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1.
The influence of an ultrasonic field frequency of 22 kHz and intensity of 0.5 W/cm2 has been examined on the flotation of barite, fluorite and quartz as well as on their ability to adsorb dodecyl- and cetylsulphates. The tests affected the flotation of pure minerals in a Hallimond tube as well as the flotation of a natural barite-fluorite ore. It has been found that ultrasonic pretreatment of minerals causes an increase in the flotation rate of barite and a decrease in the flotation rate of fluorite. Ultrasonic pretreatment of the natural barite-fluorite ore before its flotation is the most advantageous. In this case it is possible to obtain concentrates of barite composed of a low amount of CaF2. This may be explained by the different effects of ultrasonic vibrations on barite and fluorite which cause some improvement of the selectivity of their flotation separation.For a full explanation of these results the effects of ultrasonic pretreatment of the minerals on their adsorption properties and surface topography have been investigated, as well as the direct influence of ultrasound on the adsorption process. 相似文献
2.
The Jabali Zn–Pb–Ag deposit is located about 110 km east of Sana'a, the capital of Yemen, along the western border of the Marib-Al-Jawf/Sab'atayn basin. The economic mineralization at Jabali is a nonsulfide deposit, consisting of 8.7 million tons at an average grade of 9.2% zinc, derived from the oxidation of primary sulfides. The rock hosting both primary and secondary ores is a strongly dolomitized carbonate platform limestone of the Jurassic Shuqra Formation (Amran Group). The primary sulfides consist of sphalerite, galena and pyrite/marcasite. Smithsonite is the most abundant economic mineral in the secondary deposit, and is associated with minor hydrozincite, hemimorphite, acanthite and greenockite. Smithsonite occurs as two main generations: smithsonite 1, which replaces both host dolomite and sphalerite, and smithsonite 2, occurring as concretions and vein fillings in the host rock. At the boundary between smithsonite 1 and host dolomite, the latter is widely replaced by broad, irregular bands of Zn-bearing dolomite, where Zn has substituted for Mg. The secondary mineralization evolved through different stages: 1) alteration of original sulfides (sphalerite, pyrite and galena), and release of metals in acid solutions; 2) alteration of dolomite host rock and formation of Zn-bearing dolomite; 3) partial dissolution of dolomite by metal-carrying acid fluids and replacement of dolomite and Zn-bearing dolomite by a first smithsonite phase (smithsonite 1). To this stage also belong the direct replacement of sphalerite and galena by secondary minerals (smithsonite and cerussite); 4) precipitation of a later smithsonite phase (smithsonite 2) in veins and cavities, together with Ag- and Cd-sulfides.The δ18O composition of Jabali smithsonite is generally lower than in other known supergene smithsonites, whereas the carbon isotope composition is in the same range of the negative δ13C values recorded in most supergene nonsulfide ores. Considering that the groundwaters and paleo-groundwaters in this area of Yemen have negative δ18O values, it can be assumed that the Jabali smithsonite precipitated in different stages from a combination of fluids, possibly consisting of local groundwaters variably mixed with low-temperature hydrothermal waters. The carbon isotope composition is interpreted as a result of mixing between carbon from host rock carbonates and soil/atmospheric CO2.The most favorable setting for the development of the Jabali secondary deposit could be placed in the early Miocene (~ 17 Ma), when supergene weathering was favored by major uplift and exhumation resulting from the main phase of Red Sea extension. Low-temperature hydrothermal fluids may have also circulated at the same time, through the magmatically-induced geothermal activity in the area. 相似文献
3.
The adsorption of octyl hydroxamate on electrolytic manganese dioxide was investigated through adsorption studies, electrophoretic mobility measurements, infrared spectroscopy and Hallimond tube flotation. The adsorption measurements at room temperature and flotation studies show that a peak in adsorption density and flotation response occurs around pH 9. IR spectra indicate the presence of basic manganous hydroxamate complex at the surface. The electrophoretic mobility studies suggest that hydroxamate adsorbs specifically at the manganese dioxide/water interface. Adsorption measurements at an elevated temperature show that adsorption density increases with increasing temperature. It is postulated that the reactive species in adsorption could be the hydroxamic acid species. 相似文献
4.
The possibility was investigated of carrying out selective flocculation in the model set smithsonite-dolomite using polymers containing nitrogen atoms, which should interact selectively with zinc minerals.A high activity of flocculants in relation to smithsonite and a low activity towards dolomite was observed. However, the activation of the dolomite surface by Zn2+ ions was determined whereby the selective flocculation was not observed in the mixture of smithsonite and dolomite. 相似文献
5.
Hallimond tube flotation experiments have been carried out on the two calcium minerals scheelite and calcite using dodecylammonium chloride as collector. The main variables studied were the calcium ion concentration and the pH.In the case of scheelite, addition of calcium chloride markedly lowered the flotation recovery. Recovery was also lowered when the pH was reduced below about 10. Since it is known that the zeta potential of scheelite is almost independent of pH this confirms that co-adsorption of un-ionized amine is necessary for good flotation. Other un-ionized long-chain molecules can replace the amine; thus it was shown that excellent flotation can be obtained event at about pH 7 by adding dodecanol together with dodecylammonium chloride. With the completely ionic trimethyldodecylammonium chloride recoveries were poor and were independent of pH.In the case of calcite, calcium chloride had no immediate effect on flotation recovery, but at low collector concentrations marked depression occurred after many hours standing in the presence of calcium ions. The effect of pH on flotation of calcite was anomalous and there appear to be two pH regions in which recoveries are high.The results are discussed and attention is drawn to the need for more thorough studies of the calcium carbonate/water interface. 相似文献
6.
T.N. Khmeleva J.K. ChapeletW.M. Skinner D.A. Beattie 《International Journal of Mineral Processing》2006
The effect of sodium bisulphite on the xanthate-induced flotation of copper-activated sphalerite has been studied using batch flotation testing, surface analysis techniques (XPS and ToF-SIMS), and FTIR. The various techniques have been used to identify the mechanisms of interaction of sulphite ions with both collector and the sphalerite surface. The results indicate that sodium bisulphite depressed the flotation of sphalerite particles pre-treated with copper and xanthate at pH 9 with nitrogen and air purging. It was found that sodium bisulphite interacts with the sphalerite surface, as well as with xanthate in its adsorbed state. Based on the evidence obtained in the present study, and in conjunction with previous work, the mechanisms involved in the depression of the xanthate-induced flotation of copper-activated sphalerite by sulphite are proposed. It is suggested that copper xanthate decomposition on the surface of the activated sphalerite and the decomposition of the hydrophobic copper-sulphide-like species on the sphalerite surface are the active mechanisms for sphalerite depression by sodium bisulphite. 相似文献
7.
The distribution characteristics and existing state of cadmium in the Jinding Pb-Zn deposit were studied. It was discovered that Cd was mainly distributed in sphalerite as an isomorphic impurity. There was a good correla-tion between Cd and Zn in the primary ore. With the oxidation and resolution of pyrite, sphalerite, sulfide, and etc., many secondary minerals, such as colloform sphalerite and smithsonite, were formed. The distribution of Cd is not symmetrical, and enrichment and dilution were observed in partial area of the oxidation zone in the deposit. Cd, except in external pore space or cracks of secondary minerals as independent minerals, such as greenockite, was mainly distributed in sphalerite as an isomorphic impurity in the secondary sphalerate and smithsonite in the oxida-tion zone. The research showed that Cd showed a very strong active transfer ability in the oxidation process, not only indicating that supergene leaching might be the main reason for Cd enrichment in some Pb-Zn deposits, but also reflecting that Cd was easily mobilizeed and transferred to pollute ore areas in the oxidation process. Furthermore, Cd in oxidation ore was more easily mobilized and transferred to induce bad hazards for ore areas with the effect from AMD which was produced from oxidation of sulfides. 相似文献
8.
Electro-flotation tests were conducted on chalcopyrite particles with a modified Hallimond tube designed for electro-flotation, using platinum anode—copper cathode and graphite anode—copper cathode systems. Flotation tests were carried out for fines of chalcopyrite of size below 20 microns with potassium ethylxanthate as collector. Studies were done on flotation with hydrogen and oxygen separately with the usual variables. Dissolution of chalcopyrite at various current densities, with reagent at optimum conditions and without reagent was also studied. It is observed that electro-flotation particularly with oxygen, is effective in the flotation of fine particles of chalcopyrite. 相似文献
9.
The change in collectorless flotation of sphalerite with pH and Cu(II) concentration was correlated with the type and proportion of species present on the sphalerite surface. The solution and surface species were determined using a combination of analytical techniques including zeta potential measurement and X-ray photoelectron spectroscopy. An optimum copper concentration for maximum sphalerite flotation was identified, beyond which flotation decreased. This decrease in flotation coincided with the precipitation of copper hydroxide in neutral to mildly alkaline pH conditions. The hydrophobic polysulfide and hydrophilic copper hydroxide species were the main surface species influencing sphalerite flotation. 相似文献
10.
The suitability of a new reagent, Kr6D, as a depressant for galena and sphalerite in a differential sulphide flotation stage has been tested. Small-scale laboratory flotation tests on pure sulphide minerals indicated that the reagent is capable of depressing both galena and sphalerite when used in small doses. At higher concentrations, chalcopyrite is also depressed. Single-stage batch-scale flotation tests have been carried out on bulk sulphide concentrates containing the three sulphide minerals. Kr6D has been compared with starch as a depressant both in the presence and in the absence of sulphur dioxide. In each case the new modifier has been shown to be more effective. When using sodium dichromate as a differential depressant in similar tests, it has been shown that the quantity necessary to achieve selectivity between chalcopyrite and galena may be considerably reduced if small quantities of Kr6D are added. 相似文献
11.
Flotation tests were conducted in a Hallimond tube on chalcopyrite, with a collector system of cupferron and fuel oil. The reagent concentration, pH and conditioning time were studied as variables. The necessity of the fuel oil was verified by conducting experiments without it. Contact-angle measurements have been conducted by the captivebubble technique. From the results it was found that fuel oil is necessary to promote adhesion of the conditioned mineral particles to the air bubbles. Adsorption experiments were carried out in a column apparatus under similar conditions as in flotation, except for the addition of fuel oil. The adsorption density and flotability were high at weakly acidic range where the reagent complexes the metal ions effectively in an aqueous medium. 相似文献
12.
W.J. Trahar 《International Journal of Mineral Processing》1976,3(2):151-166
The selectivity of galena flotation from a synthetic mixture with sphalerite and quartz and from a typical Broken Hill ore has been determined. It was found that the selectivity was limited by the relative flotabilities of coarse galena and sphalerite of intermediate sizes. The use of split conditioning in the preparation for flotation resulted in significant improvements in lead-zinc selectivity for both samples. By contrast the use of conventional zinc depressants in the flotation of the ore resulted in only slight changes in the behaviour of the minerals and had no discernible effect on the selectivity. 相似文献
13.
A. Boulton D. Fornasiero J. Ralston 《International Journal of Mineral Processing》2003,70(1-4):205-219
The surface analytical techniques of X-ray Photoelectron Spectroscopy (XPS) and Time of Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) have provided information on the type and concentration of species on the surface of sphalerite and pyrite particles in flotation concentrate and tail samples, but also on their distribution on each particle and across particles of different sizes. From this surface analytical study, a more accurate interpretation of the flotation results of sphalerite and pyrite minerals in a mixed mineral system could be made as a function of the concentrations of copper sulphate activator and xanthate collector, and particle size. In particular, it was found that sphalerite particles reporting to the concentrate are larger in size and contain less iron hydroxide on their surface than particles reporting to the tail. As for the pyrite particles, their lower recovery than the sphalerite particles is the result of a larger proportion of iron hydroxide on their surface inhibiting copper and collector adsorption. 相似文献
14.
The effect of dextrin on molybdenite surface properties has been investigated experimentally through measurements of zeta potentials, adsorption densities, contact angles, Hallimond tube flotation and oil flotation response. These studies indicate that the adsorption of dextrin on molybdenite occurs through physical interaction with the surface, possibly due to hydrophobic bonding. The hydrophobic bonding mechanism is in accord with the magnitude of the adsorption free energy, which was estimated to be—5.4 kcal per mole of dextrin monomers. Dextrin was found to be a very effective depressant for the air flotation of molybdenite in the absence of a collector, whereas it does not effectively depress molybdenite in an oil flotation process using iso-octane. This has been discussed qualitatively from the contributions of electrical double layer repulsion, van der Waals' attraction, and hydration effects. 相似文献
15.
M. Kongolo J. M. Cases P. de Donato L. Michot R. Erre 《International Journal of Mineral Processing》1990,30(3-4)
Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), Hallimond tube flotation and microelectrophoresis have been utilized to investigate the reactions in the adsorption-abstraction of K-amylxanthate on finely ground galena. The mineral was ground in a laboratory stainless steel rod mill under controlled conditions (pH 4.0 and 7.0) using HCl as a pH regulator. X-ray photoelectron spectroscopic (XPS) studies have been carried out in order to characterize the surface oxidation products after grinding (weak amounts of Sn and PbS2O3). The two-stage adsorption process discovered in previous studies was confirmed. For low concentrations or submonolayer capacity, the layer is formed with 1:1 monocoordinated lead xanthate and dixanthogen. For higher values of surface coverage, it is composed of lead xanthate (stoichiometric at pH 7 and non-stoichiometric at pH 4), amyldixanthogen and amylcarbonate disulphide. In the second stage mainly dixanthogen is formed. This stage corresponds to complete flotation and to a sharp decrease in zeta potentials. 相似文献
16.
R.H. Yoon 《International Journal of Mineral Processing》1981,8(1):31-48
The flotation of chalcopyrite and sphalerite from copper and copper-zinc ores has been achieved without using thiol-type collectors. Typically, a sulfide ore sample is first treated with sodium sulfide either during grinding or during the preflotation conditioning period, and then the chalcopyrite is floated with frother alone. With a copper-zinc ore, sphalerite is subsequently floated from the chalcopyrite tailings by activating it with copper sulphate. Results of the collectorless flotation tests are comparable to those obtained by using thiol collectors. The mechanisms of selective collectorless flotation are discussed on the basis of differences in the solubilities of sulfide minerals. 相似文献
17.
本文扼要叙述浮选管的构造、装置及使用方法。浮选管应用于提取单矿物,是一种很有实用性的分离工具。它的最大特点是能够处理少量矿物试样(如0.5—0.2g),分选效果良好,可分选各种矿物。 相似文献
18.
Flotation studies using a Hallimond tube have been carried out on purified samples of chrysocolla. The results confirm that by heating the sample to 550°C, flotation of the sulphidized sample with amyl xanthate is considerably improved. Flotation with sodium dodecyl sulphate is also considerably higher. The recovery with cationic collectors is not modified by the thermal treatment.Electrophoretic mobility measurements and flotation studies using benzene instead of air for the collection of the particles suggest that the increase in flotation after thermal treatment is a consequence of (1) an increase in the solubility of copper ions and their adsorption on to the surface of the particles, and (2) an increase of the intrinsic hydrophobicity of the particles due to condensation of some of the free silanol groups on their surface. 相似文献
19.
云南省富乐分散元素多金属矿床地质特征
—一个分散元素超常富集的铅锌矿床 总被引：3，自引：0，他引：3
云南富乐分散元素多金属矿床位于扬子地台西南缘,川滇黔铅锌多金属成矿域东南部,是一个中型的铅锌矿床,伴生Cd、Ge、Se、Ga四种具有工业价值的分散元素,其中Cd、Ge、Se储量达到大型矿床规模。矿体赋存于二叠系茅口组二段白云岩中的层间破碎带内,形态呈透镜状、似层状、脉状,矿体一般长100～1000m,宽50～500m,厚0.5～25m。矿石发育粗粒结构,角砾状构造。矿石矿物主要为闪锌矿、方铅矿,脉石矿物主要为白云石、方解石,分散元素主要呈类质同像形式赋存于闪锌矿中。分散元素富集的原因是含有机质的古油田卤水对矿源层——石炭、二叠纪地层中Pb、Zn、Cd、Ge、Se、Ga的强烈萃取,分散元素主要富集在闪锌矿中。 相似文献
20.
S.K. Mishra 《International Journal of Mineral Processing》1982,9(1):59-73
Calcite is generally associated with apatite minerals in phosphate deposits. To explore the possibility of separating these minerals by a soap flotation technique, their electrokinetic properties and flotation behaviour were studied in the presence of sodium oleate.Microelectrophoresis data indicate oleate adsorption on these minerals, and from Hallimond-tube flotation tests it has been noted that in a controlled pH environment and for a certain sodium oleate concentration range, separation of these minerals is possible.The study of apatite/calcite-sodium metasilicate-sodium oleate systems indicates the preferential adsorption of silicate at the calcite surface. This suggests the potential use of sodium metasilicate as the modifying agent for the separation of apatite from calcite by depressing calcite when using sodium oleate as collector. 相似文献