Engineering Commons^™

High-Pressure Slurry Ablation For Improving Separation Of Copper/Molybdenum And Flotation Of Gold Tailings, Mitchell Harvey

Graduate Theses & Non-Theses

Disa Technologies’ High-Pressure Slurry Ablation (HPSA) is a patented particle attrition technology for the comminution and selective liberation of minerals. Two slurry streams are pumped at high pressure through opposing nozzles and collisions between solid particles suspended in the slurry streams cause breakage of the feed material. HPSA was evaluated for improving the rougher flotation of molybdenite from Cu-Mo bulk concentrate and gold-bearing pyrite from gold tailings.

Copper/molybdenum samples were provided by Montana Resources in Butte, Montana. A two-factor factorial design of experiments was used to identify HPSA operating conditions which gave the highest increase in flotation performance. Variables were …

Using Ultrasonication For The Improvement Of Grade And Recovery In Molybdenum Sulfide Flotation, Wayne Alexander Campbell

Open Access Theses & Dissertations

Experimentation was performed on molybdenite slurry by using ultrasonication to elucidate the effects of ultrasonic-induced bubble cavitation on the grade, recovery, and gangue reduction during small-scale flotation tests and was followed by a topographical analysis of quartz particles using SEM. Ultrasonic waves at 20-80 kHz that propagate through a liquid medium cause microbubbles to form, grow, and implode. The cavitation bubble's implosion causes brief extreme local conditions where temperatures can reach 5,000 K and pressures of 1,000 bar. The resulting microjets create mechanical and chemical changes to the system and were directed at improving flotation dynamics in these experiments. Through …

Reverse Cationic Flotation Of Hematite, Natalia Parra Alvarez

Dissertations, Master's Theses and Master's Reports

The reverse cationic flotation of hematite is the most common method to process hematite ores. The goal of this research is to understand the impact of fundamental water and surface effects to enable the optimization of the flotation process. At present, reverse cationic flotation is performed using a single chemical as both collector and frother. Excessive amounts of frother or collector should lead to diminished performance. This research investigates this phenomenon by replacing some of the collector with frothers. It was found that flotation recovery can be improved up to 2.5wt% via 10% replacement with methyl isobutyl carbinol (MIBC). Since …

Calcite Depression In Bastnaesite-Calcite Flotation System Using Organic Acids, Emmy Muhoza

Graduate Theses, Dissertations, and Problem Reports

Bastnaesite is the primary source of light REEs, namely cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd), to name a few. Bastnaesite is typically concentrated using the froth flotation beneficiation method. Flotation of bastnaesite suffers from high reagent consumption due to the similar surface characteristics of bastnaesite and associated gangue minerals, including calcite. Additionally, complex stages of high-temperature conditioning are often required to suppress the detrimental impact of dissolved calcium ions on the flotation of bastnaesite. This research seeks to investigate the capabilities of organic acids in the bastnaesite-calcite flotation systems to selectively depress calcite minerals and effectively chelate calcium …

Specifically Adsorbed Ions In Hematite Flotation, Natalia Parra Alvarez

Dissertations, Master's Theses and Master's Reports

Specifically adsorbed ions, such as calcium and magnesium in iron ore flotation, are ions that can chemically bind with the mineral surfaces and alter the surface properties. Calcium and magnesium are unavoidable in process water and their concentrations are increasing due to water recirculation and reagent additions. These ions are detrimental to the flotation process. Calcium has always been the main focus in research, yet we found that magnesium is more detrimental in flotation due to its smaller atomic size. Starch adsorption in iron ore flotation is key for the effective depression of hematite. It has been determined by flotation, …

Recovery Of Phosphorus From Florida Phosphatic Waste Clay, Amir Eskanlou

Graduate Theses, Dissertations, and Problem Reports

This MS thesis examines the recovery of phosphorus (P) from Florida waste clay (WC). A comprehensive literature review revealed that: (i)-The most important values being lost to WC are P and rare earth elements (REEs). For the recovery of these values from WC, two crucial attempts are the removal of extremely fine-sized clays, followed by the recovery of phosphate content, which can pave the path for the recovery of REEs; (ii)-Any scientific/ technological solution should, at the same time, be economically and environmentally attractive to the industry. As such, moving from mostly chemical separation processes to the primarily physical/ physicochemical …

Investigation Of The Stability Of Liquid And Air Films By Synchronized Tri-Wavelength Reflection Interferometry Microscope, Yuesheng Gao

Dissertations, Master's Theses and Master's Reports

Liquid films are widely involved in many processes, such as froth flotation, oil extraction, foam/bubble stabilization, etc. In the meantime, air films are commonly seen in diverse fields like dust control, ink print, coating industry, and so on. Stabilities of these liquid/air films are of great importance to improve the processes. As more and more researchers are paying increasing attention to liquid/air films, tremendous efforts have been made to explore the properties of the films. On the one hand, some theoretical models have also been well developed in recent decades. State-of-the-art technologies, such as AFM, SFA, and RICM, have also …

Investigation Of Surface Treatment And Density Separation For Selective Recycling Of Plastics, Adilbek Baigabelov

Graduate Theses & Non-Theses

Froth flotation has been a useful method for flotation separation of plastics. Teeter bed concentration may also be potentially employed to accomplish gravity-based separation of plastics from a mixture. This work investigates selective separation of six different types of plastics using a novel method by combining advanced gravity concentration and froth flotation techniques. Surface active reagents were used during flotation studies for modification of surface properties of certain plastics in order to enhance selectivity. Elutriation technology in a teeter bed separator was successfully employed to achieve gravity-based concentration of certain plastics. The novel flowsheet was shown to recover plastics of …

Mechanism For Disodium Carboxymethyl Trithiocarbonate (Orfom® D8) Depression In Chalcopyrite-Molybdenite Flotation Systems, Simon Timbillah

Graduate Theses & Non-Theses

The chalcopyrite-molybdenite (Cu-Mo) flotation industry is increasingly turning to organic depressants as suitable replacements for inorganic reagents such as NaHS due to environmental and safety concerns as well as high consumption rates of the inorganic reagents. An opportunity arises for improving, designing and synthesizing new alternative reagents. Disodium Carboxymethyl Trithiocarbonate (Orfom^® D8) depressant is an organic depressant with a carboxylate group on one end and a trithiocarbonate group at the other end. Fundamental results are shown regarding the interaction of the Orfom^® D8 depressant in the bulk flotation of a Cu-Mo concentrate from an operating North American mine. …

Comparison Of Salicyl Hydroxamate Adsorption On Rare Earth Phosphates To Oxides And Carbonates, Stephanie Trant

Graduate Theses & Non-Theses

Adsorption behavior of the anionic collector salicyl hydroxamic acid (SHA) on a group of selected rare earth phosphates (REPs) was studied by means of experimental methods and modeling software. These REPs were then compared to rare earth carbonates (RECs) and rare earth oxides (REOs) to develop a trend. A suite of rare earth elements (REE) were studied that included light (LREE) and middle (MREE). Results for heavy (HREE) were inferred. Synthetic phosphate, oxide and carbonate powders of the rare earth elements Lanthanum (La), Cerium (Ce), Europium (Eu) and Dysprosium (Dy) were tested for these studies. Dysprosium phosphate was the only …

High Fidelity Kinetic Model For Flotation: Applications To Rare Earth Elements And Copper/Molybdenum Separations, Richard Ladouceur

Graduate Theses & Non-Theses

A high-fidelity kinetic model was developed to identify and elucidate the effects of varying principle froth flotation parameters on the sub-processes that occur within and between the flotation zones. Whereas traditional models fail to adequately address froth recovery and recovery by entrainment, the high-fidelity model defines these phenomena based on an improved understanding of the pulp/froth interface. Solution chemistry considerations that govern rare earth mineral separation by flotation were identified, characterized, and optimized. Application of novel surfactants such H205 and salicylhydroxamic acid (collectors) and dimethyl glycol monobutyl ether (depressant) was evaluated to define optimal flotation conditions. The effect of pressure …

Mitigation Of Environmental Hazards Of Sulfide Mineral Flotation With An Insight Into Froth Stability And Flotation Performance, Muhammad Badar Hayat

Doctoral Dissertations

"Today's major challenges facing the flotation of sulfide minerals involve constant variability in the ore composition; environmental concerns; water scarcity and inefficient plant performance. The present work addresses these challenges faced by the flotation process of complex sulfide ore of Mississippi Valley type with an insight into the froth stability and the flotation performance. The first project in this study was aimed at finding the optimum conditions for the bulk flotation of galena (PbS) and chalcopyrite (CuFeS₂) through Response Surface Methodology (RSM). In the second project, an attempt was made to replace toxic sodium cyanide (NaCN) with the biodegradable chitosan …

Adsorption Of Salicylhydroxamic Acid On Selected Rare Earth Oxides And Carbonates, Greer Galt

Graduate Theses & Non-Theses

Adsorption behavior of the anionic collector salicylhydroxamic acid (SHA) on a selected group of rare earth oxides (REOs) and carbonates (RECs) was studied via experimental methods and modelling software. Synthetic oxide and carbonate powders of the rare earth elements cerium (Ce), praseodymium (Pr), europium (Eu), and terbium (Tb) were tested for this research. Studies were conducted at different pH levels to analyze the kinetics of collector adsorption onto the oxide and carbonate surfaces in attempts to optimize recovery parameters for commercial flotation processes using SHA. In addition, thermodynamic software StabCal was implemented to compare theoretical adsorption behavior of collectors SHA …

Surface Chemisty Study Of Monazite Flotation In Coal Refuse Systems, Wencai Zhang

Theses and Dissertations--Mining Engineering

Rare earth mineral recovery from alternative resources such as coal and coal byproducts is increasingly important to provide an opportunity for economic recovery from U.S. sources. Currently, China produces the majority of the 149,000 tons of rare earth elements used annually worldwide of which the U.S. imports 11% or around 16,000 tons. There are no significant mining operations producing rare earth elements in the U.S. However, there are many U.S. sources containing rare earth minerals such as monazite including heavy mineral sand and phosphate operations. Monazite mineral particles of a few microns have also been detected in Fire Clay seam …

Investigation Of Recycled Paper Deinking Mechanisms, Veronika Husovska

Dissertations

The use of water-based inks is on the rise. Sub-micron pigment particles are used for flexographic and inkjet water-based inks. Conventional deinking eliminates larger particles than those from these new ink systems. Therefore, water-based inks represent recycling difficulty.

Deinking experiments of water-based inks are carried out. The deinking strategy initially investigated elimination of pressure sensitive adhesive due to similar acrylic polymer chemistry used in water based inks. The impact of pH on stickies and ink agglomeration during deinking is studied. Experiments in acidic regions show growth of acrylic inks and stickies agglomerates, simplifying elimination.

Pre-recycling of water-based inks is explored. …

Study On The Surface Chemistry Behavior Of Pyrochlore During Froth Flotation, Saeed Chehreh Chelgani

Electronic Thesis and Dissertation Repository

Separation of pyrochlore from its associated minerals is typically accomplished by froth flotation. The surface chemistry of pyrochlore is similar to many of its associated non-value minerals. Therefore, understanding the surface chemical properties of the pyrochlore for selective pyrochlore flotation will potentially aid in the design of flotation strategies for optimized recovery. In this study, pyrochlore samples were collected from various points in the flotation scheme at the Niobec plant, Quebec, Canada. The SEM-EDX analysis revealed that pyrochlore from the Niobec deposit occurs as high and low iron varieties, and that recovery favours varieties with a lower Fe content. To …

Separation And Concentration Of Stibiconite, William Howard Painter

Bachelors Theses and Reports, 1928 - 1970

Primarily, the purpose of this study is to separate stibiconite from associated gangue minerals. The ore containing antimony, as an oxide stibiconite, occurs in Mexico and its benefication would be an advantage to the mineral resources of that country. While the deposit from which this ore is derived is American owned, the resource is presently non-economic. A concentrate must be derived of suitable grade for its use in a smelting operation and from which metallic antimony would be produced.

Flotation Of Artillery Peak Manganese, Joseph W. Town

Bachelors Theses and Reports, 1928 - 1970

The concentration of low-grade manganese ore from Artillery Peak, Arizona, was studied. Flotation with various emulsions failed to yield concentrations of commercial grade, although manganese recoveries of over 90 per cent were obtained.

Beneficiation Of Scheelite Ore From The Potosi Tungsten Mining District, James A. Ndulue

Bachelors Theses and Reports, 1928 - 1970

The now increasing importance of tungsten as a metal with desirable properties in high strength and high temperature resisting alloy steels, coupled with the recent discoveries of low-grade tungsten ore deposits in Montana, has spurred a search for suitable and economical methods of treating tungsten ores of the State. This search has been conducted on a variety of tungsten ores and the present work is rather an aspect of the whole tungsten beneficiation problem in Montana.

Froth Flotation Of Phosphate Rock., David L. Spitzer 1923-2012

Electronic Theses and Dissertations

No abstract provided.