Conventional flotation

    1 Sample preparation
    Taking into account the representation of the specimen and laboratory efficiency of small ball mill, flotation test particle size generally less than 1 to 3 mm. The original sample can be used jaw crusher crushing score based on the required segment or segments broken into about 6 mm below, and then closed with a vibrating screen machine on roller mill for crushing the ore particle size. The crushing process should avoid the loss of dust flying, especially in high grade when the dust.
    If the ores contain sulfide minerals, in particular, contains large amounts of pyrrhotite, the oxidation of the flotation test results may have significant impact, and therefore the sample should be as broken phases, so that a large number of samples in the coarse under the storage size. In the sample preparation process, but also to prevent contamination of the sample, mixed with a small amount of oil will prevent the normal flotation. Sealed sample shall be stored in a dry, cool, ventilated place and not susceptible to pollution, but even so, not easily oxidized ore appropriate for long-term placement.
    2 grinding
    Laboratory flotation tests each sample volume is generally 500, 1000 or 2000 grams, corresponding to the inner wall of the grinding machine Ф200 mm and down size than those appropriate to prepare a small mill for regrinding intermediate products with. Cylindrical shape with a good body, It can also be loaded ball rod length and diameter of the same or slightly longer. China is also heavily used 240 × 90 and 150 × 50 mm in two specifications of cone ball mill, it has the advantage does not lie in its body shape, but because the entire structure designed to be relatively easy to operate and save energy. Weight of ball mill with total volume of 40% or so. According to the mineral particle size and particle size and tube size selection of 2 to 3 different sizes of ball, the smallest for the 12.5 to 15 mm, greatest for the 25 to 32 mm. Coarse grinding ball when the same number of medium and small can, when finely ground can equal the weight of medium and small ball, usually can be in between. Concentration by grinding a lot of literature often 50 to 67% solids, the equivalent of liquid to solid weight ratio equal to 1:1 to 1:2, while the author was inclined to use existing plant with a similar concentration, for example, in the general hard ore is 75% (solid (liquid to solid ratio of 1:3) or so, in this case more uniform particle size, less than coarse particles; the other hand, if the ore contains more clay and fine particle size or density-hour , to adopt a lower concentration in the sample density is large or very small, but also change the concentration by volume (solid volume accounted for the total volume of slurry) for 40 to 50% of the grinding water. In short, the slurry viscosity should be moderate .
    Open laboratory using batch ball mill, and closed-circuit grinding compared to the industry, product size features inconsistent. In general, higher levels of fine particles. Some people prefer to use the rod mill which, and the experimental data shows that open laboratory rod mill product size distribution is closer than the laboratory is now open milling milling plant closed. But this does not take into account, with the classifier in closed circuit grinding, heavy mineral grains are usually worn thin than some other mineral particles. Laboratory rod mill rod size is generally 12.5 to 25 mm.