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Potassium zinc phosphate was synthesized by solid-state reaction using K3PO4·3H2O and ZnSO4·7H2O as reagents. To investigate the influence of molar ratio, grinding time, holding temperature, holding time on yield and zinc content of the product, experimental project was designed by uniform design and data mining technology. Obtained product was characterized by X-ray diffraction, scanning electron microscope and energy disperses spectroscopy. The results show that the two mathematical models can be established by regression analysis according to yield and zinc content, which can be used to obtain the best technology conditions of solid-state reaction. Under the optimum reaction conditions: molar ratio of K3PO4·3H2O: ZnSO4·7H2O = 1.01, grinding time 31min, holding temperature 750°C, holding time 3.2 h, the prepared product is KZnPO4with nano-lamellar structure, and the reaction average yield value is 84.33% and zinc content is 31.29%. [ABSTRACT FROM AUTHOR]

Multi-stage countercurrent extraction (MCE) technique has been developed for the extraction of glycyrrhizic acid (GA) from Glycyrrhiza uralensis Fisch, a particular plant species of licorice. The effects of extraction stage numbers, temperature, extraction time and solvent to licorice ratio on the extraction yield of GA were investigated in detail. The process conditions of MCE were optimized using orthogonal array experimental design (OAD) technique. Under optimum process conditions (five stages, 60 min extracting time for every stage, 60 °C temperature and 6 ml/g solvent to licorice ratio), the extraction efficiency of MCE has been compared with those of conventional techniques including batch single pot extraction (SPE), microwave-assisted extraction (MAE), ultrasonic extraction (USE), Soxhlet extraction (SHE) and room temperature extraction (RTE). Results show that the MCE process offers the highest GA extraction yield and considerable savings in time, energy and solvent consumption. [Copyright &y& Elsevier]

Catalysts of aluminum dihydrogen tripolyphosphate supported by activated carbon ((ATP-AC) were prepared by using activated carbon oxidized by Na2S2O8, H2O2 and HNO3, respectively, and characterized by Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). The orthogonal design experiment was used to obtain the best condition of the three kinds of catalysts. The results show that the three kinds of ATP-AC catalyst disply higher activity and selectivity. The optimal conditions are: for preparation conditions of catalyst ATP-AC-1: oxidant concentration c (Na2S2O8) = 0.75 mol/L, bonding temperature t = 603 K, mass ratio W% (ATP) = 60%; for catalyst ATP-AC-2: oxidant concentration c(H2O2) = 1.0 mol/L, bonding temperature t = 603 K mass ratio W% (ATP) = 60%; for catalyst ATP-AC-3: oxidant concentration (HNO3) = 0.5 mol/L, bonding temperature t = 603 K, mass ratio W% (ATP) = 60%. The yield of tributyl citrate is over 90%. Three kinds of oxidants increase the carbon-oxygen functional groups of activated carbon and improve its hydrophilicity. The pore structure of oxidated AC is more regular, and the quantity of microporous and larger pores is increased. All these changes promote the chemical bonding between activated carbon and ATP. [ABSTRACT FROM AUTHOR]