HEAT-RESISTANT CONCRETE BASED ON ORTHOPHOSPHORIC ACID, WASTE OF NON-FERROUS METALLURGY AND CHEMICAL INDUSTRY

Currently, as numerous studies show, raw natural resources are running out, so it is necessary to involve in the production turnover of industrial waste for the manufacture of heat-resistant concrete. At the same time, the costs of geological exploration, construction and operation of quarries are excluded, and significant land plots are freed from the impact of negative anthropogenic factors. Multi-tonnage waste of non-ferrous metallurgy-ferrite-calcium slag containing 50-51 % Fe2O3, was used as an iron-containing filler for the production of heat-resistant concretes. Ferrite-calcium slag is a man-made raw material (production waste) of processing copper-zinc concentrates, obtained by slow cooling of the material to complete scattering, light yellow in color and resembling fine sand. The trivalent iron oxide Fe2O3 contained in the slag reacts very slowly with orthophosphoric acid H3PO4 at normal temperature; therefore, it is necessary to heat the mixture to 70 °C, since its own heat is not released by the reaction. A, the ferrous iron oxide FeO contained in the slag, as well as Fe(OH)3 hydroxide, on the contrary, reacts with the acid vigorously, releasing a significant amount of heat, so the binder dough begins to set after 2 minutes at a temperature of 20 °C due to significant heat release. Chemical industry waste - the spent IM-2201 catalyst was used as an aluminum-containing raw material and is a fine powder with a specific surface area of up to 8000 cm2/g and a fire resistance of up to 2000 oС. Studies have shown that due to the use of orthophosphoric acid as a binder, it is possible to dispose of up to 80-90 % of non-ferrous metallurgy and chemical industry waste and at the same time obtain heat-resistant concretes with high physical and mechanical properties.

Copper Chloro-Complexes Concentrated Solutions: An Electrochemical Study

Basic studies on concentrated solutions are becoming more and more important due to the practical industrial and geological applications. The use in redox flow batteries is one of the most important applications of these solutions. Specifically, in this paper we investigated high-concentrated copper chloro-complexes solutions with different additives. The concentration of ligands and additives affects the physicochemical and electrochemical properties of 2 M solutions of Cu(I) and Cu(II). Solutions with calcium chloride and HCl as Cl− source were investigated with Cu:Cl ratios of 1:5 and 1:7, the 1:5 Cu:Cl ratio being the best performing. The substitution of calcium chloride with ammonium chloride increased the conductivity. However, while the effect on the positive electrode process was not very evident, the reversibility of the copper deposition–stripping process was greatly improved. Orthophosphoric acid could be a viable additive to decrease the complexation of calcium with chloride anions and to improve the stability of Cu(II) chloro-complexes. Absorption spectroscopy demonstrated that phosphate ions do not coordinate copper(II) but lead to a shift in the distribution of copper chloro-complexes toward more coordinated species. Electrochemically, the increased availability of chloride anions in solution stabilized the Cu(II)-rich solution and led to increased reversibility of the Cu(II)/Cu(I) redox process.

Characterization of novel stress degradation products of Bempedoic acid and Ezetimibe using UPLC–MS/MS: development and validation of stability-indicating UPLC method

Background A receptive and easily comprehended technique was evolved for simultaneous assessment of Bempedoic acid and Ezetimibe and its impurities characterized by UPLC–MS/MS. Results This technique involves chromatographic separation with a C18 column of water symmetry (150 mm × 4.6 mm, 3.5 µm). A mobile phase of 0.1% OPA (orthophosphoric acid) and acetonitrile in 50:50 v/v with 1 mL/min flow rate and ambient temperature was used. UV observation was taken at 230 nm. The recoveries, linearity, and quantification limits were found to be within the acceptable limit. Conclusions This technique was successfully tested with UPLC–MS to confirm the chemical structures of newly formed degradation products of Bempedoic acid and Ezetimibe and stress studies as per ICH Q2 (R1) guidelines.

Detection and Evaluation of process related impurities in Obeticholic Acid Drug material using HPLC Method

Obeticholic acid (OBE) is being used to treat primary biliary cirrhosis and cholangitis. An HPLC with refractive index detection method for eight process related substances of OBE was developed and verified for use in quality assurance laboratories for regular analysis. The separation and analysis were performed on YMC Triart C18 (3.0 µm particle size, 250 mm × 4.6 mm) column. Mobile phase employed consisted of 0.01N potassium phosphate buffer (3.0 ± 0.05 pH, set with 0.1% orthophosphoric acid) and acetonitrile at 45:55 (v/v) ratio. The method established for determination of eight impurities in OBE was validated and verified in keeping with International Council for Harmonisation guidelines. This method can be used for routine analysis of eight impurities in OBE bulk samples.

Microwave-assisted preparation of polyphosphoric acid in a continuous-flow reactor

Polyphosphoric acid (PPA) is widely used in inorganic salt production, petrochemical industry, electronic material preparation and other manufacturing industries. Conventional preparation methods of PPA has disadvantages of pollution, high energy consumption and long production time. To address this problem, microwave continuous-flow preparation may be a desirable way due to its advantages of environmentally-friendly, rapidity and high efficiency. Therefore, to explore the process of preparing PPA by microwave continuous-flow method, a continuous-flow microwave reactor was designed for the dehydration process of orthophosphoric acid to prepare PPA in this paper. The microwave-assisted dehydration process was studied in comparison with the conventional dehydration process and the “closed” microwave-assisted dehydration process in terms of energy efficiency, process times and treatment capacity. The effect of input microwave power, reduced pressure and inlet flow velocity of orthophosphoric acid on the performance of the dehydration process was studied. The results showed that the influence of the microwave power on the temperature rise process during dehydration is greater than that of the reduced pressure. Moreover, the inlet flow rate has a great impact on the treatment capacity and product quality of the dehydration process. Bedsides, the comparison with the other two methods showed that microwave heating can effectively shorten the dehydration time, and the continuous-flow treatment can effectively improve the treatment capacity of microwave heating. The perspectives of the process scale-up by continuous-flow microwave heating method is also discussed.

Simple, Accurate and Efficient High Performance Liquid Chromatographic Method for Determination of Vandetanib in Bulk and in Pharmaceutical Forms

A simple, selective, linear, precise and accurate isocratic RP-HPLC method was developed and validated for rapid assay of Vandetanib, an anticancer drug, in both bulk and tablet dosage form. Elution at a flow rate of 1ml/min was employed on a symmetry C18 column at ambient temperature. The mobile phase consisted of acetonitrile, water and orthophosphoric acid in the ratio of 90:08:02 (v/v/v). Linearity was observed in concentration range of 50-200 ppm. The retention time for Vandetanib was 3.326 min. The method was validated as per the ICH guidelines. The proposed method can be successfully applied for the estimation of Vandetanib in pharmaceutical dosage forms. Moreover the detection alone was also verified through LC-MS of the Vandetanib drug using ESI method which provides future scope for study of this drug using LC-MS method also.