A New Method for the Production of Tungstic Acid from Tungstates

This paper deals with a characteristic property of tungstic acid and its reaction with hydrochloric acid solution. The authors' experiments prove that tungstic acid freshly formed from tungstate by decomposition with hydrochloric acid, dissolves in its concentrated acid solution forming a chemical compound, provided that the produced tungstic acid is brought into contact with concentrated hydrochloric acid immediately after its formation. It was found also that if the degree of its concentration 1s reduced, this chemical compound gives the insoluble tungstic acid as a precipitate in the solution. Details are given for lixiviating the tungstic acid from tungstate · and for preparing it

The Effects of Impurities in the Electrolysis of Sodium Chloride Solution by Mercury Process

This investigation deals with the effects of impurites in the electrolysis of sodium chloride solution by mercury process, especially a particular action of magnesium ions, and experimentally points out such an action and its mechanism in the following aspects. 1. Relations between the current and potential. 2. The eddy flow on the electrode surface. 3. Surface tension on the electrode. 4. Potential distribution. It was noticed by this investigation that the action of magnesium ions has a connection with the polarographic maximum in the relations between the current and potential, and also, reference was made to the cause of the appearance of the maximum phenomenon

Strain Measurements of Prestressed Concrete Cylindrical Tank Walls

This paper presents the results of strain measurement on prestressed cylindrical concrete tank walls at the time of transferring of prestress. Freyssinet's method as well as Preload's method are employed to transfer prestress to the prestressed concrete tank walls. By means of Carlson type strainmeters embeded in the concrete, strains due to prestressing and bending moments accompanied by prestressing in the longitudinal direction are measured and compared with the theoretical values for each of the above described methods. The results obtained show that the prestresses applied meet fairly well the design requirements and the measured strains satisfactorily coincide with the theoretical values in the angular (tangential) direction. It is expected that comparatively large strains occur due to the circumferential prestressing, while the measured strains are approximately a half of the theoretical values

Studies on the Electrolysis of Sodium Sulfate Solution

Presented at The Indianapolis Meeting of The Electrochemical Society, May 3, 1961.The electrolysis of sodium sulfate solution by the 1500 amp. vertical mercury cell was investigated. Lead alloy containing 2% Ag and 1% Te was selected as the anode, and fine porous rubber sheet or blue asbestos cloth were used as the diaphragm. The concentrations of sulfuric acid and caustic soda obtained were 200-250 g/l H₂SO₄ and 30-40% NaOH, respectively, under the condition of 30 amp/dm² of current density by continuous operation. The terminal voltage was less than 5.0 volts and the current efficiency and the consumption of the anode were 90% and 2-3 mg/AH, respectively