Processing Challenges for Sustainability in Energy, Environment and Materials

The triangular relationship between mineral resources, energy consumption and environmental damage is examined. Problems facing the mineral industry due to the challenge of world population, increasing materials consumption, decreasing resources and environmental constraints can be viewed in terms of the mineral resources triangle. Further understanding can be achieved by assessing these problems through consideration of the materials cycle. Mineral pro-cessing technology has a definite role in meeting some of these challenges

Particle charge spectrometer

An airflow through a tube is used to guide a charged particle through the tube. A detector may be used to detect charge passing through the tube on the particle. The movement of the particle through the tube may be used to both detect its charge and size

Emergent Changes in Enterprise Architectures: Framework and Case Study

We suggest an emergent change framework for enterprise architecture. Drawing on Leavitt’s Change Model of Organizations, our framework focusses on socio-technical changes in tasks, structures, actors, and technologies. By applying the framework to a medium-sized company from the media industry and drawing on a relatively unique panel data set (2014, 2016, 2018), we demonstrate the amount of emergent changes and confirm three patterns of change. These findings help to advance the study of change and its propagation across different components of an enterprise over time

Hydroxamate vs. fatty acid flotation of iron oxide

Journal ArticleData were obtained with hematite with octyl hydroxamate and oleate as collectors to determine the mechanism of collector adsorption and also to establish the roles that conditioning time and temperature assume in this system. The presence of hydroxy complexes of iron are apparently necessary for chemisorption of collector to occur, and it appears as if extended conditioning times and elevated temperature promote greater dissolution of the mineral and hence greater concentrations of hydroxy complexes. Data were also collected with two natural hematitic ores. With one ore that was ground to 70% - 15p, an addition of 0.4 Ib per ton hydroxamate resulted in a final concentrate recovery of 86% at a grade of 64% iron. Satisfactory concentrate grade could not be obtained with fatty acid under these conditions. The effect of conditioning time prior to the addition of collector was also examined with another ore. When the ore was conditioned for 3 min, 19% of the iron was recovered in the concenbrate at a grade of 67% Fe. With a conditioning time of 7 min, 73% of the iron reported to the concentrate at a grade of 62% Fe. These products were obtained with an addition of 0.2 lb per ton hydroxamate. This ore also responded well to flotation with fatty acid

Flotation behavior of chromium and manganese minerals

Journal ArticleFlotation behavior of chromite and manganese-bearing minerals has been reviewed. Flotation of these minerals and ores with fatty acids, amines, sulfates, sulfonates and hydroxamates has been presented and is discussed in terms of surface charge and chemical interaction between the mineral surface and collectors. The role of metal hydroxy complexes such as FeOH+ , CrOH++ , MgOH+ and MnOH+ is also discussed

Screening and classification

Journal ArticleThe processing of minerals almost invariably involves the reduction in size of the minerals contained in an ore to effect liberation of disseminated values or, in other instances, to effect increased surface area. Separation of solids according to size usually is undertaken to promote maximum production from crushing and grinding equipment. Screens are generally used for making this size separation when coarse material is involved, whereas classifiers and cyclones usually are employed when fine particulate material is being processed. However, special screening devices may be used for separations as fine as 325 mesh. The term "mesh" refers to the number of openings per linear inch on a screen. Mesh number vs. size of screen opening is listed in Table 27-12

Selective flotation of iron oxide

Journal ArticleThe response of pure goethite and two natural iron ores to flotation with potassium octyl hydroxamate is presented. The ores contained 12.5% and 39.7% iron; concentrates containing 69.5% and 61.5% iron, respectively, were obtained with additions of 0.4 lb/ton hydroxamate

Resources for Workplace Diversity: An Annotated Practitioner Guide to Information

[Excerpt] We are pleased to offer this updated edition of Resources for Workplace Diversity: An Annotated Practitioner Guide to Information, a unique offering of The Workplace Diversity Network. Our goal is to assemble a selected, annotated list of compelling and useful resources available to help diversity practitioners create organizations that are diverse and productive. As a working group, we agreed that useful resources would include newly published books as well as historic, seminal works that provide insight and illumination irrelevant of their age. In the updated edition, we’ve expanded existing sections, added new ones and referenced online access where possible. Designed with practitioner needs in mind, Resources for Workplace Diversity is meant to be an evolving document, one that will grow according to the needs and recommendations of its users. To capture the advantage of networking, we invite you to suggest additional resources that you have found to be valuable

Particle-Charge Spectrometer

An instrument for rapidly measuring the electric charges and sizes (from approximately 1 to approximately 100 micrometers) of airborne particles is undergoing development. Conceived for monitoring atmospheric dust particles on Mars, instruments like this one could also be used on Earth to monitor natural and artificial aerosols in diverse indoor and outdoor settings for example, volcanic regions, clean rooms, powder-processing machinery, and spray-coating facilities. The instrument incorporates a commercially available, low-noise, ultrasensitive charge-sensing preamplifier circuit. The input terminal of this circuit--the gate of a field-effect transistor--is connected to a Faraday-cage cylindrical electrode. The charged particles of interest are suspended in air or other suitable gas that is made to flow along the axis of the cylindrical electrode without touching the electrode. The flow can be channeled and generated by any of several alternative means; in the prototype of this instrument, the gas is drawn along a glass capillary tube (see upper part of figure) coaxial with the electrode. The size of a particle affects its rate of acceleration in the flow and thus affects the timing and shape of the corresponding signal peak generated by the charge-sensing amplifier. The charge affects the magnitude (and thus also the shape) of the signal peak. Thus, the signal peak (see figure) conveys information on both the size and electric charge of a sensed particle. In experiments thus far, the instrument has been found to be capable of measuring individual aerosol particle charges of magnitude greater than 350 e (where e is the fundamental unit of electric charge) with a precision of +/- 150 e. The instrument can sample particles at a rate as high as several thousand per second

Sulfonate Adsorption and Wetting Behavior at Solid-Water Interfaces

The electrophoretic mobilities of silver iodide sol particles have been measured as a function of pAg in the presence of var,ious concentrations of C5, C8, C10, C12 and C14 sodium alkyl sulfonates at constant ionic strength and temperature. Contact angles in the solid-air-solution system both in the absence and in the presence of the C14 sulfonate have also been determined. These results have been compared with previously reported work on the effect of alkyl sulfonates on the electrokinetic and wetting behavior of alumina. Application of the Stern-Grahame model of the electrical double layer allows delineation of the various mechanisms contributing to the adsorption phenomena. In the case of the aluminasulfonate system the adsorption process is purely physical, viz. electrostatic and hydrocarbon chain-chain interactions, while for the AgI-sulfonate system both physical and chemical processes are involved, viz. electrostatic, hydrocarbon chain-solid, chain-chain, and solid-polar head interactions