The Indaba Mining Consortium is currently engaged in mining operations within a steeply dipping large massive copper$-$gold $($Cu$-$Au$)$ deposit, situated at depths ranging from $100$ m to $1,000$ m$.$ The deposit spans an area $7$ km long and $4$ km wide, with scattered mineralization zones. This project focuses on extracting the LT$008$ mineralised zone, which has an average width of $30$ m and extends longitudinally for approximately $500$ m$,$ with an average height of $300$ m$.$ The target production from LT$008$ is $30,000$ metric tonnes $($t$)$ per day which includes planned dilution of $15\%.$ Previous mining activities primarily employed open$-$pit methods, reaching depths of up to $500$ m$.$

The estimated average grades for copper $($Cu$)$ and gold $($Au$)$ are $3\%$ for Cu and $5$ grams per tonne $($g$/$t$)$ for Au$.$ The recovery rates at the processing plant are anticipated to be $98\%$ for Cu and $97\%$ for Au$.$ Copper represents $75\%$ of the Mineral Resources and Reserves. For the life of mine, the price of Cu is projected to average approximately US$$9,240\mathrm{.}30$ per metric tonne $($t$),$ while the price of Au is forecasted to average US$$2,343\mathrm{.}30$ per troy ounce $($oz$).$ Conversely, the anticipated all$-$encompassing mining costs per unit for Au are expected to amount to US$$5,000/$t and US$$1,500/$oz for Au$.$

Geotechnical conditions dictate a maximum stope span of $25$ m$,$ incorporating rib and sill pillars of $5$ m thickness and a $10$ m crown pillar.

INSTRUCTIONS:

Your task as mining engineering students is to design and schedule mining operations for one level, ensuring the achievement of the required daily production of $30,000$ metric tonnes $($t$)$ per day from this level.

$1.$The longhole massive mining method I've chosen is Sublevel stoping $,$ give reasons for the selection of the mining method $(15$ marks$)$

$2.$Development required for stope access $($design the necessary development for accessing the stope efficiently and safely $,$provide computer aided drawings and specifications for each development, specifications must include type of development, purpose and dimensions for each development, development dimensions must match the equipment and production requirements$)$

$3..$ Stope Design and Mining Sequence$-($Develop a comprehensive stope design for LT$008,$Specify the dimensions of stopes, pillars, and extraction sequence,Include detailed plans for pillar extraction and stope sequencing to optimize ore recovery and minimize dilution,Develop a monthly production schedule until the entire level is depleted,Specify the how it will take to deplete the level,Determine the monthly revenue and profit expected per month $($i$.$e$.$ monthly cashflow for the entire life of the level.$)$

$4.$ Drill and Blast Operations$-($Outline the drill and blast operations required for stope preparation and ore extraction,Specify drilling patterns, hole sizes, explosive types, and blasting sequences$)$

$5.$ Load and Haul Requirements$-($Determine the equipment and procedures for loading and hauling ore from the stopes to the surface,Specify the types and capacities of loaders, trucks, and haulage routes$)$

$6.$ Backfill Operations$-($Develop a backfilling strategy to ensure the stability of excavated stopes and minimize subsidence,Evaluate different backfill materials and methods and select the most efficient method of backfill,Specify the equipment, logistics$,$ and quality control measures for backfill placement$)$