Wheal Jane Mill Gallery 1, the mill treated the ore from South Crofty until the mine closed during 1998. The mined material already been crushed to sub 150mm before drawing up the shaft. It was then loaded into lorries and brought to the mill by road.
After closure the mill which was the biggest building on the site (approx 67,000 SqFt) lay dormant and neglected. South Crofty purchased some of the equipment whilst the rest was scrapped. The building was finally demolished during 2006/7, the site is now occupied by a solar farm with 5680 panels.
Paul Chesterfield has once again kindly supplied information on the images.
Wheal Jane Mill Gallery 1.1: The newly mined ore on the conveyor belt on its way to the Primary Crusher at the mill. This had already been crushed underground at the mine to enable easier handling.Wheal Jane Mill Gallery 1.2: This is where the ore was washed prior to crushing.Wheal Jane Mill Gallery 1.3: The ore washer from the other side, the water sprays were used to remove mud, and also small particles.Wheal Jane Mill Gallery 1.4: The interior of the Crusher House showing the gravity feed into the Gyratory Crusher.Wheal Jane Mill Gallery 1.5: Looking across the Crusher House. The image gives an idea of the height of the building.Wheal Jane Mill Gallery 1.6: This image shows the 2 crushers, the Long head and Short head crushers. The rocks passed through the first (Longhead) to crush them to a smaller size and then through the second (Shorthead). Further reducing the size of the material to approximately 25mm.Wheal Jane Mill Gallery 1.7: A more detailed image of the crusher showing part of the drive mechanism.Wheal Jane Mill Gallery 1.8: This image shows the pulleys and drive belts from the 3 phase 415 volt motors to the crusher drive shaft.
The crusher drive having the larger pulley 3 or possibly 4 vee belts were used. These were regularly changed on routine maintenance shutdowns. Usually once a month for around 10 hours to prevent failure when in operation.
Changing the motors was a challenging task, necessitating the use of the overhead crane due to their size and weight.
Wheal Jane Mill Gallery 1.9: A more detailed image of the crusher drive wheel.Wheal Jane Mill Gallery 1.10: After the initial crushing the ore is classified by size. This piece of equipment is called a screw classifier. It is designed to separate the coarse from fine material to ensure an even grind. The more uniform the size the better the Tin recovery would be. Wheal Jane Mill Gallery 1.11: Another view of the spiral classifier from above.Wheal Jane Mill Gallery 1.12: The in and out conveyor belts in the crusher house.Cornish Mine Images 1.13: A second image of the distribution area.Cornish Mine Images 1.14: Once washed, crushed and classified the product travels down this conveyor to the Processing Mill. The emergency stop pull cable can be seen running parallel with the conveyor on the left. Pulling this would stop the conveyor in the event of a spill, or other emergency. The guarded equipment is the underside of the hydraulic “hopper” which fed gravel to the conveyor at a constant rate as required.Cornish Mine Images 1.15: The first stop in the processing plant was the ball mill which would grind the ore into even smaller particles to allow the release the Tin.
The control panel and monitoring system can be seen on the left. This is the primary ball mill, the steel balls were 50mm in diameter, and the drum was rubber lined. This area was extremely noisy.
Behind this, and not in view would have been the rod mill. This worked on a similar principle but was first in the process and used steel rods. These were 50mm diameter and around 4 metres long, to further crush the gravel.
The control panel could control the speed of the ball mills as these were driven by DC 500volt electric motors with variable speed control. The 2 round chart recorders plotted the flow of material through the mills.
Cornish Mine Images 1.16: A second image of the ball mill, as the name suggests this was filled with metal balls along with the ore slurry. As the mill rotated the cascading balls held within the drum would reduce the rocks inside into a coarse powder ready for processing.Cornish Mine Images 1.17: Maintenance time on the Ball Mill, This shows the bearing on which the Ball Mill rotated, also the guarded structure around the circumference is the drive gear which engaged with the motor.Cornish Mine Images 1.18: This image shows the removable access hatch on the top of the mill. The fitters would enter on maintenance shutdowns to check and repair the mill linings. Also, Rod mill far left, primary ball mill centre, centre rear the distributor and DSM screens.
Mr Stan Williams was employed in the Mill for 8 years, he has written a short account of one of his memories:
I remember the work we did working for Press in between Consolidated and R T Z. Myself, Ros Spargo and Peter May were given the job of fabricating the rubber lining for the floatation baths. After we had cut the rubber we had to glue it in place, after a little while we started to giggle, sadly we could not stop.
The manager called us into his office accused us of being drunk. So he was just about to sack us when our shift boss came in and told him what we were doing, the glue had affected us. Out of that we got a danger bonus.
Cornish Mine Images 1.19: A closeup image showing the gravity feed into the Ball Mill.Cornish Mine Images 1.20: I would have loved to see these machines running. But sadly they were shutdown for maintenance on my visit. So this image really shows the size of the mill building.Cornish Mine Images 1.21: This part of the building contained three Ball Mills.Cornish Mine Images 1.22: Finally a lower angle on the mills showing the array of feed pipes. Unfortunately the drive motors cannot be seen in any of the pictures. Because these were mounted approx 6ft off the floor on a concrete plinth, effectively under the mill.
