THE DETERMINATION OF THE METALS OF THE PLATINUM GROUP IN NICKEL ORES AND CONCENTRATES

1940 ◽  
Vol 18b (11) ◽  
pp. 333-344 ◽  
Author(s):  
F. E. Lathe
Keyword(s):  
Nitric Acid ◽  
Reliable Method ◽  
Similar Material ◽  
Platinum Metals ◽  
General Application ◽  
Substantial Modification ◽  
Method Of Determination ◽  
Sulphide Ores ◽  
Nickel Ores

Most published methods for the determination of platinum and associated metals are not of general application to ores and concentrates, and their accuracy as applied to unknown material is in many cases seriously open to question. The methods here described are chiefly based upon experience with the products of the Sudbury area, but are believed to be applicable without substantial modification to all sulphide ores of nickel and to smelter and refinery products derived therefrom. Methods of concentrating the platinum metals are described, an outline is given of an approximate method of determination based on sulphuric acid parting, and details of a more reliable method in which nitric acid is the parting medium are set out. The results obtained are compared with those of Beamish and associates on similar material.

Analysis of existing methods for calculating loading of parts at assessment of fatigue strength

2021 ◽  
pp. 44-47
Author(s):  
Tatyana Anatolyevna Antropova ◽  
Keyword(s):  
Fatigue Strength ◽  
Reliable Method ◽  
Method Of Calculation ◽  
Method Of Determination ◽  
Strength Tests

The paper shows the results of analysis of methods used for determination of loads on parts of fatigue strength tests. As an example, the author has calculated loading of open-box car vertical body posts by means of two currently used methods. At comparison of gained results the author has established that calculated values of forces and amplitudes of body posts loading differ almost 3 times. Consequently, key differences of the methods have been revealed. As a result, it is proposed to improve a method of calculation and to develop the only reliable method of determination of forces and amplitudes of loading of parts that are tested on fatigue strength.

Contributions to the Analysis of Rubber. IV. Determination of Manganese in Crude Rubber; in Rubber Mixtures and in Fillers

1940 ◽  
Vol 13 (2) ◽  
pp. 430-436
Author(s):  
P. Dekker
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Reliable Method ◽  
Orthophosphoric Acid ◽  
Manganese Ions ◽  
Potassium Periodate ◽  
Mineral Fillers ◽  
Manganese Compounds

Abstract A scheme for the determination of manganese in mineral fillers, compounding ingredients, crude rubber, rubber mixtures and rubberized materials is described. It is shown that with this method the use of potassium persulfate and two drops of orthophosphoric acid, as proposed by Kehren for the oxidation of colorless manganese ions to red permanganate ions, is advisable. When potassium periodate is used, small quantities of manganese escape detection. It is further shown that there is no appreciable difference between concentration with nitric acid and evaporation with hydrochloric acid and a little sulfuric acid. If, however, the ash is decomposed by soda-potash mixture, the manganese contents are considerably higher. Doubtless these higher values can be accounted for by manganese compounds which are occluded in silicates, and which can be regarded as harmless. A reliable method for the decomposition of the manganese compounds is therefore desirable. The results of analyses of the manganese contents of a large number of various materials are tabulated, and the maximum manganese contents of various materials allowed by the Netherlands Government Rubber Institute are given.

ORGANIC REAGENTS FOR PLATINUM METALS: II. THE GRAVIMETRIC DETERMINATION OF RHODIUM

1949 ◽  
Vol 27b (2) ◽  
pp. 72-75 ◽  
Author(s):  
R. L. Haines ◽  
D. E. Ryan
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Organic Compounds ◽  
Atomic Weight ◽  
Similar Type ◽  
Platinum Metals ◽  
Organic Reagents ◽  
Molecular Weights ◽  
Gravimetric Determination

Rhodium may be precipitated quantitatively with 2-mercaptobenzoxazole or 2-mercaptobenzothiazole. An acetic acid precipitating medium is preferred; slight variations in the concentration of acid, when nitric acid was used, caused low results. Several similar type organic compounds showed no advantages over the above two. The complex appears to have three molecular weights of the reagent combined with one atomic weight of rhodium.

Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  
Keyword(s):  
Thin Layer ◽  
Expanded Uncertainty ◽  
Considerable Decrease ◽  
X Ray ◽  
Precipitation Efficiency ◽  
Method Of Determination ◽  
Sensitivity Curves ◽  
Order Of Magnitude ◽  
Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

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