Two-meter direct reading optical emission spectrometer was specially built for quantitative determination of impurities in precious metals. The optical system in the electronic equipment is arranged so that spectral lines corresponding to the particular elements found in the precious metals are focused on the phototubes. The light energy is then converted into electrical energy and the analysis of
each element is read out directly on the recording console. Thirty elements can be analyzed simultaneously on this special automatic spectrometer which operates 16 times faster than older models. Its sensitivity also is greater and it determines extremely low concentrations, permitting improvement in products such as catalysts through greater accuracy in purity determinations
LABORATORY OF THE MONTH
Precious Metal Research Requires Refined Techniques T H E UNIQUE USES OF PRECIOUS metals
-*- present unusual problems to those engaged in research and development programs with these materials. These range from developing platinum catalysts for production of heavy water for atomic research and platinum-tipped spark plugs for military aircraft to more mundane materials such as catalysts for petroleum refining, platinumrhodium gauze catalysts for nitric acid, and palladium diffusion apparatus for purification of hydrogen. Purities of 99.999+ and impurity levels as low as 0.1 p.p.m. are common in the metals produced. Engelhard Industries, Inc., refiner and fabricator of precious metals, located at Newark, N. J., has been serving every major modern industry since 1875 through its 12 divisions and foreign subsidiaries. Of interest to analytical chemists are the activities of its Research and Development Division, Instrumental Analysis Department, and Assay Department.
Most research operations are carried out in a laboratory in Newark, constructed in 1959. This 37,000 squarefoot laboratory, staffed with 120 scientists and technicians, is equipped to meet special needs of precious metal research. Other research is carried out in separate buildings occupied by the Instrumental Analysis, Assay, and Electro-Chemical Departments. The 20-man Instrumental Analysis Department, organized as a separate unit in 1940, conducts studies for the research laboratories and manufacturing units. This department analyzes 12,000 samples each year representing a total of 133,000 separate determinations. These involve gold, silver, the platinum metals, and uranium and uranium isotopes. Engelhard scientists have developed many optical emission spectrographic methods to determine impurities in precious metals. Other techniques used include x-ray diffraction to obtain fundamental data and for production control of platinum
metals and catalysts; x-ray spectrographic techniques for determination of platinum in alumina-base catalysts; and other catalytic studies. The work of the Instrumental Analysis Department is so vital in product control that most of its sections operate 16 hours a day. This unit has laboratories devoted to sample preparation, optical emission spectroscopy, densitometry, x-ray spectroscopy, x-ray diffraction and low angle x-ray scattering, infrared spectrophotometry, and thermocouple calibration. The Assay Department, with a staff of 45, makes about 15,000 assays each year. Because of cost of materials involved and the need for exact knowledge of composition, this department stresses extreme accuracy in its analytical work. Analytical techniques used include spectrophotometry, separation and solution methods, trace analyses, flame photometry, and microanalytical techniques. Materials involved range, from sweepings to bullion to in-process streams. VOL. 34, NO. 7, JUNE 1962 ·
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Thermocouple calibration is accomplished swiftly on test equipment which upgraded and with new test procedures developed by Engelhard scientists. innovation, an automatic potential comparator, was modified and is in cessful use. Faster calibrations are possible without loss of accuracy." tured above is a technician taking a direct reading on the equipment
was One suc Pic
PoSarographic determinations of trace amounts of base metals are carried out in the Assay Department. The instrument covers extremely low con centration ranges. Base metal analy sis is done for such products and ma terials as clad metals, electrical con tact backings, and extracts from catalysts
Engelhard's research laboratory serves as the central point for most of its research activities. Other re search is done in separate facilities (Instrumental Analysis, ElectroChemical, and Assay Departments)
Sample preparation room in Instru mental Analysis Department is kept clean and dust free by triple air filtering system. Shown in fore ground is a special pelleting press de signed by the department's tech nicians for the preparation of pellet samples. Pictured in background are three stations for weighing samples of precious metals to be ana lyzed 94 Α
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ANALYTICAL CHEMISTRY
WACO
LABORATORY OF THE MONTH
REFRIGERATED BATH Controlled Cooling and Heating Minus 10° C to Plus 65° C
X-Ray spectrographic equipment is used for quantitative procedures in the analysis of a wide variety of precious metals alloys and precious metal-containing catalysts. The x-ray spectrograph is used for trace analysis of impurities, as well as determination of major constituents. New x-ray spectrographic procedures have been developed by Engelhard technicians for precise determination of metal content
• WIDE RANGE Visibility bath with BOTH mechanical refrigeration and heating. Provides constant temperature from minus 10° C to plus 65° C using 10" of liquid in a 16" uninsulated Pyrex jar. Using less liquid minus 20° C is obtainable. • SENSITIVITY Mercury Thermoregulator and a WACO Thyratrontube Relay controls operation of the compressor and heating until within plus or minus .01 ° C ALREADY USED FOR- Viscosity vapor pressure and other physi. cal data determination, organic syntheses, ASTM petroleum tests, etc. Also as COOLANT CIRCULATING SYSTEM for spectrophotometers, refractometers, distillation condensers. NO. F882 WACO LO-TEMP REFRIGERATED BATH with Pyrex jar 12" diameter. For 115 volt 50/60 cycle AC. $390.00
• Other sizes and many accessories available to fit your needs. Please write for WACO BATH BULLETIN N-6 for complete information.
LABORATORY SUPPLIES AND EQUIPMENT
Analysis of liquid hydrocarbons and gases for nitrogen, arsenic, chlorine, and sulfur is carried out by the Assay Department using the equipment shown. This analytical work is used in the study of catalysis
WILKENS - ANDERSON CO. 4525 W. DIVISION ST.
CHICAGO 5 1 , ILL.
Circle No. 99 on Readers' Service Card
VOL.
34, NO. 7, JUNE 1962
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