Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Cementation process


Related Topics

In the News (Fri 17 Feb 12)

  
  Hydrometallurgical process for the treatment of sulphidized compounds containing lead - Patent 4902343
The process of claim 6 wherein the chloride ion concentration is maintained by the addition of an alkali metal chloride in an amount equal to at most 2 gram-equivalents per liter of chloride.
Whilst remaining within the scope of the process in accordance with the invention, it is thus possible to lixiviate with an excess of the chloride of copper, bismuth, antimony and/or of silver, which may reach 10 and even 20%.
Among the methods capable of providing regenerating agents, it is possible to cite the cementation by means of iron which yields ferrous chloride, or of zinc which yields zinc chloride which may be at least partly pyrohydrolysed into zince oxide or stychloride and hydrochloric acid, and the reduction of lead chloride by means of hydrogen.
www.freepatentsonline.com /4902343.html   (6367 words)

  
 Pack cementation   (Site not responding. Last check: 2007-11-02)
This processing is usually performed by a pack cementation process, in which the aluminum deposition and the heat treatment occur simultaneously.
Pack cementation is widely used to confer oxidation resistance on ferrous alloys.
Thus, the transfer process continues until all of the aluminum in the pack is used or until the process is stopped by cooling.
www.corrosion-doctors.org /MetalCoatings/PackCement.htm   (249 words)

  
 EPA Nonferrous Metals Industry Notebook Section IIb
In the cementation process (which is rarely used today), the copper in the acidic solution is deposited on the surface of scrap iron in exchange for the iron.
Once the wastewater exits the flotation process it is sent to a sediment control pond where it is held long enough for most of the sediment to settle.
Processing of copper scrap produces air pollutants during the drying stage which removes excess oils and cuttings fluids and causes discharges of large amounts of dense smoke containing soot and unburned hydrocarbons.
www.msu.edu /course/prm/255/CopperIndustryCase.htm   (1540 words)

  
 Skanska.co.uk
The inclusions formed by this process may be used for structural support, or for the control of groundwater.
The process involves the insertion of a special drilling tool to the required depth using a rotary drilling technique, followed by carefully controlled grout injection whilst rotating and withdrawing.
Cementation Foundations Skanska's plant depot and workshops are centrally located in the UK and provide first class support to sites and projects worldwide.
www.skanska.co.uk /skanska/templates/page.asp?id=8581   (719 words)

  
 Glossary of ferrous metallurgy terms   (Site not responding. Last check: 2007-11-02)
Blister steel: Steel produced by the cementation process; the blisters on the steel surface are due to gas formation from the chemical reaction between carbon and impurities in the slag.
Stopping the decarburization process to produce steel instead of wrought iron was apparently a very challenging task due to the diffuclty of estimating the carbon content of the steel being produced.
The process includes repeated hammering to remove slag and other impurities, reheating the wrought iron allowing it to absorb sufficient carbon from a carburizing fuel such as charcoal, quenching (rapid cooling) to achieve hardness and tempering (slow reheating and cooling) for a final softening of the steel.
www.davistownmuseum.org /TDMtoolGlossary.htm   (13852 words)

  
 Cementation process - Wikipedia, the free encyclopedia
The process probably originated in Bohemia in the 16th century and was in use in Bavaria in 1601.
The process was patented in England by William Ellyot and Mathias Meysey in 1614.
In the early modern period, brass, an alloy of copper and zinc, was usually produced by a cementation process in which metallic copper was heated with calamine, a zinc ore. For details of this see calamine brass.
en.wikipedia.org /wiki/Cementation_process   (557 words)

  
 United States Patent: 5,453,111   (Site not responding. Last check: 2007-11-02)
During the leaching process of the present invention, 95-100% of the zinc present as zinc oxide is extracted, compared to about 55% in Peters; 50-70% of the lead present is removed, compared to less than 5% in Peters; and 50-70% of the cadmium is removed, compared to less than half in Peters.
Minimizing the amount of zinc dust required increases the economy of the process first by reducing the quantity of zinc needed, second by reducing the mass of material to be processed, and third by allowing the removal of a proportionally greater quantity of lead and cadmium.
The present process uses dispersants in the ammonium chloride solution to keep the zinc powder from clumping and thus increasing the efficiency of the cementation process.
members.aol.com /mikecudahy/p5.html   (13940 words)

  
 glowna
The cementation process is already known from the ancient times of human culture but the early knowledge about the process was spread in Europe at the beginning of the Middle Ages.
At that time, the process was used by alchemist mainly for the performing of the miracle of metals transmutation.
From several decades cementation is commonly used in industry for recovery of metals, removal of metal ions from dilute wastes and for purification of solutions.
www.chemia.uj.edu.pl /~sulka/encementacja.htm   (563 words)

  
 Aluminide coating process - Patent 6881439
A process according to claim 1, wherein the second surface is an internal surface defined by a hole in the component, and the first surface is an external surface intersected by the hole.
In contrast to slurry processes, pack cementation and VPA processes are widely used to form aluminide coatings because of their ability to form coatings of uniform thickness.
In pack cementation processes, the aluminum halide gas is produced by heating a powder mixture comprising the source material, the activator, and and inert filler such as calcined alumina.
www.freepatentsonline.com /6881439.html   (3667 words)

  
 ARMOR-CHAPTER-XII-A
The result of this treatment was to raise the carbon content of the face to between 1 per cent and 1.10 per cent, with a gradual reduction in carbon content beneath the surface until the effect of the carburization vanished at a depth of about 1 inch.
Krupp also adopted the cementation process for armor, but instead of using solid hydrocarbon as in the Harvey process, used a gaseous hydrocarbon, illuminating gas being passed while hot across the face of the heated plate.
This process, called decremental face hardening, produces a very hard face, between 30 per cent to 40 per cent of the plate’s thickness, and at the same time leaves the other 60 per cent to 70 per cent of the thickness in its original tough condition.
www.eugeneleeslover.com /ARMOR-CHAPTER-XII-A.html   (3071 words)

  
 Seventeenth-century Islamic brassmakers were far ahead of European peers, engineers say
"A practical limitation of the cementation process is that the maximum zinc composition is approximately 32 weight percent zinc due to the thermodynamics of the reaction," Newbury wrote in an article published in 2004 by the journal Powder Diffraction.
Cementation, a brass-making technique developed by the ancient Romans, is a more complicated fabrication method than co-melting, says Newbury.
Sheet brass made by cementation requires many cycles of working and annealing, which is the process of heating the metal to relieve the internal stress that results from pounding (working) it into its desired shape and thickness.
www.eurekalert.org /pub_releases/2005-05/lu-sib052505.php   (981 words)

  
 The Barbarian Keep
The cementation process was used to produce steel by taking wrought iron and tightly surrounding it with carbon powder, then heating both, without any contact with air, so that the iron absorbed more carbon.
This process also produced a higher grade of steel than the cementation process, and created a steel that was homogeneous throughout, meaning, the carbon was equally distributed throughout the piece of iron.
The crucible process produced such high quality steel, that it was used until the modern electric arc and basic oxygen furnace processes were invented during this century.
www.barbariankeep.com /steel.html   (3719 words)

  
 index
The last part in the formation of sedimentary rocks is the process of cementation.
Cementation occurs when the sediment begins to stick to each other.
This process can attach several layers to each other and the layers are often visible in many examples of sedimentary rocks.
www.albany.edu /~sisp12/compact.htm   (210 words)

  
 Prefeasibility Process Flowsheets for Cobalt Recovery
This route is similar to the process developed by the USBM which was developed to treat dump leach/copper cementation effluent liquor.
Cementation of copper from the raffinate is required to reduce copper concentration, consume acid and reduce ferric ions.
In order to adapt the USBM process to an existing SX-EW process to recover cobalt the pH of the raffinate stream would have to be raised to pH 3 and all ferric precipitated.
www.biomet.com.au /Extract/CoFS.htm   (4922 words)

  
 AQUEOUS ELECTROTECHNOLOGIES: PROGRESS IN THEORY AND PRACTICE: V: New Processes and Products
The nickel sulfide depolarized cementation process developed previously by GECAMINES was inefficient to treat such a high level of Nickel contamination and it was decided to produce alloyed Cobalt-Nickel cathodes in the Shituru tankhouse.
Cementation while being simple and able to achieve the required recovery has the undesirable properties of; requiring a solid-liquid separation and adding iron to solution which must be precipitated, ultimately increasing the weight of residue to landfill.
In the mining industry the process has been successfully evaluated for the separation of excess sulphuric acid from copper electrolytes, the removal of magnesium and manganese contaminants from zinc electrolytes, and antimony, bismuth and nickel from copper electrolytes.
www.tms.org /Meetings/Annual-97/Program/Sessions/WA231A.html   (2118 words)

  
 OEDILF - Word Lookup
The cementation process was an ancient method for alloying metal.
The amount of zinc and other impurites which got incorporated was difficult to control, which is why modern processes simply mix metallic zinc and copper.
Cementation of iron with charcoal was used to make steel.
www.oedilf.com /db/Lim.php?Word=cementation   (203 words)

  
 Leaching: MicrobiologyIndia   (Site not responding. Last check: 2007-11-02)
Microbial leaching is used today in commercial operations to process ores of copper, nickel, cobalt, zinc and uranium.Biooxidation is used in gold processing and coal desulfurization.
There are a few impediments for the process of leaching to be accepted as a major commercial process.
Prior to the development of the solvent extraction-electrowinning process in 1959, the only way to recover copper from an acid solution was by a process called cementation.
users.cjb.net /microbiologyindia/leaching.htm   (483 words)

  
 Industrial process Summary
Industrial processes are procedures involving chemical or mechanical steps to aid in the manufacture of an item or items, usually carried out on a large scale.
Most of the processes are complex and require large capital investments in machinery, or a substantial amount of raw materials, in comparison to batch or craft processes.
Temperatures of 1300 K were produced around the 8th century by blowing air through the heated mixture in a bloomery or blast furnace (12th century); producing a strong but brittle cast iron.
www.bookrags.com /Industrial_process   (1105 words)

  
 Final Environmental Impact Statement - Plutonium Finishing Plant Stabilization, May 1996
Process residues consist primarily of sand, slag, crucibles, and furnace ash.
After all the cement had been added and well mixed, the mixer would be shut off and the container removed from the mixer.
In order to estimate the amount of plutonium-bearing material that could become airborne during the cementation process (pouring the material into a mixing container, adding cement, etc.), the bounding airborne release fraction of 2 x 10-3 and the respirable fraction of 0.3 from DOE Handbook HDBK-3010-94 for free falling powders (DOE, 1994b) were used.
www.eh.doe.gov /nepa/eis/eis0244f/EIS0244F_e.html   (8175 words)

  
 Hand tools in history
This two stage wrought iron production process was necessary because the higher heat of the larger blast furnaces liquefied and carbonized the iron bloom, creating brittle and useless cast iron that had to be reprocessed into useable wrought iron bar stock.
The uniform quality of the cast steel produced in the crucibles after the invention of the puddling process in England was much superior to blister steel produced from pig iron refined into wrought iron and then made into steel by the tedious cementation process.
Bessemer steel process successfully expanded after discovery that spiegeleisen needed to be added to the pig iron during the refining process, producing a steel with a higher carbon content and greater strength
www.davistownmuseum.org /TDMtoolHistory.htm   (5769 words)

  
 ROD, 61-36352
The environmental effects associated with these alternative stabilization processes to population and socioeconomics and historic resources are similar to those discussed for the preferred alternative.
In order to utilize the vertical calcination process, some of the plutonium-bearing solutions will require pretreatment by ion exchange to remove chemical constituents that are not compatible with the vertical calcination process or the process equipment.
This alternative is a thermal process involving distillation and decarbonization, that separates the plutonium oxides from the polystyrene.
www.hanford.gov /doe/eis/0244f/rod.html   (6598 words)

  
 Ru Fang's home page
To clarify details of the microstructure of Cu cementation, two TEM images in Figure 1 show the cross-sectional view of the structure.
This is due to longer DFO process time, 3 min, rather than the 15 sec to produce seed layer.
Since the Al dissolution phenomena has been studied in our previously in the organic system which is the same as the organic used in our Cu cementation DFO process, the etch pattern is thought to be caused by the aluminum dissolution corresponding to the cathodic reaction - copper cementation from cupric ions.
web.umr.edu /~emlab/student/rui/results.html   (558 words)

  
 Interaction Between Quartz Cementation and Fracturing in Sandstones   (Site not responding. Last check: 2007-11-02)
Modeling quartz cementation provides a means to understand the evolution of fracture characteristics when used in concert with basin and geomechanical models.
The modeled surface area evolves in response to both the cementation process (which tends to reduce the surface area) and the fracture process (which tends to increase the surface area).
Importantly, the model reproduces (1) the amount of quartz cement in the unfractured portions of the sandstones, (2) the textures of residual pores within quartz occluded fractures, and (3) “crack seal” structures associated with “quartz bridges” that span fracture apertures and tend to be much longer than adjacent quartz overgrowths.
aapg.confex.com /aapg/hu2002/techprogram/paper_42906.htm   (316 words)

  
 A Summary of the Late D. Chattopadhyaya's Critique of Charaka Samhita
Biswas describes the earliest method of making brass by the cementation process in which finely divided copper fragments were intimately mixed with roasted zinc ore (oxide) and reducing agent such as charcoal, and heated to 1000
If there is a trace of oxygen then zinc vapour would be reoxidised and hence the successful operations must have been done in closed crucibles.
The brass founders trying the cementation process have verified this observation.
www.indianscience.org /reviews/t_rv_minerals_metals.shtml   (765 words)

  
 A process for calorising of mild steel/Low alloy steel
A process for calorising of mild steel/Low alloy steel
The pack cementation process known also as 'Alonising' is used calorising of steel tubes and any other fixtures and can be done on mild steel, Low alloy steel, alloys and stainless steels.
The process is standardised on one foot length of mild steel tube with sufficient coating thickness on both inside and outside of tubes.
www.tifac.org.in /offer/tsw/nml5.htm   (208 words)

  
 Glossary
cementation: The process by which clastic sediments are converted into rock by precipitation of a mineral cement among the grains of the sediment.
mud flows: A general term for a mass-movement landform and process characterized by a flowing mass of fine-grain earth material with a high degree of fluidity.
weathering: The destructive processes by which rocks are changed on exposure to atmospheric agents at or near the earth's surface, with little or no transport of the loosened or altered material; specifically the physical disintegration and chemical decomposition of rock that produce an in-situ mantle of waste and prepare sediments for transportation.
seis.natsci.csulb.edu /basicgeo/Landslide/glossary.htm   (627 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.