Analysis of the Corrosion Behavior of the TiNi Alloy in the Coarse-Grained State

In this work was investigate the corrosion behavior of the TiNi alloy in a coarse-grained state in inorganic field with different concentration and holding time. An increase in the concentration of the solution leads to a significant acceleration of corrosion processes in the Ti49.1Ni50.9 alloy with a high Ni content, including until the samples are completely dissolved. It was revealed that solutions of 1 M sulfuric and hydrochloric acids after a month's exposure did not change in color and no precipitations were found, while solutions of 5 M hydrochloric and sulfuric acids acquired a violet and then green color, which is due to the predominant release of titanium ions (+4) and nickel (+2).

Leaching of Rare Earth Elements from NdFeB Magnets without Mechanical Pretreatment by Sulfuric (H2SO4) and Hydrochloric (HCl) Acids

A simplified approach for rare earth elements leaching from NdFeB (neodymium-iron-boron) magnets was investigated. The possibility of simplifying the magnet recycling process by excluding grinding, milling and oxidative roasting unit operations was studied. Attempts to skip the demagnetization step were also conducted by using whole, non-demagnetized magnets in the leaching process. The presented experiments were conducted to optimize the operating conditions with respect to the leaching agent and its concentration, leaching time, leaching temperature and the form of the feed material. The use of hydrochloric and sulfuric acids as the leaching agents allowed selective leaching of NdFeB magnets to be achieved while leaving nickel, which is covering the magnets, in a solid state. The application of higher leaching temperatures (40 and 60 °C for sulfuric acid and 40 °C for hydrochloric acid) allowed us to shorten the leaching times. When using broken demagnetized magnets as the feed material, the resulting rare earth ion concentrations in the obtained solutions were significantly higher compared to using whole, non-demagnetized magnets.

Extension of the method for identifying crystals in the composition of wine sediment

Одной из функций технохимического контроля в виноделии является обеспечение разливостойкости готовой продукции. Для этого необходима система методов и тестов, позволяющих оценить склонность вин к помутнениям физико-химического характера, также установить причины появления осадков, образующихся в случае недостаточной технологической обработки вин или при нарушениях условий их хранения. В случае кристаллического осадка общепринятым методом идентификации калиевой или кальциевой природы виннокислой соли является воздействие 10 %-ными растворами соляной и серной кислот. Указанные кислоты в более высокой концентрации являются прекурсорами, применение которых строго регламентируется на законодательном уровне. Целью данной работы являлось обоснование возможности применения общедоступных реактивов при анализе кристаллического осадка вин. Объектами исследований являлись растворы неорганических кислот и сульфата натрия в качестве источника сульфат-аниона, кристаллический осадок вин, а также промышленные препараты битартрата калия и тартрата кальция. Показано, что эффективной заменой соляной и серной кислот для растворения кристаллов является азотная кислота. Предложен новый реагент для идентификации калиевой и кальциевой природы осадка, представляющий водный раствор азотной кислоты (10 %) и сульфата натрия (не менее 15 %). Растворение виннокислых кристаллов в капле данного препарата свидетельствует, что кристаллообразующим катионом является калий; появление отдельных звездчатых, игольчатых структур или их сростков демонстрирует присутствие кальция. Усовершенствованная методика предназначена для применения в рамках технохимического контроля в лабораториях винодельческих предприятий, профильных учебных и научных заведений. One of functions of techno-chemical control in winemaking is to ensure wine stability of the finished product after bottling. This requires a system of methods and tests to assess the tendency of wines to haziness of physicochemical nature, as well as to establish the appearance origin of sediment formed as a result of insufficient technological processing of wines or violation of the storage conditions. In the context of crystal sediment, the action of 10% solutions of hydro-chloric and sulfuric acids is a generally accepted method for identifying the potassium or calcium nature of tartrate salts. In a higher concentration, these acids are precursors, using of which is strictly regulated at the legislative level. The purpose of this work was to substantiate the possibility of using generally available reagents in the analysis of crystal sediment of wines. The objects of research were solutions of inorganic acids and sodium sulfate as a source of sulfate-anion, crystal sediment of wines, as well as commercial preparations of potassium bitartrate and calcium tartrate. It is indicated that nitric acid is an effective substitution for hydrochloric and sulfuric acids to dissolve crystals. New reagent, constituting aqueous solution of nitric acid (10%) and sodium sulfate (not less than 15%), is proposed for identifying the potassium or calcium nature of the sediment. Dissolving of tartaric crystals in a drop of this preparation indicates that potassium is a crystal-forming cathion; the appearance of single stellar, needle-like structures or their intergrowth demonstrates presence of calcium. The extended technique is intended for application as a part of techno-chemical control in laboratories of winemaking enterprises, industry-specific educational and scientific institutions.

A novel application of hematite precipitation for high effective separation of Fe from Nd-Fe-B scrap

Rare earths, e.g. neodymium (Nd), praseodymium (Pr) and dysprosium (Dy), are abundant in the rare earth sintered magnet scrap (Nd-Fe-B scrap), but their recycling is tedious and costly due to the high content of impurity Fe. Herein, a novel approach was developed to effectively recycle rare earths from the scrap via an integrated acid dissolution and hematite precipitation method. The scrap contained 63.4% Fe, 21.6% Nd, 8.1% Pr and 3.9% Dy. It was dissolved in nitric, hydrochloric and sulfuric acids, separately. Nearly all impurity Fe in the scrap was converted to Fe3+ in nitric acid but was converted to Fe2+ in hydrochloric and sulfuric acids. After hydrothermal treatment, the rare earths in the three acids were almost unchanged. From nitric acid, 77.6% of total Fe was removed, but total Fe was not from the hydrochloric and sulfuric acids. By adding glucose, the removal of total Fe was further increased to 99.7% in nitric acid, and 97% of rare earths remained. The major mechanism underlying total Fe removal in nitric acid was the hydrolysis of Fe3+ into hematite, which was promoted by the consumption of nitrate during glucose oxidation. This method effectively recycled rare metals from the waste Nd-Fe-B scrap and showed great potential for industrial application.

The Forerunners of Celtium and Hafnium: Ostranium, Norium, Jargonium, Nigrium, Euxenium, Asium, and Oceanium

Of the naturally occurring nonradioactive elements, hafnium was the next to last to be discovered, preceding the discovery of rhenium by 3 years. It can boast of holding a very strange record: the number of claims for its discovery over the years is unequaled by any other element. This record was the cause of frustration for many scientists who, over the years, took turns in attempts to isolate it. The reason that hafnium remained undiscovered until 1922 lay not so much in that its presence in nature (long known to be quite scarce) wasn’t looked for, but in its peculiar chemical properties that bound it up intimately with zirconium. Toward the end of the 18th century, Martin Heinrich Klaproth melted some forms of yellow-green and red zirconium with sodium hydroxide and then digested the residue several times with hydrochloric and sulfuric acids to eliminate the extraneous silicon. The solution, thought to contain a number of elements, produced, upon addition of potassium carbonate, a generous precipitate. The oxide that Klaproth collected did not seem to belong to any known substance, and he called it terra zirconia. With the passing of the years, he and many other chemists, among them the renowned Jons Jacob Berzelius, determined the elemental composition of zircon and of its correlative minerals. Far from being simply ZrSiO4, zircon contained traces of iron, aluminum, nickel, cobalt, lead, bismuth, manganese, lithium, sodium, zinc, calcium, magnesium, and uranium and small amounts of the rare earths. Some impurities persistently resisted separation from zirconium oxide or zirconia and were taken erroneously for oxides of new elements (new earths). In 1825, Johann Friedrich August Breithaupt (1791–1873) reported the presence of a new element, ostranium, isolated from ostranite, a mineral similar to zircon. Twenty years later, the Swedish chemist, mineralogist, and metallurgist Lars Fredrik Svanberg (1805–78) announced the discovery of a new element. In his publication of 1845, he asserted that the zirconium oxide obtained from a variety of Siberian, Norwegian, and Indian zircon samples was in reality composed of two earths: one, zirconia, already noted, and another unknown earth.

HASTELLOY HYBRID-BC1 ALLOY

The importance of hydrochloric and sulfuric acids to the chemical process industries cannot be overstated. There has always been a desire for materials with improved resistance to these two acids, without the drawbacks associated with the nickel-molybdenum alloys. The Hybrid-BC1 alloy is significantly more resistant to HCl and H2SO4 than the Ni-Cr-Mo alloys and additionally, is resistant to oxidizing chemicals in the acid that are very detrimental to B-Family alloys. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-679. Producer or source: Haynes International Inc.