Articles

Role and application of niobium carbide

Niobium carbide is a green cubic crystal with metallic luster, belonging to the sodium chloride cubic crystal system. It has high melting point, high hardness (microhardness 235GPa, harder than corundum), good chemical stability (stable at 1 000~1 100℃, and rapid oxidation into niobium pentoxide above 1 100℃), insoluble hydrochloric acid, sulfuric acid and nitric acid, A mixture of hot hydrofluoric acid and nitric acid soluble only. Niobium carbide is easy to melt in titanium carbide, zirconium carbide, tungsten carbide [...]

Determination of vanadium content in vanadium carbide

Vanadium carbide is an important alloy additive, which can improve the corrosion resistance, wear resistance, strength and other comprehensive properties of hard alloys, so it is widely used in alloys. At present, the main methods for the determination of high vanadium content are REDOX titration, inductively coupled plasma atomic Emission spectrometry (ICP-AES), X-ray fluorescence spectrometry and spectrophotometry, but they all have their shortcomings. Chemical titration is widely used because of its high accuracy, easy to master and low operating [...]

Preparation and application of lanthanum manganate

Composite oxides are widely used as catalysts in modern chemical industry because of their excellent oxidation/reduction properties, high mechanical strength and good thermal stability. Among them, perovskite compound oxide is particularly eye-catching. Since the 1950s, perovskite-type composite oxides have been used in catalytic combustion, photocatalysis, fuel cells and metals Air cell, environmental catalysis, catalytic hydrogenation, catalytic cracking and so on have been widely used and studied. At present, there are many methods used to synthesize perovskite, such as coprecipitation method, [...]

Ruthenium trichloride was prepared from ruthenium containing waste

Preparation of Ruthenium trichloride directly from ruthenium-containing waste material Ruthenium trichloride is one of the most important compounds of ruthenium and is an important chemical raw material in the fields of heterogeneous catalysis, homogeneous catalysis, electroplating, coating and so on. A method of preparing ruthenium trichloride directly from ruthenium waste material was introduced. The process is simple, the cost is low, the operation is simple, and the direct yield of ruthenium is more than 90%. Ruthenium waste generally comes from [...]

Method for preparing subnickel oxide from nickel precipitate

The invention relates to a method for preparing subni oxide by reusing nickel precipitate. Firstly, the unqualified products produced by solution precipitation are screened to obtain a part of nickel precipitate with diameter > 5.0μm and a part of nickel precipitate with diameter ≤5.0μm. Then sediment diameter of 5.0 microns or less nickel and nickel salt solution to join the spray pyrolysis device, spray reaction, resulting atomized droplet during spray contains nickel deposits, in the pyrolysis reaction, nickel salt [...]

Recovery of potassium fluosilicate in the production of potassium fluotitanate

This technology provides a kind of fluorine in the production of potassium titanate recycling process of potassium fluosilicate, fluorine is obtained by hydrofluoric acid will react with titanium ore leaching of iron titanate slurry, solid-liquid separation are clarified the fluorine titanium acid leaching liquid iron, then add the potassium liquid cooling crystallization, solid-liquid separation of potassium fluosilicate solid and refined fluorine titanium acid leaching of iron liquid; Will be refined fluorine iron leaching liquid and potassium titanate liquid reaction [...]

Methods for the production of molybdenum carbide

1. Programmed temperature reduction method Temperature programmed method is put forward in the eighty s is still the most widely used in a laboratory for the means of the MoC, the reaction experiment, molybdenum oxide is used as the source of molybdenum, hydrocarbon gas and hydrogen were used as the basis of carbon dioxide gas and reduction of materials, and temperature rising slowly to ensure in balance in the process of catalytic reaction speed, the composition and content of the [...]

A method for preparing rhenium trichloride

Rhenium itself has no independent deposit, and is often dispersed in other non-ferrous ore bodies. It is mainly associated with molybdenite and mostly occurs in trace minerals such as molybdenum, copper, lead, zinc, platinum and niobium. Therefore, we should make full use of regional resources, give full play to regional advantages, and vigorously build the high-tech industry of scattered metals. A former Soviet union carbide plant, oxidizing roasting – sedimentation method to extract the rhenium: flue gas containing a Re2O7 [...]

Titanium carbon nitride, a new material of the century

In the manufacture of all kinds of mechanical parts, all need to be processed with cutting tools. The cutting performance of tool material is one of the key factors to determine the machining efficiency, machining quality and machining cost. WC-Co – based carbide tool is the most used tool material at present. However, tungsten and cobalt are rare resources, resulting in high cost of WC-Co based cemented carbide materials. Carbon titanium nitride material with high melting point, high strength, wear [...]

Sodium potassium niobate – bismuth sodium titanate solid solution structure

In recent years, great progress has been made in the lead-free conversion of electronic materials. Sodium potassium niobate (KNN) and bismuth sodium titanate (BNT) are the two most competitive components that are expected to partially replace the currently used lead zirconate titanate (PZT) component. KNN undergoes cubic, tetragonal, orthogonal and tripartite phase transitions from high temperature to low temperature; The phase transition behavior of BNT is relatively complex. From high temperature to low temperature, BNT experiences cubic, tetragonal and [...]