MNG 301 final Real Exam with 100% Accurate Solution

Flocculants increase particle size less effectively than electrolytes or cogulants - ANSWERSF Finer particles are more difficult to dewater than larger particles due to their large surface area - ANSWERST 80% - 200 mesh means that 80% of the material is coarser than 200 mesh - ANSWERSF The role of frothers in flotation is to absorb onto desired particles to make them more hydrophobic - ANSWERSF thickeners and fillers are both used for dewatering process stream solids but they operate independently with minimal effect on each other - ANSWERSF Float/sink washability is a lab procedure used to predict the quality and yield of products that can be recovered at various separation densities - ANSWERST Since the primary function of filter cloth is to retain particulars during filtration it is specified by opening size - ANSWERSF A mixture of good and poor electrical conductors can be separated using the corona charging electrostatic separator - ANSWERST Filter media is necessary for retaining solids during filtration but as the cake accumulates, it also acts as filter media - ANSWERSF Release analysis is used to predict the limits of separation that can be achieved by flotation - ANSWERST Since electrostatic separation is a dry process, it cannot be used to separate minerals - ANSWERSF 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 - ANSWERST Froth flotation is a selective separation process that is unique to mineral processing - ANSWERSF Wet drum magnets are not used in coal preparation because coal has no magnetic properties - ANSWERSF Hydroclones are much less efficient than spiral classifiers due to their small size - ANSWERSF Gravity separation is an old technology that is rarely used anymore - ANSWERSF colloids are very fine particles that will remain is suspension unless action is taken to destabilize them by coagulation and flocculation - ANSWERST Thickeners are commonly used in tailings treatment to increase pulp density by gravity sedimentation - ANSWERSF Particle settling velocity in water is primarily determined by its shape and specific gravity - ANSWERSF The underflow of a classifying cyclone represents finer product, while the overflow represents coarser product - ANSWERSF 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? - ANSWERSParamagnetic, 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? - ANSWERSpressure, 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 - ANSWERSnonionic, 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? - ANSWERSIncrease particle size, change contact angle, increase driving force. Add coarse material, add surfactant, change the vacuum.