3D analysis of particulates in mineral processing systems by cone beam X-ray microtomography

Journal ArticleIn general, x-ray computed tomographic (CT) techniques are able to provide 3D images of the internal structure of opaque materials in a nondestructive manner. The unique cone beam geometry allows acquisition of all 2D projections with only one rotation of the sample thus providing for fast data acquisition and better x-ray utilization, as a complete 2-D detector array receives the cone-shaped flux of rays

Hydrometallurgy

Journal ArticleThe science and technology of hydrometallurgy and chemical processing continues to advance both at the laboratory level and in plant practice. In past decades, hydrometallurgy was rather limited in scope and received relatively little attention, being largely a laboratory curiosity. But curiosity is the mother of invention and with the dawn of the seventies this technology has come into its own; prompted to a large extent by the interest of society in protecting the environment

Concentration

Journal ArticleThe most startling development in concentration processes this past year would have to be the results obtained after magnetic treatment of aqueous systems. Beneficial effects were reported in both flotation and thickening on an industrial scale following the application of a magnetic field to the pulp prior to processing. The physical forces controlling this phenomenon as yet remain unknown

Mineral processing fundamentals

Journal ArticleThe reported claims in several Russian articles that magnetic fields change the viscosity and other basic properties of water and as a result produce beneficial effects such as increased flotation rate, improved grades and recovery, and increased settling rates appear to be unfounded. This conclusion was reached after critical experiments had been conducted with both pure and impure water and the results failed to indicate any of the effects which had been claimed at the VII International Mineral Processing Congress

PC image-based analysis system for particle characterization of deinked pulps

Journal ArticleA low cost PC image-based particle analysis system is being developed for particle characterization of deinked pulps at the University of Utah. Initial R&D efforts of such an image analysis system were made for on-line particle characterization in the mineral processing field but now it has been found to be applicable for the analysis of deinked pulps in the wastepaper recycling industry. Both the size and shape of ink particles in hand sheets and paper pulps for all three typical wastepaper resources (newsprint, xerographic, and magazine) can easily be determined by the image analysis system. Preliminary results indicate that the system is quite successful for the evaluation of products obtained from deinking air-sparged hydrocyclone (ASH) flotation tests. Quantitative analysis can give both the size and shape of ink particles for such products. In addition, the hardware and software used to implement this image analysis system are discussed. Finally, on-line instrumentation of such a system for the direct measurement of wastepaper pulp is considered as part of future research activities

Minerals beneficiation in '69 steps up tonnage, engineering, environmental control and automation: size analysis and flotation chemistry highlighted by basic science researchers

Journal ArticleThe application of computers to the control and study of mineral processing operations such as grinding, classification and notation has created an interest in simulation studies of these operations with mathematical models. Evidence of this interest is confirmed by papers presented at the 1969 International Computer Application Symposium held concurrently with the Fall Meeting of the Society of Mining Engineers in Salt Lake City, September 17-19, 1969. Proceedings of this symposium, entitled A Decade of Digits Computing in the Mineral Industry, were edited by Alfred Weiss and published by SME. Two sections of this book are devoted to computer application and simulation of mineral processing operations

Flotation chemistry of nonsulfide minerals

Journal ArticleThe dimensions of nonsulfide flotation technology extend in many different directions, as might be expected from the diversity of t he mineral classes, which include soluble salt minerals (potash, borax, and trona), semi-soluble salt minerals (phosphate minerals, fluorite, calcite, and barite), insoluble oxides/silicate minerals (iron oxide minerals, rutile, mica, quartz, and feldspar), and energy minerals (coal and oil sands). As a consequence, some flotation separations are accomplished from saturated brine, while other separations are achieved in solutions of rather low ionic strength

Capillary network model for filter cake based on pore structure analysis

Journal ArticleDewatering of fine coal by continuous filtration involves filter cake formation and removal of surface moisture by drawing air through the capillaries of the cake. In order to gain a better (understanding of the complex transport phenomena that occur in the filter cake, analysis of the effect of three-dimensional pore geometry on the effective transport properties of the filter Bake is necessary

Fine coal washability-liberation analysis by cone-beam X-Ray microtomography

Journal ArticleA new method based on cone-beam x-ray microtomography is described for direct determination of the three-dimensional liberation spectrum of multiphase particles 100 microns in size or less. Such a technique may provide the basis for more detailed and accurate washability analysis in fine coal characterization. Previous research has demonstrated the ability to use traditional medical x-ray CT scanners to determine the liberation spectrum of coarse coal particles of 1 cm in size (washability analysis). Now it is possible to determine fine coal (-100 mesh) washability by cone-beam microtomography. Rather than stacking a series of two-dimensional slices for volumetric imaging as is commonly done in traditional medical computed tomography, with this new microtomographic technique a three dimensional reconstruction image array is prepared directly from the two-dimensional projections for cone beam geometry. The advantage of high spatial resolution (approximately 15 um) with a microfocus x-ray generator combined with the benefit of direct processing of three-dimensional data, provide an excellent opportunity to overcome many of the limitations of current techniques being used for fine coal washability analysis

Experimental evaluation of a mineral exposure model for crushed copper ores

Journal ArticleCopper mineral inclusions dispersed in crushed ore particles have a certain size distribution (grain-size distribution). For efficient heap leaching processes, the crushing plant should be designed and operated to crush the ore to an appropriate particle-size distribution so that copper mineral grains are exposed and can be leached. In this regard, based on the approach of Hsih, Wen, and Kuan (1995), a mineral exposure model has been evaluated to describe the extent of grain exposure as a function of particle size. Experimental evaluation of the mineral exposure model for different copper ores has been accomplished by 3D analysis of crushed ore particles using cone beam x-ray microtomography. The model evaluation with micro-CT data suggests that the extent of preferential grain boundary breakage varies both with ore type and with particle size for a given ore type