Process route: three-stage one closed-circuit crushing → closed-circuit grinding → centrifuge roughing → shaking table selection
Applicable ore: rock gold ore with medium and fine grains, coexistence of gold and sulfide or high free gold content.
1. Crushing stage Coarse crushing (jaw crusher) The raw ore is screened by a sieve (sieve hole 30-50mm), and the +30mm ore enters the PE series jaw crusher and is crushed to -100mm. Purpose: Reduce the energy consumption of subsequent grinding and improve the system processing capacity. Medium crushing (cone crusher) The coarse crushed product is conveyed to the HP series hydraulic cone crusher by belt and crushed to -30mm. Key control: The discharge port is adjusted to 10-15mm to avoid over-crushing. Fine crushing and closed-circuit screening (cone crusher + vibrating screen) The fine crushing adopts a short-head cone crusher, which forms a closed-circuit cycle with a double-layer vibrating screen. Screening particle size: 12mm on the upper layer (return material is crushed), 3mm on the lower layer (qualified particle size enters grinding).
2. Closed-circuit grinding stage The ball milling and classification system uses MQG series grid ball mill and hydrocyclone to form a closed circuit. Grinding fineness: -200 mesh accounts for 65%-75% (adjusted according to the degree of gold dissociation). Cyclone overflow concentration control: 40%-45% to ensure the centrifuge sorting efficiency. Reagent addition (optional) If the mud content is high, a dispersant (such as sodium carbonate, 100-300g/t) can be added to the mill. 3. Selection of centrifuge roughing equipment SL type continuous ore discharge centrifugal concentrator is selected, and the processing particle size range is: 0.074-2mm. Sorting parameters Feed concentration: 20%-30%, number of revolutions: 300-400r/min, backwash water pressure 0.05-0.1MPa. Output: high-grade coarse concentrate (gold content ≥500g/t) and tailings (tailing rate 40%-60%). Advantages: Highly efficient recovery of free gold + sulfide-encapsulated gold, large processing capacity (10-20t/h for a single unit).
4. Shaking table selection equipment configuration uses a 6-S shaking table to process centrifuge coarse concentrate and cyclone sand settling (including medium ore circulation). Sorting conditions Stroke: 12-16mm, strokes: 280-320 times/min, bed surface lateral slope 2°-5°. Concentrate interception position: 1/3 area near the transmission end, output final concentrate (gold content ≥2000g/t). Tailings treatment Shaking table tailings return to the mill for re-grinding, or enter the tailings pond (gold grade ≤0.5g/t).
5. Process characteristics Recovery rate: total gold recovery rate 85%-92% (depending on the occurrence state). Energy saving: Centrifuge pre-selection reduces the processing volume of the shaking table and reduces energy consumption by 20%-30%. Flexibility: The flotation/cyanidation process can be expanded to treat fine gold particles.
VI. Key control points Balance between grinding fineness and gold dissociation degree; stability of centrifuge feed concentration; precise adjustment of shaking table flushing water volume.
