Concentrates, mineral processing

Concanavalin, 2, 773 Concanavalin A, 6,572 manganese, 6,587 Concentration mineral processing flotation, 6,780 Concerted electron transfer oxidases, 6,683... 

See also Minerals recovery/processing Minerals recovery/processing, 16 595-668. See also Minerals concentration Minerals processing classification in, 16 618-622 economic aspects of, 16 606-609 environmental aspects of, 16 609—610 flow sheets in, 16 603-605 materials handling in, 16 660-663 from ocean waters, 17 695—697 ores, 16 598-603 process control in, 16 663-665 size reduction (comminution) in, 16 610-615... 

Flotation or froth flotation is a physicochemical property-based separation process. It is widely utilised in the area of mineral processing also known as ore dressing and mineral beneftciation for mineral concentration. In addition to the mining and metallurgical industries, flotation also finds appHcations in sewage treatment, water purification, bitumen recovery from tar sands, and coal desulfurization. Nearly one biUion tons of ore are treated by this process aimuaHy in the world. Phosphate rock, precious metals, lead, zinc, copper, molybdenum, and tin-containing ores as well as coal are treated routinely by this process some flotation plants treat 200,000 tons of ore per day (see Mineral recovery and processing). Various aspects of flotation theory and practice have been treated in books and reviews (1 9). 

Flow Sheets. AH minerals processing operations function on the basis of a flow sheet depicting the flow of soHds and Hquids in the entire plant (6,13,14). The complexity of a flow sheet depends on the nature of the ore treated and the specifications for the final product. The basic operations in a flow sheet are size reduction (qv) (comminution) and/or size separation (see Separation, size), minerals separation, soHd—Hquid separation, and materials handling. The overaH flow sheet depends on whether the specification for the final mineral product is size, chemical composition, ie, grade, or both. Products from a quarry, for example, may have a size specification only, whereas metal concentrates have a grade specification. 

Processing costs include those for size reduction, size classification, minerals concentration and separations, soHd—Hquid separation (dewatering), materials handling and transportation, and tailings disposal. Size reduction, one of the most expensive unit operations in minerals processing, could account for as much as 50% of the total energy consumed. This cost varies considerably from deposit to deposit and quite often from one area of a deposit to another. Ore bodies are extremely heterogeneous and the associated minerals Hberation, complex. 

Mineral Applications. The flotation process is most widely used in the mineral process industry to concentrate mineral values in the ores. 

The technologies involved in the minerals processing industry can be broken down into those where the desired metal component is in high concentration, such as scrap iron, iron ore, phosphate ore, and bauxite, and those where the concentration of the valuable constituent is low, such as gold and silver ore, lean copper ore, and certain types of scrap and wastes. 

Once the comminution process is completed, the succeeding operations in mineral processing are taken over by what is known as separation. Regardless of the method or methods used, the aim is always the same-to take a natural aggregate of minerals (an ore) and separate it into two or more mineral products. In general, the products of separation are (i) the concentrate which contains the valuable minerals and (ii) the tailings which contain primarily materials of little or no value. It may be borne in mind that minerals have been liberated, either by grinding or by chemical means, must usually be sized prior to... 

Separation processes, as could be seen from Figure 2.1, position themselves at the back end of the sequence in operations in the mineral processing flowsheet. The front-end operations has been found virtually to terminate with the liberation or the size-reduction processes involving crushing and grinding. It is important to limit the amount of size reduction to that at which adequate liberation is accomplished. The term adequacy is related to the cost involved in comminution and to performance of the concentration methods that follows. The concentration is obtained by separation processes which rely on differences in the properties of the particles, the physical and physico-chemical characteristics of minerals. In this context, it will only be relevant to refer to Table 2.5 which presents a summary of the processes along with the properties of the minerals that are exploited. 

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