Blending silica bodies in centrifugal runner mills, “model 115”

Conclusions

The output of “model 115” centrifugal runner mills for mixing dinas bodies is 1.7 times higher than that of runner mills with heavy rollers. Goods pressed from bodies prepared in centrifugal runner mills are no different in quality from those pressed from bodies made in runner mills with heavy rollers. The difference in output of acceptable product is slight.

In the preparation of bodies in “model 115” runner mills there are few fines in the batch. When formulating the batch it is necessary to introduce 20–30°% quartzite ground in a tube mill with a content of not less than 80% fraction finer than 0.088 mm. With this, the fraction finer than 0.5 and 3–2 mm should be considered; air blowing of the body should be started 2–2.5 min after the start of blending.

To observe the norms for alkalinity and moisture content of the batch, with a moisture content of 2–2.4% the total content of CaO in the lime-iron slip is 23.5–24.5% and with a wet weight of 700–750 kg the amount of slip varies from 43 to 50 liters, the blending time lies in the 4–5 min range.

Scrapers and the lining of the runner mills should be made from manganese steel and the bottom of the mills from carbon steel.

A drawback of “model 115” runner mills is the sticking of the lime-iron slip and the need to clean them more than once during 24 h.