The questions are under Mining Engineering, specifically Mine Mechanization and Material Handling Question $1$

A$.$ A $200$ m long inclined belt conveyor is being used to convey ore from a

stockpile to the processing plant at a speed of $1\mathrm{.}4\frac{m}{s}.$ The belt is $0\mathrm{.}75$ m

$(30$ inch$)$ wide, has a capacity of $500\frac{t}{h}r(551to\frac{n}{h}r)$ and discharges

material at a height $10$ m above the loading point. The material being

conveyed has a density of $1\mathrm{.}4\frac{t}{m^3}(90l\frac{b}{t^3}).$ The conveyor system is

being used for a permanent application and has the head pully lagged and

an angle of wrap of $220$ with automatic $($counterweight$)$ take up$.$ The

carrying idler spacing is $1\mathrm{.}22m(4ft)$ and the return side spacing is $3\mathrm{.}05$ m

$(10$ft$).$

Determine the following:

$($i$)$ What is the effective tension?

$($ii$)$ What is the tension required to minimize the sagging of the belt to

$2\%?$

$($iii$)$ What is the maximum tension required? $($iv$)$ What is the slack side

tension?

B$.$

$($i$)$ Mention the main functions of belt conveyor idlers.

$($ii$)$ Discuss the factors that affect the selection of idlers

Question $2$

A$.$ A $20t$ locomotive is coupled to a train of $10$ loaded cars each of weight $6t.$

The locomotive is drawing this load through a curve radius $100$ m at an

average acceleration of $0\mathrm{.}10\frac{m}{s^2}$ down its grade of $1$ in $400.$ The rolling

resistance of the locomotive and the cars are $73\mathrm{.}5\frac{N}{t}$ and $49\frac{N}{t}$

respectively. If the coefficient of adhesion between locomotive wheels and

the rail is $0\mathrm{.}27,$ determine the following:

$($i$)$ The tractive effort of the locomotive

$($ii$)$ Curve resistance

$($iii$)$ The drawbar pull

B$.$

$($i$)$ Write short notes on trolley locomotive for underground mining

applications including one advantage and disadvantage

$($ii$)$ Briefly discuss the grandby type of mine car.

Question $3$

A$.$ A slusher is to be employed to handle material in a cut and fill stoping

operation. Scraping over a distance of $30$ m at a rope speed of $76\frac{m}{m}in.$

The operating efficiency of the slusher is $0\mathrm{.}65.$ The slusher is required to

meet a daily production target of $500$ t $.$ The muck density is $1\mathrm{.}7\frac{t}{m^3}.$ The

effective operating hours per day is $7$ hours. Determine the bucket

capacity $(m^3)$ of scraper required for the slusher to meet the target.

B$.$ A $5m^3$ bucket LHD having a rated payload of $9$ tonnes is being employed

to load and haul ore from a room and pillar stope to an ore pass located

$250$ m away. The haul profile with the distances and corresponding speeds

in the direction towards the ore pass and towards the loading point is

presented in Fig. $1.$

The loading and dumping times $($including manoeuvring$)$ are $45$ seconds and

$35$ seconds respectively. The operating minutes per hour is $50.$ Two $8$ hr

shifts are used for LHD operation. Determine the daily production rate