Floatability Of Galena Research Articles

Enhancing flotation efficiency: Optimizing galena and chalcopyrite separation through high-temperature pre-oxidation with recycled sulfuric acid

Galena and chalcopyrite pose challenges in their separation owing to their similar surface chemistry. The flotation separation of galena and chalcopyrite significantly depends on the use of depressants. However, conventional depressants are often associated with several drawbacks, such as toxicity and inefficiency. Hence, exploring efficient and environmentally friendly techniques to separate galena and chalcopyrite is vital. This study investigated the use of sulfuric acid as a surface oxidant for the pre-oxidation treatment of galena and chalcopyrite at high temperatures. This approach facilitated acid recycling and eliminated the need for multiple flotation chemicals. The floatability of galena and chalcopyrite was investigated through micro-flotation. The results revealed that at a pre-oxidation temperature of 100℃, galena exhibited a recovery rate of only 9.98 %, while chalcopyrite maintained a recovery rate of 96 % across the temperature range. The selective depressant mechanism of sulfuric acid in the flotation separation of galena and chalcopyrite was investigated through scanning electron microscopy, zeta potential measurements, X-ray photoelectron spectroscopy, thermodynamic calculations, and electrochemical analyses. The results indicated that the high temperature facilitated the dissolution of the sulfide layer on the galena surface. Consequently, S2− ions underwent oxidization into SO42− to form a stable oxide film on the galena surface through interaction with Pb2+. Conversely, the high-temperature pre-oxidation had a minimal effect on the surface of chalcopyrite, indicating selective oxidation benefits. Findings from the pre-oxidation floatation separation test of galena–chalcopyrite mixtures revealed the efficient and thorough separation of the two minerals under high-temperature pre-oxidation conditions. The lead concentrate obtained from the floatation process exhibited a Pb grade of 79.38 % and a recovery rate of 97.17 %, while the Cu concentrate featured a Cu grade of 32.14 % and a recovery rate of 97.06 %. Additionally, the sulfuric acid solution was recycled. Overall, this study provides a sustainable and cost-effective approach for the green separation of copper–lead sulfide ores.

Selective passivation behavior of galena surface by sulfuric acid and a novel flotation separation method for copper-lead sulfide ore without collector and inhibitor

Here, we present a novel efficient passivation-separation method for galena and chalcopyrite that includes a novel sulfuric acid selective passivation process for galena and a special flotation process in which conventional inhibitors and collectors are not added. The surface passivation mechanism of galena was characterized by surface contact angle measurements, scanning electron and dispersive spectrometry (SEM-EDS) analysis and X-ray photoelectron spectroscopy (XPS) analysis. The contact angle measurements indicated that sulfuric acid passivation increased the surface hydrophobicity difference between galena and chalcopyrite, which led to the large difference in their floatabilities. The results of the passivation-flotation experiments for the galena-chalcopyrite mixture confirmed that the selective inhibition of galena was realized with this new process, and the floatability of galena was drastically reduced while that of chalcopyrite was slightly promoted; thus, the efficient separation of galena and chalcopyrite was achieved only with the addition of frothers. The SEM-EDS and XPS results revealed that the S element on the galena surface was gradually oxidized from S2− to SO42− during the passivation process, which generated a layer of hydrophilic lead sulfate (PbSO4), while a layer of floatable copper sulfides was formed on the surface of chalcopyrite. In this study, a new highly efficient copper-lead sulfide ore separation method was developed, and the interrelatedmechanism was studied in detail.

Microthermokinetic study of xanthate adsorption on impurity-doped galena

Six kinds of galena with different impurities were synthesized and the effects of impurities on the floatability of galena were investigated. The thermodynamic and kinetic parameters on the galena surface were measured using microcalorimetry, and the adsorption configuration and energy of butyl xanthate on the surfaces of galena with different impurities were simulated by density functional theory. Flotation experiments showed that Ag and Bi significantly promoted the recovery of galena, while Zn, Sb, Mn, and Cu reduced the recovery of the flotation. Microthermokinetic results indicated that the absolute value of xanthate adsorption heat was directly proportional to the flotation recovery of galena. Adsorption heat and reaction rate coefficients of xanthate on galena containing Ag or Bi were larger than those on pure galena, but smaller on galena containing Cu or Sb. Additionally, the relationship between the heat of unsaturated adsorption of xanthate and the adsorption energy of impurity atom on galena surface was investigated.

Effect of dissolved oxygen and galvanic contact on the floatability of galena and pyrite with Aerophine 3418A

Tests were performed to evaluate the galvanic interaction of synthetic mixtures of galena (valuable mineral) and pyrite (gangue mineral) on their flotation response, both in air and nitrogen atmospheres, when the anionic collector sodium-di-isobutyl dithiophosphinate is added. The effect of lead activation of pyrite is also examined. Floatability of galena from mixtures is similar to that of galena alone indicating that the galena–collector interaction is not affected by the galvanic contact. In the presence of oxygen the floatability of pyrite from mixtures increases slightly compared to pyrite alone, due to the migration of Pb species, arising from galena dissolution, which adsorb onto pyrite as hydrolysed lead species. Galena–pyrite galvanic contact lowers the adsorption of lead species (from a Pb-bearing solution) onto pyrite, compared to that observed with pyrite alone. When the galvanic interaction is weakened due to the absence of oxygen (e.g., by using a nitrogen atmosphere), the concentration of lead onto pyrite surface increases to levels similar to those of pyrite alone. The collector chemisorbs onto galena forming a layer of low electroactivity that slows down the dissolution of the mineral; nevertheless, this layer does not completely prevent the galvanic interaction with pyrite.

Correlation between surface free energy and floatability of galena with potassium ethyl xanthate

From the maximal extrapolated film pressure πmax values for n-octane and n-propanol, the dispersion and non-dispersion components of the surface free energy of galena precoated with potassium ethyl xanthate (collector) were estimated and they were then correlated with the floatability of galena. The collector layer deposited by methanol evaporation did not produce any significant changes in the surface free energy of galena. Polymolecular adsorption of the collector occurred from aqueous solution. The adsorbed collector layer of ~8 statistical monolayers in thickness produced a considerable decrease in the dispersion component of the surface free energy and complete disappearance of non-dispersion interactions. At this surface coverage, a certain change in the properties of the adsorbed layer appeared which was probably connected with the formation of polymolecular layers containing dixanthogen. The work of the water adhesion being significantly lower than the work of water cohesion appeared insufficient ...

ポリプロピレングリコールモノメチルエーテル系起ほう剤のザンセート捕収に及ぼす影響

Effect of polypropylene glycol monomethyl ethers (polyPGME), such as mono-(1PGME), di-(2PGME), tri-(3PGME), and tetrapropylene glycol monomethyl ether (4PGME), on the floatability of galena with xanthate was investigated. α-terpineol and cineol were also used in the test as the reference. The floatability of galena was measured with a bubble pick up tube at 25°C. In order to investigate the adsorption property of poly-PGME at the liquid-gas interface, surface tension was measured with Du Nouy tensiometer at 20°C.The floatability of galena with xanthate in the region of pH 4-10 increased in the presence of the poly-PGME as well as α-terpineol and cineol. The more the number of propylene group in the molecule of polyPGME was increased, the more the floatability of galena with xanthate was promoted. The adsorption property of the polyPGME at the liquid-gas interface decreased with decreasing the number of propylene group in the molecule. From these results, Dowfroth 250, α-terpineol, and cineol were comparatively discussed on the viewpoints of frothing property and selectivity for collecting of mineral particles in the practical flotation system.

硫化鉱物の浮選におけるα-テルピネオールとシネオールの作用に関する基礎的研究

The present investigation was undertaken in order to make clear the adsorption property of α-terpineol and cineol onto the mineral surface and to clarify these influences on the floatability of mineral particles surface-chemically.The gas chromatographic method was successfully used to analyze the concentration of a frother in the solution to determine the adsorption of α-terpineol and cineol on galena surface. The wettability of galena to frother was determined by capillary penetration tests. The floatability of galena was measured with a bubble pick up tube.The adsorption density of frother molecules on galena increased with increasing the concentration of a frother in the solution. The adsorption quantities of cineol on galena were larger than those of a-terpineol in either case with or without xanthate addition in the solution. The critical flotation curves of galena were determined when xanthate was used alone and also was used together with one of the frothers. The floatability of galena with xanthate increased greatly in the presence of frother, and decreased in the following order: cineol+ xanthate>α-terpineol+xanthate>xanthate.From these results, it was confirmed that the adsorption property of frother molecules onto the mineral related closely with the floatability of mineral and consequently the frother adsorption should play an important role in flotation.

ザンセートの各種硫化鉱に対する吸着と青化物の影響について

Effects of pH on the adsorption of ethyl xanthate on several kinds of sulfide minerals, such as chalcopyrite, galena and pyrite, are investigated by means of a radio tracer technique.Measurements of adsorption of ethyl xanthate are also made on chalcopyrite and galena in the presence of CN- as a depressant. Experimental results are as follows:1. The adsorption of ethyl xanthate decreases rapidly when the pH exceeds 8 on pyrite and 10 on galena, while no remarkable decrease of adsorption takes place on chalcopyrite even at high pH ranges. The results of adsorption experiments described above are correlated to the floatability of these sulfide minerals in xanthate flotation.2. Neither the floatability of galena nor the adsorption of ethyl xanthate on galena is effected by CN-.3. No correlation exists on chalcopyrite between the floatability and the adsorption of ethyl xanthate in the presence of CN- the recovery of chalcopyrite is fairly depressed by CN- while the considerable surface coverage of ethyl xanthate is still remained by the addition of CN- at pH 12.4. The remarkable reduction in the adsorption of ethyl xanthate with CN- is really found by an introduction of air bubbles into the pulp under examination. This fact may be explained by the theory proposed by de Bruyn, Overbeek and Schuhmann that the collection or depression is greatly depended on the difference of adsorption density of concerned components between solid air and solid-solution interfaces5. The depressing action of CN- in the flotation of chalcopyrite disappears during a course of the test with the rapid increase in adsorption of ethyl xanthate. This may be due to the decrease of CN- concentration by violent agitation in the flotation cell.