As gold grade of the tailings in shaking table for fine screening is comparatively high, it is suggested that these tailings be collected and further ground to -325 mesh by a small-scale ball mill at intervals so that gold can be recovered through intensive cyanide leaching. If mercury is allowed to be used in the country where the project is conducted, such tailings can be ground to -150 mesh so that gold can be recovered through amalgamation, which, though, for the sake of health and environment, is not recommended.

According to the properties of raw materials and the demands of clients, the gravity concentration plant is usually composed of crushing module, grinding and classification unit, gravity concentration module, water supply module and power supply module to maximize the recovery ratio. The equipment layout of the gravity concentration module varies according to the particle size distribution and the occurrence status of gold.

Rocks are crushed to the particle size suitable for grinding and the module consists of composed of hopper, crusher, belt conveyor, ore feeder.

The crushing of ore is usually two-stage. The first crusher can be placed in the mining area ( driven by a diesel engine) or the processing plant.

The closed-circuit grinding and classification system consisting of the ball mill and spiral classifier can dissociate ore into particles suitable for recovery. The module can be adjusted to a closed-circuit system consisting of the ball mill, slurry pump and hydrocyclone according to customers' needs.

The grinding and classification unit is completely set on a steel frame.

The water supply module is composed of the water tank, water pump and water supply pipeline. This module can fully control the use ratio of water, achieving ideal water balance.

It is composed of the diesel generator, the electrical distribution device and the electrical starter panel, which is suitable for areas that are hard to get to and has difficulties in power supply.

The coarse gold, fine gold and residual gold are recovered through the jig, centrifugal concentrartor and sluice in turn for the best recovery rate. Shaking table is used to improve gold grade of the rough concentrate produced by jig and sluice box. The concentrating table is further adopted to purify higher grade concentrate generated from centrifugal concentrator and shaking table.

The concentrate of the concentrating table can be smelted and casted to the bullion bars directly. The tailings also contain gold of high grade and usually are finely grinded for intensive cyanide leaching and Merrill-Crowe process to recover gold.

Sawtooth Wave Jig, used as the initialconcentration equipment to recover large-grained monomer goldm, is an energy-saving gravity concentrator developed on the basis of the traditional jig. The sawtooth shape of the pulsation curve makes upward waterflow faster than downward one. This processing sawtooth wave jig overcomes the shortcomings of other jigs in which the water flows upward and downward at the same rate. There for, this jig increases the porosity of the bed, alleviates the asorption effect, enables the heavy mineral particles to fully settle. So, this sawtooth wave jig suits separation of particle sizes of a wider range and greatly improves the separation capacity and recovery ratio. What's more, the water consumption is saved by 30% to 40% comparing with traditional jigs.

The sawtooth wave jig we provide is easy for installation and stroke regualtion. Control of the jig frequency is infinitely variable via frequency converter.

The centrifugal concentrator separates heavy particles and light particles by increasing the mineral grains' gravity through centrifugal force. The key component of the concentrator is a conical centrifuge bowl with good wear resistance which rotates at high speed driven by the electric motor and is surrounded by pressurized backwash water. Slurry is fed from the top to the bottom of the conical centrifuge bowl whose inner place is designed with rows of rib-like grooves. The mineral particles are pushed to the grooves by the centrifuge force generated from the rotating conical centrifuge bowl. Since the backwash water in the grooves is sprayed outward, only heavy particles can overcome the resistance, stay in the grooves, and become concentrates; while light particles, because they are less subjected to centrifugal force and cannot overcome the resistance of backwash water, are brought out of grooves, overflow the conical bowl along with the water pumped in, and finally become tailings.

The equipment has a remarkable effect on monomeric gold of different particle size ranges, especially on thinner monomeric gold. The installation of this centrifugal concentrator is after that of the jig concentrator in this gravity concentration module. With the centrifugal concentrator, the recovery ratio of gold can be more than 90% and the concentration ratio can reach 1000 times.

1 High benification ratio and recovery ratio;
2 Stable and reliable mineral processing；
3 Environmentally friendly (no chemicals are added);
4 Low consumption of water and electricity;
5 Low production costs, good wear resistance of fragile components, reduced maintenance;