Gravity spiral chute is also called spiral concentrator or gravity separator, it's a kind of gravity concentrator which can separate mineral particles according to density, granularity and shape by the interaction of centrifugal force, friction force of chute surface, water flow pressure and gravity of minerals. Spirals are made of high-density fiberglass, high quality emery and unsaturated resin. It has the advantages of simple and reasonable structure, no moving parts, light weight, small floor area, low price but high separation effect. It is the best roughing gravity equipment, which has been widely used in ferrous and nonferrous metal mines. The spiral chute is suitable for separation of 0.3-0.02mm fine materials such as iron ore, ilmenite ore, chromite ore, pyrite ore, zircon ore, rutile ore, monazite ore, tungsten ore, tin ore, tantalum ore, niobium ore and other materials with enough specific gravity difference.
The gravity spiral chute of larger diameter and pitch should be used for the coarse grain material with a little part of -0.074mm, the spiral chute of smaller and pitch should be used for fine grain material with 60-70% of -0.074mm. The spiral chute is usually used in combination of multiple units, such as 4 units for a group, 8 units for a group or 12 units for a group, etc. Multiple units can be combined into a large cluster, which can theoretically form an infinite capacity spiral concentrator processing plant.
Gravity spiral chute working principle
The spiral chute separate mineral by the difference of gravity, inertial centrifugal force, water flow force and friction force of chute surface caused by the light and heavy material particles flow downward along the inclined spiral surface. The movement of slurry flow on the spiral chute surface is relatively complex, which generally creates two directions of movement. One is the longitudinal flow that rotates around the vertical axis of spiral chute and goes down along the chute surface, which is called the main flow. The other one is the transverse flow that rotates itself at a certain equilibrium layer of the material flow, which is called the transverse circulation flow or side flow. The flow speed of upper layer of longitudinal flow is fast, and the flow speed of lower layer is slow. The upper layer of transverse circulation flow goes the outer edge of chute, the lower layer goes inner edge of chute. The feeding grains on the spiral chute surface, under the combination of longitudinal flow and transverse circulation flow, and because of the different density, size, shape, etc., forms move speed difference of longitudinal and transverse when flow along the spiral, make early or late and fast or slow different sedimentation at the bottom of chute, material gets layering according to the density and particle size. After layering, zoning is the second stage of separating process, which usually takes 3-5 turns to complete. After the above two stages, the mineral divider and the mineral receiver discharge the separated products out of the chute, thus completing the separation process.
Gravity spiral chute diagram
Advantages and features
1. Low price, long service life, low operating cost, low investment and quick revenue;
2. Light weight, easy installation, small floor area, save foundation construction investment;
3. Moisture-proof, rust-proof, wear-resistant and corrosion resistant;
4. Water and power saving, simple operation, no moving parts, no maintenance;
5. The separating process is stable and easy to control;
6. Strong adaptability of feeding amount, concentration, particle size and grade. High enrichment ratio and high recovery rate;
7. The special friction force formed on the emery surface makes the separation effect better than other plastic surfaces.
Application case video
Chrome ore processing plant: https://youtu.be/rACFDCrujxY
Main technical parameters
