Application of Ball Mill in Morocco 300t/d Silver Mine Project
Type of ore: silver
Processing scale: 300TPD
Grinding equipment: wet grid type ball mill, wet overflow type ball mill
Process flow:Two stages of semi-closed circuit crushing and screening-two stages of closed circuit grinding-one coarse, three sweeping, two fine flotation stages-five stages of washing-zinc powder replacement smelting-tailings dry discharge process.
The silver concentrator located in Morocco was rebuilt and equipment updated by Xinhai, which increased the silver recovery rate to 83.95% and reduced the cost by 15%. In the grinding stage, the first stage grinding uses a wet lattice type ball mill, and the second stage grinding uses a wet overflow type ball mill.
Background of the project
With the continuous increase in ore mining depth, M Mining Company found that the original 300t/d silver cyanide plant has gradually failed to meet the current demand for beneficiation. The long-term disrepair of plant equipment and unreasonable process flow have caused the processing capacity to fail to meet the expected design, and the silver recovery rate has been decreasing year by year. Therefore, M Mining Company decided to build and renovate it. The metal minerals of the project ore are natural silver, pyrite, limonite, etc.; the gangue minerals are quartz, feldspar, clay minerals, etc. The recyclable element is silver.
1. Silver ore crushing stage:
Two semi-closed ore crushing processes are used. The jaw crusher is used for coarse crushing and medium crushing, the cone crusher is used for fine crushing, and the circular vibrating screen is used for screening. The crushed ore products are transported by belt conveyor to the original fine ore warehouse, and then loaded and transported to the proposed new plant site;
2. Silver ore grinding stage:
Two-stage closed-circuit grinding process is adopted. The first stage grinding uses a wet lattice type ball mill, the discharging uses a jigger for gravity separation, the concentrate uses a shaker for selection, and the gravity separation tailings uses a high weir single spiral classifier; the second stage grinding uses a wet overflow Type ball mill, the second stage classification selects the hydrocyclone group;
3. Flotation stage of silver ore:
Adopt one rough, three sweep and two fine processes. The concentrate dewatering operation uses two mechanical dewatering processes. A thickener is used for the first-stage dehydration, and a filter press is used for the second-stage dehydration. The filter cake contains about 20% water. The tailings are directly discharged to the original tailings pond, and the backwater is recycled;
4. The slurry adjustment stage of the dressing plant:
The slurry mixing system is newly built in the original beneficiation plant, using the method of grabbing the ore, mixing slurry through a high-concentration stirring tank, and using the existing grinding and grading system for operation. After the overflow of the cyclone is concentrated by the thickener, it will go to the existing leaching system. The leaching time will be more than 60h. After five stages of washing, the precious liquor will be replaced with zinc powder for smelting. The tailings will be treated and pumped to the tailings pond.
The complete set of concentrator services has reduced the production cost of the silver ore beneficiation project by 15%, which is 5% lower than the customer’s expected investment cost control; after the raw ore is ground, the recovery rate of silver is as high as 83.95% after heavy separation and flotation operations. The operation of the whole concentrator is stable, the quality of equipment is reliable, and the beneficiation indexes and economic benefits have reached expectations. The strength of Xinhai Mining Equipment’s professional mining industry chain service (EPC+M+O) has been strongly affirmed and recognized by the project customers.