Rock to metal product
The metal products we use every day are the result of a series of transformation through selected mineral processing. The transformation which starts with the rock present in the Earth’s crust. Rocks are natural groupings of one or more minerals. The rocks formed and transformed over millions of years by the forces of nature. They are essential materials which make up the Earth. The rocks can contain both minerals that are consider as valuable and others consider as undesirable. These are relative terms influence by extraction cost, metal prices, minerals associate with, and other characteristics of a particular deposit.
The goal of mineral processing is to separate the valuable minerals from each other and from gangue. Mineral processing takes place in a concentrator, often called a mill. The concentrator is usually identified by its main product, for example a copper concentrator.
The essential purpose of mineral processing in short is to reduce the bulk of the ore which must be transported to and processed by the smelter. More over those process should be using relatively cheap, low-energy physical methods to separate the valuable minerals from the waste (gangue) minerals. In addition, this enrichment process considerably increases the contained value of the ore to allow economic trans- portation and smelting.
Mineral processing reduces not only smelter energy costs but also smelter metal losses. It is due to the production of less metal-bearing slag. Although technically possible, the smelting of extremely low-grade ores, would be very difficult. The need to produce high-grade metal products free from deleterious impurities apart from being economically unjustifiable, are the main reasons.
The selection method of mineral processing really depend on the mineralogy of ores and the final product we desired for. The mineralogy include the degree of liberation, particle size, gangue, hardness, etc. One example, the mineral processing for some kind of nickel ore only need the comminution process. This kind of ore do not need the flotation process, the ore will directly send to the smelter. In the other hand, sulphide copper ores need flotation process to enhanced the concentration.
Product of mineral processing
The main product of mineral processing process from concentrator are the concentrate streams. Concentrate streams mostly consist of valuable minerals. The other product is the tailings streams, mostly gangue. The mineral processing, most of all will always consist of these two final products.
In many cases not only is it necessary to separate valuable from gangue minerals, but it is mineral processing also required to separate valuable minerals from each other. For instance, porphyry copper ores are an important source of molybdenum and the minerals of these metals must separate for different smelting process.
Mineral processing operations are often a compromise between improvements in metallurgical efficiency and milling costs. This is particularly true with ores of low value. Not only the low milling costs are essential but also cheap unit processes are necessary. With such low value ores, hence mineral processing improvements in metallurgical efficiency by the use of more expensive methods or reagents cannot always be justified.