1. Introduction

This chapter introduces the field of Mineral Processing. A mineral processing plant can be divided into four distinct operational units: comminution, concentration, dewatering and pulp transport. Comminution is the process of reducing the particle size of an ore until the free particles of minerals can be separated by available methods. Froth flotation is the most important mineral processing technique to recover sulphide minerals, such as copper, zinc and lead. It uses the differences in physicochemical surface properties of particles of different minerals and gangue to recover a concentrate and leave the gangue as tailing that is discarded. Dewatering is a process of solid–liquid separation achieved by thickening and filtration. Thickening uses the force of gravity to separate the particles from the water by sedimentation in large cylindrical tanks called thickeners, while filtration uses pressure forces to pass the slurry through a cloth and separate it into a filter cake on the cloth and clean water called filtrate. Safe and environmentally friendly deposition of mining waste is a major concern in the mining industry worldwide. Almost all the treated minerals in sulphide concentration plants are deposited as tailings since the recovered product represents a very small percentage of the total tonnage. Water has become a major concern in processing raw materials, in terms of water conservation and reuse. The chapter discusses water consumption in the various stages of concentration and the need to recover most of that water by recycling.