Ferro-alloys

PU-21713 Polypropylene, PP, rubber modified alloy Ferro-Eurostar... 

RxLoy, Specialty polyolefin alloys, Ferro Cotp., Filled Reinforced Plastics Div. 

A 2.05 g sample of an iron-aluminum alloy (ferro-aluminum) is dissolved in excess HCl(aq) to produce 0.105 g H2(g). What is the percent composition, by mass, of the ferroaluminum ... 

Ferrotantalum Ferro tellunum Ferrotitanium Ferrous Ferrous acetate Ferrous alloys... 

On a fresh surface the metal has a steely lustre but rapidly tarnishes in air as a result of surface formation of oxide and carbonate species. For protection against oxidation the metal is usually stored in a light mineral oil. When made finely divided, eg, on being cut, it can be strongly pyrophoric, and, for this reason is used, as the ferro-alloy mischmetal, in lighter flints and ordnance. Cerium reacts steadily with water, readily dissolves in mineral acids, and is also attacked by alkafl it reacts with most nonmetals on heating. 

An alternative commercial form of a metallic mixed lanthanide-containing material is rare-earth siUcide [68476-89-1/, produced in a submerged electric-arc furnace by the direct reduction of ore concentrate, bastnasite, iron ore, and quart2. The resulting alloy is approximately 1/3 mischmetal, 1/3 sihcon, and 1/3 iron. In addition there are some ferro-alloys, such as magnesium—ferrosilicons, derived from cerium concentrate, that contain a few percent of cerium. The consumption of metallic cerium is overwhelmingly in the mixed lanthanide form in ferrous metallurgy. 

The suitability of gas absorption as a pollution control method is generally dependent on the following factors 1) availability of suitable solvent 2) required removal efficiency 3) pollutant concentration in the inlet vapor 4) capacity required for handling waste gas and, 5) recovery value of the pollutant(s) or the disposal cost of the unrecoverable solvent. Packed-bed scrubbers are typically used in the chemical, aluminum, coke and ferro-alloy, food and agriculture, and chromium electroplating industries. 

Both silicon and aluminium are added to zinc to control the adverse effects of iron. The former forms a ferro-silicon dross (which may be removed during casting). Aluminium forms an intermetallic compound which is less active as a cathode than FeZn,] . Similarly in aluminium and magnesium alloys, manganese is added to control the iron . Thus in aluminium alloys for example, the cathodic activity of, FeAl, is avoided by transformation of FeAlj to (Fe, Mn)Al/. This material is believed to have a corrosion potential close to that of the matrix and is, therefore, unable to produce significant cathodic activity . 

After dissolution of the alloy in a mixture of concentrated nitric and hydrochloric acids the iron is masked with triethanolamine in an alkaline medium, and the manganese titrated with standard EDTA solution using thymolphthalexone as indicator. The amount of iron(III) present must not exceed 25 mg per 100 mL of solution, otherwise the colour of the iron(III)-triethanolamine complex is so intense that the colour change of the indicator is obscured. Consequently, the procedure can only be used for samples of ferro-manganese containing more than about 40 per cent manganese. 

The above considerations will be illustrated by the simultaneous determination of manganese and chromium in steel and other ferro-alloys. The absorption spectra of 0.001 M permanganate and dichromate ions in 1M sulphuric acid, determined with a spectrophotometer and against 1M sulphuric acid in the reference cell, are shown in Fig. 17.20. For permanganate, the absorption maximum is at 545 nm, and a small correction must be applied for dichromate absorption. Similarly the peak dichromate absorption is at 440 nm, at which permanganate only absorbs weakly. Absorbances for these two ions, individually and in mixtures, obey Beer s Law provided the concentration of sulphuric acid is at least 0.5M. Iron(III), nickel, cobalt, and vanadium absorb at 425 nm and 545 nm, and should be absent or corrections must be made. 

Entzelt, Christoph.De re metallica translated by Nellie E. Lutz, edited by Lloyd M. Swan. Canton (OH) Ohio Ferro-Alloys Corporation, 1943. 95p. 

Ammoniacal leaching is typically applied to oxidic nickel-bearing materials that have been subjected to a reductive roast, which converts the cobalt and nickel present to their metallic form (or as ferro-alloys) and most of the iron to Fe11.106,107... 

Stable oxides, such as those of chromium, vanadium and titanium cannot be reduced to the metal by carbon and the production of these metals, which have melting points above 2000 K, would lead to a refractory solid containing carbon. The co-reduction of the oxides with iron oxide leads to the formation of lower melting products, the ferro-alloys, and this process is successfully used in industrial production. Since these metals form such stable oxides and carbides, the process based on carbon reduction in a blast furnace would appear to be unsatisfactory, unless a product saturated with carbon is acceptable. This could not be decarburized by oxygen blowing without significant re-oxidation of the refractory metal. 

Since the ferro-alloys are liquid over a wide range of composition at 1900 K, the temperature of operation of these processes is no higher than that used in electric arc steel scrap-melting furnaces, for which the technology is well established up to 100 megawatt power input. 

Other metals having very stable oxides can be reduced by the aluminothermic reaction to produce useful ferro-alloys. Niobium oxide, NbO, can be reduced to form a ferro-alloy by the inclusion of iron in the reacting mixture as haematite or magnetite, depending on the niobium content which is required in the product. 

Figure 4.12. The position in the Periodic Table of a few classes of commercially important metals. L Light metals, R Refractory metals, F Ferro alloy metals, P Precious metals, C Coinage metals and S Soft solder metals.

Main uses. Calcium is important in steel production. It has a strong ability to alter the oxides and sulphides. Treatment with calcium modifies the melting points of inclusions which rapidly float out of the steel. Calcium is important in one method of producing a neodymium-iron alloy which is a neodymium ferro boron raw material (through, for instance, the reaction Nd203 + Ca + Fe — NdFe + byproducts). 

A kind of summary of the similarities which, albeit with some uncertainties, may be evidenced between the single lanthanide and actinide metals is reported, according to Ferro et al. (2001a) in Fig. 5.13. According to this scheme the alloying behaviour of plutonium could be simulated by cerium whereas a set of similarities may especially be considered between the block of elements from praseodymium to samarium with those from americium to californium. 

Preparation. Commercially it is prepared mainly as ferro-vanadium alloy. It can be obtained by aluminothermic reduction of the oxide. Pure V may be obtained through the de Boer-Van Arkel process by iodide thermal decomposition (vanadium iodide is decomposed on an electrical heated W wire). 

Ferro-alloys Master alloys containing a significant amount of bon and a few elements more or less soluble in molten bon which improve properties of bon and steels. As additives they give bon and steel better characteristics (increased tensile sbength, wear resistance, corrosion resistance, etc.). For master alloy production carbothermic processes are used for large-scale ferro-sihcon, ferro-chromium, ferro-tungsten, ferro-manganese, ferro-nickel and metallothermic processes (mainly alumino and sihco-thermic) for ferro-titanium, ferro-vanadium, ferro-molybdenum, ferro-boron. 

Taylor DM, Davies JGA Ferro-alloy workers disease. A report of a recent case against the background of twelve years experience. Cent Afr J Med 23 28, 1977... 

Bowie DS Ferro-alloy workers disease. Cent AfrJ Med 2 5) 8l, 1978... 

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