Heap Leaching - Process

Process

The mined ore is usually crushed into small chunks and heaped on an impermeable plastic and/or clay lined leach pad where it can be irrigated with a leach solution to dissolve the valuable metals. While sprinklers are occasionally used for irrigation, more often operations use drip irrigation to minimize evaporation, provide more uniform distribution of the leach solution, and avoid damaging the exposed mineral. The solution then percolates through the heap and leaches both the target and other minerals. This process, called the "leach cycle," generally takes from one or two months for simple oxide ores (e.g., most gold ores) to two years (for nickel laterite ores). The leach solution containing the dissolved minerals is then collected, treated in a process plant to recover the target mineral and in some cases precipitate other minerals, and then recycled to the heap after reagent levels are adjusted. Ultimate recovery of the target mineral can range from 30% of contained (run-of-mine dump leaching sulfide copper ores) to over 90% for the easiest to leach ores (some oxide gold ores).

Read more about this topic:  Heap Leaching

Famous quotes containing the word process:

    Interior design is a travesty of the architectural process and a frightening condemnation of the credulity, helplessness and gullibility of the most formidable consumers—the rich.
    Stephen Bayley (b. 1951)

    The toddler’s wish to please ... is a powerful aid in helping the child to develop a social awareness and, eventually, a moral conscience. The child’s love for the parent is so strong that it causes him to change his behavior: to refrain from hitting and biting, to share toys with a peer, to become toilet trained. This wish for approval is the parent’s most reliable ally in the process of socializing the child.
    Alicia F. Lieberman (20th century)

    A process of genocide is being carried out before the eyes of the world.
    Pope John Paul II (b. 1920)