The copper ore dressing plant adopts semi-autogenous grinding + ball milling grinding process design

With the development of mining technology, the semi-autogenous grinding (SAG) process has been widely used in modern copper ore dressing plants due to its advantages such as high efficiency and energy saving. The SAG process combined with the ball milling process has formed an efficient grinding process, which is especially suitable for processing ores with high hardness and requiring fine grinding. This article will introduce in detail the grinding process design and production commissioning experience of the SAG combined with ball milling adopted by a copper ore dressing plant.

Analysis of copper ore characteristics

The physical and chemical properties of copper ore are crucial to the design of the grinding process. The ore of a copper mine belongs to the granite-type copper sulfide ore, which contains valuable components such as copper, gold, and silver, as well as harmful components such as arsenic. The hardness, crushability and grindability of the ore are the key parameters for the selection test research.

Design of semi-autogenous grinding process + ball milling

Design of semi-autogenous grinding process

The SAG grinding process uses the ore's own fragments as the grinding medium, with a small amount of steel balls, and realizes the initial grinding of the ore through a large mill. The advantage of the SAG process is that it can handle larger ore blocks, reduce the crushing process, and reduce overall energy consumption.

Ball milling process design

The ball milling process is a further fine grinding process after SAG grinding. The deep fine grinding of the ore is achieved through the steel balls inside the ball mill. The selection and operating parameters of the ball mill need to be optimized according to the product characteristics after SAG grinding.

Equipment selection and simulation

Through the JK drop weight test and ball mill work index test on the ore, combined with the JKSimMet simulation software, the model and supporting installed capacity of the semi-autogenous mill and ball mill are determined. The simulation results guide the selection of actual equipment and the determination of process parameters.

Production commissioning and problem solving

Problems in the commissioning stage

During the production commissioning stage, the ore dressing plant faced problems including excessive power and oil pressure of the semi-autogenous mill, short service life of the liner, low stubborn stone yield, and large circulation load of the ball mill.

Solution

1. Reduce the feed size of the SAG mill: By optimizing the blasting parameters and adjusting the size of the crusher discharge port, the feed size of the SAG mill was significantly reduced, thereby reducing the grinding energy consumption and increasing the production capacity.

2. Increase the yield of stubborn stones: By replacing the grating plate and adjusting the aperture of the gravel discharge grating plate, try to increase the output rate of stubborn stones.

3. Extend the life of the cylinder liner: Cooperate with the liner manufacturer to extend the service life of the liner by adjusting the liner hardness and optimizing the lifting bar design.

4. Explore high-voltage frequency conversion control technology: Use high-voltage frequency conversion technology to adjust the speed of the SAG mill to adapt to different oil pressure and power conditions, protect the liner, and improve the grinding efficiency.

5. Optimize the classification efficiency of the cyclone: By adjusting the operating parameters of the cyclone and replacing the sand settling nozzle, the classification efficiency is improved and the return sand ratio is reduced.

Production and operation of the copper ore dressing plant

After a series of commissioning and transformation, the production and operation of the ore dressing plant has been significantly improved. The processing capacity of the SAG mill has reached the design requirements, and the hourly processing capacity of the ball mill has also been greatly improved. By flexibly adjusting the speed of the SAG mill, energy consumption has been reduced.

Conclusion

The experience of designing and commissioning the grinding process combining SAG and ball milling in the copper ore dressing plant shows that the production efficiency and stability of the dressing plant can be effectively improved through accurate ore characteristics analysis, reasonable equipment selection, careful production commissioning and continuous process optimization. In particular, the control of feed particle size, the adjustment of stubborn stone yield, the extension of liner life and the application of high-voltage frequency conversion technology play a key role in achieving the production and standard of the SAG system.

With the advancement of mining technology and the improvement of environmental protection requirements, copper ore dressing plants in the future will pay more attention to energy efficiency and environmental impact. Further optimization of SAG and ball milling processes, combined with the application of automation and intelligent technology, will bring higher production efficiency and lower operating costs to copper ore dressing plants. In addition, a deeper study of the ore, such as the analysis of mineral composition, structure and hardness, will also provide more accurate guidance for the optimization of the grinding process.