Rail-Veyor Bulk Material Transport System

Merton F. Dibble, PE
Rail-Veyor Technology, Inc.
FIPR Publication # 01-152-147 (link to complete publication on FIPR web site)
2002

ABOUT THE PROJECT:

Abstract

The phosphate industry has traditionally used slurry pipelines to move phosphate matrix from the mine site to the processing plant. As phosphate matrix grade decreases and transport distances increase, the transport cost per ton of product has significantly increased. These increased costs are forcing alternative matrix transport methods to be evaluated.

The Rail-Veyor represents a possible replacement for slurry pipelines by combining the best features of a railroad and overland conveyor without the high capital cost requirements. The Rail-Veyor system can move phosphate matrix at a much higher percent solids than pipelines.

The demonstration Rail-Veyor system operated successfully as it was able to load, transport, and dump phosphate debris in a very efficient manner. The system was able to operate continuously, with only the stationary drive units in physical contract with the 42-car 168-foot open trough train in operation at any time. The system operated at about 588 feet/minute, with energy required of about 0.3 KWH per ton-mile to move the train and load.

The Rail-Veyor met the objectives of the project and offers a potentially cost-effective, environmentally attractive bulk material transport system.

Introduction

The Rail-Veyor System is a bulk material transport concept that represents a cost-effective, environmentally safe approach to moving a wide variety of materials. FIPR felt that the phosphate industry needed to actively investigate alternative methods of moving phosphate matrix from the mine site to the plant site. The present slurry transport system has been an extremely successful means of moving matrix and is the accepted standard of moving matrix.

Materials and Methods

• The system proposed for demonstration purposes was a loop of 1/4 mile of 25#/yard track with 42 four-feet-long cars, each consisting of a 10-inch radius 180-degree trough and an overlapping dust flap of urethane. When connected, these cars made a 168-foot long continuous trough that allowed articulated movement without spillage.
  
• The drives consisted of two opposing horizontal drive tires pressing against a vertical drive plate on both sides of a car. The rotary action of the drive tires provided forward thrust by the friction on the side plates.
  
• Sensors were located just before and after each drive station, that when activated either energized or de-energized the system.
  
• Each car had two wheels at the rear, with the trailing car having a clevis blade that fit between two clevis blades of the car in front just behind the two wheels. This configuration supported each car except the front car at three points. The front car had a movable axle, which allowed both twisting and turning.
  
• The 42 cars, when loaded, contained about 8 tons of material. At 588 feet/minute with a 168-foot train, the loading time was only 17.1 seconds. This required a loading system that had the incremental capacity of 1,686 tons per hour to fully load the train operating at the design speed. The proximity of the dumping station to the loading station did not allow speed reduction, as the dumping speed could not be reduced in the space available to operate the loading system at lower train speeds.
  
• Although the track was built to a length of 1/4 mile, the effective dumping/loading system would only have been 1/8 of a mile. The cycle time for the train was under 3 minutes, or about 27 trips per hour.

Results

• This study shows that the Rail-Veyor System has lower capital cost than the conventional system at distances of more than 2 miles.
  
• In terms of operating cost per yard-mile, the Rail-Veyor has lower cost for systems that transport matrix two miles or more.
  
• In terms of savings, the Rail-Veyor shows huge potential as the transport distances increase.

Discussion and Conclusions

• All phases of the test program operated successfully.
  
• Data collected indicated that the system concept would be applicable to much larger capacities. Operation of multiple trains on a single-track loop would allow more efficient use of the drives and loading rates.
  
• A cost estimate was made on a two mile (11,000 feet) 600 TPH haul distance with 22 drive stations for the entire loop, three trains and a loading and dumping station tied to a radial stacker.
  
• The installed price for the entire system was estimated to be $218 per foot for 11,000 foot of haulage distance (includes all costs for the 22,000-foot loop). The capital cost for this 600 TPH capacity would be $4,000/TPH. By quadrupling this capacity, or 2,400 TPH (twelve trains), the capital cost per foot of haul distance would increase to $424 and decrease to $1,942 per TPH capital cost. In essence, increasing the capacity four times increases the total capital cost by a multiple of 1.94.