Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Phosphorus, from

Shaft Furnaces The oldest and most important application of the shaft furnace is the blast furnace used for the production of pig iron. Another use is in the manufac ture of phosphorus from phosphate rock. Formerly hme was calcined exclusively in this type of furnace. Shaft furnaces are widely used also as gas producers. Chemicals are manufac tured in shaft furnaces from briquetted mixtures of the reacting components. [Pg.1221]

Similarly tire removal of phosphorus from liquid iron in a silicate slag may be represented by the equations... [Pg.353]

Ca +, Fe + etc. which are the cationic species in the slag phase). Fellner and Krohn (1969) have shown that the removal of phosphorus from iron-calcium silicate slags is accurately described by the Flood-Grjotheim equation widr... [Pg.353]

The hydriodic acid is then decomposed by chloiine, and ICl regenerated. Phosphorus acts by for.ming the chloride of phosphorus from which the acid chloride is produced, which is more readily attacked by chlorine than the acid. Sulphur behaves in a similar fashion, sulphur chloride converting the... [Pg.252]

Phosphorus from organophosphorus compounds, which are combusted to give mainly orthophosphate, can be absorbed by either sulphuric acid or nitric acid and readily determined spectrophotometrically either by the molybdenum blue method or as the phosphovanadomolybdate (Section 17.39). [Pg.114]

Coleman, A. S. and Holland, H. D. (in press, January 2000). The global diagenetic flux of phosphorus from marine sediments to the oceans redox sensitivity and the control of atmospheric oxygen levels. In "Marine Authigenesis from Microbial to Global" (C. R. Glenn, L. Prevot-Lucas and J. Lucas, eds), SEPM Publication No. 66. [Pg.374]

Tracer techniques are used widely in biology. Botanists, for example, work to develop new plant hybrids that grow more rapidiy. One common way to determine how fast plants grow is to measure how quickly they take up elemental phosphorus from the soil. New hybrids can be planted in a plot and fertilized with phosphoras enriched 32 32... [Pg.1609]

Migration of phosphorus from oxygen to aromatic carbon is induced by lithium diisopropylamide and provides a convenient... [Pg.157]

In addition to a complete water balance, EPIC estimates plant biomass production, fertilizer use, wind and water erosion, loss of nitrogen and phosphorus from the soil, and the effect of nutrient loss from the soil on plant growth. [Pg.1076]

LD/AC [Named after L-D, ARBED (a company in Luxembourg), and CNRM (a Belgian metallurgical research laboratory)] Also called the OCP process. A version of the L-D steelmaking process in which powdered lime is introduced with the oxygen in order to remove phosphorus from the steel. See also OLP. [Pg.161]

Perrin A modification of the Bessemer process which accomplishes the removal of phosphorus from iron by treating the initial molten metal with a molten mixture of lime, alumina, and fluorspar. [Pg.208]

The global biogeochemical cycle of P is almost open. This differentiates phosphorus from carbon and nitrogen, whose natural biogeochemical cycles are, on the contrary, almost closed. [Pg.251]

The global phosphate system is described in Figure 7.10 (Lasaga, 1980). Table 7.1 gives the amounts held by each reservoir, and Table 7.2 the fluxes between reservoirs. Assuming steady-state, calculate the evolution of the world phosphate system if 10000 x 109 kg of phosphorus from fertilizer (mined from an isolated reservoir) were dumped on land in a short period of time. [Pg.376]

The data presented in this paper indicate that excess levels (0.75%) of dietary zinc result in decreases in the bioavailability of calcium and phosphorus in rats and interfere with normal bone mineralization. High dietary levels of calcium or zinc appeared to cause a shift in the excretion of phosphorus from the urine to the feces, while the presence of extra phosphorus tended to keep the pathway of phosphorus excretion via the urine. The presence of large amounts of phosphorus in the Intestinal tract due to high intakes of zinc would increase the possibility of the formation of insoluble phosphate salts with various cations, including calcium, which may be present. A shift in phosphorus excretion from the feces to the urine, however, could result in an environmental condition within the system which would tend to increase the bioavailability of cations to the animal. The adverse effect of zinc toxicity on calcium and phosphorus status of young rats could be alleviated with calcium and/or phosphorus supplements. [Pg.172]

Phosphorus (P, [Ne]3.v23// ), symbol and name from the Greek word Ojj s(jopoe (bringer of light). Discovered (1669) by the German alchimist Hennig Brand, who extracted phosphorus from urine. [Pg.508]

In a recent study involving the inorganic analysis of human ribs from 10 subjects,66 it has been found that the calcium content varied from 24.12 to 26.91 per cent, the phosphorus from 10.75 to 12.11 per cent, and the carbonate as carbon dioxide varied from 2.81 to 3.95 per cent. Inter-individual differences of this magnitude would seem to exist since the inorganic composition of bone is probably relatively stable and not subject to short-term fluctuations. [Pg.92]

It is worth mentioning at this point that the formation of a a -phosphorus from a -phosphorus resulted in a-aromatic compounds in the case of the l//-phosphirenium cation as well. Disubstitution at the phosphorus in l//-phosphirenium cation (5) resulted in the preservation of aromaticity with proper substituents (fluorine) in 36, as a result of the interaction with PF2 a -orbitals,as indicated by isodesmic reactions. A similar phenomenon has been observed also for 1,1-difluorocyclopropene, 1,1-bissilylcyclopentadiene, and 1,1-bisstannylcyclopen-tadiene. In the latter case, the phenomenon has been called hyperconjugate aromaticity . The effect of... [Pg.14]

The iron-based redox cycle depicted in Figure 18.9 provides an effective preconcentrating step for phosphorus by trapping remineralized phosphate in oxic sediments. The conversion of phosphorus from POM to Fe(lll)OOH to CFA is referred to as sink switching. Overall this process acts to convert phosphorus from unstable particulate phases (POM to Fe(lll)OOH) into a stable particulate phase (CFA) that acts to permanently remove bioavailable phosphorus from the ocean. This is pretty important because most of the particulate phosphate delivered to the seafloor is reminer-alized. Without a trapping mechanism, the remineralized phosphate would diffuse back into the bottom waters of the ocean, greatly reducing the burial efficiency of phosphorus. [Pg.464]

The manufacture of phosphorus-derived chemicals is almost entirely based on the production of elemental phosphorus from mined phosphate rock. Ferrophosphorus, widely used in the metallurgical industries, is a direct byproduct of the phosphorus production process. In the United States, over 85% of elemental phosphorus production is used to manufacture high-grade phosphoric acid by the furnace or dry process as opposed to the wet process that converts phosphate rock directly into low-grade phosphoric acid. The remainder of the elemental phosphorus is either marketed directly or converted into phosphoms chemicals. The furnace-grade phosphoric acid is marketed directly, mostly to the food and fertilizer industries. Finally, phosphoric acid is employed to manufacture sodium tripolyphosphate, which is used in detergents and for water treatment, and calcium phosphate, which is used in foods and animal feeds. [Pg.403]

In the specific case of wastewater generated from the condenser water bleedoff in the production of elemental phosphorus from phosphate rock in an electric furnace, Yapijakis [33] reported that the flow varies from 10 to 100 gpm (2.3-23 m /hour), depending on the particular installation. The most important contaminants in this waste are elemental phosphoms, which is colloidally dispersed and may ignite if allowed to dry out, and fluorine, which is also present in the furnace gases. The general characteristics of this type of wastewater (if no soda ash or ammonia were added to the condenser water) are given in Table 9. [Pg.416]

Figure 12 Summary of materials balance in a pilot plant for recovery of phosphorus from phossy water (from Ref 15). 1 ppm = 1 mg/L. Figure 12 Summary of materials balance in a pilot plant for recovery of phosphorus from phossy water (from Ref 15). 1 ppm = 1 mg/L.
More recent research on treatment or recovery of phosphates and phosphorus from wastewater can be found from the literature [57,58,60-69,73]. [Pg.447]

Unlike Brandt, Kunckel published a paper describing the properties of phosphorus, without revealing anything about how it was made. He also discovered that phosphorus could be made from many organic substances and claimed that he could make phosphorus from mammals, fish, birds, and plants. Thus, for more than a century, he came to be regarded as the discoverer of phosphorus. [Pg.72]

Fig. 8. Geometrical dependence of P-O-C-H couplings in derivatives of trivalent phosphorus [From Kainosho and Nakamura.a989,90)]... Fig. 8. Geometrical dependence of P-O-C-H couplings in derivatives of trivalent phosphorus [From Kainosho and Nakamura.a989,90)]...
The second reason for acid-digestion is the determination of the total soil elemental content of, e.g. potassium, phosphorus or trace elements. This is seldom done for potassium in normal soil samples, mainly because the total K in soils is of no value as an index to the availability of K to plants, nor is it always of value in tracing the movement or accumulation of applied fertilizer K (Pratt, 1965). The unreactive soil phosphorus is obtained by subtracting the naturally leached reactive phosphorus from the total phosphorus, and a method for determining the latter by extraction with sulphuric acid and potassium persulphate is cited by Turner and FHaygarth (2000). They analysed... [Pg.30]


See other pages where Phosphorus, from is mentioned: [Pg.32]    [Pg.39]    [Pg.50]    [Pg.99]    [Pg.252]    [Pg.34]    [Pg.47]    [Pg.52]    [Pg.71]    [Pg.351]    [Pg.353]    [Pg.249]    [Pg.249]    [Pg.111]    [Pg.448]    [Pg.201]    [Pg.72]    [Pg.76]    [Pg.294]    [Pg.106]    [Pg.227]   


SEARCH



© 2024 chempedia.info