What is copper corrosion inhibitor?

Copper corrosion inhibitor can be adsorbed to form a thin film on the surface of metal, copper and other metals from corrosion protection of the atmosphere and harmful medium. Copper corrosioninhibitor BTA in circulating cooling water system with a variety of scale inhibitor, biocide used in conjunction, circulating cooling water system of good corrosion inhibition. It also can be used as anti tarnish agent, coolant, lubricant additive copper silver.

Generally, there are two kinds of copper corrosion inhibitors: one is Benzotriazole (BTA), the other is Tolyltriazole(TTA).

In China, there are four shape of Benzotriazole: granular, flake, needle and powdery. And in foreign, most are particles and flakes. United States production Benzotriazole is mostly granular. However, granular, hard to dissolve, triazole-need p-parallel domestic manufacturers often need to use solvent after the dissolution of placed inside the product. In recent years, more and more manufacturers use Germany producing Benzotriazole, Germany p-triazole-parallel export in accordance with EU REACH and needles, water and oil soluble. Either directly can also be dissolved in the solvent dissolve in water, and very easy to use. Benzotriazole can be used as rust preventive oil (grease) products, copper and its alloys, silver and copper alloy corrosion effect is particularly evident, usually used in vapor corrosion inhibitor for copper and copper alloys, circulating water treatment chemicals, automobile antifreeze, photographic antifogging agent, macromolecule stabilizer, plant growth regulator, lubricating oil additives. And Benzotriazole can also be used as chrome fog contain agents for chromium plating industry, prevent chrome fog and damage. It can increase the brightness of coated parts.

The abbreviation of Tolyltriazole is TTA. The chemical formula of it is C7H7N3. And the molecular weight of it is 133.15. It is of white granular or powder, can be processed into a large form, small particles,-like, fine particle-like, powder.

Tolyltriazole is mainly used for metals (such as silver, copper, lead, nickel, zinc, etc) and inhibition agent of antirust, widely used in antirust oil (grease) product, usually used in vapor corrosion inhibitor for copper and copper alloys, lubricant additive, water treatment agents, automobile antifreeze. This product is also available with a variety of scale inhibitor, algicide sterilization is used especially for closed-loop cooling system corrosion inhibitor effectiveness well.

Oxygen supply system of Vanadium extraction technology of BOF blowing

Oxygen consumption:

Refers to the 1t oxygen blowing into molten iron containing vanadium for semi steel oxygen consumption, the unit is m3/t. According to the general basis: hot metal composition, different blowing mode supply intensity and stirring. Converter re-vanadium oxygen consumption of per ton iron is within 14 to 18m3, 16000 to 18000m3/h.

The intensity of oxygen supply:

The intensity of oxygen supply of oxygen consumption per ton of metal refers, in unit time unit is m3/ (t.min).

The oxidation reaction of v-extraction process affects the intensity of oxygen supply intensity, big splash seriously, over an hour slow reaction, converting time is long, will cause the temperature of the molten pool increase, over temperature, leading to decarburization reaction dramatically accelerated, semi steel residue from the new increasing vanadium content.

General in the early oxygen can improve oxygen supply intensity, decreased at the later stage.

Oxygen pressure and the gun position

Oxygen pressure: under the same oxygen supply conditions, oxygen pressure can strengthen the bath stirring strengthen dynamics conditions for vanadium and other elements of the oxidation rate. Oxygen pressure control is more suitable in the range of 0.7 to 0.8MPa.

Gun: gun position refers to the oxygen lance nozzle end from the pool surface height. Such as vanadium Russia Nizhny tagil 160t oxygen top blown converter, blowing lance height control in early 2.0m to late lance position is reduced to 1m. When the silicon content in molten iron is higher, the gun position remained lower limit.

In general, the primary product of vanadium is a by-product in with other metals and oil extraction or use to produce (V2O3or V2O5). In iron ore by smelting vanadium is dissolved into molten iron, molten iron by oxidation, slag (10% to 25% V2O5), and then through the processing production of calcination / leaching process for vanadate or vanadium oxide of the final product. In the roasting / reached 1.8% on the V2O5 content in leaching process of mineral processing production of vanadate or vanadium oxide directly. Power plant fly ash recycling, waste catalyst and other residue contain vanadium. The process is the roasting / leaching process generates vanadate or vanadium oxide.

Cold isostatic pressing forming regularity of Molybdenum powder

Powder metallurgy method is the preparation of conventional coagulation conditions is difficult to obtain the structure of the materials, functional materials and composite materials. Compared with the melting method, powder metallurgy method can guarantee the stability of alloy has a uniform organization and performance. It can reduce the work even without cutting.

Usually can use smelting production of products, also can use the method of powder metallurgy production. Although the artificial environment of high temperature enough to make any high melting point metal (W and Mo) melt, but from point of view, the cost of production and efficiency are difficult to replace powder metallurgy technology.

At present, the mainstream of pure Molybdenumand Molybdenum alloy products forming method for powder metallurgy. Mo powder metallurgy process including basic pulverizing, forming and sintering process. Each working procedure for the final Mo has direct influence to the sintering products and its subsequent processing. In powder source is selected, forming and sintering will be decided and the key factor affecting the quality of sintered products.

In the aspect of forming, the main influence factors are pressing pressure, forming agent, one forming or more forming and injection molding, forming soft mode, different forming methods such as steel. So far, the Mo powder compacting process also study is less.

In the production of powder metallurgy, compact density of sintering exhaust, complicated and will have a direct effect on the densification process. According to different Mo powder, ideal compact density is obtained by controlling the size of the suppression of pressure. With the increase of pressing pressure, compact density also increases accordingly, but Mo powder in cold isostatic pressing down the mathematical relationship between the thrust pressure and density of the billet is not clear. This gives Mo powder compacting pressure in the process of enterprise production bring certain difficulty choices. 

A brief overview of Formic Acid

Formic Acid, is also called Methanoic Acid. Formic Acid is contained in the ant and bees secretions, people made distillation ants and obtained Formic Acid, reason has this name. Formic Acid is colorless and stimulating odor and corrosive, foaming swelling after exposure of human skin. The melting point of it is 8.4 ℃, and the boiling point of it is 100.8 ℃. Due to the special structure of Formic Acid, one of its atoms of hydrogen and carboxyl group is directly connected. It can also be seen as a hydroxyl formaldehyde. Therefore, Formic Acid is with acid and aldehyde properties at the same time. In the chemical industry, Formic Acid is used in rubber, pharmaceuticals, dyes, leather type industry.

The properties of Formic Acid:

Formic Acid and water and in the majority of polar organic solvents miscible, also have certain solubility in hydrocarbons. In hydrocarbon and gaseous, Formic Acid is by the dimers form of hydrogen bonding. In the gaseous, hydrogen bonding leads to large deviation between the acid gas and ideal gas equation of state. Liquid and solid acid is by continuous Formic Acid molecules by hydrogen bonding. Formic Acid has the same nature with most other carboxylic acids, although typically do not generate chloride or acid anhydride. Until recently, all attempts to Formic Acid into the derivatives of attempt to product carbon monoxide. Phthalic anhydride can be obtained by formyl fluoride and Sodium Formate at minus 78 ℃. Benzoyl chloride can be made of hydrogen chloride gas through minus 60 ℃ 1-formyl imidazole. Dehydration of Formic Acid decomposition to carbon monoxide and water. Formic Acid is of a similar reducibility and aldehyde.

Solubility of Formic Acid:

Miscible with water, not soluble in hydrocarbons, miscible with alcohol. HCOOH also known as Formic Acid, is a colorless, flammable smoke, pungent odor of the liquid, has a strong corrosive, Formic Acid and water, ethanol, ethyl ether, glycerol and other miscible volatile liquids with strong corrosion and spicy spicy sour. 

The factors affecting the corrosion inhibition

1. The effect of the concentration:

1). The corrosion inhibition efficiency increases with the increased concentration of corrosion inhibitor.

2). The relationship between the inhibition efficiency and the concentration of the extremum.

3). The amount of corrosion inhibitor was inadequate, not only can not afford to the inhibitor but also will accelerate corrosion.

Such as: when the amount of the oxide inhibitor adding less, accelerated corrosion, localized corrosion occurs.

2. The effect of the temperature:

1). In the lower temperature range, the corrosion effect is good, at higher temperature, a significant reduction in the efficiency of the corrosion. The temperature is high, the adsorption decreased, increasing the surface area of the medium and the effect of the metal and increase the corrosion rate of metal. And when the temperature is high, the accelerated diffusion media, the electrolyte solution resistance decreases, increasing the rate of metal corrosion.

2). In a certain temperature range has little effect on the corrosion inhibitor efficiency.

3). Withing the increasing of the temperature, the inhibition efficiency is increased. Temperature is conducive to the formation of a protective film.

3. The effect of the flow velocity

1). The flow velocity increases, the inhibition efficiency decreases even promote corrosion.

2). The flow velocity increases, it is easy for corrosion inhibitor spread, the inhibition efficiency increased.

3). The concentration of corrosion inhibitor is not the same, the effects of flow rate is different.

4). In some cased, the motion of the medium, which increased the efficiency of the corrosion inhibitor.

4. The effect of the metal materials:

The same kind of corrosion inhibitor had different effects on different metal materials, metal materials should be selected in different corrosion inhibitor of different.

5. The effect of the metal surface cleanliness and roughness:

1). The smooth surface to the concentration of inhibitor is smaller than the rough surface, the protective effect is better than on the rough surface.

2). Pollution and corrosion products not only consume corrosion inhibitor, but also hinder the corrosion inhibitor and metal surface contact, damage of corrosion inhibitors.