TABLE OF CONTENTS Polymers of different chemical composition are used in the mineral processing industry as flocculants, coagulants and dispersants. The number of these polymers continues to grow and applications have expanded to include selective flocculation, anti-scaling agents and binders for dust control. All these chemicals are either organic polymers or inorganic substances. Because polymeric compounds can vary in electrical charge, molecular weight, three-dimensional structure and hydrophobicity, the range of compositions of functional polymers is virtually limitless.
The polymers used in the above applications can be broadly defined as large molecules made up of repeating units. In the case of long-chain synthetic polymers, a reactive monomer unit is polymerized with the same or other monomer units in a sequential fashion resulting in molecular strands. The number of linked units may vary anywhere from a few to as many as hundreds of thousands. This number reflects the molecular weight of the polymer.
The polymers used in flocculation, coagulation and dispersion, are either synthetic polymers (produced from polyacrylates) or natural polymers (starches, guar gums, etc.).
The chemicals used for flocculation, coagulation and dispersion can be classified into two broad groups: inorganic and organic reagents. A different classification [1] is based on the action of the flocculant and is divided into the following categories:
Polymers with flocculating action
Polymers with dispersing actions
Polymers with coagulating actions.
Inorganic flocculants are used in applications where the source of cationic charge is required. Typical inorganic flocculants include:
