Flotation Circuits

The fine mica fraction is deslimed over 0.875—0.147-mm (80—100-mesh) Trommel screens or hydrocylcones, or is separated with hydrosi2ers. The deslimed pulp (<0.589 mm (—28 mesh)) of mica, feldspar, and quart2 is then fed to a froth flotation circuit where these materials are separated from each other either by floating in an acid circuit with rosin amine and sulfuric acid (2.5—4.0 pH), or an alkaline circuit (7.5—9.0 pH) with tall oil amine, goulac, rosin amine acetate, and caustic soda (see Eig. 2). 

Molybdenite [1309-56 ] M0S2, normally floats with the copper sulfides. Therefore, the copper concentrate from the cleaner cells frequently has to be separated from molybdenite in a separate flotation circuit before the copper concentrate goes to the smelter. Gold, silver, selenium, and tellurium are collected with the copper concentrate. 

In the molybdenum flotation circuit, the use of sodium sulfide as a depressant is quite important in order to depress sulfides of copper which are invariably associated. In solution, sodium sulfide hydrolyzes and then dissociates ... 

Lead Flotation Circuit Cells 1-2 Cleaners Cells 3-5 Roughers Cells 6-8 Scavengers... 

The flowsheet used in this plant (Figure 19.8) consists of a rod mill-ball mill grinding system and a copper rougher-scavenger flotation circuit, followed by two cleaning stages. Initially, the plant used a rake classifier, but now the rake classifiers have been replaced by cyclones. 

By adding a flotation circuit, the overall tin recovery increased from 65% to 87%. In 2005, the project was in the feasibility study stage. It is not known if the Huanuni flotation plant, which was under construction in 2001, has been completed. 

In 1980, Bemic Lake introduced a flotation circuit to float Ta/Nb from the gravity tailings using succinamate collector at a pH of about 4.5 controlled by hydrochloric acid. The main depressants used included Na2SiF6 and oxalic acid. 

Performance of the flotation circuit was related to the flotation pH. The effect of pH on Ta/Nb recovery is illustrated in Figure 23.6. 

The flowsheet (Figure 25.18) shows the final flowsheet developed for the beneficiation of the Guadalajara ore. This flowsheet consists of two flotation circuits (a) gangue prefloat circuit, where the apatite and calcite are recovered, and (b) titanium flotation circuit, where... 

Under suitable pulp potential in the OPCF process, the flotation speed of galena is very fast and most galena has been floated just in rougher flotation stage. So the flotation cell of galena scavenger flotation operation can be diminished and the flotation circuit is further optimized. The comparison of operation parameters between traditional flowsheet and OPCF flotation is presented in Table 10.13. As can be seen, the flotation potential and time are lower in OPCF than in traditional flowsheet. 

Electrostatic-type separation is being tested as an alternative to the presently used process of flotation of pebble phosphates for coarser-size fractions. Advantages sought include reduced reagent costs, a lower water requirement, and fewer tailings-disposal problems when a part of the flotation circuit is eliminated. The largest application of triboelectric separation is in the salt industry where sodium and potassium salts are separated after preconditioning. 

In the processing of mined potash ores, clay in the pulped ore causes higher consumption of collector reagents by adsorption of these, and reduced sylvite recoveries. The clay may be separated from the pulped ore prior to the addition of the amine collector by a desliming decantation, which is a gentle, preflotation collection of the clays in a clay-laden froth. The brine from the clay/brine froth is recycled to the flotation circuit after flocculation of the clay followed by removal of the floe in a thickener [22]. 

Guria, C., Verma, M., Mehrotra, S. P. and Gupta, S. K. (2006). Simultaneous optimization of the performance of flotation circuits and their simplification using the jumping gene adaptations of genetic algorithm-II More complex problems, Int. J. Miner. Process, 79, pp. 149-166. 

The use of the jumping gene operator (any of the adaptations) increases the randomness/diversity and, thus, usually gives better results. Among the various JG adaptations discussed above, the sJG adaptation is found to be better for the benchmark problems studied here. But the choice of a particular adaptation is problem-specific, e.g., in froth flotation circuits the mJG adaptation (Guria et al., 2005b) is found to be better. 

Polyvalent metallic ions can adsorb specifically on oxides and silicates this phenomenon occurs when the cation involved hydrolyzes to its first hydroxy complex or its dioxide precipitates on the particle surface. Unintentional activation of silica by dissolved metallic species in anionic flotation circuits is a typical example (Hanna and Somasundaran, 1976). 

Sulphur recovery consists of a hydrocyclone and two parallel flotation circuits. Normally, over 95% of the elemental sulphur is recovered in this circuit. Work is ongoing to improve the recovery of the finer sulphur size fraction. The sulphur concmtrate is dewatered on a belt filter, melted and passed through a molten sulphur filter to remove unreacted minerals and ash to produce a marketable sulphur product. 

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