Sodium Butyl Xanthate Research Articles

Adsorption Thermodynamics and Kinetics of Bornite Using Sodium Butyl Xanthate as Collector in Flotation

Adsorption Thermodynamics and Kinetics of Bornite Using Sodium Butyl Xanthate as Collector in Flotation

Selective depression of pyrite with a novel functionally modified biopolymer in a Cu–Fe flotation system

In the flotation of copper sulfides, pyrite is often activated by Cu2+ ions dissolved from copper-bearing minerals in alkaline media (pH ˃ 9), which results in pyrite entering the copper concentrate. To reduce the floatability of pyrite, we designed a novel functionally modified biopolymer, tricarboxylate sodium starch (TCSS), that showed superior depression selectivity towards pyrite in low pH solutions when employed in Cu–Fe flotation separation in the presence of sodium butyl xanthate (SBX) as a collector. TCSS depressed the floatability of pyrite more strongly than that of chalcopyrite in single mineral flotation in the pH range 4–6. The most selective separation was achieved at pH ∼ 6; the recovery of Cu in the concentrate was over 77%, and the grade was improved to 24.50% compared to the initial feed grade of 12.50%. Surface characterization analyses, including zeta potential, X-ray photoelectron spectroscopy (XPS) analysis, and Fourier transform infrared (FTIR) spectroscopy, confirmed the different degrees of interaction of TCSS with the two minerals. TCSS was adsorbed on the pyrite surface, possibly via a chemisorption mechanism, as reflected in the FTIR and XPS analyses. The adsorption of TCSS passivated the pyrite surface, which inhibited the adsorption and oxidation of the collector. On the other hand, the adsorption and oxidation of the collector on chalcopyrite surface were effective even in the presence of TCSS, attesting to the weak interactions between chalcopyrite and TCSS.

Recovery of digenite from heavily oxidized Cu-S ore using Na2S as an activator

When valuable digenite is heavily oxidized, it may not respond to the flotation process and remain largely in the tailing with the pyrite. This is problematic because the recovery of digenite from heavily oxidized Cu-S ore is of great significance. In this study, the effect of sodium sulfide on the selective flotation separation of heavily oxidized digenite and pyrite was investigated. The micro-flotation results showed that the floatability of digenite could be effectively restored with the addition of sodium sulfide and sodium butyl xanthate (SBX). However, pyrite showed a poor floatability under the same conditions. Based on this, the flotation separation of artificially mixed minerals was carried out, and a satisfactory result with 51.4% Cu grade and 93.1% Cu recovery could be obtained in the optimized flotation conditions. Then, the sulfidization mechanism of heavily oxidized digenite was discussed in detail through an examination of zeta potential measurements, adsorption measurements, contact angle measurements, and X-ray photoelectron spectroscopy (XPS) analyses. The results indicated that the negatively charged SH− could adsorb on the surface of digenite through chemisorption, and lower the quantity of hydrophilic copper sulfate and oxides/hydroxides on the digenite surface in the presence of SBX, thus significantly increasing the surface contact angle, decreasing the amount of SBX adsorbed to the value observed for unoxidized digenite, and promoting the flotation of heavily oxidized digenite.

Mechanism and application on sulphidizing flotation of copper oxide with combined collectors

Abstract The effect of sodium butyl xanthate (NaBX) and dodecylamine (DDA) as combined collector on the sulphidizing flotation of copper oxide was investigated by flotation test, fluorescent pyrene probe, zeta potential, and infrared spectroscopy analyses. The micro-flotation results show that combined use of NaBX+DDA yields better effect than using NaBX at pH 7-11 only, and the optimal molar ratio of NaBX to DDA is 2: 1. The actual ores flotation shows that when the dosage of NaBX+DDA is (100+54) g/t, the copper concentrate grade and recovery are 15.93% and 76.73%, respectively. The fluorescent pyrene probe test demonstrates that the NaBX+DDA can reduce the micelle concentration in the pulp. The zeta potential and the infrared spectroscopy analyses indicate that chemical adsorption, hydrogen-bonding and electrostatic interaction can help to adsorb NaBX+DDA on the surface of malachite. Meantime, copper xanthate and copper-amine complexes may be generated during the adsorption process.

Microcalorimetry and enzyme activity to determine the effect of nickel and sodium butyl xanthate on soil microbial community

In non-ferrous metal tailings, combined pollution in the surrounding soil is caused by heavy metals and flotation chemicals. The combined effects of nickel (Ni) and its primary ore processing collector, sodium butyl xanthate (SBX), on soil microbial activity were investigated following the fluorescein diacetate hydrolase (FDA) and sucrase (SA) activities, and isothermal microcalorimetry during 60 days. FDA and SA activities as well as overall soil microbial activity were significantly affected by Ni, SBX and Ni/SBX mixture. The inhibition rate (I) of the growth rate constant (k) being higher with the Ni/SBX mixture than with SBX alone during the experiment. The growth rate constant (k) was positively correlated (p < 0.05 or p < 0.01) with enzyme activities (FDA and SA) indicating that k represented a valuable proxy to evaluate the toxic effect of metals and flotation reagents on soil microorganisms. Thus, microcalorimetry was a useful method to characterize soil microbial communities.

Improved hemimorphite flotation using xanthate as a collector with S(II) and Pb(II) activation

The flotation of hemimorphite using the S(II)–Pb(II)–xanthate process, which includes sulfidization with sodium sulfide, activation by lead cations, and subsequent flotation with xanthate, was investigated. The flotation results indicated that hemimorphite floats when the S(II)–Pb(II)–xanthate process is used; a maximum recovery of approximately 90% was obtained. Zeta-potential, contact-angle, scanning electron microscopy–energy-dispersive spectrometry (SEM–EDS), and diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements were used to characterize the activation products on the hemimorphite surface and their subsequent interaction with sodium butyl xanthate (SBX). The results showed that a ZnS coating formed on the hemimorphite surface after the sample was conditioned in an Na2S solution. However, the formation of a ZnS coating on the hemimorphite surface did not improve hemimorphite flotation. With the subsequent addition of lead cations, PbS species formed on the mineral surface. The formation of the PbS species on the surface of hemimorphite significantly increased the adsorption capacity of SBX, forming lead xanthate (referred to as chemical adsorption) and leading to a substantial improvement in hemimorphite flotation. Our results indicate that the addition of lead cations is a critical step in the successful flotation of hemimorphite using the sulfidization–lead ion activation–xanthate process.

Peculiar Features of the Willgerodt–Kindler Reaction of 1-Adamantylpropan-2-one and Its Derivatives

The Willgerodt–Kindler reaction of 1-(1-adamantyl)propan-2-one and its derivatives was studied by gas chromatography–mass spectrometry. The reaction time was found to be 3–4 times longer than in the case of alkyl aryl ketones due to considerable steric hindrances in the molecules of adamantyl ketones. The use of diglyme as solvent and sodium butyl xanthate as catalyst significantly shortened the reaction time and improved the yield to 92%.

Flotation of heavily oxidized pyrite in the presence of fine digenite particles

The ease or complexity of the selective separation of copper sulphur minerals during sulphide flotation is always dominated by the level of surface oxidation. The interaction between oxidized pyrite and other base metal sulphides is important for the flotation process. In this study, the effects of fine digenite particles on the flotation of heavily oxidized pyrite in the presence of sodium butyl xanthate were investigated. The micro-flotation results showed that the floatability of pyrite declined sharply once it was over-oxidized. However, the addition of fine digenite significantly restored the floatability and flotation rate of pyrite, even in strong alkaline solutions. Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) of the flotation products indicated no copper ions on the pyrite surface. This restoration can be attributed to fine digenite particles adsorbing on the surface of coarse pyrite particles and removing a large number of fine pyrite particles covering the pyrite surface in the presence of sodium butyl xanthate. The extended Derjaguin–Landau–Verwey–Overbeek theory based on zeta potential measurements and contact angle measurements was used to calculate the interaction energy between mineral particles. The calculation results showed good agreement with the flotation and SEM-EDS analysis results and explained the mechanism of particle interaction.

Enhanced sulfidation xanthate flotation of malachite using ammonium ions as activator

In this study, ammonium ion was used to enhance the sulfidation flotation of malachite. The effect of ammonium ion on the sulfidation flotation of malachite was investigated using microflotation test, inductively coupled plasma (ICP) analysis, zeta potential measurements, and scanning electron microscope analysis (SEM). The results of microflotation test show that the addition of sodium sulfide and ammonium sulfate resulted in better sulfidation than the addition of sodium sulfide alone. The results of ICP analysis indicate that the dissolution of enhanced sulfurized malachite surface is significantly decreased. Zeta potential measurements indicate that a smaller isoelectric point value and a large number of copper-sulfide films formed on the malachite surface by enhancing sulfidation resulted in a large amount of sodium butyl xanthate absorbed onto the enhanced sulfurized malachite surface. EDS semi-quantitative analysis and XPS analysis show that malachite was easily sulfurized by sodium sulfide with ammonium ion. These results show that the addition of ammonium ion plays a significant role in the sulfidation of malachite and results in improved flotation performance.

Study of the Effect of Sodium Sulfide as a Selective Depressor in the Separation of Chalcopyrite and Molybdenite

Two kinds of collectors, sodium butyl xanthate and kerosene, and a depressor, sodium sulfide, were used in this research. The study applied flotation tests, pulp potential measurements, contact angle measurements, adsorption calculations, and Fourier Transform Infrared Spectroscopy (FTIR) analyses to demonstrate the correlation between reagents and minerals. For xanthate collectors, the best flotation responses of chalcopyrite and molybdenite were obtained at pH = 8, and, for kerosene, these were obtained at pH = 4. The flotation of molybdenite seemed to be less influenced by xanthate than by kerosene, while that of chalcopyrite showed the opposite. The optimum concentration of sodium sulfide for separation was 0.03 mol/L, which rejected 83% chalcopyrite and recovered 82% molybdenite in the single mineral flotation. Pulp potential measurements revealed that the dixanthogen and xanthate were decomposed and desorbed, respectively, from the mineral surface in a reducing environment. The contact angle measurement and adsorption calculation conformed to the flotation response, indicating that few functions of the xanthate and sodium sulfide on the molybdenite flotation were due to their low adsorption densities. The FTIR results further clarified that the xanthate ion was adsorbed on chalcopyrite by forming cuprous xanthate and dixanthogen; however, on molybdenite the adsorption product was only dixanthogen. After conditioning with sodium sulfide, the chalcopyrite surface became clean, but the molybdenite surface still retained slight peaks of dixanthogen. Meanwhile, the possible mechanism was expounded in this research.

Flotation performances and surface properties of chalcopyrite with xanthate collector added before and after grinding

Abstract In this study, effects of the collector added before grinding and after grinding on the subsequent flotation and mineral surface properties were investigated. The pH was controlled at 10 during the grinding and flotation processes opened to the atmosphere. With enough amounts of sodium butyl xanthate addition, adding the collector before grinding recovered more chalcopyrite than adding it after grinding in single mineral flotation. The Eh of each ground pulp before and after conditioning were measured and it was found that adding collector before grinding obtained higher and relatively suitable pulp potential for chalcopyrite flotation. Particle size analyses of the flotation products indicate that the different flotation recoveries occurred due to the different flotation losses in fine particles (

Selective chalcopyrite flotation from pyrite with glycerine-xanthate as depressant

Micro-flotation tests, adsorption, electrokinetic and FTIR measurements were carried out in order to investigate the selective depression mechanism of sodium glycerine-xanthate (SGX) on pyrite in chalcopyrite flotation. The flotation results showed a large difference in chalcopyrite (>85%) and pyrite (<30%) recovery as stirred pulp-mixing with SGX before the addition of collector sodium butyl xanthate (SBX), at the range of pH 7–10. A much stronger adsorption of SGX on pyrite than chalcopyrite was dramatically revealed by zeta potential measurements, which can explain the better floatability of chalcopyrite than pyrite. The adsorption of SBX onto pyrite was depressed intensely while that onto chalcopyrite was affected slightly when SGX was used as depressant, because of more stronger adsorption between SGX and SBX occurring onto the pyrite surfaces. The absorbed amount of SGX on chalcopyrite increases slightly, over the pH range from 3 to 12, while that on pyrite increases rapidly with the increased SGX concentration, which is consistent with the flotation results. FTIR reflection spectroscopic measurements further demonstrated the depression effect of pre-absorbed SGX on SBX adsorption, which is attributed to its hydrophilic hydroxyl groups.

Decomposition of sodium butyl xanthate (SBX) in aqueous solution by means of OCF: Ozonator combined with flotator

In this study, ozonator combined with flotator (OCF) have been applied to treat the mineral processing wastewater. The process efficiency has been evaluated in the bench scale. Removing xanthate from aqueous solution was conducted by OCF. In all cases, the butyl xanthate concentration in the treated water was found to be negligible (<0.42mgL−1). The experiments were preceded under different reaction conditions to study the ozonation time and pH on the oxidation of butyl xanthate. The concentration of butyl xanthate and sulfide are analyzed at special time intervals to elucidate the decomposition of butyl xanthate. In addition, oxidation reduction potential and pH are continuously measured in the course of experiments. Chemical oxygen demand is chosen as a mineralization index of the ozonation of butyl xanthate. The degradation mechanism between butyl xanthate and ozone has been discussed. The OCF technology showed to be an efficient process, which requires ozone and flotator, and the treated water ended up with a very low residual concentration of xanthate and COD. It can be inferred from ultraviolet spectrum, HPLC-MS and COD measurement that SO42− is produced. The COD of butyl xanthate solution declined dramatically, the removal rate of COD reached 72.21% when ozonation time is 60min. And the biodegradability (BOD/COD) of butyl xanthate solution increased markedly and shifted from 0.251 to 0.361. It is believed that this ozonation–flotation technique, here named OCF, using ozonator and flotator has a high potential as a alternative method for pollutants removal (flotation reagents, such as butyl xanthate) form waste mining effluents.

FTIR studies of xanthate adsorption on chalcopyrite, pentlandite and pyrite surfaces

The Fourier transform infrared (FTIR) spectra of sodium butyl xanthate, dibutyl dixanthogen, metal xanthate compounds and surfaces of chalcopyrite, pentlandite and pyrite treated with sodium butyl xanthate solution were systematically studied. The products of xanthate adsorpted on the three different minerals were characterized by comparing their FTIR spectra to those of dixanthogen and metal xanthate. Both metal xanthate and dixanthogen are formed on the surfaces of these minerals. However, the relative proportions of metal xanthate to dixanthogen on the minerals are different. In the cases of chalcopyrite and pentlandite, the quantity of metal xanthate is larger than that of dixanthogen. For pyrite, on the contrary, the quantity of dixanthogen is much greater than that of ferric xanthate. Therefore, the formation of dixanthogen is more essential for the flotation of pyrite.

Flotation performances of polymorphic pyrrhotite

The floatability of different crystalline structures of pyrrhotite (monoclinic and hexagonal) was studied. It is shown that the floatability of monoclinic and hexagonal has obvious difference, and that the flotation recovery of monoclinic pyrrhotite is larger than that of hexagonal pyrrhotite using different collectors. When butyl dithiophosphate is used as the collector, the recovery is larger than that by sodium butyl xanthate and sodium diethyl dithiocarbamate. At the pH values ranging from 6 to 9, monoclinic pyrrhotite can be floated well, and the flotation recovery is higher than 90%. Monoclinic and hexagonal pyrrhotites are more easily activated by Cu 2+ in acidic conditions than in alkaline conditions. But Cu 2+ cannot activate hexagonal pyrrhotite using sodium diethyldithiocarbamate as the collector. By the measurement of contact angle, it is indicated that monoclinic and hexagonal pyrrhotites float well and are easily activated by Cu 2+ when dithiophosphate is used as the collector. Using sodium diethyl dithiocarbamate as a collector, the relationship between potential and pH range for pyrrhotite flotation is established. At pH 5, the optimal potential range for flotation of monoclinic pyrrhotite is about 125−580 mV (vs SHE), with the maximum flotation occurring at about 350 mV (vs SHE); the optimal potential range for flotation of hexagonal pyrrhotite is 200−580 mV (vs SHE), with the maximum flotation occurring at about 300 mV (vs SHE).

Use of sodium and potassium butyl xanthate as accelerator for room temperature prevulcanization of natural rubber latex

AbstractSodium and potassium butyl xanthates (Nabxt and Kbxt) were prepared in the laboratory. Characterization of these xanthates were done using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (1H NMR) spectroscopy, thermogravimetric analysis (TGA), and differential thermal analysis (DTA) techniques. These xanthates were used as accelerators for the prevulcanization of natural rubber latex (NRL) at room temperature. Optimization of prevulcanization time was done. Films were casted from these prevulcanized NRL. Tensile properties of latex vulcanisates were measured and potassium butyl xanthate gave superior properties to the NRL films compared with sodium butyl xanthate. Effect of thermal ageing on tensile properties of these prevulcanized NRL films was also investigated and these properties were found to be improved after thermal ageing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Improving copper flotation recovery from a refractory copper porphyry ore by using ethoxycarbonyl thiourea as a collector

In this paper, N-propyl- N-ethoxycarbonyl thiourea (PECTU) collector was investigated to concentrate copper minerals from a refractory copper porphyry ore through bench-scale and industrial flotation tests. The flotation results indicated that PECTU had strongly collecting power for copper sulfide minerals and excellent selectivity against iron sulfide minerals under moderately alkaline conditions. Compared with sodium butyl xanthate (SBX), PECTU increased the grades and recoveries of Cu, Au and Mo in the copper concentrates, and performed the flotation separation of Cu/Fe sulfide minerals at cleaner pH ∼10.5 as well as decreased 2/3 lime consumption. The results of UV–visible measurements further demonstrated that PECTU could be used as a high selective collector for copper minerals. The experimentally obtained results have been explained from the structure–reactivity relationship of collector by density functional calculation.

Bulk flotation of auriferous pyrite and arsenopyrite by using tertiary dodecyl mercaptan as collector in weak alkaline pulp

Laboratory and industrial scale experiments were conducted to investigate the effect of tertiary dodecyl mercaptan (TDM) as a collector on the flotation of auriferous pyrite and arsenopyrite. The optimum recovery of gold associated with auriferous sulphides was obtained by adding a mixture of TDM and sodium butyl xanthate, together with only a little CuSO 4 as an activator in a weak alkaline pulp adjusted by NaOH. A two-month industrial trial at the Liumei plant in Guangxi, China showed that an average gold recovery of 90.8% into a concentrate assaying 81.1 g/t Au from a feed assaying 2.9 g/t Au could be achieved at pH 8–8.5 using TDM as a collector.

Inhibition of Thiobacillus ferrooxidans by mineral flotation reagents

Ferrous-iron oxidation by Thiobacillus ferrooxidans was inhibited by a number of mineral flotation reagents. Dowfroth 250 and sodium butylxanthate were the least toxic reagents studied.