Problems with thickening machines in hydrometallurgical processing
Thread Content
In the wet smelting of zinc, 1. Thickening machines are used for leaching; how should one understand the thickening capacity of these machines? 2. In zinc smelting, filter presses are required in multiple processes. I would appreciate it if experts could advise whether there are any methods or tips to reduce the moisture content in the slag produced by these filter presses
Regarding the concentration capacity of thickeners, you can consult experts who specialize in this area; it seems there’s little information on this topic in the forums. I suggest that the forum moderators initiate a discussion on this subject. It is necessary to consider various aspects such as the composition of the solution, the selection of the filter press, the material used for the filter cloth, and the filtration method.
-- Those who are interested can follow up with discussions. The timing for a separate edition is not yet right. --
To reduce the moisture content of the filter residue, a diaphragm filter press can be used, or a chamber filter press combined with compressed air backwashing at a pressure of over 4 kilograms can be employed. Generally, the moisture content is around 25~30%.
Can it go any lower than 25-30? Hehe, like around 20.
1. The thickener is actually used in conjunction with a concentration tank. It has three zones: the supernatant zone, the clarification zone, and the sludge zone. Its performance depends mainly on the quality of the supernatant and the ability to remove waste material through the underflow. 2. Regarding filter presses, what’s needed is waste material with low moisture content; box-type and plate-and-frame filter presses are recommended for this purpose. There are many factors that influence performance, including the composition of the waste material, its pH value, temperature, filtration time, pump pressure, the choice of filter press, and the material used for the filter cloth.
1. The thickener is a complex device that also functions as a solid-liquid clarification unit, equipped with a rotating rake mechanism inside. It is related to factors such as the viscosity and density of the clarified slurry. 2. In zinc smelting, filter presses are mainly used for separating the liquid phase from the acid-leached slag (lead slag) in wet processes. To reduce the moisture content of the slag, filter presses equipped with diaphragm pneumatic or hydraulic crushing devices can be utilized.
The concentration capacity (processing volume) of a thickener depends primarily on the settling area; the processing volume per unit area varies depending on the material being processed. This information can be found in relevant books. In actual production, it is also necessary to conduct settling tests on the material to be processed, as a larger settling area results in a higher processing volume. A plate and frame filter uses the pressure exerted by the plates and frames to filter minerals, but it can withstand only a limited amount of pressure; the moisture content in the filter cake is ideally around 25%. To achieve a lower moisture level, a vertical press filter can be used. The principle is similar, but the book states that the moisture content can reach as low as 8% (this varies depending on the material).
5# lifei7772 Haha, if that level of moisture is reached, the simplest way is to set up a drying facility for natural ventilation and drying. Some zinc oxide manufacturers do exactly this. It can reduce the consumption of coke dust.
A plate and frame filter uses the pressure exerted by the plates and frames to filter minerals, but it can withstand only a limited amount of pressure; the moisture content in the filter cake is ideally around 25%. To achieve a lower moisture level, a vertical press filter can be used. The principle is similar, but the book states that the moisture content can reach as low as 8% (this varies depending on the material).
It mainly depends on the properties of the slag; acidic slags have a higher water content, and countercurrent washing can be considered to reduce the acidity!