Hydroxamate vs. fatty acid flotation of iron oxide

Journal ArticleData were obtained with hematite with octyl hydroxamate and oleate as collectors to determine the mechanism of collector adsorption and also to establish the roles that conditioning time and temperature assume in this system. The presence of hydroxy complexes of iron are apparently necessary for chemisorption of collector to occur, and it appears as if extended conditioning times and elevated temperature promote greater dissolution of the mineral and hence greater concentrations of hydroxy complexes. Data were also collected with two natural hematitic ores. With one ore that was ground to 70% - 15p, an addition of 0.4 Ib per ton hydroxamate resulted in a final concentrate recovery of 86% at a grade of 64% iron. Satisfactory concentrate grade could not be obtained with fatty acid under these conditions. The effect of conditioning time prior to the addition of collector was also examined with another ore. When the ore was conditioned for 3 min, 19% of the iron was recovered in the concenbrate at a grade of 67% Fe. With a conditioning time of 7 min, 73% of the iron reported to the concentrate at a grade of 62% Fe. These products were obtained with an addition of 0.2 lb per ton hydroxamate. This ore also responded well to flotation with fatty acid

Flotation behavior of chromium and manganese minerals

Journal ArticleFlotation behavior of chromite and manganese-bearing minerals has been reviewed. Flotation of these minerals and ores with fatty acids, amines, sulfates, sulfonates and hydroxamates has been presented and is discussed in terms of surface charge and chemical interaction between the mineral surface and collectors. The role of metal hydroxy complexes such as FeOH+ , CrOH++ , MgOH+ and MnOH+ is also discussed

Screening and classification

Journal ArticleThe processing of minerals almost invariably involves the reduction in size of the minerals contained in an ore to effect liberation of disseminated values or, in other instances, to effect increased surface area. Separation of solids according to size usually is undertaken to promote maximum production from crushing and grinding equipment. Screens are generally used for making this size separation when coarse material is involved, whereas classifiers and cyclones usually are employed when fine particulate material is being processed. However, special screening devices may be used for separations as fine as 325 mesh. The term "mesh" refers to the number of openings per linear inch on a screen. Mesh number vs. size of screen opening is listed in Table 27-12

Selective flotation of iron oxide

Journal ArticleThe response of pure goethite and two natural iron ores to flotation with potassium octyl hydroxamate is presented. The ores contained 12.5% and 39.7% iron; concentrates containing 69.5% and 61.5% iron, respectively, were obtained with additions of 0.4 lb/ton hydroxamate

Role of the hydrocarbon chain in anionic flotation of calcite

Journal ArticleThe response of calcite to flotation with saturated fatty acids and alkyl sulfonates of various chain lengths is presented. The amount of collector required for flotation is shown to decrease systematically with increasing carbon content from 8 to 12-carbon atoms per molecule. This systematic flotation response is correlated with the solubilities of the calcium-collector salts, which were established with a nephelometer. The 14-carbon collectors deviate from this systematic behavior, and no flotation is possible with the 16-carbon homologs. As determined by infrared analysis, the mechanism of collector adsorption involves a specific chemical reaction between the collector and the surface

Metal ion activation in xanthate flotation of quartz

Journal ArticleQuartz cannot be floated with potassium amyl xanthate as collector at any pH. Complete flotation is achieved with certain minimal additions of amyl xanthate and Pbtt from pH 5.8 to 8.5 and with amyl xanthate and Znt+ from pH 7.5 to 8.1. The active species of these metal ions responsible for activation are shown to be PbOHt and ZnOHt. No flotation was effected when Cu and Mg were added as activators

Adsorption mechanisms in nonmetallic activation systems

Journal ArticleAdsorption of lead and ferric iron on quurtz and alumina is presented as a function of pH. Only the hydrolyzed species of these metal ions, FeOHt+ and PbOH', adsorb significantly on each of these minerals. Zeta potentials of quartz were measured as a function of pH in the presence of various additions of aluminum, lead, and magnesium salts. Sign reversal occurs at the pH values where significant concentrations of hydroxy complexes are formed. Models of adsorption are presented in the absence and presence of collector

Chrysocolla flotation by the formation of insoluble surface chelates

T he flotation characteristics of the oxide copper minerals, malachite, azurite, and cuprite, have not presented the difficulty for concentration as have those of the copper silicate, chrysocolla. The copper carbonates and oxides respond reasonably well to flotation with conventional collectors, whereas chrysocolla will not respond to flotation with fatty acids or xanthates under nonnal flotation conditions. In this view then, other reagents will have to be devised to function as collectors for chrysocolla. The most obvious general class of reagents for this purpose would seem to be the organic copper chelating compounds. The utility of chelating agents as collectors in flotation systems has already been demonstrated. For example Vivian I has floated cassiterite using ammonium ni trosopheny lhydroxy lamine. Holman 2 studied the flotation of nickel oxide ores with dimethylglyoxime and also suggested the use of taurine on oxidized lead ores. A rather detailed study on the application of certain chelating agents to some flotation systems was presen ted by Gu tzeit. 3 This work indicated that the formation of surface insoluble chelates is probably responsible for flotation in many cases. The role that soluble chelating agents assume was also presented, that is with effective removal of polyvalent cations by complex formation, effective depression of quartz can be obtained