Showing papers on "Sodium sulfide published in 1970"

Interaction of Proteins with Sulfide

Abstract: The addition of sodium sulfide to disulfide-containing proteins dissolved in 0.01 N NaOH produces an absorption in the range of 320–350 nm similar to that exhibited by cystine or cystamine treated under the same conditions. Proteins free of cystine and cysteine and proteins containing disulfide bonds which have been reduced with sodium borohydride do not produce this absorbance. Urea and guanidine at 6 M concentration increase the rate of production of the absorbance while sodium dodecyl sulfate at concentration of 0.02 M has an inhibitory effect both on the rate and the extent of the absorbance. The effect of pH, concentration of reagents and of the additions of cyanide and hypotaurine has been studied. The 320–350 nm absorbance as been related to the production of persulfide groups (R-SSH) as a result of the cleavage of disulfide bonds by sulfide. Attempts to prepare a purified model protein containing persulfide groups have failed owing to the instability of the persulfide group in conditions far from those used for its preparation.

Separation of molybdenum sulfide from copper sulfide with depressants

Abstract: Molybdenum sulfide is separated from a molybdenite-containing copper ore concentrate by subjecting an aqueous pulp of the concentrate to froth flotation in the presence of a collector for molybdenum sulfide and a Nokes-type (e.g., arsenic trioxide/sodium sulfide) depressant for copper sulfide, the aqueous pulp being aerated with an inert gas to effect flotation of the molybdenum sulfide constituent of the pulp while maintaining the emf of the pulp above about minus 200 millivolts.

Method of preparing polysulfide solution

Abstract: In this method hydrogen sulfide and sulfur dioxide are reacted with each other in a water phase at a temperature below 150.degree.C to form a sulfur suspension, and the obtained sulfur is then reacted with a strong sodium sulfide solution. The sulfur formed in the first reaction is fed into a polysulfide reactor in the form of an unpurified suspension without separating the sulfur. However, the sulfur is conducted through a concentrator, in which the sulfur content of the suspension rises over 20 per cent of weight, advantageously to 50-60 per cent of weight, and the clear solution separated from it is returned to the sulphur preparing reactor.

Continuous production of anthranilic acid

Abstract: 1. A PROCESS FOR THE CONTINUOUS PRODUCTION OF ANTHRANILIC ACID WHICH COMPRISES REACTING A STRATING COMPOUND SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL SALTS OF PHTHALAMIC OF STAGES, THE FRIST REACTION AQUEOUS MEDIUM IN A PLURALITY OF STAGES, THE REACTION STAGES FOR CONVERTING THE STARTING COMPOUND INTO THE ALKALI METAL SALT OF PHENYL ISOCYANATE-2-CARBOXYLIC ACID BEING CARRIED OUT UNDER SUBSTANTIALLY ADIABATIC CONDITIONS WHILE SUBSTANTIALLY AVOIDING ANY BACKMIXING, THE RESULTING REACTION MIXTURE BEING IMMEDIATELY WITHDRAWN FROM THE REACTION ZONE OF SAID FIRST STAGES AND THEN SUPPLIED SUBSTNATIALLY WITHOUT BACKMIXING TO THE REACTION ZONE OF AT LEAST ONE SUBSEQUENT STAGE FOR HYDROLYSIS AND DECARBOXYLATION OF SAID PHENYL ISOCYANATE-2-CARBOXYLIC ACID INTO ANTHRANILLIC ACID, A REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF SODIUM BOROHYDRIDE, LITHIUM TRIETHOXY ALUMINUM HYDRIDE, SODIUM SULFIDE, SODIUM HYDROGEN SULFIDE, AMMONIUM SULFIDE, SULFUROUS ACID, SULFUR DIOXIDE, SODIUM DITHIONITE, SODIUM, THIOSULFATE, SODIUM FORMALDEHYDE SULFOXYLATE, THIOUREA DIOXIDE, HYDRAZINE AND ITS SALTS, GLUCOSE SODIUM SULFITE AND SODIUM BISULFATE BEING ADDED TO THE REACTION MIXTURE WITHDRAWN FROM THE REACTION ZONE OF SAID FIRST STAGES AND BEFORE THE REACTION HAS BEEN COMPLETED.

Process for increasing reaction rate in conversion of sulfides and hydrosulfides

Abstract: A CATALYTIC PROCESS FOR ENHANCING THE RATE OF OXIDATION OF ALKALINE SOLUTIONS OF WATER-SOLUBLE, OXIDIZABLE, INORGANIC SULFIDES AND/OR HYDROSULFIDES WHEREIN EFFECTIVE CATALYTIC AMOUNTS OF WATER-INSOLUBLE SMELT SOLIDS ARE EMPLOYED. THESE SOLIDS SELECTIVELY CATALYZE THE REACTION BY WHICH THIOSULFATE IS FORMED. THIS CATALYTIC PROCESS MAY ALSO BE EMPLOYED FOR SUBSTANTIALLY INCREASING THE RATE OF OXIDATION OF SULFIDES IN A PULPING GREEN LIQUOR TO THEREBY GREATLY DEPLETE THE AMOUNT OF SODIUM SULFIDE PRESENT THEREIN AND SIMULTANEOUSLY FORM SUBSTANTIAL QUANTITIES OF SODIUM HYDROXIDE WHICH MAY BE EMPLOYED TO ABSORB EFFLUENT SULFUR DIOXIDE EMANATING, FOR EXAMPLE, FROM BOILERS.

6,15 dialkoxy 5,14 diazo iso violanthrones

Abstract: A novel class of compounds are provided which are 6,15-dialkoxy5,14-diaza-isoviolanthrones. The compounds are synthesized from 1-aza-2-hydroxy-benzanthrone via a novel process comprising bromination of the starting material to form 1-aza-2-hydroxy-3bromo-benzanthrone; the hydroxy group is then alkylated, followed by treatment with sodium sulfide to produce novel intermediates of the invention, 3,3-thio-bis(1-aza-2-alkoxy-benzanthrones). The 6,15-dialkoxy-5,14-diaza-isoviolanthrones of this invention are excellent blue vat dyes, which yield bright blue shades on cellulosic fibers. The dyeings have been found to possess excellent fastness properties.

Recovery of sodium chloride from spent pulping liquors

Abstract: A sodium sulfide and sodium chloride-containing smelt formed from waste pulping liquor is fractionated to separate the sodium sulfide from the sodium chloride.

Process for controlling pulp chip deterioration with kraft green liquor

Abstract: THIS INVENTION RELATES TO A TREATMENT USED TO CONTROL THE DETERIORATION OF PULP CHIPS DURING OUTDOOR STOCK PILING FOR LONG PERIODS OF TIME. THE TREATMENT INVOLVES A SPRAYING OR DIPPING OF THE PULP CHIPS WITH A KRAFT GREEN LIQUOR WHICH IS A MIXTURE OF SODIUM SULFIDE AND SODIUM CARBONATE IN WATER. THE TREATMENT GREATLY REDUCES THE LOSS OF WOOD SUBSTANCE OVER LONG PERIODS OF OUTDOOR STORAGE. THE LOSS OF WOOD SUBSTANCE IN WOOD CHIPS WITH THE TREATMENT IS APPROXIMATELY ONE-THIRD OR LESS THAN THAT WITHOUT THE TREATMENT.