The influence of technological factors on the densification of forsterite green ware

Conclusions

The grading of bodies made of dunite containing 20% additions of metallurgical magnesite ensuring a reduction in green porosity lies in the range 50–80% fraction 3–0.5 mm, 0–30% 0.5–0.088 mm and 20–50% finer than 0.088 mm.

With an increase in fabricating pressure the relationship between the porosity of the green ware and grading diminishes.

With a reduction in the grain sizes of the top and lower fractions the green porosity increases. An increase in moisture content from 4 to 6% in most cases increases the green porosity.

An addition of 2–4% sulfite lye reduces the porosity (without a correction for pore filling by lye).

The porosity of the green brick is greatly increased during firing. With the presence in the body of finely ground metallurgical magnesite the region of minimum porosity of fired specimens compared with the corresponding region for green brick moves to the side with the large content of fines.

Dunite bodies with 20% fine magnesite giving the minimum porosity and shrinkage in firing should be used with the following grading: 10–40% fraction 3-0.5 mm, 10–40% 0.5–0.088 mm, and 50–70% finer than 0.088mm.

An increase in the fines in the body leads to high shrinkage and deformation of the specimens in firing.