Mining Engineering flashcards
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33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Bond work index
- Specific energy parameter Wi from the Bond ball mill test; used in W = 10·Wi·(1/√P80 − 1/√F80) to estimate grinding energy in kWh per short ton.
- 80% passing size
- The particle size at which 80% of the material by mass passes; denoted F80 for feed and P80 for product; standard size descriptor in Bond comminution calculations.
- Liberation
- The degree to which valuable mineral grains are physically separated from gangue after comminution; determines the grind size needed for effective concentration.
- Froth flotation
- A separation process in which hydrophobic particles attach to rising air bubbles and are recovered in a froth, while hydrophilic particles remain in the pulp.
- Collector
- A reagent that adsorbs on a mineral surface and makes it hydrophobic; xanthates are typical collectors for sulfide minerals such as galena and chalcopyrite.
- Frother
- A reagent that stabilizes bubbles and controls froth structure in flotation, improving bubble-particle attachment and froth transport; examples include pine oil and MIBC.
- Depressant
- A reagent that selectively prevents a mineral from floating, such as cyanide depressing pyrite or zinc sulfate depressing sphalerite, enabling selective flotation.
- Activator
- A reagent that increases the floatability of a mineral; copper sulfate activates sphalerite by forming a copper sulfide surface layer that adsorbs xanthate.
- Heavy medium separation
- Density-based separation using a suspension of fine magnetite in water; particles lighter than the set density float and heavier sink; used for coal and ore preconcentration.
- Shaking table
- A gravity concentrator with a riffled inclined deck and asymmetric shaking motion; separates particles by density and size, typically for 0.05–2 mm feed.
- Jigging
- A gravity separation method using pulsating water to stratify a bed of particles by density; effective for coarse coal and ore feeds from millimeters to centimeters.
- WHIMS
- Wet high-intensity magnetic separation, used to recover weakly magnetic minerals such as hematite and ilmenite from fine slurries at high magnetic field strength.
- Elsner equation
- 4Au + 8CN⁻ + O₂ + 2H₂O → 4[Au(CN)₂]⁻ + 4OH⁻; describes the stoichiometry of gold dissolution in aerated alkaline cyanide solution.
- Cyanide leach pH
- Gold cyanidation is operated near pH 10–11 to limit formation of volatile toxic hydrogen cyanide gas and to reduce cyanide consumption.
- Heap leaching
- A leaching method where crushed ore is stacked on a lined pad and irrigated with lixiviant; suited to low-grade ores and slow, low-cost recovery.
- Two-product formula
- A mass-balance equation using feed, concentrate and tailings assays to compute concentrate grade and recovery; assays must satisfy the weight balance.
- Washability curve
- A float-sink test result plotting yield against ash or density; used to select the separation density and predict coal preparation plant performance.
- Circulating load
- The mass flow returned from the classifier to the mill divided by fresh feed; typically 200–350% in closed-circuit ball milling.
- SAG mill
- A semi-autogenous grinding mill using ore itself plus steel balls as grinding media; often paired with a ball mill in SAB or SABC circuits.
- Cut-off grade
- The grade above which material is classified as ore and sent to processing; derived from break-even cost including mining, processing and refining.
- Acid rock drainage
- Acidic, metal-laden water formed when sulfide minerals in waste or tailings oxidize; mitigated by lime neutralization, covers and water management.
- Thickening
- Dewatering by gravity settling of solids, often accelerated by flocculant addition; produces a thickened underflow and clarified overflow for reuse.
- Hydrocyclone
- A centrifugal classifier that separates particles by size and density; used in closed grinding circuits to return coarse material to the mill.
- Rod mill
- A tumbling mill using steel rods as grinding media; produces a relatively uniform product and is applied to coarse grinding, typically 10–25 mm feed.
- Ball mill
- A tumbling mill charged with steel balls; used for fine grinding in closed circuit, often with hydrocyclones; consumes a large share of plant power.
- Gy sampling theory
- A framework stating sampling error depends on particle size, heterogeneity and sample mass; correct sampling requires all particles to have equal selection probability.
- Biooxidation
- A pretreatment using bacteria to oxidize sulfide minerals and expose gold in refractory ores before cyanidation; carried out in heaps or stirred tanks.
- Pressure oxidation
- A hydrometallurgical pretreatment in which refractory sulfide ore is oxidized under elevated temperature and oxygen pressure to liberate encapsulated gold.
- Filtration
- A dewatering process that removes liquid from a slurry by passing it through a porous medium under vacuum or pressure, producing a moist filter cake.
- Tailings dry stacking
- A tailings management method in which filtered, low-moisture tailings are stacked as a solid; reduces dam failure risk and water loss.
- Gravity recovery
- Concentration based on density differences using jigs, tables or spirals; effective when the density contrast between valuable mineral and gangue is large.
- Flotation pH control
- pH governs collector adsorption and mineral surface charge; lime is commonly added to raise pH and depress pyrite during selective sulfide flotation.
- SABC circuit
- A grinding flowsheet combining SAG mill, ball mill and pebble crusher; the crusher treats SAG mill pebbles too coarse to pass the trommel.