Mill Sign (Lebanon Mine CO)
Follow the numbers to see how the ore is processed through the mill. Picture show what the main components look like.
Step 1: ore‐bearing rock is taken to the part of the building (on the left) where ore is to be received.
Step 2: ore is shoveled on a grizzly where it is sized in a
broad sense. From here on, the ore moves as a slurry. This means it travels in water.
Step 3: ore then goes through a rock crushing machine. Ore first passes through the machine's jaws, and then is further crushed by its rollers.
Step 4: ore slurry is lifted to a higher level in the mill by a bucket elevator.
Step 5: ore slurry is dumped onto sizing screens. These are rotating mesh drums, each with mesh of a different size opening.
Step 6: rock sorted by size, then passes down a wooden chute onto jigs. The jigs are shaken much like a gold pan. Lighter waste rock washes away; heavier metal‐bearing rocks fall to bottom.
Step 7: the remaining silver‐lead concentrate is then sacked for shipment by wagon or railroad to a smelter for final refining. The Lebanon Mill, like others of the period, was crude and very inefficient by today's standards. Less than 50 percent of the lead and silver were recovered. The rest ended up on the tailings pile below the mill. Some of the tailings pile has been washed away in the one hundred plus
years since the mill operated.
Mill Sign (Lebanon Mine CO)
Follow the numbers to see how the ore is processed through the mill. Picture show what the main components look like.
Step 1: ore‐bearing rock is taken to the part of the building (on the left) where ore is to be received.
Step 2: ore is shoveled on a grizzly where it is sized in a
broad sense. From here on, the ore moves as a slurry. This means it travels in water.
Step 3: ore then goes through a rock crushing machine. Ore first passes through the machine's jaws, and then is further crushed by its rollers.
Step 4: ore slurry is lifted to a higher level in the mill by a bucket elevator.
Step 5: ore slurry is dumped onto sizing screens. These are rotating mesh drums, each with mesh of a different size opening.
Step 6: rock sorted by size, then passes down a wooden chute onto jigs. The jigs are shaken much like a gold pan. Lighter waste rock washes away; heavier metal‐bearing rocks fall to bottom.
Step 7: the remaining silver‐lead concentrate is then sacked for shipment by wagon or railroad to a smelter for final refining. The Lebanon Mill, like others of the period, was crude and very inefficient by today's standards. Less than 50 percent of the lead and silver were recovered. The rest ended up on the tailings pile below the mill. Some of the tailings pile has been washed away in the one hundred plus
years since the mill operated.