How Does Flocculant Work ?

Solid Liquid suspensions vary greatly in their proporties particularly with respect to the rate of settling of solid particles.

In many industrial processes separation of solid particles from the liquid is a critical step. In many cases solids settle at a very low or even negligible velocity and the clarity of supernatent liquid may also be poor.
When a very small quantity of dilute solution of flocculant is mixed with such suspensions, a large number of solid particles form a loosely adhering agglomorate of particles called flocs.
This floc behaves as a large size particle and settles at a very high velocity in the liquid.
Flocculants are very long linear molecules of polymers and act by neutralising repulsive electrical charge on suspended particles and further the solid particles get attached loosely to the polymer chain forming flocs. Thus the floc consisting of solid particles attached to polymer behave as a large sized mega particle and settle at a high velocity. Intrestingly extremely small size particles are also trapped in flocs and the resultant supernatent aqueous phase is relatively very clear.
In case of emulsion of water with oil or grease, etc. the later will separate at a faster rate and float at the surface. Similarly the flocculant can form large size flocs in air floatation technique for faster upward movement of flocs aided by small air bubbles.

  • Some of the factors that can affect floc fomation are as follows;
  • Major effects:
    1. Type of flocculant.
    2. Nature of solids.
    3. pH of aqueous media
    4. Weight ratio of solids to flocculant
    Minor effects :
    1 Manner of mixing the flocculant with solid-liquid suspension.
    2 Agitation.
    3 Strength of flocculant solution.

    Prior treatment of solids with a conditioner in some cases can bring about major favorable change in behaviour of solids towards floc formation eg. Organic solids or highly stable suspenions of colloidal particles. It is extremely useful to know the influence of the above factors which play a role in floc formation and settling rate while selecting type of flocculant, designing the system on plant scale and in troubleshooting to get the best results.

    Information about Flocsure Flocculants

    FLOCSURE can reduce cost.

    By the use of FLOCSURE can make remarkable improvement in solid-liquid separation.

    FLOCSURE range of flocculants are available in various grades.

    Kindly note that Laboratory tests are essential to choose right grade of flocculant and dosage for your application.

    Flocculant can enhance performance of

    Settlers, Thickners, Clarifiers, Filters, Drying beds Solid bowl centrifuge system. Air floatation units. Oil recovery units. Effluent treatment plants.

    Solubility in Water

    Flocculants dissolve slowly in water.Use of warm water can hasten dissolution. Overnight soaking in water helps in dissolution. FLOCSURE solution of 0.5 to 2 % concentration should be used. Dilute solutions give better results. Dilute Solution of FLOCSURE should be used within 1-2 days. FLOCSURE jelly has shelf life of approx 6 months.

    Save Energy

    Flocculants can reduce electrical power consumption due to higher through-put from equipment. Too low or high dose of flocculant compared to the optimum can result in poor floc formation.

    To Enhance Flocculation

    Positive displacement pumps are recomended for pumping dilute solution of flocculants. Centrifugal pumps should not be used for pumping flocculant solution or flocs. Vigorous agitation of solution of flocculant or floc should be avoided. Pumping through small diameter pipelines over a long distance should be avoided.

    Prior treatment with Conditioner

    Polymer gets attached to solid particles irreversibly. Behaviour of certain solids towards floc formation can be altered by prior treatment with conditioners. In certain cases difficult looking objectives can be achieved by use of flocculants.