Mixing problem in thickener
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This post was last edited by the Project Team on 2010-7-8 at 10:17. I would like to discuss with everyone what methods can be used to address the issue of mixing occurring due to the overflow water during thickening in the process of dense medium washing and concentration, or how such mixing can be avoided. Our company is in the field of hydrometallurgy, and the thickeners in use often experience mixing problems. The method currently adopted is the addition of flocculants, but the results are not very good. The thickener is semi-efficient, with deep feeding as the feeding method. The flocculant used is polyacrylamide, which is added directly to the tank by hand; after adding water and air and stirring, it is then introduced into the feed pipe. The bottom flow concentration is around 47%.
Reply to 1# Project Team: First of all, what type of thickener do you have? Is it a conventional thickener or a high-efficiency deep-cone thickener? What is the structural design of the thickener? What is its processing capacity, the feed rate, and the feed concentration? In what manner is the flocculant added and mixed? What is the method used for mixing the flocculant, and what is the effectiveness of this mixing? Additionally, have you conducted any static tests on the material? What is the settling rate? Only by answering these questions can we provide you with a targeted response. The issue of poor mixing could be due to an incorrect choice of flocculant, poor mixing efficiency, an improper method of preparing the flocculant, or problems related to the settling rate. Of course, the feeding method of the thickener is also very crucial
In my opinion, there are three points: 1. It is related to the efficiency of your thickening machine. 2. It is related to the solid-to-liquid ratio of your slurry. 3. It is related to the amount of slag discharged by you; a high amount of slag from the thickener will definitely cause mixing, so it is necessary to increase the pressing capacity of the filter press used downstream.
I think the most likely issue is with the settlement rate; it’s best to do a better job in the previous steps, as otherwise it will be difficult to resolve!
Combining the views of the aforementioned experts, along with one more point: the composition of the roasted ore, such as the contents of iron, silicon, etc
Deaerate, maintain the height of the clear layer, and control the bottom flow concentration.
1； The feed concentration is too high 2 ； Incorrect selection of flocculant 3 ； Insufficient amount of flocculant used 4 ； The slag layer is too high, and the clear liquid layer is too low.
Another point to note is that the concentration of the feed material needs to be controlled; the optimal flocculation concentration varies for each type of material. Therefore, relevant static tests need to be conducted. As for the selection of flocculants, you can contact relevant flocculant manufacturers and ask them to help with the selection! Deep love and a gentle attitude are both good qualities. There are also some manufacturers in China that one can turn to. From what I can see regarding your materials, they settle quite well. Could it be that the force exerted by the incoming material is too high? If that’s the case, it’s necessary to reduce the flow rate of the incoming material; degassing should also be carried out before it enters the thickener, otherwise frothing will occur.
Endpoint control acidity； Material particle size ； Material composition ； liquid-solid ratio ； flocculant ；
Reply to 1# Project Team: (1) Using continuous feeding yields better results； (2) Add a supernatant filter behind the thickener ； (3) Increase the straight section of the thick liquid tank by 500-1000 ； (4) Replace the supernatant with directly collected supernatant ；
After passing through the thickener, it can be further treated using pressure filtration and a precision filter. At present, the acid leaching processes used by domestic manufacturers of copper, cobalt, nickel, and other metals generally involve a thickener + pressure filtration + precision filtration. The thickener can only be used for preliminary treatment; if specific requirements are imposed on the suspended solids, further treatment is necessary.