Selective depression of galena and chalcopyrite by O,O-bis(2,3-dihydroxypropyl) dithiophosphate

A novel synthesized reagent, O,O-bis（2,3-dihydroxypropyl） dithiophosphate （DHDTP）, was investigated as depressant on the depression of chalcopyrite and galena, when ammonium dibutyl dithiophosphate （DDTP） was used as the collector in flotation tests. Zeta potential and adsorption measurement were performed to study the interaction between depressant and minerals. The flotation tests of two minerals show that DHDTP has slight depression on chalcopyrite in the whole pH range and strong depression on galena in the pH range of 6-10. When DHDTP dosage is increased, the recovery of galena decreases rapidly, while that of the chalcopyrite decreases slightly. The satisfied separation results of artificially mixed samples are that the copper grade and recovery rates of concentrate are 24.08% and 81%, respectively, when the pH is 6 with 278 mg/L DHDTP. Zeta potential and adsorption measurements show that DHDTP has more strongly adsorotion capacity to galena than chalcoovrite.

Floc flotation of marmatite fines in aqueous suspensions induced by butyl xanthate and ammonium dibutyl dithiophosphate

The hydrophobic flocculation of marmatite fines in aqueous suspensions induced by butyl xanthate （KBX） and ammonium dibutyl dithiophosphate （ADD） was investigated using laser particle size analysis, microscopy analysis, electrophoretic light scattering, contact angle measurement and infrared spectroscopy. The studies were performed on single minerals with size 〈20 μm by varying several parameters, including pH, collector concentration and kerosene addition. The results show that the floc fotation closely correlated with the size of flocs and the particle hydrophobicity, but was not lowered with increasing the particle surface charges due to collector adsorption. Under good operating conditions, the floc flotation of marmatite fines as a function of KBX and ADD can all reach floatability over 90%, in comparison with conventional flotation obtaining floatability of about 60%. It also has been found that a small addition of kerosene greatly improved the floc flotation because of the formation of oil films on marmatite particles. The results of FTIR spectra indicate that adsorption of the two collectors onto marmatite were chemical adsorption.

Floc flotation of jamesonite fines in aqueous suspensions induced by ammonium dibutyl dithiophosphate

The hydrophobic flocculation of jamesonite fines in aqueous suspensions induced by ammonium dibutyl dithiophosphate was investigated using laser particle size analysis, microscope analysis, electrophoretic light scattering and infrared spectroscopy.Single minerals of 4.607 μm for the 50% volumetric diameters were researched by varying several parameters, including p H,ammonium dibutyl dithiophosphate concentration, stirring strength and kerosene addition. It is found that the maximal floatability of jamesonite fines is induced by ammonium dibutyl dithiophosphate at p H 6, and the floc flotation increases with increasing ammonium dibutyl dithiophosphate concentration despite a simultaneous increase in the negative ζ potential of jamesonite, meaning that hydrophobic interaction between the particles increases much more strongly than electric double layer repulsion from the adsorption of ammonium dibutyl dithiophosphate. It is also found that the floc flotation is closely correlated with the size of flocs,which is strongly influenced by the stirring strength and enhanced by the addition of a small amount of kerosene. The results of FTIR spectra indicate that adsorption of ammonium dibutyl dithiophosphate onto jamesonite is chemical adsorption and the adsorption product is lead dibutyl dithiophosphate.

UV-Vis Spectrophotometry and AFM Observation of Diethyl Dithiophosphate Adsorption on Chalcopyrite at Varied pHs

Adsorption of diehtyl dithiophosphate on chalcopyrite has been studied using UV-visible spectroscopy at pH values of 4, 6, and 9. It was found that the adsorption of diethyl dithiophosphate decreased with the increasing pH treatments. The inhibition of diethyl dithiophosphate adsorption was found prominent in higher pH as a result of metal hydroxide species formation onto chalcopyrite surface. First order kinetic has been proposed and represented the adsorption mechanism. Flotation test using Hallimond tube has also been conducted and the results were consistent with the proposed mechanism. Furthermore, the morphological changes of the treated chalcopyrite were observed using Atomic Force Microscopy （AFM） showing the propensity of growth of islands, the new surfaces as products of the reaction. The hydrophobicity was measured in the form of force of adhesion. The results resembled with the approached mechanism.

Studies on Tricyclohexyltin ( Ⅳ ) Diaryldithiophosphates

Fourteen new tricyclohexyltin (Ⅳ)-O,O-diaryldithiophosphates were synthesized and determined by IR, 1H NMR, 13C NMR, 119Sn NMR MS, and elemental analysis. The structures of all the compounds consist of discrete molecule containing a four-coordinated tin atom. Results from the preliminary biological test show that these compounds have a high miticidal activity.

Crystal Structure of Bis(O,O′-diisopropyl dithiophosphate): [(C_3H_7O)_2PS_2]_2

The crystal and molecular structures of [(C 3H 7O) 2PS 2] 2(CCDC No.217201) were determined by means of X-ray crystallography. It crystallized in a triclinic system with space group P1 and lattice parameters a=0.82794(3) nm, b=0.84764(2) nm, c=0.85034(3) nm, α=97.78(3)°, β=110.77(3)°, γ=94.95(3)°, V=0.54701(9) nm3, Z=1. In this molecule, the two diisopropyl dithiophosphate groups, [(C 3H 7O) 2PS 2] 2, which are parallel to each other, are linked by an S—S bond and there exist inversion centers in the molecule. In the structure, the PS bonds in the two dithiophosphate units are trans-oriented to each other.

Synthesis,Characterization and Crystal Structure of[Ni(S_2P{O}OC_6H_4CH_3-p)(dppv)]

O-（p-tolyl）dithiophosphato nickel complex [Ni（S2P{O}OC6HaCH3-p）（dppv）] has been synthesized by the treatment of （dppv）NiCl2 （dppv = Ph2PCH=CHPPh2） with （p-CH3C6HaO）2P{S}SH＇Et2NH in THF. The new complex was fully characterized by elemental analysis, IR, 1H NMR, 31p NMR spectroscopies and thermo-gravimetric analysis. The molecular structure of the complex was established by X-ray crystallography. The crystal crystallizes in monoclinic, space group P21/c with a = 9.2739（5）, b = 17.8803（8）, c = 20.1879（12） A, fl = 93.269（5）, V = 3342.1（3） A3, Z = 4, C33H29NiO2P3S2, Mr = 673.30, Dc = 1.338 g/cm3, F（000） = 1392 and #（MoKa） = 0.877 rnm-l. The final R = 0.0578 and wR = 0.1045 for 4138 observed reflections with 1 〉 20（/） and R = 0.1050 and wR = 0.1204 for all data. The Ni centre atom adopts a NiP2S2 square-planar geometry with two phosphorus atoms from the dppv ligand and two sulfur atoms from the O-（p-tolyl）dithiophosphate ligand. The most interesting structural feature of the title complex resides in its 1D helical chain structure constructing via intermolecular C-H＇＂O secondary interactions along the b-axis. The adjacent helical chains running in opposite directions are connected into a 1D double-stranded helical chain and further linked into a 2D supramolecular network by weak C-H.--C interaction.

Study on the mechanism of rapid formation ofu ultra-thick tribofilm by CeO_(2)nano additive and ZDDP

CeO_(2)nanoparticles are potential anti-wear additives because of their outstanding anti-wear and load-bearing capacity.However,the shear-sintering tribo-film formation mechanism of oxide nanoparticles limits the tribo-film formation rate and thickness greatly.In this study,by compounding with zinc dioctyl dithiophosphate(ZDDP),ultra-fine CeO_(2)nanoparticles modified with oleylamine(OM)can quickly form 2μm ultra-thick tribo-film,which is 10-15 times thicker than that of ZDDP and CeO_(2),respectively.The ultra-thick tribo-film presents a nanocomposite structure with amorphous phosphate as binder and nano-CeO_(2)as filling phase,which leads to the highest loading capacity of composite additives.The results of adsorption experiments tested by dissipative quartz crystal microbalance(QCM-D)showed that the Ps value of additive has nothing to do with its equilibrium adsorption mass,but is directly proportional to its adsorption rate in 10 s.The compound additive of CeO_(2)and ZDDP presented the co-deposition mode of ZDDP monolayer rigid adsorption and CeO_(2)viscoelastic adsorption on the metal surface,which showed the highest adsorption rate in 10 s.It is found that the tribo-film must have high film forming rate and wear resistance at the same time in order to achieve super thickness.Cerium phosphate was formed from ZDDP and CeO,through tribochemistry reaction,which promotes the formation of an ultra-thick tribo-film with nanocomposite structure,which not only maintains the low friction characteristics of CeO,but also realizes high Pg and high load-carrying capacity.

Effects of hydraulic oil and lubricant additives on dynamic friction properties under various reciprocating sliding conditions

The friction characteristics of a shock absorber are very complex because the reciprocating motion is not always identical.In this study,a device was developed and used to analyze the dynamic friction characteristics under various reciprocating sliding conditions to determine the sliding materials and hydraulic oils that improve the shock absorber performance.This study describes the influence of hydraulic oil additive on the fine reciprocating friction characteristics of steel and copper alloy.Hydraulic oils were prepared by blending a paraffinic mineral oil with zinc dithiophosphate(ZnDTP)and polyhydric alcohol ester as additives.The results show that the dynamic frictional characteristics vary mainly depending on the additive concentration.A specific additive formulation induces a unique amplitude-dependent friction behavior.In addition,the influence of different additives on the lubrication mechanism is investigated based on the instrumental analysis of the friction surface.

Differences in nano-topography and tribochemistry of ZDDP tribofilms from variations in contact configuration with steel and DLC surfaces

In this work,we evaluated the effect of the counter-body material(the same or dissimilar)and contact configuration(moving or stationary body),at similar contact tribological conditions,on the tribochemical and nanotopography characteristics of adsorbed surface films.Zinc dialkyldithiophosphate(ZDDP),the best performing anti-wear additive,was used in self-mated steel/steel and DLC/DLC contacts,which were compared with mixed steel/DLC and DLC/steel contacts in 1-h and 6-h sliding tests.The macroscale(tribometer)and nanoscale(atomic force microscopy)friction,thickness,topography,and chemical(attenuated total reflection-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy)properties of the tribofilms were studied.The results revealed unexpectedly large differences in all the studied tribofilm parameters;this is because all the tribofilms are completely different;this includes the chemical composition,which is known to have a crucial effect on the nano-and macro-scale tribological properties.These results clearly demonstrate that the surface material,additives,and common contact operating parameters,that is,pressure,velocity,and temperature,crucially affect the ZDDP tribofilm as well as the position of the moving or stationary surface within the contact,and the material of the moving/stationary bodies.

EQUILIBRIUM CONSTANT OF ADDUCTIVE REACTION BETWEEN BIS-(O, O′-DICYCLOHEXYLDITH-IOPHOSPHATO) NICKEL(Ⅱ) AND BENZYL-AMINE AND CRYSTAL STRUCTURE OF ADDUCTS Ni[(C_6H_(11)O)_2PS_2]_2·2NH_2CH_2C_6H_5

Ⅰ. INTRODUCTIONEsters of dithiophosphoric acid are a kind of excellent extractant for separating Co-Ni and Co-Mn. It was found that Co（Ⅱ） is easy to oxidize and to form the stable six-coordinated octahedral complex Co[（RO）2PS2] during extraction process. And it made back-extraction process very difficult. It was found that pydridine is able to cause substitute-reduction reaction with Co[（RO）2 PS2]3 and to form Co[（RO）2PS2]2·2Py. It is