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Preparation and application of zinc telluride

Zinc telluride is a gray or brownish-red powder that is a compound of zinc and telluride, with the chemical formula ZnTe. Ruby cubic crystals can be obtained by sublimation. Stable in dry air, it breaks down when exposed to water, releasing foul-smelling and toxic hydrogen telluride gas. Zinc telluride is mainly used in semiconductors and infrared materials, can be used as fluorescence materials and phosphorescent materials, but also can make light emitting diodes, infrared detection, radiation detection materials. Zinc [...]

A method for preparing molybdenum boride powder

Boride molybdenum compounds with high melting point, high hardness, wear resistance, high temperature resistant, corrosion candle and low coefficient of friction etc., plays a very important role in modern industry, are widely used in metal materials, coating materials, high temperature structural materials, the cathode material, corrosion resistant, wear resistant materials and other fields, and with the progress of science and technology, The application field of molybdenum-boride compounds will be further expanded, and this material will show more excellent application [...]

Brief analysis of calcium tungstate

From the chemical composition point of view, with sodium tungstate (Na2WO4) and potassium tungstate (K2WO4) is different from the cation in calcium tungstate (Ca2+) is alkaline earth metal, so they are slightly different in structure, physical and chemical properties, production process and use. Note: Sodium and potassium are both alkali metals By definition, calcium tungstate, also known as “artificial tungstate”, is a tungstate consisting of regular divalent metal calcium ions (Ca2+) and tungstate ions [(WO4)2-]. It is a typical self-activating [...]

Analysis of ammonium paratungstate

Also a kind of inorganic metal tungsten compound, ammonium paratungstate and ammonium metatungstate have certain differences in performance, production technology and application. First, the former is insoluble in water, the latter is easily soluble in water, and the aqueous solution is quite stable; Second, the former is the main raw material for the production of the latter; Third, the former is mainly used to produce tungsten products, the latter can be used to produce tungsten products, but also can [...]

Preparation of superfine tungsten carbide

In recent years, the methods of preparing ultrafine or nanometer WC powder mainly include: mechanical alloying, direct reduction carbonization, sol-gel, gas carbonization, fixed-bed chemical vapor method, plasma method, etc. Mechanical alloying Grahame, etc by mechanical alloying method, first the W powder mixes with C powder by atomic ratio 1:1, in the steel tube and argon gas is piped in, and then choose a diameter of 12 mm WC grinding ball, the ball material ratio of 18:1, finally in high-energy ball mill [...]

Preparation of boron carbide nano powder and its epoxy coating

Boron carbide is a kind of super-hard compound in nature. In normal state, its hardness is second only to diamond and cubic boron nitride, and it is hardest at high temperature (about 1000 degrees Celsius). At the same time, boron carbide is a kind of P-type semiconductor with excellent thermal conductance. Most importantly, it is particularly resistant to acid and alkali corrosion. Because of various advantages, the industry has been trying to use boron carbide as a coating material. But [...]

Silicotungstic acid can be used as a launching agent for isotope analysis of trace strontium

Strontium isotope ratio (87Sr/86Sr) is widely used in the fields of earth science, astrochemistry, environmental chemistry, food origin traceability, archaeology and so on. Thermoionization mass spectrometers (TIMS) have been regarded as the benchmark technique for 87Sr/86Sr ratio analysis since the 1960s. This method not only has excellent accuracy, but also has extremely high sensitivity. Excellent sensitivity is the prerequisite for high precision 87Sr/86Sr ratio analysis of ultramicro samples. The key to improve the sensitivity lies in the selection of [...]

Nano-europium oxide catalyzed lignin oxidation

Lignin is the only large-scale renewable source of aromatic compounds, and has the advantages of being inedible, widely available and cheap. A wide range of aromatic aldehydes, acids and esters can be obtained by directional catalytic oxygenation of polylignin. Catalysts are the key to directional catalytic depolymerization of poly (lignin). Rare earth oxides show unique properties in catalytic oxidation reaction, but the performance of nano rare earth oxides in polyphase catalytic depolymerization of lignin is rarely reported. In this [...]

Preparation of aluminum nitride powders

1.1 Direct nitriding Aluminum nitride does not exist in nature. It is now prepared by direct nitriding of metallic aluminum powder or direct nitriding method after carbon thermal reduction of Al2O3. Its chemical reaction formula is: 2 al (s) + N2 (g) – > 2 aln (s) Direct nitriding has several advantages: 1) low cost; 2) Rich raw materials; 3) The reaction system is simple and there is no side reaction; 4) The reaction temperature is lower than that of carbothermic reduction; [...]

Synthesis of nano – neodymium oxide by homogeneous precipitation method

Nano Nd_2O_3 powder material was prepared by homogeneous precipitation method. The preparation process, the kinetics of precipitation reaction and thermal decomposition reaction of precursor precipitate were studied. Other lanthanide elements (except promethium) and yttrium oxide were prepared. The main research contents and results are as follows: Nano Nd_2O_3 was prepared by uniform precipitation method by dissolving crude Nd_2O_3 in concentrated nitric acid (Nd(NO_3)_3) and urea as precipitator. The effects of the concentration of Nd~(3+), urea concentration, reaction temperature and [...]