Diisobutyl Dithiophosphinate Research Articles

The role of temperature on collector adsorption in galena flotation: Implications of seasonal temperature and climate change

This research focuses on studying the effects of the operating temperature and preconditioning time on the adsorption kinetics of sodium diisobutyl dithiophosphinate and sodium isopropyl xanthate collectors on the surface of galena, using contact angle measurements. The results indicate a strong correlation between higher operating water temperature and increased contact angles, suggesting faster adsorption kinetics and heightened hydrophobicity. Statistical analysis underscores the significance of temperature and preconditioning time, both factors being statistically significant. This study delves into the intricate interaction between temperature fluctuations and collector adsorption, contributing to a deeper understanding of flotation processes within the Pb/Cu circuit during seasonal temperature variations.Graphical abstract

The interaction mechanism and collecting performance of three sulfydryl collectors with Au(1 0 0) surface: A study combining DFT and molecular dynamics

Amyl xanthate (AMX), ammonium dibutyl dithiophosphate (ADD) and diisobutyl dithiophosphinate (DTPI) have proved to be common and effective sulfydryl collectors for gold flotation. In this study, density functional theory (DFT) and molecular dynamics (MD) methods are used to investigate the interaction mechanism and collecting performance of three sulfydryl collectors with Au(100) surface. The adsorption energy of DTPI is −283.30 kJ/mol, which is the largest among the three, suggesting its chemisorption on gold surface is the most stable. This is agreed with the prediction of polarizability and frontier orbital energy difference. The gold-collector interaction on the surface is realized by the bonding of surface Au atom and collector S atom. Density of states (DOS) results suggest that after collector adsorption the delocalization of S 3p orbital is increased, resulting in the enhancement of nephelauxetic effect, and this proves that the covalency of Au − S bond has been facilitated. DOS analysis further confirms that the S atom of DTPI is most likely to form a covalent bond with Au atom because of its strongest reactivity. Besides, molecular dynamics simulation suggests that the wetting process of water droplets on the gold surface would be hindered by the adsorption of three collectors, thus the wettability of the gold surface would change significantly. In summary, it can be considered that the gold collecting performance of three collectors follows the order of DTPI > ADD > AMX. This comparative study is helpful to understand the interaction mechanism between sulfydryl collectors and gold surface.

Selective enhancement of jamesonite flotation using Aerophine 3418A/DDTC mixture

In this study, mixed collectors containing sodium diisobutyl dithiophosphinate (Aerophine 3418A (3418A), Solvay) and sodium diethyldithiocarbamate (DDTC) were used to improve the flotation of jamesonite, and adsorption mechanism of this system was investigated by means of flotation experiments, FTIR and SEM-EDS analyses, and DFT-D calculation. The results of micro-flotation experiments indicated that 3418A/DDTC mixture with the molar ratio of 1:2 (3418A/DDTC mixture) exhibited excellent selectivity, and presented a shorter conditioning time than conventional DDTC in the flotation of jamesonite. Batch flotation experiments confirmed that 3418A/DDTC mixture could significantly improve the flotation performance of natural refractory Pb-Sb-Zn ore. FTIR and SEM-EDS analyses showed that 3418A and DDTC could perform synergistic chemisorption on jamesonite surface, while the residual amount of 3418A on the surface of jamesonite was significantly higher than that of DDTC. Further analysis with DFT calculation showed that the 3418A could rapidly overcome the binding interactions of surrounding molecules from the micelle and then form effective adsorption in the jamesonite surface, while the DDTC could strengthen the hydrophobic layer due to the H…N hydrogen bonds.

Highly selective complexation of cadmium from wet phosphoric acid by organic coordination ligands

Recently, the application of organic coordination ligands for the cadmium removal from wet phosphoric acid (WPA) has shown a great interest, and a certain number of commercially available ligands have shown some affinity and selectivity for cadmium. This technic consists in making complexes between cadmium and ligands. It is easy to integrate industrially and does not require significant investment and maintenance overhead; the cost is driven by the organic ligand stability, efficiency and price. However, the challenge still the high cost of ligand and its insufficient world production capacity in comparison to the increasingly demand. The present research article aims to experiment new organic ligands potentially proved in various media for the cadmium removal. The cadmium removal tests from WPA were carried out under the industrial conditions of 25 % (w/w) P2O5, 14 ppm Cd, and 80 °C. A number of 21 organic ligands were carefully selected based on their potential removal of cadmium. The tests were separately performed under the stoichiometric conditions corresponding to a molar ratio R (nLigand/ncd) of 2, and the excess conditions corresponding to a molar ratio R (nLigand/ncd) of 10. Distinctly, the results relatively to R equaling 10 showed significant increase in cadmium removal specifically to DIBDPi (Diisobutyl dithiophosphinate), DEDTP (Diethyl dithiophosphate), ZDDP (Zinc dialkyl dithiophosphinate), TBAI (Tetrabutyl ammonium iodide), Na2CS3 (Sodium trithiocarbonate), and Aliquat 366 (Methyltrioctyl ammonium chloride), with an efficiency of 86 %, 71 %, 68 %, 29 %, 24 %, and 21 %, respectively. The other ligands still showed no affinity for cadmium removal from WPA.

Chemical stability of xanthates, dithiophosphinates and hydroxamic acids in aqueous solutions and their environmental implications

Currently there is a wide variety of collectors used in mineral processing, the xanthates being the most used in sulfides flotation. Unfortunately, it is known that xanthates are not stable compounds and their decomposition generates carbon disulfide (CS2), a substance that is considered toxic. These aspects have motivated the search for collectors that exhibit superior performance without the health, safety and environmental (HSE) concerns associated with xanthates. In this study, the chemical stability of three xanthates of different alkyl groups (sodium ethyl xanthate (SEX), sodium isopropyl xanthate (SIPX) and potassium amyl xanthate (PAX)) was evaluated by UV/Vis spectroscopy, as a function of pH and time. Similarly, the chemical stability of three chelating collectors was evaluated: sodium di-isobutyl dithiophosphinate (SDIBDTPI), benzohydroxamic acid (BHA) and octanohydroxamic acid (OHA). Likewise, the surface tension of their aqueous solutions was measured making use of the Du Noüy method, to determine the critical micelle concentration (CMC). The results showed that the xanthate UV/Vis absorption spectra reflect the presence of a chemical reaction as the pH decreases from 4 to 2.5, which results in the formation of carbon disulfide (CS2). In addition, the generation of CS2 is favored as time elapses and the pH of the solutions decreases from 10 to 6, regardless of the hydrocarbon chain length. Conversely, dithiophosphinate and hydroxamic acids present greater chemical stability, although they form micelles at a certain concentration (CMC), a phenomenon that is not observed with xanthates. By not hydrolyzing, oxidizing, or decomposing into other chemical species, SDIBDTPI, BHA, and OHA may be considered environmentally friendly reagents. In the above context, it is important to promote the adoption of these collectors in mineral processing.

The influence of collectors containing diisobutyldithiophosphinate on the flotation of sulfides and platinum-group metals of copper-nickel ores

The paper provides the results of studies into the interaction between Aerophine 3418A, Aerophine 3416, Aerophine 3406 collectors containing diisobutyldithiophosphinate (DIP) and butyl xanthate with pyrrhotite, pentlandite, platinum black and cooperite by measuring the electrode potential and determination of DIP adsorption forms using extractive spectrophotometry. It was shown that butyl xanthate reduces the electrode potential to a greater extent compared to DIP-containing collectors. The value of electrode potential shift in the presence of collectors decreases in the series: platinum black — pentlandite — pyrrhotite. Pentlandite and pyrrhotite interaction with butyl xanthate and DIP mainly results in the molecular form - disulfide - formed on the surface with the order of magnitude less compounds of collectors with metal. After interaction with butyl xanthate, the sorption layer on cooperite contained disulfide only, and both disulfide and the complex compound of Pt with DIP in case of DIP. It was demonstrated that DIP containing collectors have a greater collecting and hydrophobic ability than butyl xanthate to pentlandite and pyrrhotite. The maximum hydrophobic effect is achieved using a composition of butyl xanthate and DIP-containing collectors with a ratio of 1:1 to 1:3. The effectiveness of Aerophine 3416 and butyl xanthate compositions in bulk flotation of platinum-copper-nickel ores is shown.

Role of pH on the adsorption of xanthate and dithiophosphinate onto galena

ABSTRACTIn the concentrators of a Mexican mining company has been observed that the pH of the flotation has a significant effect on the galena recovery: the increase of pH from 7.5 to 9.5 in the Pb/Cu flotation circuit, resulted in a decrease of about 10% of lead recovery. In the present investigation, experimental models and techniques were developed to study the effect of pH on xanthate and di-isobutyl dithiophosphinate adsorption onto galena. The results obtained by UV / Vis spectroscopy showed that once galena surface has been slightly oxidised by the dissolved oxygen of the aqueous suspension, adsorption of both surfactants increases significantly, being adversely affected by the increase of pH from 5.5 to 9.5. Microflotation measurements performed for both surfactants support these findings. Thermodynamic simulation of the system suggests that the observed behaviour is due to the nature of the solid species formed on the galena surface at the particular pH: lead sulfate (PbSO4) under neutral and slightly acid conditions, and the basic sulfate (2PbO·PbSO4) under neutral and slightly alkaline conditions, as well as to their respective solubility. Infrared spectrometry confirmed the occurrence of sulfate onto galena particles, with a higher concentration for the acid pre-conditioning compared to the alkaline pre-conditioning.

Collector attachment to lead-activated sphalerite – Experiments and DFT study on pH and solvent effects

The interactions of diisobutyl dithiophosphinate with bare (un-activated) and lead-activated sphalerite were studied both experimentally and through DFT simulations. Sphalerite activated by lead in acidic and alkaline conditions showed considerably greater affinity for diisobutyl dithiophosphinate adsorption than bare sphalerite. Experimental observations supported by DFT simulations concur in that attachment of the solvated collector to the activated sphalerite surface is through adsorbed lead cations or lead hydroxides where as for the bare sphalerite, the collector was most stable in its solvated state and not as an adsorbed specie. Accounting for solvation effects by including a swarm of water molecules in DFT simulations was necessary to infer plausible surface interactions between collector, solvent, and bare or lead-activated sphalerite. The experimental data and DFT simulations indicate, affinity of the collector toward surface-adsorbed lead species was predicted to form stable covalent bonds between collector sulfur atoms and lead.

Sulfhydryl phosphorus-containing collectors in flotation of copper–nickel platinum-group metals

The analysis involves influence of sulfhydryl phosphorus-containing collectors (SPC) on flotation of copper–nickel ore-bearing metals from platinum group. Efficiency of SPC and butyl xanthate combination is illustrated, and their optimal ratio is determined. The authors study influence of the test agents on electrode potential and hydrophobic behavior of pyrrhotine, pentlandite and platinum black. UV and IR spectrophotometry has shown origination of disulfide di-isobutyl dithiophosphinate on the surface of pyrrhotine.

Enhancing the disparity in flotation properties of nonferrous metal sulfides using sulfhydryl collecting agents with different molecular structures

The article reports analytical data on surface compounds of galena, chalcopyrite and sphalerite. By X-ray photoelectron spectroscopy and IR spectroscopy, the authors find the oxidability series: PbS ≈ ZnS < CuFeS2. Sphalerite has the largest amount of free water in the surface layer. The frother and non-frother flotation experiments show that floatability of monomineral fraction of galena is higher in neutral medium at sulfhydryl agent concentration under 10-4 mole/l. In alkaline medium floatability of galena grows with increasing concentration of sulfhydryl agents, which degrades selectivity of flotation. Galena recovery is the highest with butyl xanthate and di-isobutyl di-thiophosphinate. Tests of adsorption use the method of isomolar series and non-frother flotation conditions. Constants of adsorption velocity are calculated at different ratios of strong (butyl xanthate) and weak (thionocarbamate) agents for galena, chalcopyrite and sphalerite. If thionocarbamate prevails, the adsorption velocity constant grows, and so does the recovery of chalcopyrite as against galena and sphalerite. The experimental results agree well with the production research data on samples from Stepnoe and Rubtsovsk polymetallic ore deposits.

The collecting performance and interaction mechanism of sodium diisobutyl dithiophosphinate in sulfide minerals flotation

The interaction mechanism of sodium diisobutyl dithiophosphinate (DTPINa) with chalcopyrite, pyrite, galena and sphalerite was investigated by single mineral flotation experiment, adsorption measurement and FTIR spectrum analysis. Single mineral flotation experiments showed that sodium diisobutyl dithiophosphinate exhibited a strong ability to collect chalcopyrite and galena. For chalcopyrite and pyrite, the recovery of chalcopyrite can reach 96.2% when the dosage is 12mg/L and pH value is 8. In the same situation, the recovery of pyrite is as low as 13.5%. For galena and sphalerite, the recovery of galena reached 91.7% when the dosage was 50mg/L at pH 11, and the recovery of sphalerite was only 16.9%. DTPINa adsorbed on chalcopyrite and galena surfaces are more than that on pyrite and sphalerite surfaces. The adsorption capacity of DTPINa on the minerals surface is proportional to its dosage. The FTIR spectrum analysis results showed that the adsorption of DTPINa on sulfide minerals surface is chemical and S atoms in PS and PS may have taken part in the reaction. The natural ores experiments also confirmed the excellent performance of sodium diisobutyl dithiophosphinate.

Entrainment and true flotation of a natural complex ore sulfide

This study attempts to assess the contribution of entrainment and true flotation in the overall recovery by the laboratory tests performed on a natural complex sulfide ore, provided by la Compagnie Miniere des Guemassa (Morocco), and the effect of two different collectors, Potassium Amyl Xanthate (PAX) and Sodium di-isobutyl di-thiophosphinate (Aerophine 3418A), on the two contributions. Overall recovery and true recovery were fitted to first kinetic model and modified flotation parameters were calculated to measure of flotation separation selectivity of chalcopyrite, galena and sphalerite over gangue and pyrrhotite. To estimate the entrainment, Ross method was the most suitable in the case of complex sulfide ore with high content of pyrrhotite. Trahar method overestimates the effect of entrainment.

A novel capillary electrophoresis method with pressure assisted field amplified sample injection in determination of thiol collectors in flotation process waters

A new capillary electrophoresis method was developed for the quantification of diisobutyldithiophosphate (DTP), diisobutyldithiophosphinate (DTPI) and ethyl and isobutyl xanthates (EX, IBX) all of which are used as thiol collectors in froth flotation. This method uses pressure assisted field amplified sample injection (PA-FASI) to concentrate the analytes at the capillary inlet. The background electrolyte in electrophoretic separation was 60millimolar (mM) from 3-(cyclohexylamino)propane-1-sulfonic acid (CAPS) in 40mM NaOH solution. The similar CAPS electrolyte solution has earlier been used for screening for diuretics that contained sulphonamide and/or carboxylic groups. In this study, the functional groups are xanthate, phosphate and phosphinate. The method was developed using actual flotation process waters. The results showed that the water delivered from the plant did not contain significant amount of collectors; therefore, method development was accomplished by spiking analytes in these waters. Separation of analytes was achieved in 15min. The range of quantification was 0.27–66.6mg/L (R2 0.9991–0.9999) for all analytes other than ethyl xanthate, for which the range was 0.09–66.6mg/L (R2 0.9999). LOD (S/N=3) and LOQ (S/N=10) values for DTP, DTPI, IBX and EX were 0.05, 0.07, 0.06 and 0.01mg/L and 0.16, 0.25, 0.21 and 0.04mg/L, respectively. No interference from the matrices was observed, when the method was tested at a gold concentrator plant.

Collecting properties of diisobutyl dithiophosphinate in sulfide minerals flotation from sulfide ore

The authors experimentally compared collecting properties of diisobutyl dithiophosphinate (DDP), butyl and isobutyl xanthate, and diisobutyl and dibutyl dithiophosphate relative to pyrite, chalcopyrite and other sulfides. It was found that pyrite adsorption grew in nonfrothing flotation with all the listed collecting agents. The nonfrothing pyrite flotation by DDP showed higher rates of adsorption and flotation as against butyl xanthate. The ratio of DDP and butyl xanthate flotation rate constants was 1.19, which agreed with the ratio of the adsorption rate constants of 1.18 in nonfrothing flotation. The low selectivity of dithiophosphinates toward sulfide ores is explained.

A DFT study on the structure-reactivity relationship of thiophosphorus acids as flotation collectors with sulfide minerals: Implication of surface adsorption

Thiophosphorous compounds: diisobutyl dithiophosphate (DIBDTPA), diisobutyl dithiophosphinate (DIBDTPI), diisobutyl monothiophosphate (DIBMTPA) and diisobutyl monothiophosphinate (DIBMTPI) are widely used as flotation collectors and corrosion inhibitors, though the true nature of their bonding mechanisms to solid surfaces is still unclear. Using density functional theory (DFT) calculations, this study investigates the structure-reactivity relationship of these thiophosphorus molecules as flotation collectors with sulfide minerals. The results indicate that the O atom(s) bonded to the P atom in thiophosphorus molecules can significantly impact the chemical reactivity of the S atom(s) in the four reagents, and for DIBMTPA and DIBMTPI, they could even attend the chemical bond formation with metal atoms. The reactive power of the four compounds to mineral surfaces of Cu, Au, Ag and Pb sulfides is predicted to be DIBDTPI≫DIBMTPI≥DIBDTPA>DIBMTPA, and their flotation selectivity against pyrite and sphalerite is suggested as DIBDTPA<DIBDTPI<DIBMTPI<DIBMTPA. Moreover, the thione form of acid or ion species of DIBMTPA or DIBMTPI is more stable than its thiol form, and in aqueous phases, the ionized thione of the four thiophosphorus collectors exhibits the strongest affinity to mineral surfaces. The theoretical results provide an atomic level understanding of the adsorption activity and selectivity of the four thiophosphorus molecules to metal sulfide minerals and a potential approach to molecular design of new thiophosphorous compounds for improving the flotation recovery of them.

Experimental-analytical methods of the investigating the effect of complexing reagents on platinum flotation

The paper considers the studies into the hydrophobic properties of platinum and platinum arsenide, sperrylite, in the solution with added complexing reagents by using the method of measuring the force of the air bubble abstraction from the mineral surface. The effect of these complexing reagents on the chemical properties of sperrylite and pyrrhotine is analyzed. A new-developed procedure for treatment of pyrrhotine by chloroplatinic acid is presented, and the comparative flotation of natural pyrrhotine and platinum-pretreated pyrrhotine with the complexing reagents is described. The collecting properties of diisobutyl dithiophosphinate for platinum are determined, and the use of this reagent as an additional collector for platinum-group metals is confirmed in the course of the experimental flotation of platinum-bearing copper-nickel ore samples.

Adsorption behaviour of xanthate and dithiophosphinate from their mixtures on chalcopyrite

The beneficial effects of the synergy between two or more reagents were realized long time ago. The purpose of using a mixture of collectors was to increase both the recovery and selectivity. In this work, two thiol collectors, isopropyl xanthate (SIPX) and di-isobutyl dithiophosphinate (DTPI), having different chemical and functional properties, were used. The adsorption behaviour of these collectors from their mixtures was investigated at various SIPX:DTPI ratios and sequence of addition by cyclic voltammetry and adsorption experiments at pH 9.2. The results showed that both the ratio of collectors in these mixtures, and sequence of addition were important. The amount of total collector (SIPX and DTPI) adsorbed on chalcopyrite was measured for these various reagent mixtures and for single collectors. Two maxima were found. One was found for the 30:70 DTPI:SIPX suite in which the DTPI was added first. A second was found with the 50:50 SIPX:DTPI suite when the collectors were added together. These results revealed that the maximum synergistic effect of using mixture of SIPX and DTPI was strongly influenced by the ratio of the collectors in the mixture and particularly sequence of addition.

Impact of copper and lead on the activation of pyrite in the presence of thiol collectors

Lead and copper activation onto pyrite in the presence of thiol collectors was examined by means of cyclic voltammetry and micro-flotation techniques. Di-isobutyl dithiophosphinate (Aerophine 3418A) and alkyl thionocarbamate (AERO 3894) were employed as lead and copper collectors, respectively. Otherwise, isopropyl xanthate was also used as a collector of both lead and copper. The results revealed that, in the presence of non-conventional collectors, the increment in pyrite recovery owing to the activation by copper and lead species was noticeably smaller than that exhibited by the use of xanthate (IPX) under the same conditions. The electrochemical response of activated pyrite suggests the formation of copper and lead xanthate compounds and the increase in the peak could be attributed to the formation of dixanthogen. The voltammograms of pyrite stayed un-affected regardless of the activation by lead or copper.

Mechanism of di-isobutyl dithiophosphinate adsorption onto galena and pyrite

The interaction of sodium-di-isobutyl dithiophosphinate (DTPINa) with galena and pyrite in alkaline media (pH 9) was examined using cyclic voltammetry, open circuit potential and contact angle techniques. Analysis of results suggests that the collector interacts with the minerals by chemical and electrochemical mechanisms according to the following steps: a chemisorption process (without electron transfer) that takes place when the collector interacts with metal species (e.g., of lead) that shows chemical affinity towards the collector; an electrochemical–chemical process developed by the galena that involves two steps: the oxidation of the mineral (electrochemical step) and the formation of a metal–collector precipitate (chemical step); and an electrochemical process (adsorption of collector and dimer formation) that occurs when pyrite is held at a redox potential sufficiently anodic to produce oxidation of the collector.

The role of copper and lead in the activation of pyrite in xanthate and non-xanthate systems

Lead and copper activation of pyrite in the presence of thiol collectors was examined by means of cyclic voltammetry and microflotation techniques. Di-isobutyl dithiophosphinate (Aerophine 3418A) and alkyl thionocarbamate (AERO 3894) were employed as collector of lead and copper, respectively. Otherwise, isopropyl xanthate (IPX) was also used as a collector of both: lead and copper. The results revealed that in the presence of non-conventional collectors, the increase in pyrite recovery due to the activation by copper and lead species, was noticeably smaller than that exhibited when xanthate (IPX) was used. The electrochemical response of pyrite indicates that lead activation favors the formation of dixanthogen. In non-xanthate systems, the voltammograms of pyrite remained unaffected regardless of the activation by lead or copper species.