A presentation done by group 8 of mining engineering 3 class of the university of mines and technically, Tarkwa

A powerpoint presentation on square set stoping method in underground mining

1. SQUARE SET STOPING UNDERGROUND MINING SYSTEMS MN 3A – GROUP 8 JULY, 2024 UNIVERSITY OF MINES AND TECHNOLOGY FACULTY OF MINING AND MINERALS TECHNOLOGY

2. OUTLINE 2

3. INTRODUCTION S quare set is generally known to involve all stoping methods in which the voids created by the removal of ore are timbered with framed sets. It involves the construction of a grid-like framework of timber sets within the stope. This method is particularly effective in narrow vein mining, where the orebody is surrounded by fragile rock. It is mostly applicable to high grade ore bodies in order to cover up for the cost involved in timbering. 3

4. 4 Fig. 1 A Picture of a Square Set Stope (Source: Kohler, 2023)

5. AREAS OF APPLICATION It is mainly used in mining relatively high-grade ore. It is used in recovering of high-grade pillars left in mining by other methods. This method is applied in mining high grade orebodies where ore losses and dilution in caving are high. It is used in m ining orebodies in incompetent ground. It is sometimes used in conjunction with other underground systems. It is used when all other methods fail or have proved inadequate. 5

6. DESIGN AND DEVELOPMENT This consist of vertical (post) and horizontal (caps) timber members (usually square shaped) designed to fit and interlock each other at their ends. Timber sets are continually joined to form a cubic frame of timber fitted into a stope immediately after excavation. The stopes are filled with broken waste rock usually after one tier of sets or stope cut in order to improve the strength . 6

7. 7 Fig. 2 A picture of Square Sets Stope (Source: Haraz , 2010) Fig. 3 A picture Showing Various Timbering Units (Source: Yenzanya , 2024)

8. MINING AND ORE REMOVAL METHODS It applies drilling, blasting, and mucking of small parcels of the ore. Drilling machines include airlegs for horizontal holes and stopers applied on vertical rounds. Preferably, overhand method of advancing is applied. The muckpile is loaded into mine cars, slushed into chutes. To complete the mining cycle , back filling is done. 8

9. 9 Fig. 4 Examples of Drilling and Loading Equipment (Source: Anon, 2021)

10. ADVANTAGES Applicable in very weak ore bodies. Applicable when all other methods fail. Could be used as an auxiliary operation in other mining methods such as cut and fill stoping . The systematic arrangement of timber sets facilitates the extraction process and helps in controlling the flow. Selective for irregular deposit and variable ore occurrences; waste can be sorted and left as fill. 10

11. DISADVANTAGES Labour intensive. Applicable to only high-grade ore bodies. Due to the use of a large quantity of timber, it constitutes a fire hazard. The potential for instability if not properly constructed. 11

12. CONCLUSION Square set stoping is a mining method used to support wide ore bodies in hard rock mining which requires careful planning and skilled labour to create stable openings. 12

13. 13 THANK YOU

14. REFERENCES Adler, L., and Thompson, S.D. (1992), “Mining method classifications systems”, SME Mining Engineering Handbook , Society for Mining Engineering, Metallurgy and Exploration, Inc. pp. 531-537. Anon (2020) “Square Set Stoping : MINE 411. Underground Mining Methods” , Course Hero, https://www.coursehero.com/file/76532465/Square-Set-2018pdf/ , Accessed: 23-06- 2024. Kohler, J. (2023), “Square Set Stoping ), PennState Website https://www.eeducatuion.psu/geog00/node/908 , Accessed on 22nd June, 2024. Harraz , H. Z. (2010), ‘: Mining Methods Part V- Underground Mining’, BSc Lecture Notes: ResearchGate , https://www.researchgate.net/publication/301833045 , Accessed: June, 2024. Yenzanya , S. (2024), “Square Set Stoping Method” In Chap. 9 of Underground Mining Systems : Unpublished BSc Lecture Notes , University of Mines and Technology, Tarkwa, 10 pp. Anon (2021), “Square Set Stoping ”, Slideshare , https://www.slideshare.net/slideshow/ square-set-stoping-250010658/250010658, Accessed on 22nd June, 2024. 14