Tin ores flotation

Mining. Numerous patents have advocated the use of alkanolamines in mining appHcations. Triethanolarnine has been used as a depressent in the flotation of copper (164), in the electrotwinning of gold (165), and as an aid in the froth flotation of nickel ores. Phosphate ore flotation has been improved through the use of a fatty acid condensate with ethanolamine (166). Beneficiation of tin ore has been accompHshed using fatty acid alkanolamides (167). 

Beneficiation of tin ores exclusively includes a combination of gravity preconcentration and flotation, where the flotation includes (a) flotation of sulphides from the gravity concentrate and (b) flotation of sulphides from the fines, followed by tin flotation from the sulphide tailing after desliming. 

There are three main methods used for beneficiation of tin ores (a) physical concentration including gravity concentration, magnetic separation and electrostatic separation (b) flotation and (c) a combination of gravity preconcentration and flotation. 

Flotation is only employed for beneficiation of disseminated tin ores. 

The depressant of choice for cassiterite flotation depends very much on the type of gangue minerals present in the ore. Extensive research work has been carried out in which a number of depressants have been examined on tin ores containing different gangue minerals [12-14], A number of these depressants have been introduced into various operating plants around the world. 

Research work has shown that cassiterite from various deposits and often even from parts of the same deposit differ in chemical composition, colour, flotation properties, chemical activity and electrophysical characteristics. Therefore, the mineralogical composition of tin ores and the physiological properties of the minerals, in particular cassiterite, determine to a great extent the quantity of tin lost during gravity processing and especially during flotation. 

Polkin, S.I., Flotation of Rare Metal and Tin Ores, Gosgorte-khizdat, Vol. 637, pp. 77-82, 1971, (Russian text). 

Despite the 78-6% of tin in pure SnC>2, the tin ores for extraction of the metal often contain only a few per cent of tin. Initial concentration is carried out by flotation removal of lighter rocks, such as sUica, and magnetic removal of certain impurities such as tungsten minerals. Roasting volatilizes sulphur and arsenic and oxidizes many metals... 

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). 

The abundance of indium in the earth s cmst is probably about 0.1 ppm, similat to that of silver. It is found in trace amounts in many minerals, particulady in the sulfide ores of zinc and to a lesser extent in association with sulfides of copper, tin, and lead. Indium follows zinc through flotation concentration, and commercial recovery of the metal is achieved by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting and associated lead (qv) and copper (qv) smelting (see Metallurgy, EXTRACTIVE Zinc and zinc alloys). 

Hard rock deposits are richer in tin than in the placer deposits, ranging from 0.6% up to 5% Sn. Such known deposits are located in Brazil, Canada, Bolivia, Pem and the USA. Because the tin from these ores is disseminated, beneficiation processes include a combination of gravity preconcentration and flotation. 

Tin concentration from these deposits is further complicated because these deposits contain sulphides, and occasionally tin-bearing sulphides. These sulphides have to be removed from the final tin concentrate. Some ores (New Brunswick, Canada) contain wolframite, which is removed by either flotation or high-intensity magnetic separation. 

Lead is produced commercially from its principal ore, galena (PbS). The ore is associated with sulfides of several metals including iron, copper, zinc, silver, bismuth, arsenic, antimony and tin. The ore is crushed and ground. It then is selectively separated from gangue and other valuable minerals by one or more processes that include gravity separation and flotation. Selective... 

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