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By J. A. McAllister, H. G. Iverson, K. C. Dean

"INTRODUCTION During the course of the investigation of the occurrence of manganese deposits in the western United States, laboratory studies of concentration were conducted at the Salt Lake City station on a sample of ore from the Lake Valley mines of the Newalpitt Fluorspar Corp. of Deming, N. Mex. The ore was reported to be representative of the type that would be mined for mill feed. The sample tested was found to be amenable to beneficiation by ore-dressing methods for the production of products that, when sintered, assayed over 44 percent Mn.At the beginning of the investigation of manganese-ore beneficiation in December 1940, the only product marketable to Metals Reserve Company was ferrograde manganese grade B, the requirements for which follow: Mn, min., 48 percent; Fe, max., 7 percent; Si02, max., 10 percent; P, max., 0.18 percent; Al203, max., 6 percent; Zn, max., 1 percent, Al2O3,Later the specifications were modified gradually. As of May 15, 1943, manganese products were acceptable if they contained over 35 percent manganese and less than 3 percent zinc and 1 percent phosphorus. Prices were based upon material containing 48 percent manganese, 6.0 percent iron, and 11 percent silica plus alumina. Premiums were paid for manganese content in excess of 48 percent and iron content below 6 percent, penalties being imposed upon products containing less than 43 percent -manganese, or more than 6 percent iron, or more than 11 percent silica plus alumina. The specifications for commercial manganese further required that maximum particle size be 12 inches and that, 75 percent of the product be coarser than 20-mesh. Therefore, fine material such as table and flotation concentrates had to be nodulized or sintered. In addition, oarbcnate manganese ores were not acceptable unless calcined."

Feb 1, 1948

By Mu Chen, Ye-Shuang Xu, Dong-Wei Hou, Shui-Long Shen, Huai-Na Wu

"This paper presents a laboratory investigation on the mechanical behaviors of the cement-clay admixture improved by polypropylene fiber. Cement can significantly improve the clay admixture. The fiber additive also improves the strength and ductility of the improved clay. The Unconfined Compression Strength (UCS) of the polypropylene fiber-reinforced cement-clay presents an overall trend to grow with the increase of fiber length. The improved clay reached its peak strength at the fiber content of 0.5%. Then the UCS of the improved clay will slowly reverse if the fiber content continues to rise. For study of curing time, improved clay behaves better in its early strength, but an inhibition will be brought about if fibers are excessive.INTRODUCTIONGround improvement technology is essential for construction of structures in soft ground. Some traditional techniques often cost much but result in little. For instance, along the coastal region of China, soft ground is often improved by backfill with high quality sandy soil transported far away, leading to high additional haulage costs and long construction period. Reutilizing the excavated soil as backfill or subgrade after treatment, by contrast, will be more economical and effective (Hufenus et al., 2006). Many researches have been conducted to improve the compression strength of soft soil, among which, the method of mixing the soft soil with cement and fly ash is one of the most common ways (Kolias et al., 2005; Horpibulsuk et al., 2009; Porcino et al., 2012). It is known that soil resists well against compression and shear force but behaves poorly in resistance to tension. Therefore, utilizing tensile elements such as fibers and strips to improve the tensile strength will be effective because of its strength isotropy, better durability and cost effective (Haeri et al., 2000; Kaniraj and Havanagi, 2001; Consoli et al., 2010)."

Jan 1, 2015

By Zhan-fang Cao, Hong Zhong, Li-feng Li, Shuai Wang, Xiao-yu Cao, Guang-yi Liu, Ming-ming Wang

"In recent years, there has been an increasing focus on the hydrometallurgical processing of molybdenite, with the decline of high-grade and easily handled molybdenum minerals. In this work, a novel method of selective extraction of complex molybdenite concentrate, which is characteristic of high-grade copper ore, has been investigated. The results show that the leaching of chalcopyrite was impacted by the pH of the electrolyte when sodium carbonate and ammonium acid carbonate were added to the electrolyte. The leaching rate of molybdenum reached 99.39%, but chalcopyrite could not be leached at all in 240 min under experimental conditions of liquid-to-solid ratio 25:1, concentration of NaCl 4 mol/L, pH=9, room temperature and agitation speed 400 rpm. The grade of copper in the residue was 21.84%, with a recovery 99.93%. The technology of selective electro-oxidation leaching of molybdenum and recovery of copper from complex molybdenite concentrate is an effective separation method. The diffusion control model can be used to describe the process of leaching of molybdenum. The activation energy of the leaching reaction was found to be approximately 9.21 kJ/mol.IntroductionWorldwide, high-grade and easy-to-handle ore is decreasing, while the proportion of low-grade and complex ore is increasing. Porphyry copper ores with associated low-grade molybdenite are very abundant in China. Molybdenum is a valuable byproduct in the processing of porphyry copper deposits where the molybdenum is present in low quantities in the form of molybdenite (MoS2). In the conventional processing of copper sulfide ores by froth flotation, most of the molybdenite in the ore floats along with the copper sulfides. In this way, a bulk copper-molybdenum concentrate is produced. Afterward, the bulk coppermolybdenum concentrate is treated by differential flotation to obtain a rougher molybdenum concentrate, which requires several successive cleaning steps to produce a final molybdenum concentrate. However, it is widely recognized that flotation alone cannot economically produce a high-grade molybdenite concentrate, i.e., with less than 0.5% Cu. Therefore, in most cases, it is necessary to use a final step of chemical purification of the molybdenite concentrate to reduce the copper content to a level suitable for the market (Antonijevic and Pacovic,1992; Gerhardt et al., 2001; Fu and Zhong, 2003; Reza et al., 2006, Rafael et al., 2013)."

Jan 1, 2015

By N. Gurulaxmi Srikakulapu

The demand for high-grade iron ore has increased the importance of beneficiation of low-grade iron ores. The captive mines of Tata Steel Limited, India has reserves of Banded Haematite Jasper (BHJ) ore assayed 40% Fe, 40% SiO2 and <1% Al2O3. QEMSCAN study has revealed haematite and quartz as a major iron bearing and gangue mineral phases respectively. Liberation characteristics have showed 80% liberation can be obtained at particle size below 10µm. In the present study, reverse cationic froth flotation of BHJ using ether diamines is explored in Denver-D12 flotation cell. Polynomial response surface regression equation coupled with six-factor Box-Behnken design of experiments is used to generate the correlation between process separation efficiency and flotation parameters. Flotation studies of BHJ indicated that concentrate of 62% Fe can be achieved with 62% Fe recovery from Jig concentrate at optimum conditions. The obtained product can blend with pellet fines to feed in blast furnace. Keywords: banded haematite jasper, flotation, box-behnken design, response surface methodology

Sep 1, 2012

By Daniel Antonio Kapper Fabricio

O módulo de tenacidade é um parâmetro que representa a energia absorvida por um material até a ruptura, e é uma variável importante para avaliar se o material sofrerá fratura quando em serviço. A tenacidade é determinada através da área sob a curva tensão-deformação de engenharia, a qual é difícil de ser calculada analiticamente. Assim, o presente trabalho propõe a utilização de métodos numéricos para o cálculo do módulo de tenacidade através de planilhas eletrônicas. Como resultados são apresentados o procedimento desenvolvido e os valores obtidos na estimativa da tenacidade de uma amostra, assim como a comparação do resultado com o valor calculado analiticamente e com o valor calculado através de um método simplificado. Conclui-se que o valor numérico calculado é tão próximo do verdadeiro quanto maior o número de pontos obtidos na curva tensão-deformação de engenharia, viabilizando a utilização desse método na estimativa da tenacidade de uma ampla gama de materiais. Além disso, o método numérico pode ser usado na determinação de outras propriedades calculadas através da área sob curvas.

Aug 7, 2018

By M. P. Neira

In-situ leaching of copper from chalcocite relies on ferric iron concentration in the lixiviant being reduced to ferrous. To re-establish the ferric concentration in solution, ferrous must be re-oxidized. This reaction is slow under normal chemical conditions but it is catalyzed by Thiobacillus ferrooxidans bacteria. BHP Copper&apos;s Miami In-situ unit developed a bio-reactor as a method of oxidizing ferrous to ferric. The effects on oxidation of temperature, CO2? oxygen, and air injection flowrate were defined. This paper summarizes the results of ferrous bio-oxidation using plastic column packing and oxide ores as bio-reactors and the leaching results of the bio-reacted lixiviant on chalcocite ores.

Jan 1, 1997

By Wemerson Junio Gandra

Para a redução do minério de ferro no alto-forno é necessária a utilização de uma fonte de carbono, que pode ser encontrada no carvão mineral e/ou carvão vegetal. Diante do cenário atual, a busca constante por maior competitividade, associada ao atendimento da qualidade e aos requisitos ambientais, exige a implementação de várias ações alternativas no processo de fabricação de gusa. Dentre elas, destaca-se a utilização de combustíveis alternativos no sistema de injeção dos altos-fornos, como por exemplo, a substituição parcial do carvão mineral pelo carvão vegetal. Do ponto de vista ambiental, é altamente favorável a utilização de uma fonte renovável de carbono. O objetivo desse trabalho é apresentar a adequação do processo, desde o recebimento do material até sua injeção nos altos-fornos, bem como os resultados já alcançados e os desafios futuros. A utilização do carvão vegetal na mistura de carvão pulverizado resulta em flexibilidade na utilização de matérias primas e contribui para preservação do meio ambiente.

Oct 30, 2017

By Fiorella Polanco Martínez

El presente trabajo describe una forma de financiamiento en la minería a través del mercado de valores. Es decir, que desde un análisis del sector minero se busca convertir las reservas minerales probadas en un patrimonio fideicometido que avale una emisión de bonos titulizados. En este sentido, las reservas minerales por sí mismas carecen de valor económico pero se pueden valorizar con un proyecto de factibilidad futuro, cuya titulización de reservas minerales, se convertirá en una herramienta de financiamiento alternativa o complementaria a la BVL Venture Exchange. Po ello, el financiamiento que se obtenga a través del mercado de valores se destinaría a la ejecución del proyecto minero junior o para expandir uno en producción.

Sep 12, 2005

By H. Tan

The effect of carbonaceous matter on gold extraction was investigated in cyanide systems with pure gold as well as pre-robbing sulfide gold ores. Auger studies demonstrated that the carbonaceous matter preferentially smeared on iron sulfide rather than aluminosilicate surfaces during wet or dry grinding. During mechanically mixed leaching, coating of sulfides and silicates and stripping of carbonaceous matter occurred simultaneously. TEM and XPS studies indicated preferential coating in the form of elemental (graphitic) carbon at the edges and the defect sites of particles. Interestingly, carbonaceous matter extracted from the gold ore was predominantly graphite and not preg-robbing in a solution with a high KCN concentration. However, the carbonaceous coating had a significantly detrimental effect on gold dissolution when gold was pre-ground with the gold ore. Artificial coating on gold surfaces with the natural carbonaceous matter from the ore was also found to substantially retard gold dissolution. With the addition of the natural carbonaceous matter from the gold ore, gold extraction from two non preg-robbing sulfide gold ores was inhibited owing to carbonaceous coating. The presence of carbonaceous matter significantly reduced the current density for gold oxidation and increased the current density for pyrite oxidation. This could explain the fact that carbonaceous coating hindered gold dissolution while enhanced sulfide preg-robbing.

Jan 1, 2005

By M Lak, R Amiri, A Haratian, M Asghari, S Haji

Dry magnet separators are used to upgrade and beneficiate a wide variety of minerals such as hematite and magnetite materials. In recent years advances in dry magnetic separators have improved their performance. Fine particle separation is one of the main areas which still remain weak. This paper will present a new design of fine particle drum separators which used for particle size less than 3 mm. A big problem in processing of iron ore is the grade and recovery of mineral values in the fines fraction. The new design high efficiency drum separator is developed to handle fine feeds. In this drum separators both of the drum shell and magnetic yoke rotate in opposite direction. the results showed that when the material feed size was = 1298 μm, drum shell speed was 42.5 rev/min, magnetic yoke speed was 100 rev/min and the maximum intensity of magnetic field was at = 30° the feed grade increased from 50.87 to 65.67 in concentrate box, increase to 60.45 in middle box and tail grade was 24.44. The total achieved recovery for both concentrate and middle box was 81.89 per cent.

Nov 8, 2021

By Y. C. Guan

In an attempt to replace the traditional cyanide process of extracting gold, a new technology using ammoniacal solutions has been developed. In this study, the electrochemical behavior of gold in ammoniacal solutions at temperatures above 100°C has been investigated. An electrochemical cell in an autoclave has been introduced to carry out this study. The system consists of a gold working electrode, a platinum counter electrode, and an external saturated calomel electrode (SCE) which is connected to the autoclave system through a Birch wood plug. Techniques used in this study included potentiodynamic polarization, galvanostatic polarization, cyclic voltammetry, and Tafel polarization. The electrochemical reaction mechanisms governing the dissolution process are presented.

Jan 1, 1996

By Bengt H. Fetlenius

The "Pile Prediction Event" at the ASCE GeoInstitute&apos;s Deep Foundation Conference in February 2002 involved prediction of drivability and capacity of three 14m long, 324mm diameter, closed-toe pipe piles driven into loose to compact fine sand to slightly silty sand. Predictors were provided the results of two soil borings and three cone penetrometer tests, as well as type and model of hammer to be used for the pile driving. A total of 33 persons submitted predictions. As to penetration resistance distribution, many predictions were far below actually observed values. As to capacity in compression, the predicted values ranged from 270KN through 2,340KN with a mean of 1,070KN. As to capacity in tension, the predicted values ranged from 100KN through 1,650KN. The maximum load applied to the compression pile in the static loading test was 1,25OKN, at which no more reaction load was available. The reaction system for the tension test failed early in the test. CAPWAP analysis on End-of-Driving blows showed capacities at the end of the driving for the push and pull piles of 670KN, and 710KN, respectively. No restrike tests were made. Additional CPT soundings indicate that the pile driving had densified the soil. Static analysis and calculations from the CPT indicated that capacities ranged from 1,000KN through 2,000KN. The paper presents the data and discusses the various methods of determining pile capacity and addresses influence of set-up Lessons useful for future similar events are indicated.

Jan 1, 2004

By K. Jomoto, H. Majima

"Experimental work has been attempted to find a useful criterion of comminution which can be determined simply in a laboratory. The suitability of the ratio of the square of tensile strength to Young's modulus, St2/E, previously derived from the theory of elasticity as a criterion of comminution, was examined measuring tensile strength, Young's modulus and critical height for drop-weight impact of five different rocks. However, satisfactory correlation between St2 /E and critical height has not been obtained, suggesting the necessity of further experimental verification of the representative value of Young's modulus of rocks. The plot of St2 vs. critical height, however, shows one-to-one correspondence, and this finding suggests that St• may be a useful criterion of impact crushing. Also, a close relationship was observed between st• and the energy index for tumbling mill grinding of •the sample rocks. It is confirmed from these findings that the quantity St• is a useful criterion of comminution of rocks, not only for impact crushing but also for tumbling mill grinding. As shown in the experimental part of this paper, the determination ol St with irregularly shaped specimens is simple."

Jan 1, 1972

By D. A. Grieve

"Mineable coal seams in the East Kootenay region belong to the Mist Mountain Formation of the Jurassic -Cretaceous Kootenay Group. Three structurally separate coal fields (Crowsnest, Elk Valley and Flathead) are recognized, all of which are characterized by compressional tectonic features such as f aiding and thrust faulting, and by /ate-stage normal faulting. Tectonic history has greatly influenced coal mineability and quality. Coals range in rank from low to highvolatile bituminous, and reactive maceral content ranges from less than 60% to greater than 90%. A wide range of metallurgical and thermal coal qualities is found. Measured reserves (up to 1981) include 1.03 billion metric tonnes metallurgical and 165 million metric tonnes thermal coal. Introduction a) Location -Coal fields of the East Kootenays region occur in the Front Ranges of the Rocky Mountains, within 30 km of the Alberta -British Columbia boundary (Fig. 1). They extend over 175 km north from near the U.S. border, and occupy the regions of the Crowsnest Pass and Elk and Flathead River drainages. The deposits are accessible from Highway 3 (Fig. 1) and various secondary roads. The towns of Fernie, Sparwood, Elkford, Coleman and Blairmore serve the coal industry. East Kootenay coal deposits are contained in three structurally separate coal fields, the Crowsnest, Elk Valley, and Flathead coal fields (Fig. 1). Coal is currently being produced by B.C. Coal (now Westar Mining Ltd.) at Sparwood, by Fording Coal 20 km north of Elkford, by Crows Nest Resources at Line Creek 15 km southeast of Elkford, and by Byron Creek Collieries at Corbin. Westar Mining has also constructed a new mine on the Greenhills Range 8 km northeast of Elkford. Pre-requisite engineering and environmental studies have been carried out on the Elco Mining property, 35 km north of Elkford, and on the Sage Creek coal property near the U.S. border (Fig. 1). b) Coal land tenure -Coal rights in the East Kootenays are either held as freehold land, or are licensed from the provincial government. The former category includes lands acquired under the Railroad Act of 1890. Shortly after this the federal government also obtained 50,000 acres of coal-bearing lands from the Crown Provincial, the so-called Dominion Government Coal Blocks. Major holders of coal rights in the area are Westar Mining and Crows Nest Resources. Large blocks are also held by Fording Coal and related companies, Sage Creek Coal, and Canada Permanent Trust Company as trustee for Elco Mining, and small blocks are held by Byron Creek Collieries and Coleman Collieries. In addition the provincial government holds an area in reserve for possible future use of B.C. Hydro at the extreme north end of the Elk Valley coal field."

Jan 1, 1985

By R. C. Buehl

Pilot-plant tests have been in progress at the Bureau of Mines, Pittsburgh, Pa., on the recovery of manganese from open-hearth slag.3/4/5/ In the process, 1 the slag is first reduced in a blast furnace to make a high-phosphorus spiegeleisen containing 12 to 22 percent manganese. A slag containing 55 to 60 percent manganese is made from this spiegel by oxidation in a basic-lined converter. The metal from this blowing operation contains about 3 percent phosphorus, 1 percent manganese, and less than 1 percent carbon. Economic efficiency in the manganese-recovery process requires that this metal be converted into steel. Because of its high phosphorus content the metal is suitable for blowing in a basic-lined converter. In most of the tests described in this report, metal of this composition was used as the starting material in a 1-ton, side-blown, basic-lined converter. Although basic-lined converters are not used for steel production in the United states, in Europe a considerable portion of the steel is made in them. Open hearths largely have replaced converters for steelmaking in the United States; mainly because open-hearth steels have better physical properties than converter steels because of lower nitrogen and phosphorus contents. However, by improving converter design and operating technique during the past 15 years, metallurgists have found that low-nitrogen steels with physical properties equal to open-hearth steels can be produced in converters.6/ Tests at Jones & Laughlin steel Corp. with side-blown, acid-lined converters of 3 and 22 tons capacity showed that steel with a low nitrogen content comparable to that of open hearths operating on scrap charges could be made by surface blowing.7/

Jan 1, 1955

By B. J. Vorster

The South African Iron and Steel Company Ltd operates a large Iron Ore Mine in the Cape Province of the Republic of South Africa. The Mine is situated on the farm, Sishen, approximately 600 km west of Johannesburg. The annual capacity of the Mine is 100 million ton of ore and waste and the present production level is 60 million ton. The Mine operates continuously for 6 days a week. The primary equipment used to maintain the above production are 55, 154 t trucks (Wabco and Unit Rig) and 14 P & H shovels. During 1979 an urgent feasibility study into the application of a trolley assist system was launched at the Mine. This was due to the unrealistic escalation in the cost of diesel fuel and the appeal from the South African Government to reduce the use of fossil fuels. Tests and economic evaluations proved the system technical feasible. The estimated discounted cash flow return exceeded 50% and the diesel fuel consumption would be reduced by 120 million litres in the next 10 years. Management subsequently approved the implementation of the system at Sishen. The construction of 7,7 km of line and the conversion of 66, 154 t trucks were completed in March 1982.

Jan 1, 1985

By Xiaozhen Song, Ashish Ranjan Kumar, Shimin Liu

To investigate the influence of boreholes, fans, and curtains for large opening underground mines (LOUM), we conducted a field survey for LOUM with the survey data serving as the numerical modeling inputs using computational fluid dynamics (CFD) models. Five different CFD modeling results were obtained with different borehole, box fan, and curtain setting conditions. The results indicate that most air quantity directly escapes through outlet 1 after coming into the inlet, causing a huge loss of airflow; volumetric air exchange index (VAEI) and minimum hours of fully exchanging the air (MHFEA) measure air exchange efficiency, with zone 2 of case 5 having the highest VAEI; The borehole minimally affects zones 2, 3, and 4, but drastically alters airflow direction in zone 1; The box fan enhances airflow to zone 2, improving ventilation efficiency and increasing VAEI; Curtains have little effect on distant working faces but influence airflow near inlets and outlets. This study provides a foundation for future research on the influence of boreholes, fans, and curtains, as well as optimizing their placement and effectiveness in face ventilation.

Feb 22, 2026

By Alton B. Cook

The practice of using partly depleted oil reservoirs for gas-storage operations is proving successful. Moreover, this practice provides a method of secondary oil recovery when gas is cycled at full-storage reservoir pressure. Because of the relative newness of this operation, a study was undertaken to assist engineers in developing improved gas-injection and production procedures and in calculating the amount of gas needed for completely repressuring reservoirs. This paper is the third in a series reporting the progress of a study by the Federal Bureau of Mines of reservoir performance during complete gas repressuring and gas cycling. A procedure for estimating secondary oil recovery by this method is also under study. One report (7)3/ describes the laboratory equipment. The other report (8) gives (1) data on the New York City field, Clay County, Tex., which has been converted to gas-storage operations; (2) laboratory data from research with a model oil reservoir, in which primary production, complete gas repressuring, and gas cycling for the New York City field were simulated; and (3) theory to explain reservoir performance during gas repressuring.

Jan 1, 1961

By R. Lowery

TODAY, man uses, at will, the land, the water, and the air to transport himself and his goods everywhere across the face of the world. He no longer thinks with wonder of the magic of conquering these elements - he takes his mastery of them for granted. He is, however, constantly striving to squeeze more and more efficiency from each mode of transport. Man&apos;s first method of transporting himself and his goods was, obviously, himself; then he acquired his first beast of burden - woman. Most other two-legged female animals carried their young around clinging to their fur. Human mothers were, generally speaking, furless and their offspring less &apos;Prehensile, and so slings and other trappings were invented to carry young children. Man&apos;s inventive genius soon adopted these devices for carrying other burdens, and for countless centuries woman carried all in order that man could walk unencumbered except by his weapons. Later other ?beasts of burden were trained and used, including dogs, horses, oxen, camels, etc. Man also discovered quite early that he could drag along the ground more than he could carry on his back.

Jan 1, 1956

By D. H. Baldwin, R. E. Reed-Hill

DURING the course of experiments involving oxygen equilibrations with a high-purity Pd-5 at. pct Rh alloy, the appearance of a subscale was noted. Most of the heat treatments in a pure oxygen atmosphere were performed at 900°C. The presence of the subscale was noted when the oxygen partial pressure was in excess of approximately 95 mm, up to 1 atm, the highest pressure used. According to available thermodynamic information&apos; on the free energy of formation of Rh2O3 (the only reliably reported solid oxide of rhodium), this oxide should not be stable under these conditions, nor, of course, any oxide of palladium. Extraction of the subscale from the matrix was affected by treatment with aqua regia, and the resulting X-ray diffraction powder pattern is shown in Table I. This pattern is not that of Rh2O3, nor that of any known rhodium or palladium oxide. It can be indexed on a hexagonal lattice with a. = 5.22Å and co = 6.0Å. In addition to this unknown material, there was a weak Rh2O3 pattern. An X-ray fluorescence analysis of the powder gave 3214 palladium counts per sec and 5381 rhodium counts per sec, thus indicating the likelihood of a double oxide of palladium and rhodium. In view of the fact that the above result was obtained on a single sample, it is perhaps best not to insist upon the above ratio of about 0.6, but possibly to tentatively assume 0.5 or 1/1. The small amount of Rh2O3 in the X-ray pattern might have occurred on cooling, and it seems possible that the double oxide, below some temperature level, is not as stable as Rh2O3. To examine this point, some of the extracted double oxide was heated on a sheet of pure palladium in air at 900°C, and allowed to furnace-cool over a period of several hours. The X-ray diffraction pattern of the powder showed approximately the same intensity of Rh2O3 and the "hexagonal" oxide as before, but, in addition, a rather faint pattern of another crystalline species made its appearance. This finding again suggests partial transformation of the major (double) oxide to other oxides on cooling from 900°C. Application of the phase rule shows that only one equilibrium oxide (subscale) could have been present at temperature. Vacuum-fusion, oxygen analysis of the extracted subscale showed 7.7 ± 0.7 pct O. Combining this information with that of the X-ray fluorescence analysis suggests the formula PdRhO. This compound should have an oxygen content of 7.07 pct, which is within the range of error of the oxygen analysis. However, until a more careful stoichiometric study is made, it is suggested that the formula be written

Jan 1, 1965