Concentrators for metallic ores, particularly precious metal ores, using centrifuging cyclonic air action without water for primary separation of the heavy metal particles and ore from dust, dirt and lighter particulate. The relatively coarse ores and particulate are collected by gravity drop at the bottom of a centrifuge, while the fines and dust are withdrawn from adjacent the top thereof and fed through a further separating apparatus which blows out the dust and then passes the remaining particulate over dry riffle boards to collect the heavy particles. The cyclonic centrifuge is in the form of an upper, frustoconical, internally baffled or corrugated construction with a lower, inverted, frustoconical section likewise internally baffled or corrugated, the sections joining at their largest diameters. Pulverized ore particulate which is to be further concentrated is introduced through the upper frustoconical section. Air is drawn into the device from the top and bottom through a generally centrally located fan and then exited tangentially from the upper section, or, in another embodiment, the air is entered tangentially, with or without the fines therein, and exits the cyclonic separator from the top and bottom. A particulate collector ring may be mounted at the junction between the upper and lower centrifuge sections. The further separator comprises a velocity reducer and agitator and a dispensing box through which the fines pass with removal of the dust and with the dropping of the particulate onto the dry riffle boards.
In classifying apparatus of the type wherein upward whirling flow of fluid is used to separate coarse and fine particles of the particulate material, rotary vanes are mounted on the upper portion of a housing for separating and discharging fine particles, and a rotary disc carrying a plurality of nozzles is provided for projecting jet streams of the fluid against the inner wall of the housing. Vertical and inclined guide plates are provided near the inlet port of the fluid for smoothly guiding coarse particles falling down along the inner side of the housing without being disturbed by the whirling flow of the fluid admitted through the inlet port.
The invention relates to a material dispersion apparatus, particularly for spreading classifiers, with an upper material supply and a material feed surface. The material feed surface is constructed as a sieve-like surface, which is installed in an air channel and the material supply is fluidized above the sieve-like surface and discharged over the outer rim of the material feed surface to fall down to the spreading classifier basket.
An apparatus for removing dust from a fiber sample for subsequent analysis is disclosed. A first upper cylindrical chamber containing a fiber sample has a tangential air jet and a radial air jet installed to swirl and tumble the fiber sample in a cyclonic fashion, thus liberating the dust from the sample when either a positive or a negative pressure is applied through the air jets. The liberated dust particles are then screened out through a 100 mesh screen filter and exhausted through a funnel. The device can be equipped with a second stage chamber containing a plurality of step-stage filters and a third stage plurality of microfilters to selectively screen the dust particles. A blow bottle containing an aqueous medium to absorb even the finest dust particles or gas can also be added as a fourth stage.
In a classifier for separating particle fractions of different densities from a liquid-borne stream, means are provided to gently open a bed of heavier particles and release lighter particles entrapped adjacent the chamber wall by the heavier particles, thereby permitting the lighter particles to be displaced and move centrally for more complete separation. An adjustable throat between the lower end of the overflow pipe and the underflow outlet is provided by a telescoping external support for the overflow pipe above the cover plate.
Apparatus for separating, or classifying according to size, particles being carried by a primary flow of gas is disclosed. A vortex is imposed on the primary flow by a vortex forming device in the form of a central annular hub member having an outer periphery, angularly spaced nozzles leading to the periphery and an interior conduit for supplying high pressure gas to the nozzles. The nozzles are dimensioned and positioned to discharge a ring of high velocity jets of gas perpendicular to the primary flow and generally tangent to the periphery to create a vortex to submit the particles to centrifugal force, facilitating the separation or classification thereof.
