Wet beneficiation usually requires dewatering of certain beneficiation products. Most of the dewatering of concentrates adopts a two-stage process of concentration and filtration or a three-stage process of concentration and drying. Tailings are generally transported to a tailings pond after being concentrated by a high-efficiency thickener. Sometimes, the intermediate product (medium ore) in the separation process also needs to be concentrated to meet the concentration requirements of the next stage of operation.
At present, ordinary mechanical discharge thickeners are still widely used at home and abroad. In recent years, high-efficiency thickeners, inclined plate thickeners, and high-efficiency deep cone thickeners have also been developed and applied. There are two common thickeners: central drive and peripheral drive. The center drive type thickener can automatically lift the rake, and the maximum diameter of the foreign center drive type thickener is 20 m. The peripheral drive thickener is divided into two types: roller drive and rack drive. The diameter of the domestic roller drive thickener is 15~30m, which is mainly used for the processing of low-density materials. The peripheral drive thickeners with diameters of 45m, 50m and 53m can be divided into light and heavy. The lighter ones are used for tailings processing, and the heavier ones are used for concentrate processing.
Equipped with special flocculant addition and mixing device, the settling speed is fast; some have removed inclined plates to increase the settling area. The processing capacity of the high-efficiency concentration unit area is relatively high, which can reach 7~8t/(M2·d). The small size of the equipment is suitable for small and medium-sized beneficiation plants, especially when the plant is narrow and the thickener must be installed indoors.
Inclined plate type thickener can shorten the settling time of materials, increase the settling area, improve the concentration efficiency, and increase the processing capacity per unit area. However, the structure of the inclined plate thickener is complicated and inconvenient to maintain. The equipment is suitable for some mineral processing plants.
Magnetic separators or magnetic dewatering tanks are commonly used to concentrate ferromagnetic mineral concentrates in magnetic separation plants. A type of mineral processing equipment,
The selection of the type, specification and quantity of mineral concentration equipment should meet the requirements for the concentration of ore discharge in the next stage of operation, and should also meet the requirements for reducing the loss of useful minerals and the quality of overflow water. The maximum allowable solid particle settling speed in the overflow of the thickener is an important factor in determining the concentration area. It is related to the density and particle size composition of raw materials, solid ratio of ore input and output, slurry viscosity, flotation agent and flocculant type, slurry temperature and other factors.