The spiral chute mainly uses the inertial centrifugal force generated by the mineral of different density in the rotating motion of the spiral to separate the heavy and heavy minerals. At present, mineral resources are faced with such unfavorable conditions as depletion, refinement and hybridization, so improving the dressing efficiency of sorting equipment and improving the recovery rate have become the most important task in the development and research of mining industry. This article mainly from three aspects to teach you how to effectively improve the spiral chute dressing efficiency.
I.The structure index and performance of spiral chute
1.The diameter of spiral chute
The diameter of spiral chute has direct influence on the capacity and recovery rate. Generally speaking, the larger the diameter of spiral chute, the larger the volume and velocity of ore flow, and the greater the processing capacity per unit time. According to the practical experience, the smaller the diameter of spiral chute, the smaller the lower limit of recovery particle size and the higher the recovery rate.
2.The longitudinal angle of spiral chute
The intersection angle between the tangent line of the spiral groove section curve and the vertical axis is called the longitudinal inclination Angle. Therefore, a small dip Angle is used in the selection of fine minerals and a large dip Angle is used in the selection of coarse minerals. The suitable longitudinal inclination Angle can make the slurry run along the channel body, obtain good dressing index and improve dressing efficiency.
3.The horizontal inclination of spiral chute
The transverse inclination is complementary to the longitudinal inclination. The transverse inclination Angle also affects the distribution of slurry flow on the trough surface. The greater the transverse inclination, the deeper the water flow. Therefore, a small transverse dip Angle is used for fine ore selection, while a large transverse dip Angle is used for coarse ore selection.
4.Number of turns in a spiral chute
The number of turns in the spiral chute determines the separation distance and time. In the actual operation, it is necessary to determine according to the nature of the selected materials and the requirements of the operation indicators. When the useful minerals and gangue minerals are closely embedded and it is difficult to separate them, it is advisable to choose a large number of turns to extend the separation distance and time and improve the separation efficiency. But the number of turns should not be too much, otherwise it will increase the height of the spiral chute, increase the difficulty of the operation. Industrial choose not to use 4-6 more spiral groove.
5.Internal surface of spiral chute
The inner surface of the chute is required to be smooth, uniform and wear resistant to ensure that the slurry runs smoothly and does not clog. To enhance wear resistance, the inner surface of the spiral chute is usually coated with polyurethane wear-resistant rubber.
II.Feed ore characteristics
The suitable size, shape and density of feeding materials are of great significance for the separation of useful minerals and gangue minerals.
1.Mineral particle size
Normally, the upper limit of screw chute size is 6mm. The argillaceous minerals need to be desilted and graded before feeding to prevent material clogging from affecting the sorting efficiency.
2.Mineral grain shape
The shape of the mineral particles also affects the speed at which minerals move through the spiral chute. When the shape of useful heavy minerals is irregular or flaky and gangue minerals are round, the movement speed of heavy minerals is slow, which is conducive to stratification and settlement, reducing tailings grade and improving separation efficiency.
Because the spiral chute is mainly sorted according to the different density differences of minerals, the larger the density difference between the useful minerals and gangue minerals in the selected ores, the more favorable the separation will be.
III.Process parameters in spiral chute operation
1.The feeding volume
To some extent, the volume of ore feed affects the thickness and velocity of ore flow. Therefore, in order to improve the efficiency, the coarse material feeding volume is large, the fine material feeding volume is small.
2.The feeding concentration
Spiral chute requirements for ore concentration greater than 30%, should not be too large or too small. If the concentration of ore is too large, the slurry viscosity increases, and the ore layer is not easy to be loosened, which will lead to the blockage of ore particle settlement, seriously affecting the stratification effect and the movement speed of ore particle, thus reducing the concentrate grade and recovery. If the concentration of ore is too small, the unit time processing capacity will be reduced, the material layer will become thinner and cannot be stratified and zoned, resulting in the increase of pulp flow rate, and the useful heavy minerals will be discharged before stratification and settlement, thus the tailing grade will increase and the separation efficiency will be reduced.
These are the three points that affect the efficiency of spiral chute separation: the structure parameters and properties of the spiral chute itself, the properties of the incoming ore and the process parameters of the spiral chute operation. In practical application, spiral chute operators must improve the above aspects of monitoring, if there are problems should be specific analysis, targeted adjustment, in order to obtain the ideal spiral chute sorting efficiency, to ensure the smooth production of the selection plant.
Xinhai Mining Mineral Processing EPC+M+O Projects
1.Guinea 6000tpd gold mine beneficiation plant project
2.Yunnan 4400t/d copper mine sorting plant project
3.Pakistan 1500tpd copper ore sorting plant project
4.Armenia 1500t/d copper, lead and zinc separation plant project
5.Tanzania 1200tpd gold mine beneficiation plant project
6.Mongolia 1000tpd gold mine beneficiation plant project
From:Xinhai Mining Machinery Company