MNG 301 final Exam Guide Questions Answers All Correct.

Flocculants increase particle size less effectively than electrolytes or cogulants - correct answer F Finer particles are more difficult to dewater than larger particles due to their large surface area - correct answer T 80% - 200 mesh means that 80% of the material is coarser than 200 mesh - correct answer F The role of frothers in flotation is to absorb onto desired particles to make them more hydrophobic - correct answer F thickeners and fillers are both used for dewatering process stream solids but they operate independently with minimal effect on each other - correct answer F Float/sink washability is a lab procedure used to predict the quality and yield of products that can be recovered at various separation densities - correct answer T Since the primary function of filter cloth is to retain particulars during filtration it is specified by opening size - correct answer F A mixture of good and poor electrical conductors can be separated using the corona charging electrostatic separator - correct answer T Filter media is necessary for retaining solids during filtration but as the cake accumulates, it also acts as filter media - correct answer F Release analysis is used to predict the limits of separation that can be achieved by flotation - correct answer T Since electrostatic separation is a dry process, it cannot be used to separate minerals - correct answer F A significant amount of near density material makes density separation more difficult, just as significant amount of near sized material makes classification by screening more difficult - correct answer T Froth flotation is a selective separation process that is unique to mineral processing - correct answer F Wet drum magnets are not used in coal preparation because coal has no magnetic properties - correct answer F Hydroclones are much less efficient than spiral classifiers due to their small size - correct answer F Gravity separation is an old technology that is rarely used anymore - correct answer F colloids are very fine particles that will remain is suspension unless action is taken to destabilize them by coagulation and flocculation - correct answer T Thickeners are commonly used in tailings treatment to increase pulp density by gravity sedimentation - correct answer F Particle settling velocity in water is primarily determined by its shape and specific gravity - correct answer F The underflow of a classifying cyclone represents finer product, while the overflow represents coarser product - correct answer F What are the three classes or types of materials that are distinguished by their magnetic susceptibility, K? Which one has the highest magnetic susceptibility and can be readily concentrated with a low-intensity magnetic separator? - correct answer Paramagnetic, diamagnetic, ferromagnetic. Diamagnetic is the highest What are the three types of filters that are commonly used in mineral processing to remove water from a product of refuse steam? - correct answer pressure, vacuum, centrifuge List the three types of polyelectrolyte flocculants and briefly describe the testing that needs to be performed to determine which flocculant should be used for a thickener application - correct answer nonionic, anionic, cationic. Jar test if the structure of a filter cake considered as a bundle of capillaries, and the water contained in the cake is retained by capillary rise, as given by the capillary rise formula. What are three things you can do to improve dewatering and how can you actually do them? - correct answer Increase particle size, change contact angle, increase driving force. Add coarse material, add surfactant, change t