meybod ceramic

1- it is recommended that type of lining ball mills be selected equal to the type of consuming balls.

2-in the disconnected ball mills (Bach) it is better to replace the rotating direction of ball mills after special period to keep the quality friction operation and to private one side friction of loads lifter.

3- the circumferential speed of mill must be in a manner in which the ball rotating performs as waterfall pouring.

4- one of the most famous calculating speed rotation method of disconnected ball mills is as follow:

D= inner diameter per meter

Nc= critical speed. Proper speed to friction operation about 60% of critical speed.

5- The best rotating speed of ball mills is obtained while the angle that is between horizon level and last upper ball be about the angles of 45-60 degrees.

6- the falling angle depends on more important two factors (in wet milling) that is viscosity and density of initial materials .

7- consumed balls density is one of the effective factors to adjust rate of rotating balls per minute.

8- it is better that circumferential rotating rate of ball mills in direction of ball with average density(2.6-2.7) be about 120-125m/min.

9- suggests that ball initial charging in ball mills be about 50-55% of ball mill apparent value.

10- to initial charge of Bach balls with steel balls(D=2/6-2/7) suggests that approximate value 550-700kg/m3 balls compute and charge according to ball mill size.

11- to charge the raw materials in Bach ball mills with static balls that consist of density:2/6-2/7 , using the following formula is suggested:

= initial chargeable materials in ball mills (v u x 0.55 x d x y)/100

mill active value= v u

grout density=d

the dry material in grout which calculates in percentage=y

12- to obtain the optimized results of friction by considering to the material feed value, mill and initial particles and useful final particles sizes must apply some compound of ceramic balls various dimensions.

In this matter we must note to this point that the big balls are used to shatter and small balls are used to break materials in smaller pieces that in any case recommend they would be not bigger than 70mm.

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Some of different sizes of balls should be as the following according to the mentioned conditions:

40 ميليمتر 25%	25% گلوله درشت	20% درشت	25% درشت	33% درشت
50 ميليمتر 25%	25% گلوله متوسط	40% متوسط	50% متوسط	33% متوسط
60 ميليمتر 25%	50% گلوله ريز	40% ريز	25% ريز	34% ريز
70 ميليمتر 25%	50% گلوله ريز	40% ريز	25% ريز	34% ريز