Application of salt sludge recycling technology in preprocessors

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This post was last edited by sunjl1981 on 2013-1-6 at 19:49. The preprocessor works well with raw salt containing high levels of magnesium, and there are no strict restrictions regarding the ratio of calcium to magnesium ions in the raw salt. However, the capacity to remove magnesium depends on whether sufficient effective bubbles with a diameter suitable for the attachment of magnesium hydroxide can be generated. At the rated flow rate, there is a limit to the solubility of compressed air in brine; the amount of compressed air that can dissolve is limited, and the dissolved air released upon decompression also experiences losses, resulting in a decrease in mass. Therefore, when the effective amount of bubbles is not sufficient to coat all of the magnesium hydroxide, the magnesium hydroxide that lacks such coating cannot be floated out through the sludge discharge port; instead, it remains in the saline solution, which significantly affects the efficiency of separating the magnesium hydroxide. Therefore, the absolute value of the magnesium ion content in the raw salt is of utmost importance; when the magnesium ion content in the raw salt exceeds 0.15%, it becomes difficult for the brine pretreater to handle magnesium hydroxide. Due to the high magnesium ion content in crude salt, efforts must be made from two aspects to improve the separation capacity of the pretreater. On the one hand, the solubility of air should be increased as much as possible, so that air dissolves in the saltwater to reach saturation or near saturation. During the design, it is necessary to ensure that as much of the air dissolved after depressurization as possible is released, and to achieve high-quality bubble sizes, thereby minimizing losses in the amount of bubbles and degradation in their quality. On the other hand, by making full use of the structural characteristics of the preprocessor, the salt sludge recycling technology is integrated into it. This allows magnesium hydroxide, which cannot rise and separate due to the lack of sufficient small bubbles, to be surrounded by crystalline calcium carbonate solid particles present in the recycled salt sludge under the action of iron hydroxide. As a result, solid particles with a higher apparent density are formed, which then sink rapidly to the bottom of the tank thanks to the inclined plate effect and the principle of separation in the same flow direction. The separation speed of this preprocessor is the sum of the rising speed of the sludge and the sinking speed of the sediment, **which improves the preprocessor’s ability to separate magnesium hydroxide. . Note ← ) # ← , .