kinetics of the chemical leaching of chalcocite from a low-grade copper ore in a ferric sulfate medium was investigated using the constrained least square optimization technique. the experiments were carried out for different particle sizes in both the reactor and column at constant eh, ph, and temperature. the leaching rate increased with increase in the temperature. about 50% of the cu recove...

in this research, the adsorption destructive process of chlorpyrifos (cp,o,o-diethyl-o-3,5,6-trichloro-2-pyridinyl phosphorothioate) as a noticeable organophosphate pesticide using in agriculture on the nickel tungstate (niwo4) nanoparticles catalyst was investigated and monitored via the 31p nuclear magnetic resonance (31pnmr). the effects of various experimental parameters such as catalyst do...

background: investigating the performance of naturally operated treatment plants may be due to the fact that they cannot be operated as desired, or that they should be modified to achieve good performance e.g. for nutrients removal. the advantage of kinetic coefficient determination is that the model can be adjusted to fit data and then used for analyzing alternatives to improve the process. th...

in this research work, the dissolution of chalcopyrite was investigated under atmospheric pressure, with sulfate media at low temperatures, in 30°c to 50°c. in the galvanic interaction between chalcopyrite and pyrite, pyrite is used as a leaching catalyst. effects of different parameters such as temperature, stirring speed, pyrite to chalcopyrite ratio, particle size, and solution potential wer...

objective(s): in this work, electrospun nanofibers were explored as drug delivery vehicles using tetracycline as a model drug.  nanocomposite fibers including chitosan (cs)/poly (ethylene oxide) (peo) and antibiotic were successfully prepared using electrospinning. cs blended with peo considering a weight ratio of (90/10), and then, nanofibrous samples were successfully electrospun from their a...

polyacrylontrile synthesis, via atom transfer radical polymerization, is studied in various initiator concentrations, transitional metal catalyst and different concentrations of cubr2. the variations of monomer conversion and the lin-earity of semi-logarithmic kinetic profile which is the evidence of living polymerization and constant radical concentration in the reaction medium, were revealed ...

recently, extracts from various parts of a. occidentale had been massively investigated in themanagement and treatment of various ailments which include but not limited to diabetes, malaria,yellow fever as well as diarrhea. stem bark of anacardium occidentale was extracted with water andethanol. antioxidant activities of the extracts were using dpph. for estimation of effectivediffusivity, math...

the kinetic of fischer-tropsch synthesis over a co-precipitated fe-ce catalyst was investigated in a fixed bed micro reactor. experimental conditions were varied as follow: reaction pressure 1-15bar, h¬¬¬2/co feed ratio of 1-3 and space velocity of 3600-5400 h-1 at the temperature range of 270-310°c. 4 models according to the langmuir-hinshelwood-hougen-watson (lhhw) type rate equation were der...

Kinetic parameters of the ammonolysis reaction of dichloroethane in nonaqueous media are studied and the optimum reaction conditions are reported. A suitable reactor for running the reaction under high pressure in the range of 50 to 500 °C is designed. Kinetic behaviours of the system is studied and other reaction parameters such as rate constant, kinetic order, and activation energy are de...

The kinetic of photo oxidative decolorization of C.I. Acid yellow 23 (AY23) was investigated in UV/ process. The semi-logarithmic of the concentrations of AY23 versus irradiation time were linear, suggesting pseudo-first order reaction. A simple kinetic model is proposed which confirms pseudo- first order reaction. The results indicate that the apparent reaction rate constant is a function of l...