Alkyl dimethyl betaine activates the low-temperature collection capacity of sodium oleate for scheelite

The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size measurement.The flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures.

The Influence of Material Related Parameters on the Mechanical Properties of Foamed Asphalt Mix

By indirect tensile strength （ITS） test and unconfined compressive strength （UCS） test, the influence of various material related parameters, including asphalt foamability, aggregate temperature, mixing moisture content （MMC） and foamed asphalt （FA） content, on the mechanical properties of FA mixes was studied. The results indicated that both asphalt foamability and aggregate temperature greatly affected ITS of FA mixes. Too low aggregate temperature was unfavorable for mechanical properties of FA mixes. Foamed index alone was unfit for the evaluation of asphalt foamability. Compared with half-life, expansion ratio had more prominent influence on ITS of FA mixes. MMC had significant impact on the mechanical properties of FA mixes and should be optimized by trial and test in FA mix design. The mechanical properties of FA mix were sensitive to the change of FA content. Compared with the ITS determined with standard Marshall specimens, both the ITS and UCS determined with static compressed specimens by 15 cm diameter were more effective in terms of choosing the optimal asphalt content for FA mixes.

Decolorization Kinetics of Sludge Protein Solution by ^(60)Coγ-Ray Irradiation/H_2O_2 Oxidation

In order to carry out decolorization, sludge protein solution, a dark brown close to black solution from activated sludge, was subjected to ^(60)Co γ-ray irradiation in the presence of hydrogen peroxide. UV/Vis spectrophotometric method was used to investigate the effect of H2O2 on the coloration apparent kinetics and rate constants of sludge protein solution under γ-ray irradiation. In addition, the effects of irradiation dose, initial sludge protein solution concentration, and pH value on the decolorization efficiency of sludge protein solution were studied. Results showed that the decolorization apparent kinetics of sludge protein solution was a first-order reaction. The solution decolorization percentage increased with the increase of irradiation dose or the decrease of initial sludge protein solution concentration. The examination results of pH value showed that the sludge protein solution could be more efficiently decolorized in alkaline media than in acid media. Moreover, sensory evaluation and foamability analysis indicated that irradiated samples under H2O2 oxidation showed better sensory score and foamability.

Surface Tension and Foam Stability Prediction of Polydimethylsiloxane-Polyol Systems

The Gibbs elasticity modulus represents an important tool to predict the foamability for transient and permanent foams like polyurethane flexible systems. Elasticity is related to foamability and so is used as a synonymous for the purpose of this paper. In this article we propose a method and a thermodynamic model to analyze the espumability of silicone surfactants in polyol binary mixtures using surface tension data. The present work describes foamability through the Gibbs elasticity modulus expressed in terms of first and second derivatives of surface pressure vs bulk composition. Furthermore, the Gibbs adsorption equation and the corresponding novel surface equation of state based on a modification of the Langmuir isotherm resulted in an elasticity equation with analytical solution. It is shown that according to foam model systems of surfactant solution in polyol used at commercial processes, optimum concentration level of surfactant obtained at this article by Gibbs adsorption equation and maximus on elasticity modulus finally match.

The effect of nanosilica sizes in the presence of nonionic TX100 surfactant on CO_(2)foam flooding

The aim of this research is to study the effect of hydrophilic silica nanoparticles,sizes as CO_(2) foam stabilizer in the presence of nonionic TX100 surfactant.Two nanosilica sizes,15 and 70 nm,have been examined thoroughly.Physisorption of TX100 on silica nanoparticles(nanosilica)was characterized by adsorption isotherm and surface tension measurement,while CO_(2) foams stability was quantified based on their foamability,foam stability,particle partitioning in the foams,and bubble sizes.Results show that direct contact of TX100 with nanosilica does altered the wettability of hydrophilic nanosilica surface,enable them to lengthen CO_(2) foams life at certain surfactant and nanoparticles concentrations.For 15 nm nanosilica,CO_(2) foam stability shows excellent performance at 0.1 and 0.5 wt%TX100 concentrations.As for 70 nm nanosilica,CO_(2) foam demonstrates longer lifetime at much lower TX100 concentration,0.01 wt%.Without the presence of TX100,CO_(2) foams exhibit undesirable lifetime performances for both nanosilica sizes.Nanosilica partitioning in CO_(2) foams structures demonstrate consistent relation with contact angle measurement.Estimated bubble sizes shows insignificant effect on CO_(2) foams life.With the assists of nanosilica and TX100,enhanced oil recovery via CO_(2) foam injection succeeds in increasing oil production by 13e22%of original oil-in-place(OOIP).