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Chromium Oxide

Chromium Oxide Metallurgical Grade

Synonyms

Chromium Oxide Metallurgical Grade; Chrome Metallic Grade; Chromium Oxide Metallic Grade; Chromium Metal Grade; Chromic oxide; Chrome oxide green; Chromium (III) oxide; Chromium sesquioxide; Chrome green; Chromium oxide green pigments; Dichromium trioxide; Chromia; Chromium (III) oxide; Anhydride Chromique (French); Casalis green; Chrome ochre; Chromia; Chromic acid green; Chromium oxide; C.I. 77288; Green Chrome Oxide; Green Oxide of Chromium; Green chromic oxide; Green chromium oxide; Green cinnabar; Green oxide of chromium

Specification

Model	CR-D	CR-E
Cr2O3 (wt%)	99% min.	99.6% min.
Fe2O3	0.003 max.	0.001 max.
P(wt%)	0.001 max.	0.001 max.
Ca (wt%)	0.001 max.	0.001 max.
Mn (wt%)	0.001 max.	0.001 max.
Cu (wt%)	0.001 max.	0.001 max.
Ni (wt%)	0.001 max.	0.001 max.
Oil Absorption g/100g	25 max.	25 max.
Solution PH	5-8	5-8
Water Soulble	0.3% max.	0.05 max.

Property:

Chrome oxide is a green crystal powder, metal luster, magnetic, good covering strength, high temperature-resisting and sunlight fastness. Not soluble in water, barely soluble in acids, comparatively stable in air, unaffected by acids and alkalis of common density, sulfur dioxide, sulfur hydrogen etc. Chrome oxide green enjoys excellent quality and firmness of coloring.

Packing:

Chrome Oxide is packed in 25kgs, 50kgs woven bags lined with PE liner or as request. 20-24MT will be loaded in per 20’FCL container.

Description:

The principal uses of Chromium are in metallurgical processing of ferrochromium and other metallurgical products to impart corrosion resistance. Chromium is used to induce hardness, toughness and chemical resistance in steel. Today 85% of its use is in metallic alloys such as stainless steel and anodized aluminum.

Chromium Metal

Although it’s melting point of 1 900 °C is higher than that of platinum (1 772 °C), it is at the lower end of the range for metals. In most cases, the high melting point of refractory metals is coupled with a low vapor pressure. This is not the case with chromium. The metal has a very high vapor pressure. The density of chromium is also similar to that of iron and niobium and lies below the 10 g/cm3 of molybdenum or tungsten. Chromium's modulus of elasticity is also lower than that of molybdenum and tungsten

Chromium is most commonly produced using the aluminothermal process which is based on the principle of reducing chromium oxide with aluminum. In this process, chromium oxide is mixed with aluminum powder and the mix is then ignited. The reduction process then continues on its own as an exothermal reaction without the need for any further supply of energy. Depending on the purity of the initial powder, a chromium content of up to 99.8 % is possible. The main impurities are aluminum, iron, silicon and sulfur. The exothermal reaction involved in chromium oxide reduction:

Cr2O3 + 2Al → 2Cr + Al2O3

When exceptionally pure chromium is required, the electrolytic process is used. Using this process, purities of up to 99.995 % are possible. This is achieved by dissolving CrO3 Cr(VI) in sulfuric acid and using a galvanic deposition process to obtain chromium flakes. However, because this process comes at a significant environmental cost, it is not used in all countries.

Stainless Steel

About 70 percent of all chromium is used in the production of “stainless steel”. It contains a minimum of 10.5 - 11.0 percent chromium by mass. Stainless steel is valued for its ability to resist the corrosion common to ordinary steel. This occurs because the chromium forms a thin layer of chromium oxide on the surface of the metal, which protects the underlying metal and prevents further corrosion.

The applications of stainless steel are almost endless. They include automobile and truck bodies, plating for boats and ships, construction parts for buildings and bridges, parts for chemical and petroleum equipment, electric cables, machine parts, eating and cooking utensils, and reinforcing materials in tires and other materials. Other chromium-steel alloys are used to make armor plate, safes, ball bearings and cutting tools.

Chromium compounds are also used to anodize aluminum, a process which coats aluminum with a thick, protective layer of oxide.

Thermocouples

When alloyed with iron and nickel, it produces an alloy known as "Nichrome" which is resistant to high temperatures i.e. 1100°C and used to make heating units, ovens and other appliances. Commercial grades include “Nicrosil” (containing 14% Cr and 1.5% Si)

It is also used to make super-alloys that can perform excellent in the hot, corrosive, and high-stress environment of jet engines.