State: Foundations Are Failing At Least In Part Because Of ...
"Although [the] investigation will continue into the fall, we believe there is now sufficient evidence to conclude that significant levels of the mineral pyrrhotite in stone aggregate used in the ...
Pyrrhotite - an overview | ScienceDirect Topics
Monoclinic pyrrhotite, however, in contrast to hexagonal pyrrhotite, is magnetic and is recovered in magnetic concentrates. Previous research (Cline and Rosas, 1975; Iwasaki, 1999) has shown that flotation can be used to remove pyrrhotite. The Marcona Mine in Peru uses a reverse flotation process to float pyrrhotite from the magnetite.
Pyrrhotite: The mineral pyrrhotite information and pictures
Pyrrhotite is commonly pseudomorphed by Pyrite, with complete replacement of the Pyrhottite by sparkling Pyrite crystals. Pyrrhotite is named from the Greek word pyrrhos, which means "color of fire".This is despite the fact that the usual color of Pyrrhotite is a bronze color rather than red; however its tarnish may have hints of sparkling red.
Pyrite: The mineral pyrite information and pictures
Pyrite was once used as a source of sulfur, but is now only a minor ore for both sulfur and iron. Pyrite from some localities is auriferous, and therefore is used as an ore of gold in gold-bearing localities.Pyrite was polished by the Native Americans in the early times and used as mirrors. Today, it is used as an ornamental stone, as well as a very popular stone for amateur collectors.
Pyrrhotite | Definition of Pyrrhotite at Dictionary.com
Pyrrhotite definition, a common mineral, iron sulfide, approximately FeS but variable because of a partial absence of ferrous ions, occurring in massive and in crystal forms with a bronze color and metallic luster; magnetic pyrites: generally slightly magnetic. See more.
How is Pyrite Pyrrhotite Floatabilitt Affected by Contact
The galvanic contact improved the floatabillty of pyrrhotite, but adversely affected that of pyrite. Materials and Methods Pyrite and pyrrhotite used in this investigation were, respectively, from Coahuila, New Mexico and Falconbridge Ltd.’s Strathcona mine, Ontario.
How do pyrite and pyrrhotite damage building foundations ...
Pyrite and pyrrhotite in aggregates and concrete. Aggregates, such as sand, gravel, crushed stone, or other rocky material, are used as fill material in construction and are added to cement and water to make concrete. Aggregates come from a wide variety of sources, and sometimes the source rocks may contain pyrite or pyrrhotite.
Pyrrhotite | Definition of Pyrrhotite by Merriam-Webster
Pyrrhotite definition is - a bronze-colored mineral of metallic luster that consists of ferrous sulfide and is attracted by a magnet.
PYRRHOTITE (Iron Sulfide) - Amethyst Galleries
Thirdly, pyrrhotite is magnetic or at least weakly so. It is the next most common magnetic mineral to magnetite. Although not all specimens will show great evidence of magnetism if any, some will attract a paperclip or needle suspended from a string or move the needle of a compass.
PENTLANDITE (Iron Nickel Sulfide) - Amethyst Galleries
Pentlandite is an important ore of nickel. However, it does not produce good crystals and is generally only found in massive form. It is commonly associated with other sulfides such as pyrite, chalcopyrite and pyrrhotite in basic igneous rock intrusions. These sulfide ore bodies are probably produced through magmatic segregation.
What is pyrrhotite - answers.com
The special property that makes pyrrhotite stand out is , that it is magnetic. share: What are some uses of pyrrhotite?
Pyrrhotite - Wikipedia
Pyrrhotite is found with pentlandite in basic igneous rocks, veins, and metamorphic rocks. It is also often found with pyrite, marcasite, and magnetite. It has varying magnetic powers, depending on the number of Fe vacancies in the crystal structure.
Connecticut Crumbling Foundations - Pyrrhotite is the Culprit
Aug 25, 2016· Pyrrhotite. The mineral, pyrrhotite, is an iron sulfide which is prone to oxidation. The mineral was found to be in the aggregate used to make cement that was used extensively in pouring residential foundations in New England in the 80s and 90s, however, was previously discovered in Canadian s as far back as the 1970s.
Foundation Damage Due to Composition or Inclusions ...
The aggregate used to produce concrete was an anorthositic gabbro containing various proportions of pyrite, pyrrhotite, chalcopyrite and pentlandite. Quantitative microanalysis on sulphide minerals show that pyrrhotite contains small amount of Ni, Co, Cu and As substituting for Fe in the mineral structure.
Novel Pyrrhotite Detection Method in Concrete Aggregate ...
Aug 26, 2016· Development of the pyrrhotite detection method must show feasibility for eventual portability and field use. PHASE II: Based on the results of Phase I, develop and demonstrate a bread-board pyrrhotite detection device with natural aggregate and concrete samples, and compare to independent laboratory analyses provide by the government.
Pyrrhotite - Wikipedia
Pyrrhotite is an iron sulfide mineral with the formula Fe (1-x) S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic.
Wisconsin Geological & Natural History Survey » Pyrrhotite
The pyrrhotite apparently formed during the metamorphism of the deposit (Mudrey, 1979). — Pyrrhotite is common at the Lynn massive sulfide deposit where it occurs with sphalerite, galena, chalcopyrite, silver and gold minerals (Kennedy, 1993). — Significant pyrrhotite occurs in sec. 30 T.36N. R.11E. (Dutton and Bradley, 1970).
Home Foundations Are Crumbling: Could Yours Be Next ...
Jun 08, 2016· Why home foundations crumble. The culprit is a mineral found at high levels within the foundations' concrete called pyrrhotite, which can swell when it reacts with oxygen and water.
Failing Concrete Foundations Linked to Aggregate - Fine ...
Pyrrhotite, a mineral found in stone aggregate used to make concrete, is the suspected cause of hundreds, possibly thousands, of foundation failures in eastern Connecticut. Hundreds of Connecticut homeowners have complained that the concrete foundations holding up …
pyrrhotite Topic - American Concrete Institute
The American Concrete Institute. Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design ...
Pyrrhotite - Assignment Point
Uses of Pyrrhotite. Pyrrhotite does not have specific applications. It is mined primarily because it is associated with pentlandite, sulfide mineral that can contain significant amounts of nickel and cobalt. It is an ore of iron. Well crystallized Pyrrhotite specimens are important collector’s minerals.
What are some uses of pyrrhotite - answers.com
cavenders uses telechek, walmart uses telechek at the register and certigy to cash checks. . sheplers uses certigy and home depot uses telecheck, lowes uses certegy, tom thumb uses certigy. sears ...
Troilite - Wikipedia
Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron rich endmember of the pyrrhotite group. Pyrrhotite has the formula Fe (1-x) S (x = 0 to 0.2) which is iron deficient. As troilite lacks the iron deficiency which gives pyrrhotite its characteristic magnetism, troilite is non-magnetic.
UNDERSTANDING PYRRHOTITE IN CONCRETE - cfawalls.org
Mar 16, 2018· Pyrrhotite is the second most common iron sulfide in nature, and it is found associated with pyrite, marcasite, magnetite, and chalcopyrite (CSA 2014). Even so, aggregate that contains pyrrhotite, an unstable form of iron sulfide (Fe[1-x]S), in quantities that are able to be disruptive to concrete does not appear to be very common.
Pyrrhotite | mineral | Britannica.com
Pyrite (FeS 2) and pyrrhotite (Fe 1 - x S) are the most common sulfide minerals. Brassy yellow pyrite, often called “fool’s gold,” occurs variously as an accessory mineral in many rocks, in veins, and even as a chief component of some fossils. Pyrrhotite, which typically has…
(PDF) A Review on Pyrrhotite Oxidation - ResearchGate
A review on pyrrhotite oxidation. Nelson Belzile *, Y u-W ei Chen, Mei-Fang Cai, Y uerong Li. Department of Chemistry and Biochemistry, Laur entian University, Ramsey Lake Road, Sudbury, Ontario ...
Crumbling Foundations - portal.ct.gov
* Prohibits the use of recycled material containing pyrrhotite to make structural concrete unless (1) the State Building Inspector adopts a standard and (2) the person selling or offering the concrete provides the purchaser with written notice that the concrete meets the standard
Pyrrhotite - definition of pyrrhotite by The Free Dictionary
Define pyrrhotite. pyrrhotite synonyms, pyrrhotite pronunciation, pyrrhotite translation, English dictionary definition of pyrrhotite. also pyr·rho·tine n. A brownish-bronze iron sulfide mineral, FeS, characterized by weak magnetic properties and used as an iron ore and in the manufacture...
State links pyrrhotite to crumbling concrete Companies ...
“We believe there is now sufficient evidence to conclude that significant levels of the mineral pyrrhotite in stone aggregate used in the production of concrete is a substantial contributing ...
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