Agglomerate flotation

The reagent scheme used in this plant for agglomeration flotation included 800 g/t tall oil, 1500 g/t fuel oil, 800 g/t tall oil emulsion, 60 g/t Etoxol P19 and 50 g/t xanthate. 

A concentrate grade of 44% Ti02 at a recovery of 88% was produced using agglomeration flotation, compared to a concentrate grade of 44% Ti02 with a recovery of 74% without agglomeration flotation. 

Any of a family of flotation processes in which oil is used to agglomerate or bridge particles and enhance flotation. In extender flotation, a small amount of oil is added to improve a collector s performance. In agglomerate flotation, oil is added to agglomerate very finely divided particles to a size that can be efficiently floated. In emulsion flotation, oil is added to function as the collector, for already hydrophobic particles. 

Sadowski, Z. and Polowczyk, L, Agglomerate flotation of fine oxide particles, Int. J. Miner. Process, 74, 85. 2004. 

In general, flocculants are used in solid-liquid separation processes such as thickening and filtration. Inorganic salts are also used sometimes to aggregate fine particles. Flocculation technique has been developed further for special applications of selective flocculation, selective dispersion and agglomeration flotation. 

Very finely divided minerals may be difficult to purify by flotation since the particles may a ere to larger, undesired minerals—or vice versa, the fines may be an impurity to be removed. The latter is the case with Ii02 (anatase) impurity in kaolin clay [87]. In carrier flotation, a coarser, separable mineral is added that will selectively pick up the fines [88,89]. The added mineral may be in the form of a floe (ferric hydroxide), and the process is called adsorbing colloid flotation [90]. The fines may be aggregated to reduce their loss, as in the addition of oil to agglomerate coal fines [91]. 

In conventional chemical pulping systems, micronized talc is used for pitch control. The mechanism is not well understood, but talc does adsorb on the pitch and detackify it, preventing it from agglomerating and attaching on equipment. In de-inking talc is used both to enhance ink removal in conventional screening/centrifugation methods and as a carrier in flotation systems. 

Flotation is certainly the major separation method based on the surface chemistry of mineral particles. It is, however, not the only method. Selective flocculation and agglomeration may be mentioned as other methods used commercially to a limited extent. The former is for hematite, while the latter is for coal and finely divided metallic oxide minerals. Both processes use the same principles as described for flotation to obtain selectivity. In selective flocculation, polymeric flocculants are used. The flocculants selectively adsorb on the hematite, and the hematite floes form and settle readily. Thereby separation from the sili-... 

Separation of milled solid materials is usually based on differences in their physical properties. Of the various techniques to obtain ore concentrates, those of froth flotation and agglomeration exploit differences in surface activities, which in many cases appear to involve the formation of complexes at the surface of the mineral particles. Separation by froth flotation (Figure 4) depends upon conversion of water-wetted (hydrophilic) solids to nonwetted (hydrophobic) ones which are transported in an oil-based froth leaving the undesired materials (gangue) in an aqueous slurry which is drawn off from the bottom of the separator. The selective conversion of the ore particles to hydrophobic materials involves the adsorption of compounds which are usually referred to as collectors. 4... 

Occasionally, the phosphate slime is difficult to settle in the lagoons because of its true colloidal nature, and the use of calcium sulfate or other electrolytes can promote coagulation, agglomeration, and settling of the particles. Usually an addition of calcium sulfate is unnecessary, because it is present in the wastewater from the sand-flotation process. Generally, it has been shown [33] that the clear effluent from the phosphate mining and beneficiation operation is not deleterious to fish life, but the occurrence of a dam break may result in adverse effects [19]. 

In addition to expressing coal-mineral association as a function of particle mineral matter content, our most recent efforts have emphasized the determination of coal-mineral association based on particle surfaces. While the previous distributions were measured in terms of bulk properties to provide an indication of the probable cleaning behavior of a coal in a density-based process, they do not lend much insight into cleaning behavior during surface-based processes, such as froth flotation or oil agglomeration. There is no a priori reason to expect that association measured and expressed in terms of bulk composition is generally indicative of association measured in terms of particle surfaces. Therefore, it would also be useful to express results in terms of the proportion of coal (or minerals) present on the surface of the particles. 

The technology does not treat wastes but is used as a mixing apparatus in conjunction with other treatment technologies such as flotation (used to separate coal agglomerates), traditional screening, and sedimentation (both used to separate solids). 

Materials mined from a mineral deposit usually consist of a heterogeneous mixture of solid phases that are generally crystalline and contain various minerals. Crushing and grinding operations are used to liberate the mineral species from one another and to reduce the size of the solids to a range suitable for subsequent processing. Of the various separation techniques, those of froth flotation and agglomeration exploit the chemical and physical properties of the surfaces of minerals, which can be controlled by various chemical interactions with species in an aqueous phase. 

Oil flotation, liquid-phase agglomeration, carrier flotation... 

Emulsion flotation is analogous to carrier flotation. Here, small-sized particles become attached to the surfaces of oil droplets (the carrier droplets). The carrier droplets attach to the air bubbles and the combined aggregates of small desired particles, carrier droplets, and air bubbles float to form the froth. An example is the emulsion flotation of submicrometre-sized diamond particles with isooctane. Emulsion flotation has also been applied to the flotation of minerals that are not readily wetted by water, such as graphite, sulfur, molybdenite, and coal [623]. Some oils used in emulsion flotation include mixed cresols (cresylic acid), pine oil, aliphatic alcohols, kerosene, fuel oil, and gas oil [623], A related use of a second, immiscible liquid to aid in particle separation is in agglomeration flocculation (see Section 5.6.4). 

Flotation and agglomerate concentration of non-metallic minerals. U. S. Bur. Mines Kept. Investigations 3397. 

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