Engineering Commons^™

Optimization Of Porosity In Cold Spray Produced Copper And Zinc Coatings, Cameron Hughes

Graduate Theses & Non-Theses

Since its invention in 1981, the cold spray (CS) additive manufacturing (AM) process has been studied and optimized to produce well-adhered, dense material coatings. CS can operate at a wide range of temperatures if the feed material remains in a solid state. Copper and zinc were studied to characterize and understand the effects of heating element voltage, travel speed, and standoff distance on deposit porosity, grain size, microhardness, and coating thickness. Samples were sprayed on 3.2 mm x 25 mm x 150 mm 6061 aluminum substrates. Sections were taken from the middle of the samples to represent steady-state conditions. Sample …

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 …