One day, a company from California ran an ad in our local newspaper to hire people to run a small operation that was intended to recover copper from the "poor rock" piles as they were called in our area, left over from abandoned mining operations.
There are numerous poor rock piles throughout Michigan's Upper Peninsula, left over from a bygone era when the area was one of the richest locations on earth.
The company from California had done some sampling of some of the piles and thought some money could be made sorting through the rock for copper that had been missed by the old operation, which had used crude equipment and had ignored the waste due to the massive quantity of copper to be found at the time.
I was hired as a night maintenance supervisor, and on the first night of operation in August, the discussion soon got around to all the exposed belts used to get the rock into the processing building. We all recommended enclosing the belts and heating the enclosures with steam tracing lines.
The California management said enclosing the belts was not in the budget. We persisted, explaining that when the really cold weather came in December and January, the exposed belts would be a problem due to the amount of water in the rock that was going to be run through the process.
The piles never froze solid, as some were fifty feet deep or more. As the temperatures dropped below freezing, one could see the vapor rise from each bucket load of rock being dumped into the process. Further evidence of pending problems could be witnessed by the amount of water on the belts and the accumulation around the tail pulleys.
As we encountered our first twenty below (Fahrenheit) night, all of our predictions came true. The first "opportunity" came from water freezing on the top surface of the belt. Because of the the front end loader feeding the system, the belts had to carry periodic loads, not continuous coverage of the belt. The loads would get almost to the head pulley of the main 400' feed belt, and the come sliding backwards down the entire length of the belt, consequently piling up at the tail pulley, jamming the belt, tripping the breaker and shutting down everything.
We would clean everything from around the tail pulley and restart, only to have the problem soon repeat itself. A second problem surfaced later in the night. Water from the wet rock ran over the edge of the belt and caused ice to build up on the underside, or drive side, of the belt. The result would be that the head pulley would slip, stopping the belt and all feed into the plant.
I called the plant manager to ask his assistance to resolve the situation. His answer was simple, and he wondered why I didn't think of it. He said to fill a 55 gallon drum with fuel oil, light it, and position it under the belt near the tail pulley to keep the belt warm. The crew couldn't believe me when I returned with the news. We did as instructed, and the fire worked as a temporary solution. We manned the barrel to avert disaster, and changed the guard every half hour because of the cold.
Around 4:00 am, the temperature got down to thirty below, and during one of the changes of the guard, the belt was left unattended for five minutes. "Murphy" stepped in to do his work, and sure enough the head pulley started slipping again, giving the fire a non-moving target. The belt caught on fire over the barrel, and proceeded up the entire length of the belt in the time it takes to say "Oh boy!"
We had no means to fight the fire, and by the time the fire department arrived, there was little fire left to put out, save for some remnants of the belt that had fallen to the ground.
Previous to this disaster, the company had experienced many other cold related problems too numerous to describe, and the belt fiasco was the last straw. The company shut down a week before Christmas, and at least for me, it was the best present of all.
The plant may have been operable, exposed as it was, in California, but in the cold of U.P., it never had a chance. It's sad, because even though we were never told anything about profitability, it seemed like a lot of copper was being recovered.