V. Chromium Flashcards
What is the color and luster of Chromium?
Brownish black to black, metallic to greasy
What is the specific gravity of Chromium?
7.17
What is the hardness of Chromium on Mohs scale?
8.5 to 9
What is the melting point of Chromium?
1,615°C
Does Chromium tarnish?
No, it does not tarnish
What is the abundance of Chromium in Earth’s crust?
21st most abundant element
What is the principal mineral of Chromium?
Chromite
What are the types of Chromite based on usage?
Metallurgical, Refractory, Chemical
What is the Cr:Fe ratio of Metallurgical chromite?
2.4-3.2:1
What is the Cr:Fe ratio of Refractory chromite?
1.8-2:3.1
What are some minerals associated with Chromite?
Olivine, talc, serpentine, uvarovite, pyroxenes, biotite, magnetite, anorthite
What are the uses of Chromium?
Forms alloys with iron, nickel, cobalt; adds hardness, strength, corrosion resistance
How much Chromium is in stainless steels?
More than 10%
What finish does electrolytically deposited Chromium provide?
Hard, corrosion-resistant, lustrous finish
What are other uses of Chromium?
Pigment source, furnace lining
Where are chromite occurrences found geologically?
Ophiolite belts in the Philippine island-arc system
What is a complete ophiolite sequence?
Metamorphic peridotite, cumulate peridotite, pyroxenite, dunite, chert, spilite, pelagic sediments
What types of chromite deposits are there?
Primary (podiform) and secondary (residual / transported)
Where are major occurrences of chromite found in the Philippines?
Zambales, Palawan, Occidental Mindoro, Eastern Samar, Dinagat Island
Where are laterite and alluvial/beach placer chromite deposits found?
Associated with ultramafic exposures
