More than 30 overseas offices not only manifest our popularity, but also solve your puzzles quickly in operation. So if you are looking for crushers or mills, GMC deserves your attention!
DBy 2019, GMC has built 6 advanced manufacture bases which cover a total area of over 1,200,000 m2, contain various of grinding mill production line, such as hammer mill and Raymond mill, etc. And the annual production value can reach RMB 5 billion.
we push out the strategy of "Globalization & Localization". Currently, we have set over 30 overseas offices distributed over different continents. If there is any need, we can "knock your door" at once. It is a strategy just right for you.
The first two Grinding Efficiency Measurement examples are given to show how to calculate Wio and Wioc for single stage ball mills. Figure 1. The first example is a comparison of two parallel mills from a daily operating report. Mill size 5.03m x 6.1m (16.5 x 20 with a ID of 16).
This example shows that Mill 2 is slightly more efficient than Mill 1 even though it has a higher power consumption per tonne. This shows the use of the work index equation taking into account the differences in feed and product sizes. The calculation is only part of the total plant performance study and must be tied into the total plant operation.
The next example covers an in-plant study on the effect of mill speed on mill performance. The two speeds being studied are 68% and 73% of critical speed in 5.03m (16.5 diameter inside shell 16 inside liners) ball mills. This study was over a period of four months. Grindability tests were run on monthly composite samples of the feed to each mill. The operating data, test data and calculations are given in Table III.
The data given in Table II can be compared in several ways. A comparison based upon power per ton consumed is given in Table IIIA. This shows the difference in power per ton of mill circuit feed consumed without taking into account the variations in mill circuit feed, mill circuit product and grindabilities as shown in data tabulated in Table III.
The next comparison eliminates the variations caused by differences in the grindability of the ore. This is the more accurate comparison as it compares grinding circuit performance as referred to a cannon base or reference. Table IIIC gives the comparison based upon Wioc/Wi.
This shows the rod mill is inefficient while the ball mill is performing efficiently better than indicated from the grindability test results, with the overall circuit operating in line with grindability test results.
Figure 3 shows a rod mill-ball mill circuit with a concentration step between the rod mill and the ball mill with the tailings being removed from the circuit. There is also a concentration step between the ball mill and the classifier. In determining grinding efficiency, each stage is considered as a single stage. The power per tonne for rod milling is determined from the rod mill feed rate and the power per tonne for ball milling is determined from the ball mill feed rate.