Application of overflow ball mill in Mongolian gold mine project
Type of ore: gold
Processing scale: 300-1000TPD
Grinding equipment: wet overflow ball mill
Process flow: three stages and one closed circuit crushing and screening-two stages of closed circuit grinding-gravity separation-cyanidation, carbon slurry-desorption electrolysis-tailings dehydration process
Xinhai Mining Equipment provides EPC+M+O mining industry chain services for a 1000t/d gold mine project in Mongolia. It adopts two-stage closed-circuit grinding process in the grinding and classification stage, and the grinding equipment uses a wet overflow ball mill. In the design of the beneficiation plant, Xinhai Mining Equipment focuses on protecting the interests of investors, minimizing investment, and increasing efficiency. At the same time, it pays attention to the health and safety of operators, and emphasizes harmony with the environment, resource conservation and recycling, and the combination of single machine and machine group High efficiency and energy saving, and strive to achieve efficient recovery of gold ore and target metal minerals for each operation and the entire process.
Crushing and screening stage
Three stages and one closed-circuit crushing and screening process. Coarse crushing adopts a jaw crusher. After coarse crushing, it is sent to the circular vibrating screen by a belt conveyor for screening I. The material on the upper screen (+30mm) enters another jaw crusher for crushing; the second screen is on the screen The material (15-30mm) and the third-layer sieve (8-15mm) are transported by the belt conveyor to the buffer silo, and then fed into the cone crusher by the vibrating feeder for fine crushing II, fine crushing II products and medium crushing The product is sent by the belt conveyor to the circular vibrating screen for screening II, the oversize (+8mm) enters the bar screen for re-sieving, and the oversize (+20mm) enters the crusher for fine crushing I, the product and the bar screen The under-sieve (8-20mm) is transported by the belt conveyor to the buffer silo before the fine crushing II, forming a closed circuit. The under-screen material (-8mm) at the bottom of Screening I and Screening II is the qualified material in the crushing and screening stage.
Grinding and classification stage
Two closed-circuit grinding processes. The fine ore is transported by the belt conveyor to the wet energy-saving overflow ball mill for one stage of grinding. The under-screen slurry (-3mm) is pumped into the hydrocyclone for the first stage of classification, and the underflow returns to the ball mill for regrind, forming the first closed circuit. Grinding.
Gravity separation: the first stage of grading overflow flows into the original centrifuge for gravity separation. The concentrate and the centrifuge concentrate in the other two original two-stage grinding-gravity separation equipment are distributed to the shaker for selection. The selected concentrate is granular gold, which can be smelted directly; the selected tailings and the centrifuge tailings enter a pump box and are pumped into the hydrocyclone for the second stage of classification. The underflow is with the first stage. The cylindrical sieve in the closed-circuit grinding process flows into the wet-type energy-saving overflow ball mill for the second-stage grinding, and the product returns to the aforementioned pump box to form the second-stage closed-circuit grinding.
Leaching: The second stage of grading overflow passes through a linear vibrating screen (dust removal screen) to remove wood chips, and flows to the original thickener for concentration before leaching. The overflow can be reused as return water back to the system. The underflow of the thickener (concentration about 40-45%) is pumped by the slurry pump to the leaching tank to start the cyanide leaching operation. In order to make the slurry flow convenient, the installation height of the previous leaching tank is greater than that of the next leaching tank. The sodium cyanide solution flows into several leaching tanks, and the activated carbon is added to the last leaching tank. After the activated carbon adsorbs gold, it is lifted by an air lifter and sent to the previous leaching tank. The gold-loaded carbon is separated by the carbon extraction screen, and the slurry is returned to the 2# leaching tank. The gold-loaded carbon after leaching can be desorbed and electrolyzed to obtain gold mud.
Desorption electrolysis-smelting: The gold-loaded carbon is sent to the desorption electrolysis system, the working temperature is about 150 degrees Celsius, the working pressure is about 0.5MPa, and gold mud can be produced in only 12-15 hours. The gold mud produced by electrolysis enters the smelting stage for smelting, and finally gold ingots are obtained.
Tailings dehydration stage
After leaching, the ore slurry is separated by a safety screen to separate the fine-grained gold-loaded carbon, and then sent to the filter press by a slurry pump in turn, and the filtered tailings are transported to the tailings yard by a belt conveyor. After the filtrate is regularly added with bleaching powder through the sewage buffer tank, it can be pumped back to the high-level pool by the return pump or directly returned to the system for recycling.