Showing papers on "Sodium sulfide published in 1981"

Elevated, declining pressure dehydration of poly(arylene sulfide) prepolymerization mixture

Abstract: A method for dehydrating pre-polymerization mixtures in the preparation of poly(arylene sulfide) in which a reaction mixture of a sulfur source and an organic amide are contacted at a first pressure within a range of about 20 psig to about 60 psig and an initial temperature in a range of about 300° F. to 400° F. to form a complex of the reactants with the mixture subsequently subjected to a decrease in pressure while elevating the temperature to a second temperature at which, at the chosen pressure, essentially all water is removed from the mixture. Other compounds including bases, alkali metal carboxylates, alkali metal carbonates, lithium halides, and lithium borate can be present in the reaction mixture. Preferably the sulfur source is sodium sulfide and the organic amide is N-methylpyrrolidone.

Controlled, elevated pressure dehydration of poly(arylene sulfide) prepolymerization mixture

Abstract: A method for dehydrating pre-polymerization mixtures in the preparation of poly(arylene sulfide) in which a reaction mixture of a sulfur source and an organic amide are contacted at an essentially constant pressure within a range of about 4 psig to about 40 psig and a first temperature in a range of about 300° F. to 400° F. to form a complex of the reactants with the mixture subsequently maintained at essentially constant pressure while elevating the temperature to a second temperature at which, at the chosen pressure, essentially all water is removed from the mixture. Other compounds including bases, alkali metal carboxylates, alkali metal carbonates, lithium halides, and lithium borate can be present in the reaction mixture. Preferably the sulfur source is sodium sulfide and the organic amide is N-methylpyrrolidone.

Polyyppphenylene sulfide film

Abstract: PURPOSE:To obtain a ply-p-phenylene sulfide film excellent in the thermal, mechanical and dimensional stability including phenylene sulfide as a main structural unit and having specified melt viscosity, relative crystallization, degree dimension of microcrystal and orientation. CONSTITUTION:Sodium sulfide and the like and p-dihalobenzene such as p-dichlorobenzene are polymerized under pressure in a high-boiling polar solvent to obtain a polymer containing more than 90mol% of a structural unit indicated by the molecular formula. This polymer is melt-extruded and then cooled at a speed higher than 10 deg.C/sec. to form an amorphous film. The amorphous film thus obtained is subjected to a biaxial stretching preferably at a temperature of 85 deg.C-110 deg.C so as to have an enlarged area 8.5-21 times as large as the original one, and further to a heat setting in a stretched state at a temperature of 200 deg.C-275 deg.C for 1-300sec. Thus a desired quality of film can be obtained having a melt viscosity of 100- 60,000cgs. at shear rate of 200(sec) , a relative crystalization degree of 5-35, a dimension of microcrystal of 40-150Angstrom and an orientation in the edge and end directions of 0.1-0.6.

Production of sodium hydrosulfide

Abstract: Sodium hydrosulfide is continuously produced from the reaction of hydrogen sulfide and with sodium sulfide by continuously introducing an aqueous sodium sulfide solution into an unvented reaction chamber, which may be a tower or tank, while maintaining a source of gaseous hydrogen sulfide in pressure demand relationship with the solution in the chamber, and continuously withdrawing aqueous sodium hydrosulfide solution from the chamber.

Low temperature, non-SO2 polluting, kettle process for separation of lead from lead sulfide-containing material

Abstract: 1574 LOW TEMPERATURE, NON-SO2 POLLUTING, KETTLE PROCESS FOR SEPARATION OF LEAD FROM LEAD SULFIDE-CONTAINING MATERIAL ABSTRACT OF THE DISCLOSURE Lead is separated from material containing lead sul-fide, e.g. galena ore concentrate, by a substantially auto-genous process involving establishing a pool of molten lead in a kettle, adding a metallic alkali metal, e.g. metallic sodium to the molten lead in an amount sufficient to reduce the com-bined lead of the lead sulfide to metallic lead, adding the ore concentrate to the molten lead pool, and mixing together the metallic sodium, molten lead and ore concentrate. The sodium reacts rapidly and exothermically with the lead sulfide to reduce the combined lead of the lead sulfide to metallic lead and form sodium sulfide. The thus-liberated metallic-lead reports in the molten lead pool, and a matte phase con-taining the sodium sulfide separates from the molten lead and forms on the surface of the molten lead pool. Lead sulfide from an excess of the ore concentrate, or other suitable added flux, which is usually added to the molten lead pool, serves to flux the sodium sulfide-containing matte phase to attain , desired fluid and low melting characteristics of the matte phase. The process herein employs a kettle as the reactor, ordinarily the steel refining kettle of a lead refinery, is a low temperature process requiring temperatures above the melting point of lead but ordinarily not above 650°C., and does not discharge polluting SO2 into the atmosphere.

Derivatization-Gas Chromatographic Determination Of Mercaptans

Abstract: After being precipitated as silver mercaptides, mercaptans were converted into their pentafluorobenzyl derivatives in high yields by reaction with sodium sulfide and then with pentafluorobenzyl bromide. The derivatives were analyzed down to sub-ppm levels by gas chromatography with a flame ionization detector. It is possible that the above method is developed for the trace analysis of mercaptans in environmental matrices.

Removing method for organic matter in wet process phosphoric acid

Abstract: PURPOSE:To thoroughly decompose and remove unnecessary org matter in wet process phosphoric acid by bringing the acid into contact with an alkali soln of hydrogen sulfide, removing a deposit, and subjecting the separated soln to extracting treatment after contact with an oxidizing agent CONSTITUTION:Wet process phosphoric acid is brought into contact with an alkali soln of hydrogen sulfide or other sulfide at 40-60 degC under 10kg/cm gauge pressure At this time, a sodium hydroxide soln of sodium sulfide is preferably used, and the concn is adjusted to >=500mg/l as NaSH to the phosphoric acid After separating a deposit, the soln is brought into contact with an oxidizing agent at about 110-150 degC under >= about 10kg/cm Chlorate is preferably used as the oxidizing agent, it is added by >= about 005wt% to H3PO4 in the soln, and the contact time is about 01-6hr The soln is then subjected to extracting treatment using a solvent contg >= about 005wt% phosphate in a solvent to phosphoric acid wt ratio of about 8:1-1:1 Thus, org matter contained in the phosphoric acid can be removed by >= about 98wt%

Treatment of iron material polluted by heavy metal

Abstract: PURPOSE:To purify iron material polluted with mercury by treating the material with an aqueous soln contg ferric chloride and hydrochloric acid and adding sodium sulfide to the treating soln after the treatment to make the soln harmless and reusable CONSTITUTION:Iron material which has the surface polluted with metallic or inorg mercury is treated with a treating soln consisting of a 1,500l ferric chloride soln of 37% concn, 600l hydrochloric acid of 35% concn and 1,000l water to dissolve the mercury in the soln and remove it from the material surface The material thus purified is washed with water, and the washing water is added to the treating soln to prevent mercury from being discharged from the treating system Sodium sulfide is then added to this treating soln by an equiv or more to the contained mercury while agitating the soln in an agitating vessel The mercury and excess sodium sulfide are converted into insoluble sulfide and iron sulfide, respectively, and they are removed by filtration The filtrate is a clean ferrous chloride soln free from mercury, etc, and it can be reused to dissolve mercury

Production of polysulfide

Abstract: PURPOSE:To synthesize simply and at low cost a polyalkylene sulfide in a one-stage process, by reacting an aq. soln. of an alkali metal sulfide with an alkylene halide by using a phase transfer catalyst. CONSTITUTION:An aq. soln. of an alkali metal sulfide (e.g. sodium sulfide or potassium sulfide) is reacted with an alkylene halide having the formula X-R'-Y (wherein R' is 1-20C bivalent alkylene group, X, Y are halogen) (e.g. dichloromethane or bromochloromethane) by using a phase transfer catalyst (e.g. trioctylmethylammonium chloride) to produce a polysulfide having a repeating unit of the formula -(R-S)-(wherein R is a bivalent org. group) (e.g. polymethylene sulfide). The inexpensive alkali metal sulfides can be used. The polyalkylene sulfide can be produced even if a large amount of water is present. When the process is directed to produce polymethylene sulfide, the polymer can be obtd. in a one-stage process without isolating the intermediate, a cyclic oligomer.

Stabilized polyphenylene sulfide

Abstract: PURPOSE: A polyphenylene sulfide low in content of acetone-soluble oligomer and content of nitrogen in oligomer and excellent in heat stability, prepared by reacting an alkali sulfide with a dihalobenzene in a polar organic solvent under a specified reaction condition. CONSTITUTION: An alkali sulfide (e.g., sodium sulfide) and a dihalobenzene (e.g., p-dichlorobenzene) are subjected to a polymerization reaction in a polar organic solvent (e.g., N-methylpyrrolidone). In this reaction, the following measure are taken: the heat hystereis in the polymerization and recovery processes is decreased, the polymer concentration during the polymerization is about 14W 29%, a polymerization aid such as lithium acetate is used, and a filter is used when the polymerization system is introduced into water to reprecipitate the polymer or to wash off inorganic salts. In this way, there is produced a stabilized polyphenylene sulfide consisting mainly of a structure unit of the formula and having an acetone-soluble oligomer content of below 2% and a content of nitrogen in oligomer of below 1.5%. COPYRIGHT: (C)1982,JPO&Japio

Treatment of Plating Wastewaters by Ferrous Reduction, Sulfide Precipitation, Coagulation & Upflow Filtration.

Abstract: : Current practice in treatment of mixed metal wastewaters containing hexavalent chromium consists of acidic (pH approx. 3) chromium reduction followed by alkaline, metal-hydroxide precipitation; a two-stage process. A single-stage process could reduce capital and operation costs. Synthetic chromium, cadmium, and nickel wastewaters were successfully treated by ferrous sulfate and sodium sulfide in a single cell reactor at alkaline pH (7-10), thus clarifying conflicting reports in the literature. Batch tests were performed to study this process. Solids were removed by membrane filtration. Metal residuals were analyzed by atomic absorption spectrophotometry. Chromium was rapidly and stoichiometrically reduced by ferrous sulfate. Sodium sulfide by itself negligibly reduced chromium, and was no better than hydroxide in precipitating cadmium and nickel. However, in combination with ferrous sulfate, sulfide improved chromium reduction and metal removal. Alkalinity, EDTA and cyanide interfered with chromium reduction and metal removal; calcium hardness counteracted these interferences. (Author)

Harmful gas absorber for night soil tank and treating tank, etc.

Abstract: PURPOSE:To simply remove the offensive odor of hydrogen sulfide, etc., by using the fine pieces of iron oxide to which sodium hydroxide is adhered to a filter me- dium to be attached to a stack for deodorization. CONSTITUTION:Offensive odor gas inside a night soil tank is sucked up by a fan 2b and then passed through an adsorbent 8 inside a container 5 attached detachably to the inside of a stack 1. During the passage of the gas, hydrogen sulfide present in the gas is reacted with sodium hydroxide adhered to the surface of the adsorbent to form sodium sulfide which is in turn reacted with the iron oxide in the adsorbent base material and changed into stabilized iron sulfide. The waste gas deprived of hydrogen sulfide is released from the upper part of the stack 1 to the outside.

Treatment for waste water containing heavy metal

Abstract: PURPOSE:To remove contained heavy metals economically and perfectly by adding a heavy metal capturing agent or org. type and sodium sulfide to the waste water contg. heavy metals controlled to 4-12pH then performing solid-liquid separating operation thereby removing the precipitate. CONSTITUTION:Caustic soda, slaked lime, sulfuric acid or the like is added to waste water contg. heavy metals, to control its pH to 4-12, to which a heavy metal capturing agent or org. system and sodium sulfide are added in arbitrary order or simultaneously, and the mixture is agitated for 5-15min to allow precipitate to deposit. Thence, said precipitate is removed by solid-liquid separating operation such as filtering, supernatant separation, or flotation. The comercial heavy metal capturing agents of org. system are usable as they are and the amount of addition of the sodium sulfide and the heavy metal capturing agents is usually 1.0-5.0 times equiv., more preferably 1.0-2.0 times equiv. It is possible to add filter aids such as diatomaceous earth in solid-liquid separation of the precipitate.

Reduction of redoxxsystem compound

Abstract: PURPOSE:The reduction of a redox compound such as anthraquinone or redox resin is effected by using an inexpensive reducing agent such as silfide or hydrogen sulfide in the presence of a sulfate salt or sulfurous acid to produce the reduced product used in the production of hydrogen peroxide as a hydrogen-transferring agent in high yield. CONSTITUTION:The reduction of a redox compound selected from anthraquinones and redoxy resins such as 2-ethylanthraquinone, condensation resin from hydroquinone and formaldehyde is effected in the presence of a sulfite salt such as sodium sulfite, sodium bisulfite or sodium arylsulfite or sulfurous acid in an amount of 0.1-10 times the molar quantities of the redoxy compound by using a sulfide such as sodium sulfide or sodium hydrosulfide or hydrogen sulfide as a reducing agent to give the reduction product. EFFECT:The sulfur formed in the reduction system using sulfide is converted into thiosulfate salt to prevent the decrease in the reduction efficiency.

Manufacture of polysulfide

Abstract: PURPOSE:To manufacture sodium polysulfide as digesting chemicals for the manufacture of pulp without producing sulfur compounds such as sodium thiosulfate by catalytically reacting an aqueous sodium sulfide soln. with a specified oxidation- reduction resin. CONSTITUTION:When craft pulp is manufactured from lignocellulose material, a soln. contg. sodium polysulfide collected in a process of recovering digesting chemicals for craft pulp is fed into a column packed with an oxidation-reduction resin to produce sodium polysulfide. The resin is prepared by halomethylating a matrix copolymer of an aromatic monovinyl compound and an aromatic polyvinyl compound and bonding quinones such as p-benzoquinone or 1,2-naphthoquinone to the copolymer in the presence of Lewis acid catalyst. The resin reduced by said reaction is regenerated to the oxidation type resin having quinone type structure by feeding an aqueous soln. contg. ferric ions, dichromate ions, etc.

Capturing method for heavy metal

Abstract: PURPOSE:To capture and remove harmful heavy metals quickly, inexpensively and effectively by adding polyethylene imines (salts) having dithioic acids groups and sulfur compds. to waste water contg. heavy metals. CONSTITUTION:A flocculating agent prepd. by mixing compds. added with >=1 piece of dithioic acid groups or their salts and >=1 kind of sodium sulfide, sodium polysulfide, sodium hydrosulfide, etc. is added to waste water contg. heavy metals under agitation. The amt. of the addition is about 0.3-1.2 times mole equiv. the contents of the heavy metals in the waste water. The use ratios of the polyethylene imine deriv. and the sulfur compds. are about 1:99-99:1. According to this method, the heavy metals in the waste water are captured thoroughly, and the secondary pollution by the redissolution, etc. of formed sludge is prevented.

Production of 2-benzothiazolinone derivative

Abstract: PURPOSE:A novel 2-thiobenzothiazolinone derivative is used as a starting material and made to react with an oxirane compound in the presence of an acid to produce the titled compound used as a medicine with anti-inflammatory and analgesic activities safely and simply. CONSTITUTION:The reaction between a 2-thiobenzothiazolinone derivative of formula I (X is H, halogen) and an oxirane compound is conducted in the presence of an acid such as acetic acid in an inert solvent or no solvent to produce a compound of formula II. The compound of formula I, the starting material, is novel and obtained by the following process. Sodium sulfide is made to act on a mono-or di-halogenonitrobenzene and followed by action of carbon disulfide to give a 2-mercaptobenzothiazole derivative. The product is led to 2-thiobenzothiazolinone-3-acetic acid derivative of formula III (R is lower alkyl), which is made to react with 1-(2-hydroxyethyl)piperazine to give the compound of formula I.