Showing papers on "Sodium hypophosphite published in 1980"

Reduction-distillation method for sulfate determination

Abstract: This article describes an improvement of the reduction/distillation/spectrophotometric technique that is widely used in the nuclear industry. The procedure involves the reduction of oxidized forms of sulfur to hydrogen sulfide with a hot solution containing hydroiodic acid, sodium hypophosphite, and acetic acid. The hydrogen sulfide is sparged from the reaction mixture with nitrogen which is then bubbled through a dilute zinc acetate solution which traps the sulfide. The addition of acid, p-aminodimethylaniline, and ferric chloride to the zinc acetate trapping solution quantitatively converts the sulfide to methylene blue which is then measured by absorption spectrophotometry at 667 nm. In this version of the technique, the samples and standard are added serially to a single, relatively large batch of the boiling reduction solution. The apparatus is not cooled down and disassembled between each sample run and the reduction solution is kept at a boil at all times and is continuously sparged with nitrogen gas. This reduces the total analysis time to a fraction of that necessary with the previous methods. Tables are presented summarizing the studies on: effect of matrix constituents on the determination of 100 ..mu..g of sulfate; effects of nitrates; and comparison of ion chromatographic results with those obtainedmore » by the sulfate reduction techniques. Agreement between values is good for these two techniques. The overall time for the analysis of a single solution sample is on the order of 10 min including the delay for color development. The relative standard deviations obtained on finely ground solid calcined nuclear waste containing from 0.1 to 10% sulfur as sulfate are typically on the order of 3 to 5%.« less

Noncrystalline alloyyplated layer and its manufacture

Abstract: PURPOSE:To raise the magnetic characteristics by forming the noncrystalline alloy- plated layer containing a given ratio of Co and P as the main components. CONSTITUTION:In the place of Fe-P noncrystalline alloy previously applied, a Co- P noncrystalline alloy-plated layer, containing 60-92atom% Co and 8-26atom% P as the main components, is obtained by an electric plating method using an acid plating bath consisting primarily of approx. 1/6-3mol/l of a divalent Co ion (e.g., cobalt sulfate, etc.) and approx. 0.03-0.3mol/l of hypophosphic acid and/or a hypophosphite (e.g., sodium hypophosphite, etc.). The conditions for plating includes pH1.2-2.2, a current density of 5-20A/dm , and a bath temperature of 30-60 deg.C, and also a stabilizer, e.g., L-ascorbic acid, etc., and a brightener, e.g., hydroquinolic acid, etc., are added to the plating system. Thus, a magnetostriction constant is made smaller and also magnetic permeability and coercive force are raised.

Stable antistatic air filter - comprises needled felt made of acrylonitrile! polymer fibres with metal conducting coating

Abstract: An anti-static compressed air filter is a needled felt made of acrylonitrile polymer fibres coated with metal for electrical conductivity; the filter is made in conventional manner Method eliminates problems of separation of metal filaments or of hydrolysis of the organic fibres In an example, polyacrylic nitrile staple fibres, dtex 78/80 mm were dipped in a bath of HCl (pH is not >1) of colloidal palladium soln to DT-AS 11 97 720 After stirring between 30 secs and 2 mins they are removed and washed with water, then dipped in 5% NaOH at room temp for 30 secs - 2 mins, removed and washed with water They are placed in a solution of 02 mol/l Ni-II-chloride, 09 mol/l NH4OH, 02 mol/l sodium hypophosphite and NH3 is passed in until the pH is 89-96 at 30 degrees C Fibres begin to discolour after 15 secs; after 30 secs they are coated with fine nickel, after 5 mins the nickel coating is 02um Fibres are then removed and washed with water Surface resistivity now 3 x 10 ohms at 23 degrees C and 50% RH according to DIN 54 345 Volume resistivity is 3 x 102 ohmcm2

Preparation of phosphorous acid from industrial waste material containing phosphites

Abstract: A process for the preparation of phosphorous acid from phosphites contained in industrial wastes, wherein the waste material is dissolved in an aqueous solution of phosphorous acid and reacted with a strong mineral acid that will remove the cation of the phosphite producing phosphorus acid. An alternative method for preparation is the passage of the solution of phosphite in phosphorus acid through a cation ion exchange resin to produce phosphorous acid. A typical industrial waste containing phosphites is the waste that occurs from the process of manufacturing sodium hypophosphite.

Composite plating method

Abstract: PURPOSE: To obtain a composite plated film having a stable composition and a uniform thickness by dispersing insoluble fine particles in a plating soln. contg. Ni salt and hypophosphite and by applying a DC voltage between a body to be plated and an insoluble anode at a prescribed current density. CONSTITUTION: 20g/l Insoluble fine particles of silicon carbide or the like are dispersed in an aqueous soln. contg. 30g/l Ni salt and 25g/l sodium hypophosphite. A body to be plated and an insoluble anode are set in the soln., and a DC voltage is applied at 0.1W1A/dm 2 current density while agitating the soln. By this method a composite plated film having a stable composition, a uniform thickness, superior wear resistnace and lubricity is obtd. COPYRIGHT: (C)1982,JPO&Japio