In modern beneficiation process, the vast majority of concentrators use the wet separation process, and the concentrate after this process has a high moisture content, so it is impossible to smelt the concentrate directly. As the first step of dewatering operation, concentration operation has an impact as high as 9% on the whole beneficiation process and 35% on the whole dewatering operation. The quality of concentration equipment will directly affect the dehydration effect. High quality thickener will often increase the concentration of concentrate by 20% – 30%, and then enhance the concentration effect.
LDHB gravity thickening is a kind of solid-liquid separation equipment based on gravity sedimentation. When working, the solid particles suspended in the pulp in the concentrator vertebral body settle under gravity, and the upper part becomes clear water, so that the solid and liquid can be separated. The slurry wastewater with solid content of 2% ～ 15% can be raised to slurry with concentration of 60% ～ 70% by gravity sedimentation, and the upper part of the tank can realize clear water overflow, so as to achieve the purpose of sewage purification and solid-liquid separation.
When gravity thickening is working, the slurry should first pass through the feeding pipe and enter the feeding bucket. The slurry will flocculate in the feeding bucket and then enter the dense sediment layer, and then flocculate, filter and compress in the dense sediment layer. The upper clean water will be discharged from the upper overflow weir to become overflow, and the underflow with higher concentration will be discharged from the lower cone bottom. Generally, there are three indispensable stages in order to achieve good thickening results, namely coagulation destabilization stage, coagulation granulation stage and filtration compression stage. If the flocculation is not sufficient, the solid-liquid separation will not get ideal results. The same is true for high-efficiency deep cone.
The slurry flocculates in the concentration tank. When the large flocs in the slurry increase to a certain amount, the ideal dense phase layer is formed at the bottom of the thickener. The upper part of the dense phase layer is composed of relatively thick and unstable flocs. During the thickening process, they are floating filter media, which can effectively intercept the fine particles escaping with the upwelling. Due to the gravity of the material and the extrusion of the water head of the sediment at the bottom of the dense phase layer, the underflow of the thickener is under greater pressure, which greatly increases the concentration of the discharged underflow.
LDHB gravity thickener has the advantages of small floor area, large treatment capacity, high degree of automation, energy saving and so on, which makes it used for high concentration concentration in concentrator, and also widely used for concentration of other fine and low density slurry and wastewater treatment.