Separating and recovering silicate particles from plant material

An apparatus for separating and/or extracting silicate particles from plant material, the apparatus comprising:

• a first air classifier having at least one material inlet, one air inlet below the material inlet, one air outlet, and at least one particle receiver below the air outlet, wherein
• means for flowing an air stream through the air inlet, across the first air classifier above the particle receiver, and then out the air outlet;
• means for feeding comminuted plant particles obtained by comminution into the air classifier through the material inlet such that the particles are exposed to the air stream in such a way that silicate particles contained in the plant material are discharged with the air stream via the air outlet and, by force of gravity, the plant particles drop into the particle receiver;
• and
• means for removing the particles in the receiver from the classifier.