Transport_of_Total_Tailings_Paste_Backfill_全尾砂膏体充填的运输.pdf

UNITED STATES BUREAU OF MINES UNITED STATES DEPARTMENT OF THE INTERIOR REPORT OF INVESTIGATIONS/1995 RI 9573 Transport of Total Tailings Paste Backfill Results of Full-Scale Pipe Test Loop Pumping Tests By C. C. Clark, J. D. Vickery, and R. R. Backer U.S. Department of the Interior Mission Statement As the Nation’s principal conservation agency, the Department of the Interior has responsibility for most of our nationally-owned public lands and natural resources. This includes fostering sound use of our land and water resources; protecting our fish, wildlife, and biological diversity; preserving the environmental and cultural values of our national parks and historical places; and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to ensure that their development is in the best interests of all our people by encouraging stewardship and citizen participation in their care. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration. Cover Total Tailings paste backfill full-scale pipe test loop. Report of Investigations 9573 Transport of Total Tailings Paste Backfill Results of Full-Scale Pipe Test Loop Pumping Tests By C. C. Clark, J. D. Vickery, and R. R. Backer UNITED STATES DEPARTMENT OF THE INTERIOR Bruce Babbitt, Secretary BUREAU OF MINES Rhea Lydia Graham, Director International Standard Serial Number ISSN 1066-5552 CONTENTS Page Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Engineered support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Waste reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Use of paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Paste backfill transport tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Pipe test loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Test mixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Pumping tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Slump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Slurry concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Particle size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Addition of cement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Pipe diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Flow rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Vertical flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Appendix A.Pipe test loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Appendix B.Material properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Appendix C.Terms and equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 ILLUSTRATIONS 1.Particle-size distribution of uncemented and cemented total tailings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 2.Strength of coarse and fine cemented total tailings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 3.Pipe test loop configuration and pressure monitoring locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 4.Pressure gradients for uncemented and cemented total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 5.Summary of test results for total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 6.Pressure gradients for total tailings paste backfill at different slumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 7.Slurry concentrations for coarse and fine total tailings paste backfill at different slumps . . . . . . . . . . . . . . . . . . . . . . . . . .11 8.Consistency of total tailings paste backfill at different slumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 9.Volume relationships for coarse and fine total tailings at different slumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 10.Pressure gradients for coarse and fine total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 11.Decrease in slump over time for cemented total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 12.Pressure gradients for uncemented and cemented coarse total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 13.Pressure gradients for uncemented and cemented fine total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 14.Transport distance for total tailings paste backfill through pipelines of different diameters. . . . . . . . . . . . . . . . . . . . . . . .15 15.Pressure gradients through pipelines of different diameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 16.Pressure gradients for total tailings paste backfill through horizontal and vertical 154-mm-diam pipe . . . . . . . . . . . . . . . . .16 17.Transport distance for total tailings paste backfill at different column heights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 18.System pressure and transport distance for total tailings paste backfill at different column heights . . . . . . . . . . . . . . . . . . .17 A-1.Flow rates for total tailings paste backfill at different slurry concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 A-2.Flow velocities of water through different pipe diameters at different flow rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 A-3.Positive-displacement pump mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 A-4.Electronic pressure transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 A-5.Data from strip chart recorder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 A-6.Conveyor system used to load dry total tailings into ready-mix truck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 A-7.Transferring total tailings paste backfill from ready-mix truck to pump hopper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 ii ILLUSTRATIONS C-1.Horizontal and vertical flow paths and pressure gradients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 TABLES 1.Paste backfill mixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 2.Comparison of test results for total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 A-1.Flow rates of total tailings paste backfill at different slurry concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 A-2.Velocity through different pipe diameters at different flow rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 A-3.Equipment list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 A-4.Description of monitoring system on pipe test loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 B-1.Particle-size distribution of cemented and uncemented total tailings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 B-2.Volume relationships of total tailings paste backfill at different slumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 B-3.Average unconfined compressive strength of total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 B-4.Slurry concentration of total tailings paste backfill at different slumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 C-1.Water content of bunker-stored tailings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 C-2.Weight-volume data for total tailings paste backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 C-3.Results of pumping tests with horizontal sections only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 C-4.Results of pumping tests using 154-mm-diam pipe with vertical and horizontal sections . . . . . . . . . . . . . . . . . . . . . . . . . .31 C-5.Combined test results for total tailings paste backfill at flow rate of 29 m /h. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 3 C-6.Pressure gradients for water and mix 6 at various pipe diameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 C-7.Transport distance of total tailings paste backfill through 154-mm-diam pipe at different column heights at flow rate of 29 m /h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 3 C-8.System pressure of total tailings paste backfill through different pipe diameters at different columnheights at flow rate of 29 m /h, mix 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 3 UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT Metric Units cmcentimeterm /hcubic meter per hour 3 degdegreem /mincubic meter per minute 3 ggramminminute hhourmmmillimeter kgkilogramm/mmeter per meter kg/mkilogram per cubic meterMPamegapascal 3 kmkilometerm/smeter per second kPakilopascalm/smeter per second squared 2 kPa/mkilopascal per meterpctpercent kWkilowatttmetric ton Llitert/dmetric ton per day mmetert/hmetric ton per hour mcubic meterCdegree Celsius 3 U.S. Customary Units ftfootlbfpound of force ftcubic footlb/ftpound per cubic foot 3 3 ftfoot to the 4th powermimile 4 ft /mincubic foot per minutepsipound per square inch 3 ft/sfoot per secondpsi/ftpound per square inch per foot galgallonstshort ton hphorsepowerydcubic yard 3 ininchyd /hcubic yard per hour 3 lbpoundFdegree Fahrenheit Reference to specific products does not imply endorsement by the U.S. Bureau of Mines. Mechanical engineer, Spokane Research Center, U.S. Bureau of Mines, Spokane, WA. 1 Mining engineer, Kennecott Mining Co., Salt Lake City, UT. 2 Supervisory mining engineer, Spokane Research Center, U.S. Bureau of Mines, Spokane, WA. 3 TRANSPORT OF TOTAL TAILINGS PASTE BACKFILL RESULTS OF FULL-SCALE PIPE TEST LOOP PUMPING TESTS By C. C. Clark, J. D. Vickery, and R. R. Backer 1 2 3 ABSTRACT This report presents the results of tests conducted by the U.S. Bureau of Mines to determine the transport characteristics of highly concentrated paste backfill mixes made from dewatered total mine tailings. The slurry concentrations of the mixes were all above 78 pct by weight with slumps ranging from 6.4 to 16.5 cm 2.5 to 6.5 in. Laboratory material property tests and full-scale pumping tests were conducted using pipe diameters of 102, 128, and 154 mm 4, 5, and 6 in and a positive-displacement pump. The results indicated that the tested backfill mixes can be successfully transported as a stiff paste and identified the influence of and the interaction among the various mix and system variables. 2 INTRODUCTION ENGINEERED SUPPORTfactors limit the structural strength that can be obtained at low The U.S. Bureau of Mines USBM has been active in minecontent and void ratio Landriault, 1987. There are also waste management research for over 25 years. The goal of thisadditional costs associated with pumping excess water to the research is to