chromite today is mined particularly to make stainless steel through the production of ferrochrome fecr , which is an iron-chromium alloy. chromite grains are commonly found in large mafic igneous intrusions such as the bushveld in south africa and india.
calcite is a carbonate mineral and the most stable polymorph of calcium carbonate. the mohs scale of mineral hardness, based on scratch hardness comparison, defines value 3 as 'calcite'. other polymorphs of calcium carbonate are the minerals aragonite and vaterite. aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 c, and vaterite is even less stable.
ground calcium carbonate is an abrasive both as scouring powder and as an ingredient of scouring creams , in particular in its calcite form, which has the relatively low hardness level of 3 on the mohs scale, and will therefore not scratch glass and most other ceramics, enamel, bronze, iron, and steel, and have a moderate effect on .
a powder containing a mixture of dry acid and dry carbonate or hydrogen carbonate bicarbonate compounds will certainly do it. tenofalltrades 01:16, 3 december 2005 utc i think the powdered alchopop thing is closer to what i was thinking of. it was years ago that i saw it, but in my memory the chems in it actually reacted in solution to .
the main article for this category is industrial machinery. wikimedia commons has media related to industrial equipment. pertains to equipment usually found in industrial production settings. this category has the following 10 subcategories, out of 10 total. the following 82 pages are in this category, out of 82 total.
michigan limestone and chemical company quarry about 1908 or 1909, the geologist henry h. hindshaw established the commercial value of limestone in northern lower michigan . 2 limestone is a seven trust material essential in industry for making steel, chemicals, and concrete .
a mining or caving lamp has calcium carbide placed in a lower chamber, the generator. the upper reservoir is then filled with water. a threaded valve or other mechanism is used to control the rate at which the water is allowed to drip into the chamber containing the calcium carbide. by controlling the rate of water flow, the production of .
in 1903, pyrite mining was temporarily halted, because larger mineral deposits were superseding the smaller local suppliers. there followed a period of variable production. with the advent of the first world war production climbed again. all the ore fields in the vicinity of the großer graben were now owned by drei kronen und ehrt.
it is commonly held that after a long period of exposure to light realgar changes form to a yellow powder known as pararealgar β-as 4 s 4 . it was once thought that this powder was the yellow sulfide orpiment, but has been recently shown to be a distinct chemical compound. gallery