Showing papers on "Sodium sulfide published in 1992"

Reactions of nitrochlorobenzenes with sodium sulfide: change in selectivity with phase-transfer catalysts

Abstract: o-Nitro- and p-nitrochlorobenzene were reduced to the corresponding chloroanilines with aqueous solutions of sodium sulfide both in the presence and absence of a phase-transfer catalyst. The use of phase-transfer catalysts, with solid sodium sulfide, was found to change the course of the reaction completely to dinitrodiphenyl sulfide. The role of mass transfer in the system was assessed with m-nitrochlorobenzene as the organic substrate.

Solid-liquid reactions catalyzed by alumina and ion exchange resin: reactions of benzyl chloride/p-chlorobenzyl chloride with solid sodium sulfide

Abstract: Basic aluminum oxide and Amberlyst A27 (Cl - form) ion exchange resin, in their original form, were used to catalyze the solid-liquid reactions of benzyl chloride/p-chlorobenzyl chloride with sodium sulfide. At a 5% loading of the catalysts, enhancement factors of 14 and 25 were obtained for the benzyl chloride reaction with alumina and Amberlyst A27, respectively. Alumina was also used as a cocatalyst with tetrabutylammonium bromide (TBAB) as a homogeneous-phase-transfer catalyst. Enhancement factors as high as 1.9×10 3 and 4.9×10 2 were obtained with benzyl chloride and p-chlorobenzyl chloride, respectively, as organic substrates at a 0.4% loading of TBAB and 5% loading of alumina. Ultrasound was also found to intensify the reaction

Reductive desulfurization of dibenzyldisulfide.

Abstract: Dibenzyldisulfide was reductively degraded by a methanogenic mixed culture derived from a sewage digestor. Toluene was produced with benzyl mercaptan as an intermediate in sulfur-limited medium. Toluene production was strictly associated with biological activity; however, the reducing agent for the culture medium, Ti(III), was partially responsible for production of benzyl mercaptan. Sulfide was not detected. Additions of sodium sulfide did not inhibit toluene production. Additions of 2-bromoethane sulfonic acid prevented methanogenesis but did not adversely affect toluene yields.

Electroconducting transparent film of amorphous copper sulfide on polyethylene substrate

Abstract: The reaction between 1,4,8,11-tetraazacyclotetradecanecopper(II) perchlorate and sodium sulfide gave a transparent amorphous CuS film supported on a polyethylene substrate. The surface electrical resistivity of the film was ca. 10 k Ω□ at 300 K and showed a metal-like temperature dependence down to 250 K.

Reducing copper corrosiveness of organic polysulfides

Abstract: Reducing the copper corrosiveness of organic sulfides by treating them with an alkali metal-containing or alkaline earth metal-containing substance capable of dissolving elemental sulfur (e.g., sodium hydroxide, sodium sulfide, etc.). The process is conducted in a substantially homogeneous liquid reaction medium composed of a mixture of water and at least one ketone. Experiments have shown that it is possible by use of this process to reduce the copper corrosiveness to a level below that exhibited by a product formed by treating the same initial organic sulfide in the same way but in a liquid medium composed solely of water.

Process for removal of mercury from hydroxyl-ammonium nitrate solutions

Abstract: A process for the removal of mercury from industrial waste streams is disclosed wherein the waste stream is a nitrate based solution that has been decomposed by the addition of hypochlorite. The method involves adding a reducing agent to reduce the hypochlorite and/or adjusting the pH by the use of a strong acid to less than about 2.0, converting any residual chlorine to a soluble unreactive salt, adding a soluble precipitating agent, such as sodium sulfide, to the solution in a ratio to the mercury present of greater than 1:1 to about 2:1 to precipitate out the mercury as a mercury compound. The solution is then filtered to remove the precipitated mercury compound.

Stress Corrosion Cracking of Stainless Alloys in Alkaline Sulfide Solutions

Abstract: The resistance of commercial austenitic, ferritic, and duplex alloys to stress corrosion cracking in a 5% NaOH-2% Na2S-2% Na2CO3-0.2% Na2SO4-0.1 % NaCl solution at 150° has been studied by...

Potential Pyrite Depressants for use in Oil Agglomeration of Fine-Size Coal

Abstract: A number of potential pyrite depressants were identified for use in coal beneficiation methods involving agglomeration of aqueous suspensions of fine particles with oil. Potential depressants were screened by subjecting sulfurized particles of mineral pyrite to agglomeration with heptane after application of a given material. Sulfurized pyrite was utilized because it was readily agglomerated. The following materials were found to suppress the agglomeration of sulfurized pyrite: ferric chloride, potassium monopersulfate, hydrogen peroxide, ferrous sulfate, sodium dithionite, sodium thiosulfate, sodium sulfide, titanous chloride, pyrogallol, quebracho, and milk whey. Ferric chloride was shown to improve greatly the separation of an artificial mixture of Upper Freeport coal and sulfurized pyrite by agglomeration with heptane.

Removal of dissolved chelates from aqueous solutions

Abstract: At least a portion of any iron, copper, nickel and chromium ions are removed from an aqueous liquid in which they are in solution as chelates of an alkylenepolyamine polyacetic acid or salt by (a) adjusting the pH of the liquid to above about 10; (b) adding sufficient sodium sulfide to react with at least a portion of the copper ions; (c) separating precipitated iron and copper compounds; (d) adding nitric acid to adjust the pH to the range of about 6 to 8; (e) adding sufficient sodium nitrite to the liquid to react with at least a portion of the nickel and chromium present; (f) heating the liquid to above about 575°F (302°C) for at least about 15 minutes to facilitate precipitation of nickel and chromium; and (g) separating precipitated solids to leave a non-hazardous filtrate.

Improved modified kraft cooking. Part I. Pretreatment with a sodium sulfide solution

Abstract: On a etudie l'effet d'un pretraitement du bois par une solution de sulfure de sodium a 15 et 30 g/l sur la cinetique de delignification, la selectivite et le rendement dans le cas d'une cuisson kraft modifiee. Les resultats montrent qu'apres pretraitement a 140-150°C la pâte presente une viscosite plus elevee.

Production of beta-mercaptopropionic acid

Abstract: PURPOSE:To easily obtain the subject compound in high yield at a low cost by converting thiodipropionic acid to an alkali metal salt with an alkali metal hydroxide, reacting in a concentrated aqueous solution of an alkali metal sulfide under heating for a prescribed period and acidifying the reaction solution with a basic acid. CONSTITUTION:The objective compound of formula III useful as a raw material for a resin for lens, a crosslinking agent for acrylate polymer, a hardener of epoxy resin, etc., can be produced by using thiodipropionic acid of formula I preferably obtained as a by-product of the reaction of sodium sulfide with acrylonitrile as a starting substance, converting the substance to an alkali metal salt of formula II with an alkali metal hydroxide, adding the salt to a concentrated aqueous solution of an alkali metal sulfide such as Na2S, reacting the components with each other by heating at 110-130 deg.C for a prescribed period (1 to several hours) and acidifying the reaction solution with a basic acid such as sulfuric acid or hydrochloric acid, The use of the alkali metal hydroxide in excess is economically preferable because the consumption of expensive alkali metal sulfate can be decreased in compensation for the increase of the consumption of the inexpensive alkali metal hydroxide.

Removing heavy metals from phosphoric acid and phosphate fluid fertilizer: organic and inorganic reagents

Abstract: Heavy metals in wet-process phosphoric acid (WPA) and phosphate fluid fertilizers are an environmental concern in the United States and Europe. To address this concern, several organic and inorganic reagents were evaluated as precipitants for heavy metals in a 10-34-0 (N-P2O5-K2O) fluid fertilizer and WPA. Trisodium trithiocyanuric acid (TMT-15), sodium polythiocarbonate (Thio-Red II), and sodium trithiocarbonate (5% Na2CS3) precipitated arsenic, cadmium, copper, mercury, lead, and zinc from 10-34-0. Ammonium cyanurate was ineffective in removing cadmium from 10-34-0. Thio-Red II and 5% Na2CS3 precipitated mercury, lead, cadmium, copper, and chromium from WPA. A water-insoluble starch xanthate adsorbed mercury, copper, and lead from 10-34-0 and WPA. Sodium sulfide, sodium polysulfide, and potassium ferrocyanide were tested as inorganic precipitants. The polysulfide was twice as effective as the sulfide alone, and concentrations of less than 10 ppm of arsenic, cadmium, mercury, and lead were achieved in 10-34-0. Ferrocyanide reduced the concentrations of cadmium and nickel to less than 10 ppm in WPA

Production of carboxylated arylene sulfide copolymer

Abstract: PURPOSE:To obtain the title high-molecular copolymer easily and stably at good efficiency while suppressing side reactions by reacting a dihalogenoaromatic compound with a sulfiding agent and a dihalogenoaromatic carboxylic acid (alkali metal salt) under specified conditions. CONSTITUTION:A process for reacting a dihalogenoaromatic compound (A) (e.g. p-dichlorobenzene) with a sulfiding agent (e.g. sodium sulfide) and a dihalogenoaromatic carboxylic acid (alkali metal salt) (B), e.g. 2,4- dichlorobenzoic acid, wherein component (B) is first reacted with an excess of the sulfiding agent, and the resultant solution is then reacted with component (A).

Sliding member composition

Abstract: PURPOSE:To obtain a sliding member composition improved in heat resistance, dimensional accuracy, mechanical strengths, and sliding properties by mixing a specified block copolymer resin with a fibrous reinforcement and a lubricant CONSTITUTION:p-Dichlorobenzene (i) is made to react with sodium sulfide (ii) in N-methylpyrrolidone to obtain polyphenylene sulfide (a) Component (a) is subjected to react with 4,4'-dichlorodiphenyl sulfone (iii) and component (ii) to obtain a polyphenylene sulfide sulfone (b) Component (b) is block- copolymerized to obtain a block compolymer resin (A) comprising component (a) segment and component (b) segment and having a melt viscosity (at 310 degC and in terms of a shear rate of 10E3 sec ) of 50-20000P 10-90wt% component A is mixed with 5-50wt% fibrous reinforcement (B) selected from among an inorganic fiber, an aromatic polyamide fiber and an inorganic whisker and 5-40wt% lubricant (C) selected from among a fluorocarbon polymer, a high- molecular-weight PE powder, a molybdenum disulfide, graphite and a lubricating oil

Production of sodium sulfide low-hydrate or anhydride

Abstract: PURPOSE:To enable ready control of production due to relatively low temperature conversion to a low hydrate or anhydride by adding a sodium sulfide low hydrate or anhydride to a sodium sulfide high hydrate and drying it under vacuum. CONSTITUTION:As a sodium sulfide high hydrate, a crystalline 5-9 hydrate or a pellet-, flake- or chip-shaped >=5 hydrate, etc., are used and 5-50 pts.wt. sodium sulfide low hydrate (e.g. 1-5 hydrate) or anhydride is added to 100 pts.wt. thereof. The resultant mixture is charged into a rotary evaporator and sufficiently mixed under rotation and the evaporator is then immersed in a water bath. The inner pressure is reduced (e.g. =20 deg.C and <= melting point of the sodium sulfide high hydrate for about 1-30hr. By the above-mentioned operations, the sodium sulfide high hydrate is converted to the objective low hydrate or anhydride same as the added sodium sulfide low hydrate or anhydride.

Production of pentaerythrithiol

Abstract: PURPOSE:To obtain the subject compound useful as a molecular weight modifier, etc., in polymerizing a monomer for plastic lenses having a high refractive index in high yield by reacting pentaerythritol tetrahalide with a trithiocarbonate in a polar solvent and hydrolyzing the resultant compound with an acid. CONSTITUTION:A pentaerythritol tetrahalide expressed by formula I (X is chlorine or bromine) (e.g. pentaerythritol tetrabromide) is made to react with a trithiocarbonate (e.g. sodium trithiocarbonate) prepared by reacting sodium sulfide with carbon disulfide in a polar solvent such as N,N-dimethylformamide at 100 deg.C for 2hr to provide a compound expressed by formula II (M is alkali metal). An acid such as 36% hydrochloric acid is then added to hydrolyze the resultant compound at 30 deg.C for 1hr. After completing the reaction, chloroform and water are added to carry out extraction. The resultant reactional product is collected from the chloroform layer and then treated with zinc dust and hydrochloric acid in toluene. The toluene layer is subsequently separated to distill away the toluene under reduced pressure to provide the objective pentaerythrithiol.

Process for joint treatment of NH3 and/or H2S containing process waste waters as well as sodium sulfide containing caustic soda

Abstract: The process serves for the pretreatment of both material streams for the purpose of further treatment in a biological final purification stage. The sodium hydroxide solution is first acidified with sulphuric acid to a pH between 3.0 and 7.0 and then, together with the NH3- and/or H2S-containing process effluents is subjected to NH3- and H2S-stripping. The vapours thus produced are further treated in a Claus apparatus, which is equipped with an NH3 cleavage catalyst, while the effluent flowing from the stripping column can be fed, after appropriate cooling, to the biological final purification stage.

Production of trithiocarbonate

Abstract: PURPOSE:To obtain a trithiocarbonate safely and in high yield without the need for using an excess of carbon disulfide, therefore, without the need for recovering the explosive carbon disulfide, by reaction in a sealed tube between carbon disulfide and an alkali sulfide CONSTITUTION:The objective trithiocarbonate can be obtained by reaction under heating a pressure sealed tube containing a solution of equimolar amounts of carbon disulfide and an alkali sulfide (eg sodium sulfide) The reaction solvent is pref water or an alcohol; for the reaction in an aqueous solution, after completing the reaction, the resulting liquor can be directly provided, as an aqueous solution of the trithiocarbonate, to eg a mercaptoamine production process; or, the trithiocarbonate can be isolated in the form of crystal by removing the water from said solution For the reaction in an alcohol, the reaction liquor is cooled, and the crystal deposited is collected through filtration, thus isolating said carbonate in the form of crystal Thereby, the objective trithiocarbonate can be obtained at an yield of about 94 to 99mol%

Production of sodium hydrosulfide

Abstract: PURPOSE:To provide a production method of sodium hydrosulfide of a of high quality (high purity colorless crystals). CONSTITUTION:In the mixing. tank 12, sodium hydroxide 16 is admixed to sodium hydrosulfide 31 to form sodium sulfide. The sodium sulfide 33 is fed into the sodium hydrosulfide formation column 13 where the sodium sulfide is brought into contact with a hydrogen sulfide-containing gas such as an acid gas 35 to form sodium hydrosulfide 31. In order to reduce the concentration of the sodium sulfide 33 in the sodium hydrosulfide 31 in this process, it is recommended that the pH of the sodium hydrosulfide formed in the column 13 is controlled within 10.0 to 12.0 and the; molar ratio of the hydrogen sulfide to sodium hydroxide is set to 1.02 to 1.10.

Production of sodium sulfide solution

Abstract: PURPOSE:To reduce the corrosion of a reactor and obtain a high-quality sodium sulfide having excellent uniformity by heating a mixture containing sodium sulfide, water and aprotic polar solvent at a prescribed amount and at a prescribed temperature. CONSTITUTION:A mixture consisting of 100 pts.wt. sodium sulfide, 5-45 pts.wt. water and aprotic polar solvent (e.g. N,N-dimethylformamide or N,N- diethylformamide) is prepared. The mixture is heated at 175-250 deg.C for about 3-4hr.

Production of conjugate yarn

Abstract: PURPOSE:To obtain the title yarn having high strength, high modulus of elasticity, excellent heat resistance, chemical resistance and dimensional stability, hardly peeling by subjecting a specific polyphenylene sulfide resin and a main chain type liquid crystal resin to complex melt spinning. CONSTITUTION:(A) (i) Dichlorobenzene and (ii) sodium sulfide are dissolved in (iii) N-methylpyrrolidone and polymerized to give a resin, which is washed with (iv) an acid such as acetic acid to give a polyphenylene sulfide resin. The polyphenylene sulfide resin and (B) preferably 95-10wt.% main chain type liquid crystal resin shown by the formula (n1, n2 and n3 are mol% values and total is 100) are melted by an extruder, etc., and subjected to sheath-core spinning, bimetal spinning, etc., to give the objective yarn.

Polyarylene sulfide-based block copolymer film

Abstract: PURPOSE:To obtain a polyarylene sulfide-based block copolymer film having extremely improved physical properties such as modulus of elasticity, toughness, heat shrinkability, etc., especially near at 150 deg.C by melting and molding a specific block copolymer. CONSTITUTION:A block copolymer which consists of a polyphenylene sulfide sulfone (PPSS for short) part having mainly a unit shown by formula I (phi is p-phenylene) as a repeating unit and a polyphenylene sulfide ketone (PPSK for short) part having mainly a unit shown by formula II as a repeating unit in a ratio of 20-80mol%, preferably 25-75mol% PPSS part, such as a block copolymer prepared by synthesizing end chlorophenylene group type PPSK and an end sodium sulfide group type PPSS and reacting both the substances in an organic amide solvent or a resin composition comprising the copolymer and a miscible another resin (preferably polyphenylene sulfide, PPSK or PPSS) is melted and molded into a film, which is drawn to give a film.

Mercaptans, sulfides, and disulfides

Abstract: This chapter describess the reaction of sodium hydrosulfide with activated aliphatic or aromatic halides. If aromatic nitro substituents are present, they are reduced to amino groups. Dihalides yield dithiols. Tertiary aliphatic halides give olefins. Two methods that found general applicability in laboratory are the reaction of alkylhalides with thiourea with subsequent alkaline hydrolysis and the reaction of free sulfur with aryl lithium or Grignard reagents. A widely used laboratory method for the preparation of sulfides is the action of halides on metallic sulfides. The monohydrate of sodium sulfide is a satisfactory reagent to afford high yields of symmetrical sulfides. The conversion of mercaptans to sulfides is effected by converting to the sodium mercaptide and reacting with active halides or dialkyl sulfates. The addition of hydrogen sulfide or mercaptans to olefins is another important method for the preparation of mercaptans and sulfides via ionic or free radical. The reaction of activated alkyl or aryl halides with sodium sulfide yields disulfides. The chapter discusses oxidation of mercaptans by hydrogen peroxide as the best method of preparing disulfides in good yields if the corresponding mercaptan is readily available.

Production of anhydrous sodium polysulfide

Abstract: PURPOSE:To safely produce anhydrous sodium polysulfide at a low cost by dissolving anhydrous sodium sulfide in a mixed solvent composed of a solvent having no or little dissolving power to sodium sulfide and a solvent capable of dissolving sodium sulfide and having a boiling point lower than that of the former solvent, adding sulfur to the solution and distilling out the dissolving solvent after reaction. CONSTITUTION:Anhydrous sodium sulfide is dissolved in a mixed solvent composed of the 1st solvent having no or little dissolving power to sodium sulfide and the 2nd solvent capable of dissolving sodium sulfide and having higher boiling point than the 1st solvent. Sulfur is dissolved in the obtained solution and the 2nd solvent is distilled off. The 1st solvent is preferably one or more solvents selected from halogenated hydrocarbons, ethers and ketones and the 2nd solvent is preferably one or more solvents selected from lower alcohols.

Synthesis of soluble p‐terphenyl‐4,4″‐ylene sulfide polymers

Abstract: The synthesis of substituted poly(p-terphenyl-4,4″-ylene sulfide)s was carried out via nucleo-philic displacement of the chlorine atom from 4,4″-dichloro-2′,3′-disubstituted p-terphenyls by sodium sulfide. Different aromatic groups such as phenyl, p-methoxyphenyl, biphenylyl, phenoxyphenyl and phenylthiophenyl were used as substituents. Polymers containing sulfur near the theoretical values were obtained in most cases. The synthesized polymers are soluble in common solvents at room temperature when substituents bulkier than the phenyl group were used. Inherent viscosity values of up to 0,38 dL/g were achieved. Dynamic mechanical analysis showed that polymer films were obtained with a modulus independent of temperature up to 250°C. Thermal stability of the synthesized products was evaluated by thermogravimetry, showing that the polymers are stable up to 500°C in both air and nitrogen atmosphere. Products having a glass transition temperature in the range of 135 to 230°C, determined by differential scanning calorimetry, were obtained by this method.

Method for preventing corrosion of material of apparatus handling aqueous sodium sulfide solution

Abstract: PURPOSE:To considerably reduce the corrosion of carbon steel by an aq. sodium sulfide soln. even at about 100 deg.C by adding Na2S4 to the sodium sulfide soln. by a proper amt. related to the concn. of sodium sulfide in the soln. CONSTITUTION:When carbon steel is used as the material of an apparatus ad an aq. sodium sulfide soln. is handled at ordinary temp. to 100 deg.C, Na2S4 is added to the sodium sulfide soln. by >=0.4wt.% (y) in the case of >=5wt.% concn. (x) of sodium sulfide in the soln. and an amt. (y) (wt.%) defined by the inequality in the case of <5wt.% concn. (x). The passivation of the carbon steel is accelerated and the corrosion is inhibited.