The effect of the properties of silicate melts on the formation of porous structures during bloating

Effect of the surface charge of oxidized coal on its flotability

“…Due to the absence of equilibrium between the particles of the suspension and the intermicellar liquid, conflicting results have been obtained by investigators of the relation between the sign of the charge of mineral particles [14] and the suspension effect. This apparently explains why Nazarenko et al [5] found that coal particles have a positive charge, which is rather inexplicable because the authors of [12,15,16] did not find appreciable amounts of basic groups on the coal surface.…”

“…The suspension effect was determined for a suspension of coal from a seam, oxidized in situ. The overall content of carboxyl, acid hydroxyl, and partly peroxide groups in the coal found by the method in [12] was 306 mg-eq/100 g of coal; the carboxyl content, found by the method in [13], was 36 mg-eq/100 g of coaL The content of weathered grains, determined by the microscopic method on the basis of weathering signs, was 100%.To reduce the effect of mineral components of the coal and of metal cations (largely Ca), which had replaced the hydrogen of the functional groups, the coal was treated with 1 N HC1, then washed with distilled water until no chloride ions were present. Treatment with HC1 reduced the ash content of the coal from 9.1 to 3.7~…”

Time required for adhesion of flotation reagent drops to oxidized coal particles

“…These were determined by the method in [6] ; therefore their value was the sum of the free acid hydroxyls, carboxyl groups, and partly peroxide groups. Figure 1 shows the flotability of coals with a dropwise feed of apolar and heteropolar reagents, and also in a hexyl alcohol solulion in a laboratory flotation cell with a programmed time relay.…”