Welcome to SMF. I have been reluctant to reply because of the number of variables that have not been identified. This would be a very educational project, if you have a future interest in
scrap metal. If you are only after a buck you are better off letting it go because it will not be easy or quick.
The most profitable strategy has been identified, sell it for more than scrap metal value. First I would contact the foreman that last used it and find out the history (who made it, was it working when shut down, who erected it, carrying capacity, speed, etc.) Next is it powered by electricity (one, two, or three phase), diesel, or gasoline. If the power no longer works this would not be a deal breaker because its future use will dictate the type of power and the horsepower needed. What kind of condition is the belt (mat) in, what is it composed of, and what is the replacement cost? Then I would brain storm who might benefit from this type of equipment (multi-story roofing companies, gravel pits, construction companies, etc.) A construction company hauling materials via stairs up five stories (1-1 rise) would benefit from this and have the knowledge and ability to disassemble it and rebuild it to their specifications. A horse rancher moving square bales to a loft would be in the same position. The list is endless.
Now as far as scrapping it you made reference to a square ft. of aluminum weighing .5 lbs. You did not state the gauge of the material nor the aluminum composition. Both of these elements will impact the weight. In addition, a scrap yard will probably try to buy it at sheet aluminum price. A conveyor system for rocks would not be using typical sheet aluminum and if you know the composition you can negotiate a better price. Personally I have not seen a rock conveyor belt made of aluminum, most that I have seen were stainless steel or steel plate. Asking the yard to use their metal gun on a sample will let them know you are educated and know your metal, thus a better price. Hint: different stainless steel compositions bring different prices and knowing what you have is a game changer.
Now to answer your question, yes it has value as scrap or reused. The saying: The more you learn, the more you know applies here. One person could scrap it and make a little over $ 400 based on your figures. With more education another scrapper might get twice as much. An entrepreneur could make a lot more through creativity without lifting a finger.
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