Cut and Fill mining
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The document discusses the cut and fill mining method, which is used for extracting high-grade minerals like gold and copper, detailing its application, operation sequence, and advantages such as selectivity and minimal ore loss. It includes a case study of the Lagma manganese mine, which adopts the mechanized underground horizontal cut and fill stoping with hydraulic sand backfilling, targeting a production capacity of 0.120 mtpa. The method is characterized by its cyclic nature, requiring careful management of ore production and filling material availability.
Cut and Fill mining
- 1. Cut and Fill Mining A case study of Lagma Manganese Mine (MOIL) AMRITESH 717MN1023 NIT ROURKELA
- 2. CONTENTS Introduction Method of Working Cycle of Activity Stope preparation Sequence of extraction Backfilling Application Disadvantages Case Study 2
- 3. INTRODUCTION It is used in winning high grade and high-value minerals, like gold and copper. It is expensive but is highly selective with low ore loss and dilution. It can be applied to thick and extra thick ore bodies. It has a broad range of application due to its flexibility, good recovery rate and the possibility of mining under weak rock conditions. This method has been used in MOIL, HCL and also in Hutti Gold Mines Limited (HGML). 3
- 4. METHOD OF WORKING 4 Reference: Williams Ted J. and Brady Tom M., Underhand Cut and Fill Mining as Practiced in Three Deep Hard Rock Mines in the United States, Spokane Research Laboratory, NIOSH, p. 2
- 5. METHOD OF WORKING The ore is excavated by drilling and blasting in horizontal slices starting from the bottom of a stope and advancing upwards (overhand) or from the top of the stope advancing downwards (underhand). Each slice has a thickness not more that 3 m. The broken ore is loaded and removed from the stope for ore pass and then to a lower haulage level. The resulting empty space created after removal of ore is then backfilled. Ramps or declines are excavated to connect the surface to the underground ore body. Drifts are excavated to access the ore; chute raises are excavated to provide the easy removal of ore from the mine. 5
- 6. CYCLE OF ACTIVITY 6 Reference: https://minewiki.engineering.queensu.ca/mediawiki/index.php/Cut_and_fill
- 7. CYCLE OF ACTIVITY Drilling and Blasting of a horizontal slice of ore, of 3 to 4 meters thickness, removal of the roof of the stope. Loading and transportation of ore, mechanically removed from the stope for orepass, and then to a lower horizon of transportation. Removal of loose fragments by the detonation and support or reinforcement ceiling. Backfilling the floor of the stope with a layer of composite material varied and equal in thickness with the ore ceiling. 7
- 8. STOPE PREPARATION 8 Reference: Deshmukh D.J (2014), Elements of Mining Technology Vol. II, Denett Publications, Nagpur, p. 251
- 9. STOPE PREPARATION Haulage drift along the ore body at the lower main level. Undercut of the stope, usually 5-10 m above the haulage drift. Short raises for manways and ore passes from haulage drift to undercut. Raise from undercut to the level above for transport of filling material and for ventilation. Provision of sufficient water and filling material and arrangement for their storage and transport. Adequate pumping capacity underground to pump out water overflowing from the filled stope. 9
- 10. SEQUENCE OF EXTRACTION Overhand cut and fill: In this method the ore lies above the working area and the floor is of backfill. It involves a work area of cemented backfill while mining ore from the roof. Underhand cut and fill: In this method the ore lies beneath the working area and the roof is of cemented backfill. Ore overlies the working area and the machines work on backfill. 10
- 11. SEQUENCE OF EXTRACTION (OVERHAND) 11 Reference: Hustrulid W. and Bullock R., Underground Mining Methods: engineering fundamentals and international case studies, SME, 2001.
- 12. SEQUENCE OF EXTRACTION (UNDERHAND) 12 Reference: Jain Saurabh (2011), Mining Methods, https://www.slideshare.net/, p.42
- 13. BACKFILLING The function of backfilling is to support rock walls and pillars. It provides a working surface for continuing mining. It provides opportunity for more selective mining and better recovery of ore and pillars. It prevents subsidence and provides better control over ventilation flow through the mine working. The stope is filled up to within 2-3 m of the back before the next slice is mined. Ore production from the stope needs to be stopped while filling is in progress. The filling material is mixed with water and is transported into the mine and distributed through pipelines. 13
- 14. TYPES OF FILLERS Hydraulic backfill: Deslimed mill tailing slurries, with densities raised to 70% by weight. The coarser fractions are placed underground as hydraulic backfill and the slimes are rejected to the surface dam. Paste backfill: Total mill tailings filtered or thickened to around 80% by weight to which cement and water is then added to achieve the required rheological and strength characteristics. Any rejects to the dam are at the full tailing sizing range. Rock backfill: Waste rock from the surface or underground and crushed to a typical top size of around 40 mm. This can be placed with cemented hydraulic backfill slurry or cement water slurry. 14
- 15. TYPES OF FILLERS 15 Paste Fill Rock Fill Hydraulic Fill
- 16. APPLICATIONS Ore zones are irregular in shape and orientation. Ore is of high grade and dilution control is critical. The waste rock is weak. Ore zones are large, but their rock quality is weak. Localized underground stability is required. Surface disturbance must be minimized. The value of the ore makes recovery of economically viable support pillars. 16
- 17. DISADVANTAGES As it is a cyclic method, production of ore is intermittent unless a few stopes are worked simultaneously. When ore production operations are suspended in one stope for filling the other stope should be able to supply ore. Suitable filling material may not be available in all cases. It is a very expensive mining method, so is applied to ores of very high value only. It requires intensive manual labour and skills. There are risks of instability of the rock mass is the backfill is not properly sized or applied. 17
- 18. CASE STUDY: LAGMA MANGANESE MINE, BALAGHAT (MOIL) Lagma mine is located in Baihar Tahsil of Balaghat District, Madhya Pradesh. It is 33.5 km from Balaghat town. The proposed Manganese mine (48.974 hectares) will be developed as Mechanized Mine by Underground – Horizontal cut and fill stoping with post filling by sand method. The production capacity will be 0.120 MTPA. 18
- 19. EXPLORATION 19 Reference: ABC Techno Labs India Private Limited, Project Feasibility Report for Lagma Manganese Mine, M/S MOIL LIMITED, Nagpur, p. 12,13
- 20. UNDERGROUND LAYOUT Size of the stope block: 80 metres Level interval: 30 m (vertical) Winzes/ raise: 2.5m x 2.5m Cable bolting: 1.5 m x 1.5 m of sufficient length with min 2 m inside the hang wall contact zone Roof bolt: Roof bolt of 1.5 m length will be put at the centre of 4 cable bolts 20
- 21. DRILLING AND BLASTING Drilling in the drivage for haulage road, cross cut and ore drive will be done by pneumatically operated jack hammer of 33 mm diameters of the length of 1.5 m. Generally, wedge cut and parallel cut will be carried out at Lagma Mine due to soft strata of country rock. 21 Reference: ABC Techno Labs India Private Limited, Project Feasibility Report for Lagma Manganese Mine, M/S MOIL LIMITED, Nagpur, p. 16
- 22. STOPING PARAMETERS S.N O Stoping parameters 1 Number of working stopes At a time 4-6 2 Size of the panel 80 m 3 Level interval 30 m vertical (55 to 60 m in dip direction) 4 Thickness of crown Pillar 7.5 m 5 Thickness of Sill pillar No sill pillar 6 Thickness of Rib pillar 5 m 7 Size and interval of Stopes pillar No stope pillar 8 Size/shape of manway Steel manway of 1.5 m dia. circular 9 Size/shape of ore pass Steel chute of 1.2 m dia. circular 10 Method of stowing/ back filling Backfilling of sand hydraulically from surface to stope by HDPE pipes 11 Method of drainage of stowed water Poke holes in concrete walls of cross cuts at lower levels. Stowed water will go to drains and drains it will go to sump. From sumps it will be circulated to surface. 22 Reference: ABC Techno Labs India Private Limited, Project Feasibility Report for Lagma Manganese Mine, M/S MOIL LIMITED, Nagpur, p. 16
- 23. PRODUCTION 23 Reference: ABC Techno Labs India Private Limited, Project Feasibility Report for Lagma Manganese Mine, M/S MOIL LIMITED, Nagpur, p. 16
- 24. LITERATURE REFERENCE Deshmukh D.J (2014), Elements of Mining Technology Vol. II, Denett Publications, Nagpur, p. 249-252 Chacharkar Y.P. (1994), A study of Metalliferous Mining Methods, Lovely Prakashan, Dhanbad, p.192 Harraz Hassan Z. (2014), Cut and Fill Stoping, Tanta University, p. 4-5,8, 11-12, 16, 24, 26-27, 29 ABC Techno Labs India Private Limited, Project Feasibility Report for Lagma Manganese Mine, M/S MOIL LIMITED, Nagpur, p. 3-5, 13, 15-17, 19 http://www.miningfunda.com/2016/10/cut-and-fill-stoping.html Bharti Sujeet (2014), Cut and fill stopes design and their stability analysis: a case study of a u/g metalliferous mine, I.I.T. Kharagpur, p. 4 Fernberg Hans (2007), Mining Methods in Underground Mining, Atlas Copco Rock Drills AB, SE-701 91 Orebro, Sweden, p. 35, 43 Williams Ted J. and Brady Tom M., Underhand Cut and Fill Mining as Practiced in Three Deep Hard Rock Mines in the United States, Spokane Research Laboratory, NIOSH, p. 2 https://www.newtrax.com/cut-and-fill-mining-method-101/ 24