Cement, Energy and Environment

1. An automatic, ideally size– descending separation of the ensemble of balls of different diameter in each cross-section over the entire length of the conical casing. 2. A smooth transition of optimal ball dropping velocity paths and ball turnover as a function of cone radius, viz. from impact in the beginning to crushing in the middle, and attrition at the mill end. 3. A ball charge fill factor decreasing optimally over the conical casing length. 4. Optimal self-regulation of the ball grades (of the average weighted ball). 5. An optimal trade-off between the merits and drawbacks of big and small– diameter mills (the UO ratio). 6. Adjustment of optimal operating conditions for one charge by changing casing inclination with respect to the longitudinal axis to redistribute the ball charge in the mill beginning and end. 7. The small cone inclination lowers the pressure of the balls on the mill end heads, thus reducing their mutual wear and the harmful "near– wall" effect. 8. The ideal separation of the grinding bodies eliminates diaphragms, thus increasing the grinding space and reducing the number of hatches in the TCM casing by three-fold. 9. A closed-cycle grinding cycle in a one-chamber TCM with an open-circuit separator as in coal TBMs, and elimination of an outlet grid with an airlift, thus dramatically simplifying the entire grinding process . 10. Improved aerodynamics since a one chamber TCM acts like a cone-nozzle (a convergent tube). 11 . Automatic additional charging of balls one by one with a maximum diameter over the entire length of the one-chamber TCM during continuous mill operation. 12. The TCM can operate without reducing its productivity with worn and smooth liner plates because the velocity conditions are rigidly tied to the variable mill radius, i.e. the liner plate profiles have no critical effect on TCM performance. 13. Level off the irregular wear of grinding bodies over the entire mill length and reduce ball wear due to effective ball filling and optimal mill operation. 14. Increased unit duty factor 15. Reduced power consumption, dimensions, metal capacity, capital outlay and scope of maintenance. The above TCM advantages are in line with modern grinding concepts. One can contend that the stage mill design with a rigidly-variable LID ratio is a partial solution of the generalized integral-multistage TCM design with a continuously– variable structure. By increasing the number of stages in the MAAG mill, its efficiency will grow to exceed 271%. Integration of an infinitely big number of stages into the mill will yield the TCM design. The new mechanism of separation of the ball charge in the TCM is initiated at the instance of ball separation and its free dropping along a path created by the conical casing, which differs from the conventional one for classical mills. The ball dropping vector in the TCM is perpendicular to the conical casing generatrix. Rather than dropping vertically, the balls drop at a small angle to the side opposite to the material flow along the mill, i.e. to the charging side. Under gravitational force, a bigger diameter ball (with a bigger mass) drops farther, whereas a small ball falls closer. This separates the grinding bodies by size. Besides, during their joint dropping, the bigger diameter ball drives the smaller ball to the charging side. The free ball dropping process and their ideal separation is best seen in translucent TCM models. Different ball dropping paths over the length of the conical casing, combined with ball separation, have a crucial bearing on the grinding process. Conventionally, this priority task is solved by an involved and limited-value selection of the liner plate profile. The liner plates, however, undergo rapid wear and the expected effect degrades drastically. Besides, required ball dropping paths of the conventional mill do not vary along the entire chamber length. In TCM, the ball dropping paths are rigidly tied to the conical casing radius , and the liner plate profile has no essential impact on the paths. The liner plates in the TCM serve to protect the casing and increase the ball charge friction coefficient during lifting to the point of separation for free dropping. The authors have designed liner plates that are installed in each ring of the conical casing by alternating only three standard sizes, whereas their total amount has been reduced by 20%. A rolled stock lining has also been designed for the conical casing. In the TCM, instead of having six process hatches in the casing for maintenance and additional charging (recharging) of balls, there are only one or two hatches. This streaml ines the 18