plant grinding performance was carried out. This analysis called for the development of a number of system components, and ultimately yielded a ?Plant Grinding Circuit Processing Performance Management/Improvement System.?

Feb 23, 2014

By Edward M. Dowey

The concrete lining for a long 8.05 km (5 mi) section of New York City Water Tunnel No. 3 was cast in place. The contractor, Grow-Perini-Skanska, placed over76,841 m3 (100,505 cy) of concrete, pouring 24 hours per day, 5 days per week. The concrete was dropped 204 m (670 ft) to the tunnel level, transported by rail to a concrete remixer and pump, and placed in 146.3m (480 ft) of full circle forms. Some of the many challenges include the sheer magnitude of the job, navigating through drifts, a raise and curves, dealing with ground water inflows, and placing the concrete within time limits.

Jan 1, 2001

By N Clarke, G R. Ballantyne, M S. Powell, P Elms, A Anyimadu

AngloGold Ashanti Ltd nominated Sunrise Dam Gold Mine as a case study via their involvement with the long-running Australian Mineral Industry Research Association (AMIRA) International P9P research program (AMIRA, 2015) . A group of researchers from the Global Comminution Collaborative (GCC) conducted a comminution circuit survey and review together with a large group of graduate metallurgists, senior metallurgists and operators. Fundamental and applied research understanding was used to identify productivity and efficiency improvements around the crushing and grinding circuits. The limitations of current scientific knowledge were identified through this process and this will allow future research to be more focussed on what is required by industry.The comminution circuit at Sunrise Dam comprises three stages of crushing followed by two stages of ball milling. The secondary crusher and primary ball mill classification were identified as the primary limitations of the circuit. The secondary crusher was found to be underperforming through overall equipment efficiency (OEE) analysis and an improved chamber design was identified by Chalmers University. This improved design will promote higher power utilisation, choke feeding and a finer crushed product for the milling circuit. The primary ball mill product is classified by a combination of a trommel, 3 sieve bends and a hydrocyclone. The combination of poor classification and coarse, competent feed led to a situation where the primary mill was overfilled with rocks, reducing grinding rate due to cushioning of impact. Size specific energy (SSE) benchmarking methodology was used to identify that a 10% increase in throughput could be achieved with improved primary classification.CITATION:Ballantyne, G R, Clarke, N, Elms, P, Anyimadu, A and Powell, M S, 2015. Application of research principles to identify process improvement at Sunrise Dam Gold Mine, in Proceedings MetPlant 2015, pp 221–229 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015