Preparation method of basic magnesium sulfate whiskers

The invention discloses a preparation method of basic magnesium sulfate whiskers. The preparation method comprises the following steps: S1, mixing a magnesium hydroxide source, a sulfate source and water to obtain a mixture, wherein the mass percent of magnesium hydroxide in the magnesium hydroxide source is not lower than 50%; S2, carrying out hydrothermal reaction on the mixture for 1-40 hours at the temperature of 100-300 DEG C, so as to obtain suspension; and S3, carrying out solid-liquid separation on the suspension, so as to obtain a solid phase and a liquid phase, washing, and drying the solid phase, so as to obtain the basic magnesium sulfate whiskers. According to the preparation method of the basic magnesium sulfate whiskers, the magnesium hydroxide source with relatively low magnesium hydroxide purity is taken as a preparation raw material; on one hand, the pollution and waste of byproduct magnesium hydroxide magnesium slag are reduced, and thus the magnesium harm problem is effectively controlled; and on the other hand, ammonia water, sodium hydroxide and the like are avoided from being used as a base source, and thus the preparation method is reduced. Meanwhile, the preparation method does not need other additives and is simple in technology; and the obtained basic magnesium sulfate product has high purity and good dispersibility.