Study on Ultrasonically-Enhanced Sulfuric Acid Leaching of Nickel from Nickel-Containing Residue

In this paper, nickel-containing residue, a typical solid waste produced in the battery production process, was used to study the cavitation characteristics of ultrasonic waves in a liquid–solid reaction. The ultrasonically-enhanced leaching technology for multicomponent and complex nickel-containing residue was studied through systematic ultrasonic-conventional comparative experiments. An ultrasonic leaching kinetics model was established which provided reliable technological guidance and basic theory for the comprehensive utilization of nickel-containing residue. In the study, it was found that ultrasonically-enhanced leaching for 40 min obtained the same result as conventional leaching for 80 min, and the Ni extraction degree reached more than 95%. According to the kinetic fitting of the leaching process, it was found that the sulfuric acid leaching process belonged to the diffusion-controlled model of solid product layers under conventional and ultrasonic conditions, and the activation energy of the reaction was Ea1 = 17.74 kJ/mol and Ea2 = 5.04 kJ/mol, respectively.

Elaboration and implementation technology of concentration of Magnitogorsk steel-works slime tailings

The problems of processing iron ore tailings of wet concentration plants and wastes with high content of iron, contaminated by oil products are actual from both points of view of ecology and economy. One of the reasons restraining solving the problem is absence of technologies ensuring to involve such wastes into industrial turnover. In the process` of the research, composition and opening degree of ore and non-metallic minerals of concentration slime tailing of Magnitogorsk steel-works (MMK) were studied and technology of their concentration was elaborated. Taking into consideration the contamination of initial slime tailings of MMK, it was proposed to accomplish their preliminary de-sliming to remove vegetable remains and clay slimes by disintegration in a screw-toothed crusher and washing in a spiral classifier. Results of wet magnetic separation (WMS) of the initial slime tailings of MMK, made at JSC “Uralmekhanobr” presented, the slimes having natural coarseness of –2.0+0.0 mm. It was established that WMS at the magnetic field intensity of 1500 Oe ensures effective removal of magnetite, aggregates magnetite-hematite-goetite into magnetic product. Iron content in the magnetite concentrate was varying from 61.5 to 62.6%. For processing of slime tailings of MMK, magnetic separation was proposed by high-gradient magnetic separator with permanent magnets, created specially for these purposes by “ERGA” company. To increase iron extraction degree, it was proposed to apply gravitation methods of concentration of nonmagnetic product, obtained at high-gradient WMS. It enabled to increase iron content in the final magnetite-hematite concentrate up to 59%. A technological diagram of oiled slimes processing presented. Tests with oiled slimes of bottom deposits of metallurgical production under pilot-industrial conditions of MMK exhibited a possibility to obtain additional iron concentrate with total iron content of 62.47% while oil content in it was less 0.3%.

THEORY AND TECHNOLOGY OF MANUFACTURING A FERROALLOY FROM CARBON FERROCHROME DUSTS

The article contains the research results of obtaining a ferroalloy from a carbon ferrochrome dust containing 30,2% of Сr2O3, 23.4% of SiO2, 32.7% of MgO, 5.0% of FeO, 1.6% of CaO, 4.5%of Al2O3, 2.3%of C, and 0.3 %-others. The studies were carried out by a thermodynamic modeling method using the HSC-5.1 software package (Outokumpy) based on the principle of the Gibbs energy minimum, the Box-Hunter rototable planning technique and electric melting of the dust in an arc furnace. It was found that the interaction of the dust with carbon under equilibrium conditions and in the presence of iron leads to formation of Cr4C(T>10000C),Cr3C2, Cr7C3,Cr (T>11000C), FeSi (T>13000C), SiC (T>14000C), SiOg and Si(T>15000C). In the temperature range of 1745-19000C and in the presence of 18-34% of carbon and 8% of iron of the dust mass, the resulting ferroalloy contained 18.5-25.2% of Si and 46.8-49.4% of Cr (in this case the silicon extraction degree into the alloy was 60.0-64.4%, the chromium one–99.8%). When the electrosmelting the granulated dust together with coke and steel shavings, the chromium extraction degree into the alloy was 98-99%, the silicon one–53-57%; the obtained ferroalloys containing 18.3-21.9% of silicon and 45.6-53.6%of chromium meet the requirements to FeCrSi23-grade ferrosilicochromium.

Solvent Extraction of Iron(III) from Al Chloride Solution of Bauxite HCl Leaching by Mixture of Aliphatic Alcohol and Ketone

Research into the solvent extraction of iron(III) from a chloride solution after bauxite HCl leaching by neutral oxygen-containing extractants and their mixtures were studied and the iron(III) extraction degree from chloride solutions using alcohols is presented. The effect of dilution of alcohol with a ketone by an extraction mixture in relation to its effectiveness was investigated. The iron(III) was efficiently extracted by the mixture of 1-octanol and 1-decanol (70%) with 2-undecanone (30%) from hydrochloric bauxite leach liquor at an O:A ratio = 2-4:1 at an iron(III) concentration of 7.4 g/L and 6 M HCl. For the removal of iron-containing organic phase from impurities (Al, Ca, Cr) that are co-extracted with iron(III), we used two step scrubbing at O:A = 5:1 by 7 M HCl as a scrub solution. The iron(III) stripping at the O:A ratio is shown. Using counter-current cascade of extractors, it was possible to obtain an FeCl3 solution with the iron(III) content of 90.5 g/L and total impurities less than 50 mg/L.

Methods for the Preparation of Blood Serum Samples in the Assessment of the Pharmacokinetics of Protein Drugs by the Example of Viscumin

A comparative evaluation of methods for preparing blood serum samples for determination of the lectin content of the mistletoe Viscum Album, viscumin, by high-performance liquid chromatography in combination with high-resolution mass-spectrometry detection has been carried out. Based on the results of the analysis of the lectin hydrolyzate, a specific peptide fragment with m/z 791.388 suitable for subsequent quantitative determination was selected. Isolation of viscumin from serum components was carried out without the use of specific antibodies. The study used methods employing various spin columns and the method of protein precipitation with 1% TCA (trichloroacetic acid) in IPA (isopropyl alcohol). Testing the methods of depletion of blood serum proteins was based on the determination of the degree of extraction of lectin from model serum samples. As a result of our research, we have developed a technique for the quantitative analysis of viscumin in blood serum by the most efficient method of sample preparation using the ProteoMiner spin columns. The technique allows to determine the protein concentration up to 5·10-4 mg/ml with the extraction degree (2.7 ± 0.6) %.

Dynamic Evolution of Nanoscale Pores of Different Rank Coals Under Solvent Extraction

During the coalification process, coalbed methane (CBM) is formed and mainly adsorbed in the pores of coal. Pore structure evolution is critical to CBM adsorption/desorption and extraction. This paper puts forward two parameters, namely the variety degree x and variety gene σ, for characterizing pore structure through mercury injection tests. Then, under extraction with different solvents, the dynamic evolution characteristics of nanoscale pores are addressed and quantified by taking four different rank coals (lignite, medium-volatile bituminous coal, low-rank anthracite and mediumrank anthracite) from different coal mines of China as the study object. The results indicate that the content of meso- and macropores after solvent extraction is much larger, but that there is no obvious law with the content of transition pores and micropores in the size range of 50–7.2 nm, according to the basic data sets of specific surface area (SSA) and pore volume (PV) of all coal samples. This phenomenon can be explained by the pore increase and expansion effects in nanoscale pores during solvent extraction. Generally, with the increasing of the solvent extraction degree, the difference in variety degree x with respect to the total PV and total SSA of different coals shows a significant decreasing trend, which expresses a homogeneous development in the change in pore structure. In regard to different solvents, benzene mainly causes pore expansion in meso- and macropores, and CS2 has a great effect on micropores. Whereas acetone plays an important role in mesopores and transition pores with pore expansion, THF has various effects on different size pores. Further study with higher variety gene σ values shows that the total PV mainly depends on the change in the absolute content of meso- and macropores. While the change in the absolute content of transition pores and micropores (less than 50 nm) has a great influence on the total SSA. As the extraction degree increases, the influence of the transition pores and micropores on the total PV is increased, and then, the content of meso- and macropores also plays an important role on the total SSA. However, this effect is highly different for raw coals of different ranks.

Ascorbic Acid Influence on the Extraction Intensity of the Anthocyanin Pigment from Black Currant Berries and Its Stability

The article considers the ascorbic acid effect on the extraction rate and stability of anthocyanin pigment exuded from black currant berries. The researchers treated defrosted and crushed black currant berries with 0.2–10.0 % solutions of ascorbic acid at temperatures of 20–90 °C for 5–150 minutes and 100 °C for 2.5 minutes, then filtered the solution out. They determined the color intensity of the solutions by the optical density using spectrophotometer SHIMADZU UV-1800 (Japan). To determine the anthocyanin pigment content, a man diluted samples with solvent system ethanol/water/hydrochloric acid (69/30/1) and measured their optical density at a wavelength of 540 nm. The authors calculate anthocyanins content in solutions using the formula and determine that the use of 0.2–1.0 % solution of ascorbic acid as an extractant leads to the extraction intensity increase of anthocyanin pigment from plant raw materials. Adding a 1.0 % ascorbic acid solution of to the system increases the extraction degree of anthocyanin pigment by 1.4 times. A further increase in the amount of ascorbic acid in the solution to 2.0–10.0 % leads to a slight increase in the extraction intensity of anthocyanin pigment. The most complete anthocyanin pigment is extracted from plant raw materials in the presence of ascorbic acid at exposure temperatures of 20-80 °C for 30 minutes and 100 °C for 2.5 minutes. An increase in the exposure time to 60-150 minutes leads to a drop in the extraction degree of anthocyanin pigment and a change in the solution color. The solution of the pigment color becomes brown.

Study of high-magnesia iron ore feedstock integrated processing

Introduction. Iron and magnesium form a common lattice of the initial ore and its calcination products, which is the main obstacle limiting the widespread use of the ores of the Bakal group of deposits. Research aim is to develop the physicochemical foundations of the integrated processing of high-magnesia siderite ores using pyro- and hydrometallurgy methods. Research methodology is based on data analysis from thermogravimetry, X-ray and Mössbauer spectroscopy, and chromatography. The analysis made it possible to determine suitable conditions for heat treatment, leaching, chemical and phase composition, structure and properties of integrated processing products of high-magnesia iron ore raw materials. Results. A new scheme for high-magnesia iron ore raw materials integrated processing has been proposed. Testing of the scheme in laboratory conditions has shown that it allows to increase the iron content in the concentrate by 7% and to obtain up to 100–120 kg per ton of highly active magnesia concentrate containing no less than 98% of magnesium oxide. It has been established that some products of the integrated processing are catalytically active in the processes of ethanol steam conversion and Kuznetsk Basin coal conversion, as well as in the water gas shift reaction. Summary. The proposed scheme makes it possible to increase iron and related elements extraction degree, without changing the working conditions on the operating plants.

Chromatographical Analysis of Meldonium with Preliminary Concentration by Solid-Phase Extraction on Magnetite Nanoparticles

A comprehensive method for meldonium analysis, based on a combination of magnetic solid-phase concentration of the analyte on magnetite nanoparticles modified with cetylammonium bromide (CTAB) cations and its subsequent analysis by thin-layer chromatography (TLC) were developed in the process of study. The influence of a number of factors on meldonium sorption was studied, namely: pH, sorbent mass, sorption and mixing times; optimal extraction conditions were determined. It was found that quantitative sorption proceeded in 20 min with a meldonium extraction degree of 88%. Ethanol was found to be an eluent to desorb the analyte by 95%. The calibration dependences plotted with and without concentration of meldonium were compared. It was established that the use of concentration on two mg of CTAB-modified nanomagnetite reduces the lower limit of the analyzed contents of meldonium in 25 ml of solution by 5 times.

Current Challenges of Cold Brew Coffee—Roasting, Extraction, Flavor Profile, Contamination, and Food Safety

Cold brew coffee has emerged as a new trend over the last decade. However, “cold brew” is an extraction style of ground roasted coffee with water at lower than body temperature (typically 8 °C or room temperature), rather than a beverage per se. Cold brew extraction poses several challenges, including the need for specific optimization depending on the multiple influences of coffee variety and processing, roast degree, grinding, dosage, water composition, turbulence, brew system (drip, immersion etc.), time and temperature, and their interactions. While cold brew is typically characterized by a floral sweetness, over-extraction may lead to abundant acidity and bitterness. To avoid this, an extraction degree of 70% was suggested using shorter time frames (i.e., 2 h at 15 °C with 80 g/L coffee for optimized medium roast profiles). Due to the lack of sterilizing temperatures during preparation, cold brew is significant in the coffee sector because hygiene and food safety requirements pose specific challenges. To avoid microbiological contamination and deterioration in quality, cold brew should be as freshly prepared as possible and shelf-life should be minimized.