82 
Journal of the Mitchell Society 
[November 
rapidly, readily takes off these grains and deposits them in a bin 
while the non-magnetic grains go on with the belt. There can be 
readily arranged above the travelling feed belt a series of such 
poles, each stronger than the one before, so that the first will take 
off the strongest magnetic particles. The travelling feed belt 
varies in width from 12 to 18 inches. The material fed to the 
machine is classified and allowed to pour over a revolving drum, 
which concentrates it evenly over the feed belt. The pole pieces 
are made of soft iron and weigh up to 90 pounds each. They are 
adjustable so that the length of ore gap between them may be 
varied . The strength of the current in ami>eres can be varied and 
also the distance of the feed belt beneath the poles. 
The rnonazite sand, which is fed to the travelling feed belt, 
passes along under four powerful electo-magnets. The first re- 
moves all the magnetic iron and generally all of the titanic iron or 
ilemnite and any chromite that might be present. The second 
magnet removes all the fine grains of garnet, the coarser ones, if 
present, usually being removed by the first magnet. The third 
magnet is so adjusted as to remove only the coarser particles of 
rnonazite, while the fourth removes all the finer pieces of mona- 
zite. The remaining portion of the sand, consisting largely of 
zircon, quartz, and a little rutile, corundum, cyanite, etc., is 
dropped off at the end of the large belt into a waste pile. 
In another type of machine used in the rnonazite district there 
are a series of magnets over which are travelling belts which pick 
out different minerals, according to the intensity of the magnetic 
field. In this machine the magnetic particles are carried over and 
under the magnet and dropped into a hopper as they leave the 
magnetic field, while the tailings are dropped into another hopper 
and fed to another travelling belt and over a second magnet of 
stronger intensity, which picks out the garnet. This is dropped 
into a special bin and the balance into another hopper and fed to 
a third magnet, whick picks out the rnonazite. It is possible by 
these separators to obtain a rnonazite sand of from 90 to 99 per 
cent rnonazite, according to the care that is taken in separating it. 
The other products, as the iron minerals magnetite and ilmenite, 
and garnet, can also be obtained in a very pure state. From a 
long series of experiments that have been carried on, it has been 
