A Mineral Dressing and Economic Study of a Complex Arsenical Ore

The factors that influence the choice of a method for treat­ment of an ore comprise the technical and economic limitations and advantages, derived in detail and balanced according to the exigencies of the particular situation.

Separation of Cadmium from Zinc in the Purification Step of the Leaching Cycle

The purpose of this investigation is to determine the effect of the factors listed previously by conducting a series of tests that will indicate the ex­tent to which the purification is influenced by time, temperature, zinc oust size, zinc dust quantity, iron concentration, two stage precipitation, and aeration.

Montana Talc; Problems in Physical Properties

General information on talc, including foreign and United States occurrences, origin, and uses is covered. Montana deposits are discussed in greater detail as to location, geology, mineralogy, and mining. Studies of talc by petrographic and x-ray methods and an experiment to determine the porosity are described and discussed.

Mineralization of the Bonanza Mine

The Bonanza mine of the Emery mining district in Powell County is on the largest veins in the area, and is developed to a depth of 680 feet by an incline shaft following the dip of the structure. Sulfide ores carrying gold and silver values are mined throughout the area which is easily accessible by road from Deerlodge, Montana, ten miles west of the district.

The Lilly Mine of Powell County, Montana

For many years the Elliston District, of Powell County has been a minor producer of gold, lead, zinc, and silver. Although never among the largest producing districts of the state, it has with the exception of the war years supplied a notable tonnage of ore to the neighboring mills ever since the first placer and lode claims were located there during the late eighteen hundreds.

Geology of Smoke Hollow Area 8 Miles Southeast of Deerlodge, Powell County, Montana

This investigation was undertaken primarily as a problem in geologic mapping. The stratigraphy was studied as to the character, age, and sequence of the geologic formations that are exposed. The conclusions were based principally on the field relationships and lithology because no fossils were found.

An Isothermal Study of an S.A.E. 6150 Steel

The purpose of this thesis is to set forth the method followed, the laboratory procedure practiced, the results obtained, the conclu­sions drawn, and the recommendations proposed as a consequence of a metallographic study of the isothermal transformation of an S.A.E. 6150 steel.

The Alloys of Gallium and Indium

Thermal analysis VIPS used to construct cooling and heating curves from which the phase diagram was determined. The data for the entire set of cooling curves were obtained by the use of mercury thermo­meters.

Hot-Dip Aluminizing of Low-Carbon Steels

In a relatively short period of sixty-five years, aluminum has grown to the rank of fifth in total weight of met­als produced in the world. Throughout its short life, aluminum has been found to have excellent corrosion-resistant properties; yet only in recent years has aluminum been under consideration as a corrosion-resistant coating for iron and steel.

Physiographic Surfaces and Weathering Near Butte

Three cycles of erosion have modified the Boulder batholith. The earliest cycle produced a peneplaination that has been largely obliterated by a partially completed intermediate cycle, and the recent cycle now in progress.

A Mineral Dressing Study of the Benefication of Philipsburg Manganese Carbonate Ore

The beneficiation of rhodochrosite ore to the extent that it is suitable for nodulizing and subsequent use in the steel industry is intriguing. Such ores from certain mines is relatively easy to beneficiate, but the rhodo-chrosite ore from several deposits of the Philipsburg district has never been successfully up-graded by any of the several known beneficiating methods.

The Isothermal Transformation Curve for S.A.E. 6150

More than 3000 years ago, men began quenching and tem­pering tools to improve their physical properties. The an­cient people found that iron was easier to shape and form in a heated condition. Charcoal was used as the fuel, and when the shaping process was completed, the smiths cooled the piece in the most obvious way, quenching in water. Quite un­intentionally, these people stumbled on the process for im­proving the properties of iron, and the art of blacksmithing began.

Pore depth evolution of a pyrochlore pellet

The long-term stability of ceramic materials that are considered as potential nuclear waste forms is governed by heterogeneous surface reactivity. Thus, instead of a mean rate, the identification of one or more dominant contributors to the overall dissolution rate is the key to predict the stability of waste forms quantitatively. Direct surface measurements by vertical scanning interferometry (VSI) and their analysis via material flux maps and resulting dissolution rate spectra provide data about dominant rate contributors and their variability over time. Using pyrochlore (Nd2Zr2O7) pellet dissolution under acidic conditions as an example, we demonstrate the identification and quantification of dissolution rate contributors, based on VSI data and rate spectrum analysis. Heterogeneous surface alteration of pyrochlore varies by a factor of about 5 and additional material loss by chemo-mechanical grain pull-out within the uppermost grain layer. We identified four different rate contributors that are responsible for the observed dissolution rate range of single grains. Our new concept offers the opportunity to increase our mechanistic understanding and to predict quantitatively the alteration of ceramic waste forms.

Mejoras tecnológicas en el reciclado de residuos de construcción y demolición (RCD)

La tesis doctoral “Mejoras Tecnológicas en el Reciclado de Residuos de Construcción y Demolición (RCD)” investiga la utilización de los separadores hidráulicos para mejorar la calidad de los áridos reciclados, y se demuestra que es un equipo más eficiente que las técnicas actuales basadas en la simple separación por densidad. En la tesisn se ha realizado inicialmente una revisión de la situación del sector, para a continuación centrarse en los sistemas de separación utilizados en las plantas de valorización españolas. Una vez analizados éstos y en particular los de tipo hidráulico, de los que se resume un estudio comparativo, se ha procedido a ensayar a escala de Laboratorio el comportamiento de un separador hidráulico de aceleración diferencial con diversos materiales procedentes de tres plantas de reciclaje. Adicionalmente fueron probadas otras técnicas, como es la separación magnética para mejorar la calidad de los productos reciclados. En vista de los buenos resultados de la investigación, se procede a escalar los ensayos con equipo piloto y distintas composiciones de naturaleza cerámica y hormigón. El equipo utilizado fue un jig de 3´x 1´ en el que se ensayaron las tres muestras con resultados diferentes. La limpieza de los materiales impropios y el yeso fue positiva en las tres muestras, y únicamente la separación entre sí de los componentes pétreos, resultó dependiente de su proporción en la mezcla, obteniéndose los mejores resultados en las muestras con menor cantidad de materiales cerámicos. Finalmente, se procede a analizar en un laboratorio reconocido las propiedades de los áridos reciclados obtenidos en la separación hidráulica por jig, y constatar las mejoras conseguidas para su utilización como materiales de construcción en usos ligados y no ligados. Todo lo anterior permite afirmar que los equipos de separación hidráulica con aceleración diferencial (jig) presentan una innovación tecnológica en el reciclado de los residuos de construcción y demolición (RCD). ABSTRACT The doctoral thesis “Technological Improvements in Recycling of Construction and Demolition Waste (C&DW)” researches the hydraulic separators utilization in order to improve the recycled aggregates quality, demonstrating that the equipment is more efficient than the current techniques based on the simple density separation. This doctoral thesis has been initially done reviewing the situation of the sector and focusing afterwards on the separation systems used at the Spanish recovery facilities. Once analyzed these and, particularly, the hydraulic type ones, from which a comparative study has been summarized, the behavior of a differential acceleration hydraulic separator with various materials coming from three recycling plants has been tested at laboratory scale. Additionally other techniques have been tested, such as the magnetic separation to improve the quality of recycled products. In view of the good investigation results, the testing process scaled up by using pilot equipment and different ceramics and concrete compositions. The equipment utilized was a jig 3” x 1”, in which the three samples were tested with different results. The unsuitable materials and gypsum cleanliness was positive on the three samples and only the separation among the stony components turned out to be dependent of its proportion in the mixing, obtaining the best results in the samples with less quantity of ceramic materials. Finally, the properties of the recycled aggregates obtained by jig hydraulic separation are analyzed at a recognized laboratory and the improvements gained for their utilization as construction materials, in bounded and unbounded uses, are stated. The facts cited are a basis for affirming that the hydraulic separator equipments with differential acceleration (jig) offer a technological innovation in the Recycling of Construction and Demolition Waste (C&DW).

Transformation toughened ceramics for the Heavy Duty Diesel Engine Technology Program.

Energy Department, Office of Vehicle and Engine Research and Development, Washington, D.C.