Kerosene as solvent

The modifier is only necessary in case of kerosene as solvent, because of the low solubility of the isopolytungstate-amine complex which is hence increased. Compounds used as modifiers are isodecanol (5%) or tributyl-phosphate (12%). 

Preconcentration of As(III) diethyldithiocarbamate on silica chemically modified with hexadecyl groups was examined [1]. Emulsion liquid membrane (made up of L113A surfactant, liquid paraffin as stabilizer and kerosene as solvent with HCl and KOH as external and internal phases) separation of As(III) and As(V) was applied prior to detection with silver diethyldithiocarbamate ( =510 nm) [2]. The method was applied to Cu ore and slagged ash. 

The calculation of the concentration of extractable components in a countercurrent cascade of equilibrium solvent extraction stages is first developed for the simple countercurrent extraction section of Fig. 4.3. The theory is then extended to the extracting-scrubbing system of Fig. 4.4 for fractional extraction and is illustrated by a numerical calculation for the separation of zirconium from hafnium, using TBP in kerosene as solvent. 

Another modification has been worked out by Valaer using saturated magnesium sulphate solution containing a little hydrochloric acid, and equal parts of mineral oil and kerosene as solvent. For cinnamon, cassia and clove essences most of the ethanol is removed by an air current after introducing the sample into the Babcock bottle. 

Fatty acid methyl ester have been considered and used as substitutes for kerosene as solvents in formulated i. They are biodegradable and therefore less harmful to the environment. 

A number of other words that have traditionally been used in the petroleum industry are difficult to define precisely. These refer pardy to specific hoiling ranges, but also to certain intended uses. Thus, gasoline boils lower than naphtha, and kerosenes generally higher, but these terms are applied to products that ate intended as fuels, rather than as solvents. 

High molecular weight primary, secondary, and tertiary amines can be employed as extractants for zirconium and hafnium in hydrochloric acid (49—51). With similar aqueous-phase conditions, the selectivity is in the order tertiary > secondary > primary amines. The addition of small amounts of nitric acid increases the separation of zirconium and hafnium but decreases the zirconium yield. Good extraction of zirconium and hafnium from ca 1 Af sulfuric acid has been effected with tertiary amines (52—54), with separation factors of 10 or more. A system of this type, using trioctylarnine in kerosene as the organic solvent, is used by Nippon Mining of Japan in the production of zirconium (55). 

Noncombustible solid (NIOSH, 1997) but materials used as solvents (e.g., kerosene or other hydrocarbons) are often flammable rendering the mixture as a flammable or combustible mixture... 

The use of kerosene as a solvent in paints and insecticides increases the likelihood of exposure by painters, particularly when spray applicators are used (Fidler et al. 1987), and in exterminators. Use of a respirator, alternate application methods (brush or roller), and increased ventilation can all reduce worker exposure to the solvent vapor. 

Naphtha Various volatile and often flammable liquid hydrocarbon mixtures used as solvents and diluents consists mainly of hydrocarbons with higher boiling point than gasolines and lower boiling point than kerosene principal component of chemical dispersants used prior to 1970. Naphthenes Class of hydrocarbons with similar physical and chemical properties to alkanes insoluble in water, generally boil at 10-20°C higher than corresponding carbon number alkanes. Narcosis Stupor or unconsciousness produced by chemical substances. 

As apparatus for the batch process, an enamel or steel reactor with an agitator and pressure steam or oil heating suffices. Apparatuses used in the continuous synthesis in the presence of solvents and in the bake process are described in [50] and [51,52], respectively. The choice of process depends on the availability and cost of the starting materials phthalodinitrile or phthalic anhydride. Although the phthalodinitrile process has certain advantages over the phthalic anhydride process, the latter is preferred worldwide because of the ready accessibility of phthalic anhydride. In this process the molar ratio of phthalic anhydride, urea, and cop-per(i) chloride is 4 16 1, with ammonium molybdate as catalyst. The mixture is heated in a high-boiling solvent such as trichlorobenzene, nitrobenzene, or kerosene. The solvent is removed after the formation of copper phthalocyanine. Fre-... 

These workers [20] also examined thin layer chromatography of 2,4-DP (Dichloroprop) and MCPP (mixture of Mecoprop and 2-(2-chloro 4-methylphenoxy)propionic acid). In this method the ethyl ether extract of the sample is purified on a column of silicic acid and the herbicides are separated by thin layer chromatography on silica gel-kieselguhr (2 3) with light petroleum-acetic acid-kerosene (10 1 2) as solvent. The sensitivity is 3pg of either compound per litre, the average recoveries of Dichlorprop and MCPP are 85.7% and 87.4%, respectively, and the corresponding standard deviations were 13.9% and 15.5%. 

Uranium is deposited widely in the Earth s crust, hence it has few ores, notably the oxides uraninite and pitchblende. The ores are leached with H2SO4 in the presence of an oxidizing agent such as NaClOs or Mn02, to oxidize all the uranium to the (+6) state as a sulfate or chloride complex. On neutralization with ammonia a precipitate of yellow cake , a yellow solid with the approximate composition (NH4)2U207 is formed. This is converted into UO3 on ignition at 300 °C. This can be purified further by conversion into uranyl nitrate, followed by solvent extraction using tributyl phosphate in kerosene as the extractant. 

In the various solvent-extraction circuits employed in this process, use is made of a solution of D2EHPA in kerosene as the extractant. The selective recovery of the various metals is achieved by careful control of the equiUbrium pH value of the aqueous phases in the multistage extraction and stripping operations. After the leach liquor has passed through two separate circuits, each of which comprises five stages of extraction and four of stripping, the europium product is obtained initially as a solution of europium(III) chloride. Further purification of the product is accomplished by reduction with amalgamated zinc to Eu +, which is by far the most stable of the divalent lanthanide ions with respect to the reduction of water cf. the redox potentials of the Eu /Eu and Sm /Sm + couples, which are —0.43 and —1.55 V respectively ). Sulfuric acid is added to the... 

This profile covers total petroleum hydrocarbons (TPH), which is defined as the measurable amount of petroleum-based hydrocarbon in an environmental medium (Chapter 2). TPH is measured as the total quantity of hydrocarbons without identification of individual constituents. Sources of TPH contamination in the environment range from crude oil, to fuels such as gasoline and kerosene, to solvents, to mineral-based crankcase oil and mineral-based hydraulic fluids. These products contain not only a large number and variety of petroleum hydrocarbons, but also other chemicals that, strictly speaking, are not the subject of this profile, such as non-hydrocarbon additives and contaminants. The TPH issue is further complicated by the number of petroleum-derived hydrocarbons that have been identified—more than 250—and the variability in composition of crude oils and petroleum products (see Section 3.2 and Appendices D and E for details). 

As solvent, either kerosene or mixtures of alkyl benzenes like toluene or xylene have been proposed. Due to the toxicity of the latter, kerosene is widely preferred. 

Mineral spirits — Flammable petroleum distillates that boil at temperatures lower than kerosene and are used as solvents and thinners, especially in paints and varnishes. Mineral spirits are the common term for some naphthas. Mineral spirits were used extensively in chemical dispersants made before 1970 but are no longer used due to their toxicity. (See also Naphtha.)... 

TBP meets most of these requirements except those of low viscosity and a density different from water. These deficiencies are corrected by diluting TBP with a light, saturated hydrocarbon, such as an aromatic-free kerosene. This solvent is the one most commonly used at present in fractional extraction of metals. The physical properties of TBP are summarized in Table 4.5 [FI, S4J. 

This process, developed since 1910, employs liquefied sulfur dioxide as solvent. First applied to dearomatize kerosenes and gas nils, the initial technique was modified to obtain pure aromatics. An examination of the equilibrium diagrams shows that, theoretically, it is impossible to obtain aromatics in a purity greater than 67 per cent at — 17.2 C, than 73 per cent at — 29°C, using sulfur dioxide as solvent. However, thanks to a kerosene backwash, very pure products can be obtained with good yields, up to 98 per cent for benzene and toluene, and 95 to 97 per cent for C8 aromatics. 

---