The spiral chute mainly uses the inertia centrifugal force generated by the minerals of different densities in the spiral rotary motion to realize the separation of light and heavy minerals. It is widely used in the gravity separation process because of its simple equipment structure, low power consumption and large processing capacity. At present, mineral resources are faced with unfavorable conditions such as dilution, refinement, and hybridization. Improving the beneficiation efficiency of sorting equipment and improving the recovery rate has become the top priority of current mining development and research topics. This article mainly teaches you how to effectively improve the beneficiation efficiency of the spiral chute from three aspects.

1.Structural parameters and performance of the spiral chute 

1).Diameter of spiral chute

The diameter of the spiral chute has a direct impact on the processing capacity and the recovery rate of each grade of minerals. Generally speaking, the larger the diameter of the spiral chute, the larger the volume and flow rate of the ore flow, and the greater the processing capacity per unit time. According to practical experience, the smaller the diameter of the spiral chute, the smaller the lower limit of the recovery particle size and the higher the recovery rate.

2). Longitudinal inclination of spiral chute

The intersection angle between the tangent of the cross-section curve of the spiral groove and the vertical axis is called the longitudinal inclination angle. Therefore, a small inclination angle is used when selecting fine-grained minerals, and a large inclination angle is used when selecting coarse-grained minerals. Appropriate longitudinal inclination angle can make the pulp run along the tank body, obtain good beneficiation index and improve the beneficiation efficiency.

3). Lateral inclination of spiral chute

The lateral inclination angle and the longitudinal inclination angle are complementary. The lateral inclination angle also affects the distribution of the slurry flow on the groove surface. The greater the lateral inclination angle, the greater the depth of water flow. Therefore, a small lateral inclination angle is used when sorting fine-grained ores, and a large lateral inclination angle is used when sorting coarse-grained ores.

4). The number of turns of the spiral chute

The number of turns of the spiral chute determines the sorting distance and the sorting time. In the actual operation, it needs to be determined according to the properties of the selected materials and the requirements of the operation indicators. When the useful minerals are closely embedded with the gangue minerals and it is difficult to separate, a large number of circles should be selected to extend the separation distance and time and improve the separation efficiency. Don’t be efficient. However, the number of turns should not be too many, otherwise it will increase the height of the spiral chute and increase the difficulty of the operation. Industrial selection mostly uses 4-6 turns of spiral grooves.

5). The inner surface of the spiral chute

The inner surface of the chute is required to be smooth, uniform and wear-resistant to ensure that the pulp runs smoothly without clogging. In order to enhance the wear resistance, the inner surface of the glass fiber reinforced plastic spiral chute is usually coated with polyurethane wear-resistant rubber.

2.Properties and characteristics of feed ore

Appropriate feed particle size, shape and density are of great significance for the sorting of useful minerals and gangue minerals.

1).Mineral particle size

Usually, the upper limit of the feeding particle size of the spiral chute is 6mm. Muddy minerals need to be deslimed and classified before feeding to prevent material blockage and affect the sorting efficiency.

2). Mineral particle shape

The shape of the mineral particles also affects the speed of movement of the minerals in the spiral chute. When the shape of useful heavy minerals is mostly irregular or flaky, and the gangue minerals are round, the heavy minerals move slowly, which is conducive to stratification and settlement, reduces the grade of tailings, and improves the sorting efficiency.

3). Mineral density

Since the spiral chute is mainly based on the different density differences of minerals, the larger the density difference between the useful minerals and gangue minerals in the selected ore, the more conducive to the separation.

3.Process parameters in the operation of the spiral chute

1).Feed volume

The ore feed volume affects the thickness and velocity of the ore flow to a certain extent. Therefore, in order to improve efficiency, the feeding volume of coarse-grained materials is large, and the feeding volume of fine-grained materials is small.

2). Feeding concentration

The spiral chute requires the concentration of ore to be greater than 30%, which should not be too large or too small. If the feeding concentration is too large, the viscosity of the slurry will increase, and the ore layer will not be easy to loosen, which will hinder the sedimentation of the ore particles, seriously affect the stratification effect and the moving speed of the ore particles, thereby reducing the concentrate grade and recovery rate. If the ore feeding concentration is too small, the processing capacity per unit time will decrease, the mineral material layer will become thinner, and the stratification and zoning will not be possible, resulting in an increase in the flow rate of the slurry, and the useful heavy minerals will be discharged before stratification and sedimentation, and the tailings grade will increase. , reducing the sorting efficiency.

The above are the three major points that affect the separation efficiency of the spiral chute: the structural parameters and performance of the spiral chute itself, the properties of the incoming ore, and the process parameters in the operation of the spiral chute. In practical applications, the operator of the spiral chute must improve the monitoring of the above aspects. If there is a problem, it should be analyzed in detail and adjusted in a targeted manner to obtain the ideal separation efficiency of the spiral chute and ensure the smooth production of the plant.