The seeding coefficient refers to the ratio between the amount of seeding agent added during the seeding process and the quality of the crystal produced by the seeding. The seed coefficient plays an important role in affecting the filtration performance of magnesium hydroxide slurry.
Increasing the seed coefficient can effectively improve the filtration performance of magnesium hydroxide slurry. An appropriate amount of seeding agent can provide more crystal nuclei, speed up the generation of crystals, and make the crystal distribution more uniform. This can increase the viscosity of the slurry, improve its filtration performance, reduce filtration resistance, and improve filtration efficiency.
However, an excessively high seed coefficient may lead to the generation of too many crystal nuclei, causing the crystals to aggregate unevenly and form agglomerates, thereby affecting the fluidity and filtration performance of the slurry. Therefore, in practical applications, it is necessary to select an appropriate seed coefficient according to specific conditions to obtain the best filtration performance.
The influence of seed coefficient on the filtration performance of magnesium hydroxide slurry is mainly reflected in the following aspects:
① Affects the formation of filter cake: The seed crystal is the core of filter cake formation. The higher the crystal seed coefficient, the greater the number of seed crystals, the faster the filter cake is formed, and the higher the filtration rate.
② Affects the density of the filter cake: The seed crystal can promote the aggregation of magnesium hydroxide particles and increase the density of the filter cake. The higher the seed coefficient, the higher the density of the filter cake and the greater the strength of the filter cake.
③ Affects the clarity of the filtrate: Seed crystals can adsorb impurities and improve the clarity of the filtrate. The higher the seed coefficient, the higher the clarity of the filtrate.
Specifically, the effect of seed coefficient on the filtration performance of magnesium hydroxide slurry can be studied through the following experiments:
Experimental method: Add a certain amount of magnesium hydroxide slurry into the filter bag, filter it, and measure the filtration rate, filter cake thickness, filter cake density, and filtrate clarity.
Experimental results: Experimental results show that as the seed coefficient increases, the filtration rate gradually increases, the filter cake thickness gradually decreases, the filter cake density gradually increases, and the filtrate clarity gradually increases.
Therefore, when producing magnesium hydroxide, an appropriate seed coefficient should be selected according to the actual situation to improve the filtration performance of magnesium hydroxide slurry.
The following are some suggestions for selecting seed coefficients:
When used to produce powdered magnesium hydroxide, the seed coefficient is usually 0.05% to 0.10%.
When used to produce bulk magnesium hydroxide, the seed coefficient is usually 0.10% to 0.20%.
Of course, the selection of seed coefficient also needs to consider other factors, such as the type of magnesium hydroxide, the concentration of the slurry, the type of filter, etc.