Determination of boron in nickel-base alloys by the dianthrimide method.
The dianthrimide method for the determination of boron in iron and low-alloy steels may be applied to nickel-base materials. The sample is dissolved, without any loss of boron, by hydrochloric and sulphuric acids and the resulting boric acid determined spectrophotometrically with dianthrimide. Background corrections are necessary to compensate for the absorbance from ions such as nickel and iron.
Application of 2-(octylsulphanyl)benzoic acid as Pb2+ selective ionophore in hybrid membrane system
A solution of 2-(octylsulphanyl)benzoic acid in 1,2-dichloroethane was used as a liquid membrane for selective pertraction of Pb2+ cations. Transport processes were carried out in a multi-membrane hybrid system (MHS) consisting of two cation-exchange membranes (CEM) and a flowing liquid membrane (FLM) in the following order: CEM | FLM | CEM. The liquid membrane phase was dehydrated continuously using a pervaporation method (PV). The system was capable of transporting Pb2+ ions selectively from a multi-cation aqueous solution composed of Na+, K+, Ca2+, Mg2+, and Pb2+ nitrates. A comparative study of the carrier efficiency under various feed pH conditions was performed. It was found that the carrier exhibited sufficient selectivity and transport efficiency under a broad range of operational conditions, with a maximum transport rate of Pb2+ ions attaining the value of (1.09 ± 0.03) × 10−10 mol cm−2 s−1 and the selectivity coefficient of up to 40.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.