Sandy flint and pyritic plastic clays from east-central Missouri can be beneficiated to good firing quality by ore dressing methods. Quartz and pyrite were the chief contaminants removed by the two gravity concentration methods used in the studies. Most iron-oxide minerals in these clays occur as finely-divided, low-gravity, hydrous material, often in the form of … Read more

This circular summarizes the research and technologic activities and publications of the Federal Bureau of Mines Division of Explosives Technology during fiscal year 1959 (July 1, 1958-June 30, 1959). Part I briefly describes the programs that were active during the report period and presents a summary of some of the information not published elsewhere. In … Read more

Construction of a 250-p.s.i.g. helium-recycle system to operate with gas temperatures as high as 2,500° F. appears feasible. More development work is required, however, on heat exchangers and compressors. Many problems inherent in large nuclear systems are not present in the pilot-scale ISR system. Although the cooler in the ISR loop operated satisfactorily, thermal expansion … Read more

The principal official test performed by the Bureau of Mines to determine the permissibility of coal-mine explosives, commonly referred to as the gallery test, has been in use at the Bruceton station for many years. In this test the explosive under study is loaded into the borehole of a steel cannon and fired into a … Read more

The results of this investigation indicate that the titanium-gadolinium phase diagram is composed of a single eutectic reaction and a peritectoid reaction at the alpha-beta transformation. The eutectic isotherm has been established at 1,240 ± 10° C. and extends from approximately 1 pct. gadolinium to beyond 99 pct. gadolinium at this temperature. The solid solubility … Read more

Zirconium diboride of a quality comparable to that produced commercially from zirconium dioxide may be synthesized directly from zircon. The quantities of residual carbon and silica are not excessively high, but it is believed that some refinements in procedure may lower these percentages. The grain size of the final product has been demonstrated to be … Read more

The investigation of the zirconium-gadolinium equilibrium diagram revealed a eutectic system with limited terminal solubilities and one peritectoid reaction. The eutectic point occurs at about 82 percent gadolinium. The eutectic isotherm, at 1,220° C., extends from about 12 to 99+ percent gadolinium. The peritectoid isotherm, at 890° C., involving the alpha-beta transformation of zirconium, extends … Read more

The results were surprisingly reproducible in view of the complex reactions, and the scatter of data was small. Rank of coal exerted the greatest effect on gasification. Tests with only three ranks of coals do not permit firm conclusions about the effect of rank. However, work in progress reveals the same trend for other ranks … Read more

Leonardite is a coallike substance, similar in structure and composition to lignitic coal and believed to be derived from lignitic coal by the process of natural oxidation. Leonardite is little known outside lignite-producing areas and has been developed commercially only tn a minor extent. The higher oxygen content and less compact structure of leonardite, compared … Read more

A titanium alloy containing 10 a/o vanadium and 10 a/o zirconium has potential strength and heat treatability that merits further investigation. The titanium-10vanadium-10zirconium alloy, solution-treated at 600° C. is relatively sort, having a yield strength of 73,800 p.s.i. Aging 4 hours at 450° C. strengthens the alloy to a yield strength of 142,900 p.s.i. Ductility … Read more