Belt conveyors in bulk solids handling: which statements about maximum length, speed, and capacity are typically achievable in industrial practice?

Introduction / Context:
Belt conveyors are the workhorses of bulk materials handling in mining, cement, power, and ports. Their design envelope includes long distances, high speeds, and large tonnages with predictable power and maintenance needs. This question checks practical limits routinely achieved in industry.

Given Data / Assumptions:

• General-purpose troughed belt conveyors.
• Modern idlers, motors, and belting available.
• Materials ranging from coal to ore and clinker.

Concept / Approach:
Lengths of 1 km are common; many installations exceed this considerably. Speeds of 300 m/min (5 m/s) are standard in high-capacity designs. Tonnages of several thousand tons per hour are routinely handled with appropriate belt width, speed, and surcharge angle. Therefore, all three statements align with proven practice.

Step-by-Step Solution:
Assess length: systems at or beyond 1 km are common in overland conveyors.Assess speed: 300 m/min is within typical 2–6 m/s operating bands.Assess capacity: 5000 t/h achievable with wide belts and suitable speed.Conclusion: all are valid → select “All (a), (b) and (c).”

Verification / Alternative check:
Case studies of overland conveyors in coal and iron ore corroborate these parameters, with appropriate drive power and control systems.

Why Other Options Are Wrong:
Picking only one or two understates the conveyor capability range.

Common Pitfalls:
Confusing theoretical maxima with typical design; the listed values are well within normal industrial design windows.

Final Answer:
All (a), (b) and (c).